MASSACHUSETTS INSTITUTE OF TECHNOLOGY LINCOLN LABORATORY MILLSTONE HILL THOMSON SCATTER RESULTS FOR 1969 Group 21 TECHNICAL REPORT 513 23 JULY 1974 Approved for public release; distribution unlimited. LEXINGTON MASSACHUSETTS/ / I AIR FORCE (1) APRIL 4, 1975--37: AENTRACT This reporf summarizes and ion tem~ratures, the results and vertical ionization ff.xes 1969 using the Millstone Hill (42.6”N, system. These data, gathered over 24-bour observing time resolution fortheelectron-iensity distribution, fn the F-megion obtained during 71.5”W) Thomson (incoherent) for the height interval approximately pericds, to obtain res”its scatter radar 200 to900 km, were ronghly twice percalendarmontb. over this entire 45 minutes, depending uponwhicbof electron twooperating The height interval was either 300r mcdes was employed. The results for the diurnal variation of the electron density and temperature exhibit the characteristic tionbefween summer tbefwotakes ral precipitation and winter patterns discussed place in April and October. were observed serve a stable red arc. previously. llvocases ofoverheadauro- during the year as a consequence Other instances of geomagnetically Thetransi- of efforts to ob- disturbed hehavior were infrequent. Vertical fluxes of ionization were measured, and tbeflux sphere near midday was found m have an avera~ Near midnight, the magnetosphere escaping m the magneto- value of -5 appears to s“pply thelocal x 107 el/cm2/sec. ionosphere witha flux of about half this amount. . 111 — CONTEPiTS Abstract I. 11. 111 INTRODUCTION EQUIPMENT, PROCEQUR,RS A, Equipment B. Observing C. OBSERVING A. General B. Seasonal 6 , Disturbed Winter-NightB 38 Days 39 ehavior Disturbed-Nighttime ELECTRON-AND 41 Behavior 1ON-TEMPEUTURERESULTS 42 42 A. General B. Quiet-Day C. Distm-bed-Day D. lon.Temperature Electron 94 Temperatures Electron Ternperatm-es ~~~ 95 95 IONIZATION.FLLK RESULTS 95 General 95 B. Steady -Stata-Velocity- 96 c. Veloci.*.y Results 99 D. Daytime 99 E. Nighttime F. VI. 37 Variations C. VERTICAL *i RESULTS 11 D. A. , 3 Procedure Data Reduction E. v. 2 2 111. ELECTRON-DENSITY IV. AND DATA -PROCZSSI?IG vs-He.igk,t Flux Results f~i Flux Results Flux Through Profi!es 147 65o km 130 SUMMARY APPENDIX 136 References iv . MILLSTONE HILL THOMSON SCATTER RESULTS FOR 1969 INTRODUCTION I. Since 3963, densities, Massachusetts presents ported incoherent andelectron (42.60N, the results were in earlier made years to the World (Thomson) 7i.5sW).i-6 radar measurements have been measured This paper is the seventh gathered inthisprogram during for periods of 24 hours, approximately have been published mta scatter and ion temperatures Center A, in the articles Boulder, in a series calendar listed of F-region at Millstone year twicea West ford, of annual reports, 1969. month. in Table electron Hill, and TheobservationsreThe results obtained I, and have been transmitted Colorado. TABLE I PUBLICATIONS CONCERNING THE MILLSTONE HILL UHF (68cm Wavelength) THOMSON SCATTER RESULTS Year Publication Months Covered February 1963 March, 1963 to Jonuary July, April, July, January August, Ref. 1 1964 September Ref. 7 November thro.gh Ref. 8 Ref.2 December 1964 April, July, January Jonuary, November Ref. 9 through December April, Ref. 3 Ref. 10 August 1965 Ref. 11 June June, August, January Ref. 12 September through December Ref. 4 I 966 January, January March, July, September Ref. 13 through December Ref. 5 1967 February, January June, October, December Ref. 13 through December Ref. 6 1968 0ctc6er During i968 a component by electrostatic gatheredbys reported waves inthe tudent~~:6mthe elsewhere. In addition tically and 1969, of the reflected directed Ref. )4 the UHF Incoherent signals electron scatter radar system known as the “plasma-line.tn gas impressed University of lUinois was also These employed reflections by fast photoelectrons. and the University These of Michigan, to study are produced results were and have been , to the measurements UHF radar system, reported a number here of F-region of measurements observations were made with the ver - conducted in i969 of the E-, and F2 -regions Pi-, measurements horizontal were During required pointing a solution height range,5 were could from of the ground-clutter A digital sweep, employed studies dwing i 969. shift A. of pairs function. and no fm.ther the heights. This observations achievable. of short o“t any echoes These little from Sections temperatures, in this Both require pulses whose that appearad However, - spacing to be co- this system discussion of it will be pre- observing those employed 111through in the latter V present and vertical a calculation and data-processing ionization is presented part of i96i2, the results fluxes, procedures and of the synoptic while Sec. VI pro- of the magnitude of tbe unwanted by tbe transmitter. 0BSERV2NG AND DATA-PROCESSING PROCEDURES Equipment Tbe UHF incoherent interfaced analyzer directly but require comment hi the new spectrum In addition, scatter portion radar equipment of the receiver the signals described These previously.4 by one of newer changes During design 4968, that was are fully docmnented in Ref. 20, here. analyzer, thereby the integration eliminating are no longer to a bank of 5 -pole has been was replaced into the SDS 9300 computer. further SDS 9300 computer, ployed of the equipment, In the Appendix, introdwed the spectrum crystal of the echoes virtually gated from filters all problems the time base, each of which is carried out digitally due to gain differences but instead is matched by the and drift. are continuously to the length of the pdse ELp em- (0.5 or f.O msec). Each of the (two) filter frequency pled sequentially manner the impulse returned i 969 the 0.5 -msec quency commutation a dmble- sided gathered compensation after of several to tbe manufacturer filter employed was still delay the outputs the 0.5 -nmec outputs are sampled Since line is used between correspond matched *Ii. 5 kHz about the radar for repair, to drive samples, were to position obtained; Nm.ember with only half the filters the filters, however, psr unit time. 2 in a although real it altitude. in service (in Accordingly, 1968 aud February in place. with respect the filters placed inter- must be sam- Thus, to the same filters and between at 0.5 -msec tbe filters of them was fcund to have deteriorated. bank was operated scheme spectmm spanning 75 km of altitude. for the delays all filters, a few months response 24 filters at the filter every of 20 psec ), a tapped to scan through Unfort””ately, were exact employs The voltages may be obtained (at intervals that provides 480 psec 4968), banks available with i -kHz spacing. so that a spectrum these the height resolution consisting until 1970, of operating prevented was used to subtract form a summary densities, EQUIPMENT, takes that previously tbe echo autocorrelation differed 620 been documented. , of F-region doppler vals computer and to compute lf provides a summary. plied of improving transmissions into final operating have previously 11. problem a new method to E- and Fi -region here. Section vides work began m developing to extend the measurements as well as a means was not brougbt sented of +969, radar met by employing be varied. herent radar with the beam directed obliquely. These 47,18 and the the ion composition in the FI -region, i4, i9 Inasmuch as these results have also been reported, in this paper. the last quarter UHF vertically f the L-band at determining drift in the E- and F-regions. they are not included ments employing aimed Owing to the fre- to the signal only half as many echo samples spectrum, were . ., No further difficulties a dism.epancy between pulses persisted. height interval agreement using the 0.5 -msec moved it appears the observations exactly i.0 msec application Of the SigKMIS of the first sample, 4970, pulses, were filters prior to the filter source cause of error samples although and 1.0 -msec over lengths. the The dis - of the ion temperature of this difficulty pulses, existed pulses, is believed to be and an empirical which compounded the receiver being taken from bank produced the i.O -msec the time when the suppremion estimates to the transmitted with i.0 -msec to the first thus rendering with 0.5- was observable made with both pulse by lower 1969, (see below). that a second conducted during obtained in Ref. 20, The principal devised analyzer temperature measurements by the 0.5 -msec was eventually In retrospect, For for the plasma at night when it was manifest provided s cbeme with the spectrum which has been discussed 450 to 750 km where match correction lem. the results This error, was largest Ti observed the poor were encountered transients results is removed suppression the filter this probwas.. re The sudden bank. which had not died out by the time at 450 km slightly was advanced in error. hy 0.5 msec, In October thereby diminishing this effect. The most of antenna surface serious following gain Gain measurements encountered a snow storm of tbe antenna iced was - i2 dB. over, the course late in February. to within 2 dB of its earlier the mesh produced value. by tbe snow load. through the radio being loss 1*worked!, the gain was found to be i.4 dB below tolerance was measured design value. the surface in a survey, A repetition of these was retensioned laid diagonally across In December events unwanted ground-clutter echoes, horn feed that increased the directivity over the power feed support structure. efficiency. from B. Observing During Table 1969, II lists duced; to detect were repeated urement we attempted to value. i.e., and during surface to the original the mmmer by means to by the end when the rms close of returned Thus, 2n June, of that yea? of a set of cables to the antenna, was the addition The taper and, more a quarter-wave appears the effective to the conical collecting off the tripod which raised to broaden of This had the ef- importantly, choke, to have been to reduce of the intensity about 40 to about 20 dB. edges altering designed of an extension feed pattern. from incorporated to make observations for which is the mean of tiie planetary the introduction were by the distortion as the surface gain and the gain the horn the beamwidth area. Procedure the vertical servations This off the reflector significantly the dates and times included Following mesh in antenna by hand, was caused strength of modifications of this modification about 0.7- to O.8“ without that the loss of the temperature. in 1970, of the primary ~he extension The net effect loss its previous was increased scattered the i -inch loss structure. was made. the reflector showed decreased cycling occurred the pipe supporttig the illumination residual with additional %969, the last of a series fect of reducing this storm, it was found to be 1.05 inches, and provided i 969 was a dramatic the snow was removed gradually by daily of April, During star Cygnus This This during with snow to a depth of 22 feet near the center. of the next few days, returned shape with the equipment and the dish filled made by observing During its original ) difficulty drift conducted four times 45 minutes. magnetic of the new spectrum of the ionization in which twice measurements above per month for periods were successfully index Kp over analyzer in i968, hmax l?2 (Ref. 20). each period special of 24 hours. carried of observation. efforts For this reason, the measurements made using the 1 -msec 6,2o in each cycle. This raised the time to complete out and re - were some made ob- pulses ( vC -moden a cycle of mess- ) . TABLE II lNCOHERENT Begin 5CATTER 051 SERVAT10NS End Date c’ EST Date 16 J.wary 0930 17 January 30 January 2000 31 January 5 February 0930 6 February 12 February 0520 13 February 26 February 1030 27 February 21 March 1620 22 March 23 March 2040 24 March 25 March 1630 26 March 9 Apri I 0930 10 April 2220 24 April 0800 7 May 23 April 6 May ‘q 30 May OBOO – 1969 Mean c* EST D D D Q Q 31 May Kp C4st 0930 3- Reg 0800 10 Drift 0900 3- Reg 0950 2+ Drift 1030 30 Reg 0510 w Reg 0500 70 Reg 1630 3+ Drift 0930 2 Reg 2210 2- Drift OBOO 2- Reg 0130 2+ Drift 0630 1+ Drift 0900 l– Reg OB1O 20 Drift 0 COmrnents Incomplete Antenna gain dwm 10 dl SpecirA OUrwel opemfim Quiet Combined I June 5 June q 2030 2 June 0930 6 June Q ?3 June QO B20 24 June I July DO 800 2 July 0815 3– Reg 0540 10 July 0440 2- Driff 800 3 0 July I 900 20 Drift 9 July !9 July Ql !4 August !6 August D Quiet o815 I 5 August q o845 1- Reg 1530 2 7 August D 1530 3+ Drift o900 2 Reg o800 2+ Drift 900 50 Reg Speciol 700 10 Drift Q.i.t I 700 20 Reg Drift Reg 9 September o 915 I O September !3 September oBOO 2 4 September 9 September D 22 00 1 Octcber 4 October Q 1700 I 5 Octcber 3 November D 14 00 O November q 8 December I DO QI 4 November 0 08 30 2 1 November Q 1Ooo 1- 124s 9 December D 1245 2+ Quiet oumxal operation Quiet Ccmditi.n: Q q D One of five quietest days i“ nvmth One of ten quietest days i“ month 0“. of Five most distutbed days i. month Obserwticms: Dat~ gathered and anolyzed m described Reg = Regular; Drift = Drift Measurement. ;. Li”c.al. 4 I.cibora<ory Technical Report 477 (Ref. 20). , . In the normal pulses operating in sequence, mode, the complete measurements cycle in Table II to distinguish 24 hours of each type of measurement The value of the F-region measurement which stored ment, those frequent with all the other ionosonde was modified well as to have its frequency would turn on tbe sounder turn was just perceived carried controlled by a remote the frequency range. on magnetic tape. into the computer To make the measure- synthesizer. of the synthesizer dials of a of each cycle.* on and monitored frequency The synthesizer in the form at the start who then typed tbe value it to be turned ‘Tregular” Usually, month. wai? made available in megahertz information, and %.0 -msec of ‘! drift:f out in each calendar operator, to permit 0.5-, runs are termed the determination y foF2 and advance at great These in the data reduction critical was made by the radar it, along the C-4 made using 0.4-, 30 minutes. emphasizing were of Nmax to be employed measurement This them from were occupying remotely, Thus, as the opew.tor until the F2 ordinary then gave the required re - value of foFZ. The intent of this procedure quired for processing, However, the radar night. Thus, stead, they were and values operators as a rule, these plotted recorded West Virginia. lowed the variation onto IBM cards. encountered estimates cm’ve at Millstone, were together Maynard, this curve from espectilly at variance in- and Wallops of points Is- that fol- with the observations at 30-minute between at the film records (if available); this collection employing interpolation foF2, re- of a run. in the data analysis; derived Massachusetts then processed by linear in reading with those when this was clearly read from data were obtained difficulty all the information upon completion were not employed was then drawn through except Values profiles of time, Canada; A smooth The recorded electron-density out immediately frequently as a function stations. a data tape that contained be carried real-time at Ottawa, land, at all the other was to create so that this could intervals values and punched of Nmax for the the values avaflable at half-hour internals. During 4969, Dr. J. Noxon other the first (Harvard emission from objective arcs observe of low-latitude d. auroral activity, Unfortunately, twilight, and it requires notification of people 3n the past, scatter were i approximately at their homes, although some Alouette 1. optical with measurements coincidences observations * Nmax: = 1.24 X i04(foF2)2 el/cm3 red-arc, for the activity way. due to the high gathered at Millstone to have declined This appears SAR- us to tbe presence is not detectable operations and and deter- as no overhead were luminosity 6300 -~, Massachusetts. excitation results with simulta until after fo220wing substan- to have been the case 4969. gathered between were auroral II) Dr. Noxon alerted to commence were under Boston, of impact and radar it was POSsible the 5577 -~, to be disappointing, (Table have been made to compare on lucky early proved two hours measurements on 29 September efforts obsermtions dependent and valuable a stable for in terms on two occasion8 measurements Observatory, owing to tbe fact that the auroral by the time the radar for the measurements was to observe be accounted coordinated was measuring at the Blue Hills fn this the effort However, neously. tially could made to conduct at that time, of this joint effort of the electrons. were who, the night sky, mine if the 6300 -~ emission temperature were University) lines The principal attempts by various our operations schedule when foF2 the observations d to coincide is expressed 1 5 gathered ,satellites. and satellite with passes in megahertz. in the incoherent Usually, passes the comparisons over of the topside Millstone, sounder, . Beginning Alouette in i 968, a number 11 at the request observations also satellites. were Where favorable passes, operations of scientists possible, the regular 111lists scheduled short ohserving periods purpose measurements, C. in July t 968, of interest The computer were programs spm-ious of Te/Ti, plotter, employed echoes Debye were as functions The values with 2 hours) for these cm request. of OGO VI was to permit ~id & &u probe Comparisons spectra, with Unfortunately, At high altitudes, comes inaccurate better pulse value to yield tbe absolute the dependence the correct on altitude as a graph plotted prolengths. varia- by a Calcornp Estimates of Te and Ti were also corrected for the effects provided of the changing in which the measurements were of Te and Ti were obtained by extracting width (proportional freqwmcy (proportional thathad been obtained expressions scaling theoretical power length is extremely of the transmitter pulse two parameters to Te), and the ratio to Te/Ti). to represent spectra small. These Te and Ti, computed In computing and the finite assuming these the- width of tbe filters in . in the &bye ( length temperature T obtained in the above manner for ‘ohs 20 on the spectrum, use was made of the expression 1.62 x Te -i ob s i– N, holds (1) ) only so long as the second term in the parentheses remains T may be of the order of 2000 to 3000 K and the ~o=rection then ~‘ohs as Ne approaches i 04 el/cm3. Tbw, the electron temperatures obtained near this level The existence the electron-density i963. of the electron this expression <0.3. possible. were included. the estimate of tbe change all the became made with the three the manner to that at the center the effects the measurement together reduction Basically, was avai3able 20 that placed machine (4) removed profile and that the Debye ‘ohs are believed of an em-or response to be overestimates. in the 0.5-rnsec of the i.0 -msec (B-mode) pulses 6 ! Results I in routine (typically IV. sounding in a manner (3) adjwted of Te were and width through T==T obviously to coincide that occurred have been reported. in Ref. 20. the half -peak-power into analytical of the ratio To correct or above the passes measurements V contrasts since viz., in the wings inserted ore tical power the effect Table spectra, only 0+ ions are present distorting This be noted that the estimates of the peak power values are described as log, o Ne vs altitude. in each year the measured gathered on the ionosonde, and on the printout. It should were due to satellites, length with altitude.20 made and reduced from in Table by remote i 969, I, 11 or ISfS I have yet to be made. (1) combined and on Debye length. and on a printout on plots during data tape so that complete in a way that: value of Nmax F2 as measured tions During but may be made available of this exercise in Alouette the results on a single obtained (2) removed made scheduled of operation as listed deduced Center. of ISfS I, OGO VI and Alouette of MiUstone periods with passes Reduction Beginning files of the results sounders short in this report, of the measurements and most were overflights passes Flight (AE-B), operations Additional satellite and ion temperatures of the topside Data quantities with other are not included of electron the records monttly to coincide Space of the Explorer the satellite with this in mind. to coincide The primary passes and Table scheduled we=e scheduled at the NASA Goddard made during were comparisons of observations =esults to an applied has been noted. RF pulse, Owing to the it was assumed that TABLE Ill SATELLITE PASSES DURING Date REGULAR OPERATIONS Height (km) Time (SST) IN 1969 Satellite 25 March 2041 910 10 April 0537 30May 1904 650 1200 23 June I743 OGo VI 24 June 0407 OGO VI I July 1647 OGO VI 2 July 0312 OGo VI 9 July 1550 OGO VI 10 July 0215 OGO VI 23 September 1725 630 [s1s I 29 September 2149 974 Alouette I 30 September 2202 942 Alo.ette I Alouette II 1s1sI AE-B TABLE IV SPECIAL OPERATIONS COINCIDING WITH SATELLITE PASSES IN Time (EST) Height 5 May 1541 584 Alouette IB June 1800 640 OGO VI 19 June 0420 430 OGO VI 27 June 1626 OGO VI Date (km) 1969 Satellite I 0849 650 1s1sI 29 SepterAber 1725 587 1s1sI I 7 Octcber 1453 730 Isis 17 Ockber 1937 625 Alouette 20 Octcber 153a 785 1s1sI 27 Octcber 1945 513 Afwette II 29 Octcber 1809 512 Alwette II 4 August . I 11 TABLE V OBSERVING Length of Each Cbserving Pericd (hours) Year AS A FUNCTION Time Taken tO Mewure Number of Observing Periods per Mcmth One Profile (ho”m) 4 1.5 30 1963 PROGRAM OF YEAR Number Profiles of Reduction Chined Methcd Employed per Month 80 Mean hourly profiles constructed calendar (Ref. 1) 1964 30 2 1965 48 I 1966 24 2 1.0 0.5 0.5 60 Asin 1963 96 Asin 1963 96 Each prcfile analyzed separately 1967 24 2 1968 24 2 0.5 0.5 96 or 0.75 Asin 96 or 64 for each mdnth (Ref.4) 1966 Asin 1965 until J”ly when ccmplete nwchine ~ I reduction began (Ref. 20) 1969 24 0.5or 2 0.75 96 Or 64 Machine reduction (Ref.20) the error stemmed 0.5-msec pulses. from Ln order response for the B-mode the same height. sistent results possible This work was carried results obtained were also ratios linear version below because were in error) well matched made to determine spectra Lejeune .* number obtained the proper Ln part, were of points 4.4 “sing in Figs. of the analysis the Centre ratios in this figure the shorter pulses. reliable It seems was made at 450 km (where because theerror?.ppew-s suggests corrections by the two different of as a func- -mode results that (Te/Ti)C-mode are applied to B-mode pulses des Telecommunications, 8 to de. values that it is difficdt for the B-mode they assume program, i at and con- compared. A plot of ( Te/Ti)c measured Nat,{onal d! Etudes spectrum to vs Ti a bias of up to 200 K can be seen at low values that have been devised 1 and 2, i.e., to in the two modes Unfortunately, of spectra the comparison and, to be less correction corrections curves if the temperature ,>011 leave from Seine, France. in part, is shown in Fig. 2, where The empirical in a later heights out byG. The distribution – Ti (C-mode) on the smooth appeared by comparing a large somewhat filters was obtained by J, E. Salah by comparing 22 at 525 km with the two pulse lengths. Fi&Vre ~ shows (Te/Ti)B-mode temperature of Te/TT efforts although failed, An empirical tion of (Te/Ti)C-mode. resolve this, empirically were not obtained, penal upon Te/T< (B-mode) to remedy fHters that this approach the i-msec Te/Ti the fact that the B-mode are based is COITeCt. results at 525 km differ Issy-les at aLL by more - Moulineaux, . than 0. i, These or if the ion temperatures corrections derived from the two pulses differ i < Te/Ti< i.47 by more than iOO K. are: 0.425 (Te/Ti) (Te/Ti)’ ❑ (Te/Ti)t = i.5(Te/Ti) ( Te/Ti) + 0.575 – i ‘ = Te/T,i 1.474 Te/Ti< Te/Ti >2 (3) 2 (4) 1< (Te/Ti)l T; = Ti + ZOO (2) (5) < i.2 T; = Ti - 333( Te/Ti)’ + 600 i.2< (Te/Ti)l < i.5 ~ (6) T; = Ti – 200( Te/Ti)’ + 400 1.5< (Te/Ti)l <2.25 (7) <3 (8) T;= T; ❑ Ti–50 2.25< (Te/Ti)l T. 1 (Te/Ti)l (9) >3 (40) T~ = T~(Te/Ti)’ where original the primed quantities measured values. are the comec ted parameters, ‘.. \ and the unprimed quantities are the o “0limca 0 28 — 2.6 — .0 ❑ 0. 2.4 — o ,.2 — o g t n .s 2.0 — ~. . O. ,.s — .“ n 525 km ,.4 —. . . 14-!8 ● 8-7 o ,7-,8 ❑ 28-2, AUO 69 JAN 70 AUG 70 DEC 70 ,,2 — !.0 !.2 14 !.6 ,, ,, 22 2+ “ “ 3 [T. (T,lC Fig. 1. Te/Ti derived from 0.5-msec (B-mode) and 1. O-tnsec (C-mode) 22 pulses. 3.0 [48-2 -!0442.! I ❑ ,. e — I ,.6 — ,8 “ m,. e.4 — ❑ ,2 — . “o o ~ ■ ~- 2.0 — ~. ■ !,8 — o !.. — .“ 525 R. . ,4-15AuG 0 17-18 ❑ 28-29 . ,.4 — 69 AUG70 ,.2 — I I ,.0 -20. -,00 0 (00 TEMPERATURE T,wll-rl Fig. 2, Dew iaticm between (C-mode) Since, report were C-mode only examined, the uncorrected the influence by constructing (i-IIISeC of Ne, tion of these quantities Te, As described over and a simpler limitations program that reduces spectra were B-mode results senting these does include using O. 5-msec range earlier.4 (B-mode) and 1. O-msec doppler B-mode at the time the data in this results profiles (chiefly at night in summer) that largely depended on the tbmgh and time. shift, program, to obtain drift less for F-region these vertical diagrams showing to extract of drift velocity. gave almost method the variaThese were identical Later was modified the program has been devised, To date, obtained from Owing only the C -mode to include no method owing to their on request. these drift results. op- in the main Initially, to be valuable. the signal The theoretically was incorporated data can be made available fluxes from and temperatures. proved form developed 17method this latter estimates. graphical However, were and hence densities accurate, contour . ‘1least -mean -sqwres data in a convenient results available 150 to 900 km (200 to 900 km at night). of methods the data to obtsin which, were -vs-height outlined in the analysis analyzed both with height of the poor the height of the overall to space results temperature in Ref. 20, a mmber estimates method derived and Ti were used to construct drawn by hand in the reamer timum (°K) [c] data. pulse) The profiles spectra Lx temperature 200 pulses.22 however, was minimized DEC 70 the of pre - wide spread This measurements report (Sec. V). io ..-...—... ——.. —— 111. ELECTRON-DENSITY A. General Contours Figs. of the logarithm 3(a) through which logio 4.0 (e. g., were tithe May were made (z). Ne > 3.2. of the equipment, 30-34 RESULTS (logio The contours It is possible, valley some marred on 1-2 June. that forms however, between days (e. g., by a failure These Ne) of the electron are drawnat 30-31 tithe two sets density intervals that the results the E-and January) Ne (el/cm3) of 0.2 over F-layers become analyzer, unreliable at night). are incomplete. spectrum are presented~ the range when logio for Ne< Owing to malfunctions The observations and additional of data have been combined of altitudes for measurements into a single conkmrp lot [Fig. 3(l)]. . [.1 Fig.3 (a-z). C.ntcwrsoflog, oNe .bserved if on days listed in Table Il. w 3.4 7m@L 3,4 - .OO,O N, ,0-3, ,,. 4%, 4.6 7C0 — 60. — m. .CO \Y4’” — ,? X/ b_’Q...-..J2 BJ3 ,0 —=---=Qo .“,,. I 1 I ,m ,2 58 / 6.0 ,.- - ,--—-_— ~___ ------ --- ., .-. 5.0 /’ :: .-.’ %8 ,.6 ~’” $i ES, [b) . Fig.3 (a-z). Continued. ,,. [<) Fig.3 (a-2). Continued. . EST (d) Fig.3 (a-z). Continued. Ez!!L : : r, r 50 :: 44 ..2 4,0 ,0 3.6 3.4 3,2 EST (d Fig.3 (a-z). Continued. i5 . (f) ~9.3(a-z). Continued. 46 ,,. .. ”...., 7., 40! >0 tm. u... .0.. ,*T (Q) Fig.3(o-z). Continued. .. .. — m /.. ---- -. q ::; F* h. . . J ., ‘---- ,.-” 5.6 5.4 / 3.4 3,2 4.0 R (h) . Fig.3 (a-z). i8 Continued. . ,qg.3 (0-z). Continued. I i9 Fig.3(a-z). Continued. 20 [k] Fig.3(a-z). Conti..ed. (1) Fig.3 (a-z). 22 Continued. 3., s.8 “F 4 @%Na 5-6 ‘UN 1969 4.0 am 44 ,.0 4., r---’ 4, :; 4.0 3, :: 3.2 , ,,.. > ,m , lam EST [.1 Fig.3(.-z). Continued. 23 w IW~ zoco zzou *“W 1 lEim “-’’J+--’ m. – ‘% / N. 23-24 JUNN,, 5.2 : : g ,@ I mu L E,, (n) . Fig.3 (a-.). 24 Continued. —- lmE!zL ,.. .~, 3.8 F N, l-t 4.4 4,0 m. 4.2 ,.. { 4.6 Y- 1 (.) Fig.3 (a-z). Continued. 25 WL (969 . Fig.3(a-z). &nfinued. 26 L ,00 h //1 / .00 : > ‘2 ,.0 : 4.0 ,.. ,.0 4.8 4.6 +4 4.2 4.0 38 36 ,.4 3.2 2.. EST (,1 Fig.3 (a-z). Continued. 27 EST (r) Fig.3 (a-z). 28 Cmjtin.ed. [*1 . Fig.3 (c-z). Continued. 29 Fig.3 (a-z). 30 C.antinued. (U1 Fig.3 (a-z). Continued. 34 Tmm_ ,..,... ,0. -— ,.-,50,7 Lb-----i 3.6 ,969 J/_ld \ (w) . Eg. w-z). Continued. TmEiL \ Ku /---.?8 ,/ ‘\\ /’l / ,0, – / /’ ----,4,0 _..-. : /‘ < :. >0. w ,Scc ,Ccm am ,,m EST [“) “ fig. 3(a-z). continued. 34 mmEL : : q 5.2 50 4,, 4.6 .,4 4.2 4.0 3.8 3., 3.4 3.2 4,, 4,, 4.4 j:~ 3.6 EST [Y) . Fig.3 (a-z). Continued. 35 (21 Fig. 3(CI-Z). ,— . Continued. . . .. B. ,.. ,.., Seasonal Variations As noted in earlier two characters principal tic patterns features i -6 reports, There (2) The highest (3) FoJ20wing variation that we have termed of the winter (i) the diurnal is a large behavior dim-ml values of the electron IIwinter!! and !rsummer,f follows one of respectively. The are: variation (e. g., 5: i ) in peak electron of Nmax are encountered sunrise, density the electron density near rises density i 300 local Nmax. time. to its peak near i300 and then falls again smoothly. (4) The peak height hmu above (5) lies in the range density decays 250 km by day and rises to 275 to 300 km at night. At night, pears (6) usually the electron to be maintained on many occasions, associated i.mmedia tely after for the rest there to a value in Nmu. This that ap- of the night. is a post-midnight with a downward sunset motion increase of the layer and a lowering is usually of the plasma temperature. Figures For 3(a), (b), (w), the observations mer behavior havior between by i4-i5 (2) There here, March representative there appears and 9-{0 April [Figs. may be characterized is only a small highest Following changes (4) of the winter-type from variation. winter 3(h) and 3(i)] and a return to sum- to winter be- value diurnal as follows: variation of Nmax is usually in Nmu sunrise, little the electron throughout The peak height usually less density the rest (e.g., encountered 2000 hours ), and is then considerably (3) examples to have been a transition [Fig. 3(w)]. bebavior T& and (z) provide 25-26 October The summer (i) (y), reported < 2:i). near ground than encountered increases sunset in winter (e. g., i 800 to near noon. for only i to 2 hours, and then of the dayt tie. lies between 275 and 300 km by day, i.e., higher than found in winter. (5) The thickness of tbe F-layer is considerably Figures larger (6) At night, tbe density 3(j), (k), (n), (m), (P), (e. g., in summer decays (q), as measured between points of half-peak density~ than in winter. continuously until sunrise. (t), and (u) appear to be representative examPles of this type of bebavior. The transition pletely of this change These from summer new state for the upper winds thereby sponsible is a seasonal serve altering variation to transport the ratio for removing made that are consistent to winter atmosphere. bebavior is fairly There now appears in the neutral atomic oxygen of the ionizable from constituent rapid, and appears general wind pattern of tbe upper the summer to the winter (0) tO the mO~ecu~r to signal a com- agreement that the cause io-13 atmosphere. hemisphere, sPecies (02. N2 ) re- satellite observations of neutral abundances have heen 23,24 measurements of the wind system responsible with this hypothesis, 0+ ions. have not been made in sufficient While detail to confirm 37 their role. It is also possible that there are seasonal variations However, aPPear in N2 and/or measurements made Disturbed have described 4-6,11-44 storms. magnetic and 29 September, i.e., observations subsided. Ouring variation the 23-24 at heights of N2 in the lower in these quiet -day patterns magnetic storms behavior. near thermmphere. the S. C., period, two of these. (S. C. ) at about 1300 EST on 23 March, a“d were March (Table began which promptly at Millstone II), hy which time the storm of foF2 at Addi- largely had with the behavior were obtained and we were scatter i4 lblay, [ Fig. 3(h)]. readings in the D-1ayer, during echoes obliged on the ionosonde to reconstruct in the manner outlined the time in Ref. 5. the results. TiEEmL . MILLSTONE 10NOSONDE -OBSERVER ESTIMATE x MILLSTONE . wALLOPS o ESTIMATE OASED ECHO INTENSITY IO NOSONDE -FILM ISLAND ON INCOHERENT SCATTER .. . Fig. 4. Variaticm fcm 23-24 March 0 incoherent of fOF2 MHz obtoined 1969 from v.ari atim of scatter power during period when i.mosonde was at tiines blacked out. xx . 0 i I I ,800 I I 20,0 I “q I I 2400 ,,,, I I moo I I 0.00 EST As can be seen and height. with altitude. located curring there appeared of ground of -105 temperatures at the time. were large much higher While the interpretation in the E-?egion, with a density electron in Fig. 3(g), The F-layer hy the presence reflections, of the results and that the “alley el/cm3. We believe observed, More detailed - changes in layer than normal, it appears obtained that there between calculations shape below performed only S1OW1Y maximum of ionization was filled with ionization taken together of soft (>400 eV) varied i7 O km altitude is complicated the E- and F-layers are being as well as peak density and the density was a second that this behavior, is a manifestation 38 ,, 25 i tO km 25,26 The March until 0500 EST next morning. [ Fig. 3(g)] may be contrasted few reliable of the incoherent Observations continued observations absorption mcountered in $969 on 24 March, data during 5+ for the next 39 hours. March the intensity occurred enough to gather [ Fig. 3 (f)] and a day later the disturbed of increased from major made on 25-26 the storm 4 presents changes variations commencement after were Thus, as a result Figure Three exceeding 7 hours two days before seasonal and we were fortunate to Kp valws 2040 EST, in F-region and at Mills tone of N2 densities Of large previously began with a sudden gave rise to tbe annual variation Days We also tional in France to rule Out the eXistenCe C. storm 02 that contribute electron with the elevated precipitation oc- by Dr. J. 1?. Noxon (private communication), neutral but are somewhat atmosphere during Some what similar storm 33 hours. Observations S. C., and continued level of about 4. commenced lower this night. have been seen analog support around tbe original to a detailed or from later (23-24 vertical observed and not caused Winter-Night The nighttime of up to *2 hours; temperature companied latitude from of the critical foF2 temperature was particles was much we which appear produce to penetrate the 27,28 who by Jones, ionization increases upon calculations 29 by Tanaka and Hirao, It appeared that the vertical day, of neutral and Evans hydrogen as large performed however, as using appear a to diffusion along fluxes 3f of ionization suggested into that this in tbe upper atmosphere avail- however; for example, tbe are possible, day may have been influenced by ambipolar of the electron the field at Millstone January, considerably lines, by electric as was assumed. is anomalous. of winter in density are always local and 20-2i to the more has been discussed but there accompanied cooling); in Nmax November), general extensively night pre -dawn increases and peak near 0200 EST, by increased Increases 3-4 November, which is linked ionosphere, features at about midnight to be caused appear to be: are variations hy a lowering (3) tbe increases ques in “ of the plasma are usually ac - of tbe layer. is not confined frequency latitudes 30-31 nighttime Tbe significant the east coast density (e. g., This phenomenon, of the winter 30” to 70” accordtig are seen regularly and Ottawa was an Elsewbere~i’14 increase. fields, was based Other explanations (2) the increases dictions in auroral the time the measurements has been contested on the disturbed on quiet nights with a lowering along lower on tbe disturbed solely commence This phenomenon curate evening cannot calculations 1970). near midnight. (believed values the to a in the vane y region and the electron electric fields in tbe abundance with O+. be bavior tion of the maintenance 4,43,32 earlier papers. The y usually after Behavior regularly commencing March re were of a depletion exchange are observed i i hours carried out on the post-storm days, 25-26 March i969, have been subject 30,31 m which they were contrasted with tbe behavior observed during a able to charge D. from the density March, large conclusion detailed some that tbe flux of precipitating explanation by electric This More the protonosphe drifts suggest This i.e., in the second 5 + for the following explanation. analysis because however, of substorm dusk. September exceeding to have been present on 23-24 findings (-i 00 percent). quiet day a year (i) These of the layer The observations usually appears In this case, than encountered method. the state of the by which time the Kp index had subsided there was an anomalously ionosphere that lifting fields, way at Millstone that this is a manifestation midlatitude arose at 2200 EST, also. On 30 September, circuit got under less lower concerning the night of 29-30 to Kp values Soft precipitation considerably claimed during until 0900 EST cm 4 October, order-of-magnitude proposed was observed at 1050 EST and gave rise until about 0400 EST. during by lack of knowledge the event. behavior which commenced hampered to a small geographical to ITS predictions for January of foF2 of tbe United States (45-N) to the north, reported which confirm but appears (Ref. 33). Figure 1969 at 0600 UT (0100 EST). can be seen. (say north of 50° geographic in the values region, from Wallops Island pattern 5 shows A ridge region), in the P?e - of increased this map is probably in this longitude the general 39 While to extend increases inac in (37aN) to the south of Mi31s tone of Fig. 5. ,... EAST ..s, PREDICTED Fig.5. The increase temperature content stone and consequent geostationary we proposed by a lowering in the layer. than the peak density. directly that the density The onset tube to cool of the plasma AS a result, the total This can be seen in the Mill- in measurements following conjugate sunset. Owing to the more OCCW-S 30 mirmtes later Subsequent and the onset Studies of heating of photoelectrons zemith distance gate! heating should destroys Figure westerly of total content conducted using was tamed 6 shows location by a flux of cool to be controlled the time of local of the conjugate plasma by the time point, from it takes and conjugate local the sun- midnight there than at Millstone. of the prod”cticm ,in the local of photoelectrons ionosphere following ,into the magnetosphere x ~ $OOO. If this is so, this f tiding increase of this flux was supposed set fOr MiJJstone. ization 33 for January 1968. satellites~4 Em_lier~2 escape F2(MHz) to be accompanied of the electrons percentage and has been observed the magnetosphere. field appears redistribution by a smaller profiles, ,;;, MUF(ZEROI Ccmtcws of fOF2 at 0100 EST predicted in Nmax invariably increases MEDIAN be reduced in the period the earlier should then there hypothesis. arriving Mmj”gate mid-octobe Meanwhile, the conjugate ionosphere, 35 surmise showed that the be fully developed is no time during between from whenever the solar the night at which the conju- r and mid-February the question of whether (Fig. 6); a flux of icm - from the magnetosphere could produce an increase in Nmax has been examined. among 36 others, by M ikhaylov (who, however, neglected the change in the shape of the layer associated with temperature changes ). Mikhaylov found that a flux rising to -5 x 108 el/cm2/sec appeared necessary to raise aPPear to exist The mom foF2 from at Millstone general flux of ionization from about 2.5 to 3.5 MHz. in Sec. V, such large fluxes do not at night. question of the maintenance the magnetosphere, of the nighttime has been dis cussed 40 ;— As shown ionosphere, by a large by means zmmber of a 37-42 of authors. <5 I X.90. 95 {00 405 1+0 ,400~ DATE fig .6. Because Contours of solar zenith it has seemed contributor winds, higher levels direct experimental maintaining aPPears where E. which blow toward evidence being settled. Disturbed-Nighttime Millstone be subject lies the equator the existence has recently We address it has been argued at midlatitudes and drive (For of significant that the principal of along the field lines 43 ) However, to see Rishbeth. fluxes at Arecibo, further months. is the existence ionization review been obtained this topic during winter that would assist in 44 so the question . in Sec. V. Behavior in what must be termed to changes F-layer rate is lower. showing F-layer and its ccm@gate pint is too small, of the nighttime the recombination the nighttime far from x .at Mil Istme that the flux available to the maintenance thermo spheric angle in association sub-auroral with events latitudes, taking place and the local in the auroral ionosphere may zone to the north. The penetration of substm-m electric fields into the midlatitude ionosphere at night has been dis 46 by Riister45; and, by examining ionosonde records, VanZandt, at ~, Park~7 and 48 Park and Meng have demonstrated that these fields can penetrate a range of geomagnetic lat- cussed itude of 20° to 60° during an eastward corrhng hours electric about 9 hours of local time. Prior to midnight, the layer wbfle after titiigbt it is usually lowered by westward 48 to Park and Meng, these effects can be seen most clearly during winter of darbess height with time. field, are lcxIger and the layer These vertical motions fl,mmally “ndergm!s of the FZ -layer 41 only small changes are usua13y accompanied is lifted fields. nights by Ac- when the of shape and by changes — in peak density, .% decrease lowering although in the layer of the layer Observations there appears height were conducted 3), 8-9 December ported IV. d. Particularly February, AND between increase Nma in Nmax, dis tm.bed winter 12-13 of these nights their February appear are the fluctuations February, some maxFz. but a further on t 6.17 January 2.6-27 Febmary of the effects with substorms (Kp = i-e- has not been in hmax which are associated ION-TEMPERATURE to exhibit association nights (Kp = 3+), and h observed on t 6-i 7 January, with variations in Nmax. .RESULTS General Figures electron striking and 26-27 ELECTRONA. Several magnetically (Kp . 4), hy Park and Meng,48 but at this juncture determine 12-13 during 5-6 February (Kp = 4-). relationship by an initial to a rapid decay. 47 will give rise (Iip = 4+ at 0000 hours), to be no simple often is accompanied 7(a) through temperature (z) and 8(a) through (at 2000 K intervals), vs height and time for the periods temperature -height profiles listed (z) provide and of constant in Table drawn hy hand through diagrams showing ion temperatures contours of constant (at f 00- K intervals) II. These diagrams were prepared the points plotted by the Calcomp from plotter. 5,6 (,1 Fig. 7(0-.). Contours of electron temperature Te observed cm days listed in Toble Il. 42 —— . r .... ... .......... .. . .... . ... . . ...... .. .. .,. ,. ‘.bw/z?n’-’A (c] Fig.7 (a-z). 44 Continued. . ,.. P-----Q””” -—––=2–– EST (d 1 Fig. 7(0-z). Continued. 45 /n / / ~... / .l\!l\wL’’zz2=2’25f : ~j )d%’!?’ \- T - ZS-Z7 1 ‘EB , EST [e] Fig. 7(a-z). Continued. 46 ’969 / — I /“ “0° r . ,7.23-24 .,.,,., am — m, - . ..~ : : m. . 400 — m. - *O. — h) . Fig. 7(a-z). 48 — -. Continued. ,00 ~aoo,,25-26 MAR ,96, ‘~[+ 1 3400 4400 ///// Blti$v f’ ‘o” 3200 3000 ,00 4000 3800 3600 3400 3200 2800 ;’””B\w@ ,Coo ,600 \ i 2800 2600 2400 ,200 40”h\w/@ 2---G-G ~-. ,000 I . ... 1 .?.. 1 .400 I ..00 1 I 08.. 100. 1 !2.0 ,$, 1 !40. (h) Fig. 7(0-z). Continued. 49 ! !... 1 !.0. 1 ,0.0 I ,,.. 2... I , Km Esr [0 Fig. 7(a-z). 50 C.antinued. I 01 fi9.7 (a-z). Continued. ll\3e00 ) “-36%-”/ II 1(-- . 1 1 EST (k) ., ~g. 7(a-z). Continued, 52 —. (1) Fig.7(.a-z). Continued. 53 (m) Fig.7 (a-z). 54 Continued. E,, [.1 Fig.7(a-z). Continued. 55 _- 303 t (01 Fig. 7(IJ-z). Continued. ....7 b) Fig. 7(a-2). Continued. 57 (Q] Fig.7(cJ-z). 1 58 —. Continued. _j-$\q , , g 203 — 600 .... m .... --- . .. -.. -~ - 1.~ 1... EST 1400 [r] Fig. 7(.-z). Continued, w’!! 1600 1am ‘0”0 “w 2“0” -Emz , -. .. [t] Fig. 7(a-z). Continued. 61 EST M Fig.7(a-z). Continued. 62 u. . Fig.7 (a-z). Continued, I ,. i , ,,, I (w) Fig.7 (a-z). Ccmtinued. I I { , (x] Fig.7(a-z). C.ntinued. 65 —— (Y) 66 (4 Fig.7(a-z). Continued. 67 — ,Ca Kc b-?~ “ ma - ,Co WC me ,*CO .-a .Owa o,~ EST [.1 Fig.8(a-z). Contours of ion temperature 68 Ti observed on cloys listed in Table II Tm@l.- iv ,200 / -00 220 2,00 2000 ,(00 ,,00 ,, 30-3$,., 1969 ~ ~ ,800 , SOo .Om 700 ~ I ,,.0 1 !..0 EST [b) Fig,8 (a-z). Continued. 69 I $,,, 600 [ 1 j... zoo” 2’0” -1 2“0” . B=$‘—r)\\/” ..0 “--4400 ,Ca :m~ J --—’=czx~ J \ m [c) Fig.8 (a-z). Continued. ?0 ,. .; ,, !500 , +00 4400 , zoo n //-s 1500 1300 ,0. ~ 4300 — ‘2-’5zN-si!5!ss-&’” Tmm ,.0 m=@ 2100 k, ,,00 80. ~ ~e 2,00 ,100 T800 ,,,0 \ ,00 ! ,.0 ) SW 7.. ,000 2000 1,0. ,800 ,s00 ,500 ,40, ,700 ,,00 A ,,00 — /“ ,,00 . .“ Fig. 8(cI-z). Contl.ued . . .. ., _ .- .0. L ~L ,.. ‘“ ,00 ESr (*1 Fig, 8(.2-z). Continued. ,0. ,KO WC L ,W ,, 24-22 MAR 4969 Em !Wx 7.. (mm 600 = !,00 Fig.8(a-z). Continued. 73 .- 1,, z.,. MAR ,%9 I /2,00 fig, 8(a-z), Continued. 74 T,25-26MAR !,69 &&J, moo 4.. ,200 ,00 ,0. 800 !,00 700 ‘0“-~ .m. .2.0 0-. ... .e~o “m ‘Ooo ““o EST (N Fig.8 (a-z). Continued. 75 ““c .. = E*T [i] Fig.8(a-z). Ccmtin.ed. Fig.8(0-z). Continued. 77 Es? [k) Fig. 8(0-z). COnf inued. 78 m, (1) Fig. 8(a-z). Continued, 79 EST [m) Fig. 8(a-z). Continued I ‘1 80 ,. EST (.) Fig.8(crz). Continued. Fig, 8(a-z). Continued, i ,, I 82 — / T, 9-10 4“. 1969 --IA F*T [71 Fig. 8(0-z). Continued 83 I /// ,!00 7.. 5.0 — 1 I .. . — 3.. — I ,.., ES, (q) Fig. 8(.2-z). 84 I Continued. ,,.. ,40. EST [r) Fig. 8(0-z). Continued. 85 ~ , T, 2,-27AuG ,969 \\\ \\ >500 --’,.rn\ ,~\W-q 8! ,400 *WC /2500/ , ,.. I “ 2003 ,X0 n ,8C9 ! 700 ‘7N===S3E!,, / / m EST (s) Fig, 8(0-z). Continued. 86 J— EST (1) Fig. 8(.rz). Continued. 87 ,..” k “k w ,500 mc ,,< t400 ,7< \ ! ,00 700 \ ,200 _- m. - \ 800 700 6C0 ,s, (.) Fig. 8(0-.). Continued 88 .....-. .—-.. ..— . .. .... ....:...-~a=.-a..- r——————— EST (V1 Fig. 8(a-z). Continued. .. .. ..i=.-..l.a.~- .- . .. . . ., =,..,.,.. .,=, - EST (.) Fig.8 (a-z). Continued. 90 EST (x) Fig. 8(0-2). Continued. 4,00 ,400 f mo \- \vp’ EST (Y) Fig. 8(0-z). Cent inued. 92 -G=z EST [z] Fig. 8(0-z). Continued. 93 Sin. e the lowest downward, point available is for 225 km altitude, and this was carried The results the exospheric reported out by assuming shown in Figs. neutral it was necessary a fixed 3, ?, and 8 have been temperature via thermal va~ue Te = Ti = 335°K at t20 km altitude. combined balance Quiet-Day The most dmsity) arguments, there Electron striking feature of the electron-temperature is little diurnal variation the Conjugate in winter of have been the night (Fig. 5), and this heat is lost by conduction at the conjugate On some x small nights in Te. after, 10-25 During March beginning density to the icrmsphere through botb locally than February) temperature local sunset was usually increased. Thus, gave rise to only seen to decrease tbe temperature change at, at it is sometimes possible to discern temperature insunrise, 9,35 provided that the local electron density is suffi50 is not masked by the local cooling. As mm be seen in Fig. 5, conlocal and i 5 September sunrise another 0430 makes of a temperature increase beginning hut in this case it difficult margin to be certain. beginning only during The temperature of conjugate somewhat before the temperature Similarly, before (’l to 2 hours) approximately. [ Fig. 7(f)] is an example increase instance, by a useful – 4 October, at about 0300 on 22 ‘March [Fig. 7(h)] represents nea? This to the prdtcmosphere equinox that the electron-temperature beginning so that heat is supplied with conjugate (Xconj > i05~) precedes sunrise to the in summer. the length of the day is greater i2-13 electron as the electron low so that the effect POSsihle 5-b February, The winter-night marked. associated the period on the other hand, (e. g., midnight dawn was more creases In summer, smdit variation point (Fig. 5). winter decrease ‘- or shortly point remains is that (in contrast diurnal throughout ends of the field tube. dication and tbe results behavior and a large in winter crease variation Temperatures is because jugate to obtain the diurnal in Refs. 22 and 49. B. ciently to extend the curves heating. at local that there dawn cm 24 September It is 0400 on 26 March increase it appears in- [Fig, 7 (“)], sunrise is some in- but the ef - feet is not pronomrced. A consistent close feature to or somewhat ples are provided ceeded -i.5 of the daytime hmax F2 whenever above by 26-27 February x 106 el/crn3. temperature electron and 25-26 As we move temperate the local March away from is the minimum cooling becomes which were sunspot large occasions maximum, produced enough. at a level Exam- when N~axF2 instances ex- of electron- become infrequent at Millstone, as the required high electron densities 5,6 am no lrmg’e r encountered. For the same reason, the probability of encountering a tempera5% ture inversion has always been considered to be higher in winter than in summer. During i969, howe”cr, inversions there were during sumet. worthy that cm these less These include During because winter the local 6 May, a“d the local cooling i-e density beating the electron serves This 30 May, 5 June, from is particularly encountered 1 July, varies of the inversion rise particularly It is note- was typically (-25 correspondingly. with the electron caused for example, a little to 30 km) higher would be lowered inversely the ternperatuv+ pronounced, in smmme?, and 23 September. was substantially photoprod”ction temperature to modulate were at the level the peak of the layer IIowe”er, nights, Cmrn tk,e protonc,sphe days m which inversions days the electron than 106 el/cm3. than found in wi”tei-, 4-5 several by heat on i 6-17 density conducted January and November. 94 ., . .—...——..- ...———---- C. Disturbed-Day Electron On the disturbed increasing, suggesting began that it was caused hy the growth of the F2 -laye? . i05°) night, Te increased in the valley occ”ming During density a mininmm (near remained +00 km). above was initially its normal in the valley flux. after midnight However, the night, value at most region to be levels. (near 250 km), Thereafter, the temperature to have been caused appears it is possible to the lowering observed tht that conjugate sunset of the temperature. 250 km as the F2 density high throughout geomagnetically disturbed near 0120 EST that appears suggesting declined. After Tem~ mid- ratures that the soft particle The temperabm-e in the valley at Oi45 EST. urements are too low owing to the neglect than on 23-24 the results March, However, (Sec. 11-C). flux was as high as 300 km is provided at the commencement have arisen from assuning evidence hy the large of the observations region beneath it is possible ions variation m 23 March. that only 0+ ions were density. of conjugate the layer that both sets There - sunrise peak was sub- of temperature (02+, NO+) at these that molecular - i October), the next 2 hcmrs reaching as a consequence of molecular Some (29 September during with a. peak in the F2 -region possibly less period and declined to coincide stantially interpreting observing began, gradua13y increased, occurring ions were levels mess - when abundant at altitudes of ion temperature below this level This is thought to be unrealistic and to pi-eserd. Ion Temperature The ion temperature below shortly high when the observations the temperature D. encountered at 2200 EST contributed the second .a minimum perhaps temperature at all times. Te was already after, electron again at all levels region the electron by a peak in the precipitating and reached (Xconj March, a peak near 2130 EST when it was twice with the highest to decrease present night of 23-24 and reached This coincided Temperatures 300 km where the ion temperature and the neutral [Figs. 8(a) through (z) ] exhibits the ions and the neutrals increases exospheric only a small are in good thermal and takes up a value intermediate temperature. As such, diurnal contact. between it tends to mirror change At higher the electron the changes at altitudes altitudes, temperature in the elec - tron temperature. v. VERTICAL A. IONIZATION FLUX RESULTS General The new spectrum analyzer installed vertical velocity of the plasma over pre~ented.30>31,52,53 As discussed to the direction of the magnetic field line. the sum of a component v ] 1 parallel oriented in the magnetic ‘ohs = 0“96 ’11 + 0“28 ‘1 In the F-region the drift velocity VL NS = EEW/B v permitted the first Preliminary results in Ref. 30, the antenna beam magnetic field in i968 20 Millstone. The observed to the field 1 NS velocity and a component NS direction reliable from is directed estimates of the this work have been at an angle vob~ may be considered v ~ NS pe?pendimla.r of i6to be to the where (41) NS will be controlled by the east-west electric field, i.e., {i2) . 95 —- Separate measurements which indicate by ignoring that, made using the L-band except during the V1 component, magnetically it is possible with errors ‘e=surements independent, ‘f ‘1 I it is sometimes The most useful radar directed to regard possible to remove these 19,54 have been made the observed Thus, v 1 NS < 30 111/s~C. velocities as providing Sinc,e the v component disturbed of up to *<O m/see. obliquely conditions, .L will be height- errors. the measurements of the vertical velocity are estimates of 30 the N-S component of tbe thermospheric wind and of the ionization fluxes exchanged with the 53,55 magnetosphere. Since the determination of the winds is cw-rently tbe subject of a separate 56 study> we confine our attention here to the question of the magnetospheric fhx. A limitation height re suits from of the drift velocity of the transition to measure directly altitude forhmately, .- H+ fluxes height of the layer altitudes. by pressm.e (e. g., Similarly, 10SS) or expansion vertical protonosphere, ratio reproduce the observed ratio at altitudes are reflected in tbe vertical (under in plasma drift in the at all and also establish of ionization of the fhx hmax F2 changes of production temperature) on the excba.nge disti-ib”tion Thus, the influence Lln- well above below. of changes the velocity of a geophysical as well as to reduce and hence ion. 30 the predominant in the plasma winds) to the great when Ne, with the Te, and Ti of time. to average fluctuations owing it is not possible only the flmxes of the 0+ ions of tbe ionization of the layer to study the altitude results natm-e, the uncertainty it may be noted that the standard P5/Pn, P~/Pn of neutral (as a re,wlt for a period (TIDs), drift yield 0+ is always to obtain information it is desirable to remove nection, since occm-ring and decay in order it is easiest aPPear to be constant Disturbances as a result the growth Thus, In practice, changes and contraction fluxes. in part, are present), is that, km) at this latitude, the ohservatims as shown in FWf. 34, the vertical tends to be controlled made at Millstone 0+ and H+ (-2000 Instead, the H+ thx. (even when significant measurements between deviation e.g., obtained caused OVer a number by Traveling in the (noisy) of runs, Ionospheric estimates. in this con- in the results wmies with signal-to -noise 52 An empirical result which appears to on both height and time of day. variatim for the results of the rms presented deviation with the pr-edet ector signal-to -noise in Ref. 52 is A“=%103+ +r’z‘/’” where Vi is the mean thermal observations (pdses ). range 5 to 20 m/see, fore, it is essential interval the 8-minute to average over the contours to be roughly ity were computed the velocities Ods listed constant using observed in Table VI. to the tme runs, which the densities -Height three, drift i/2 v. and temperatures VI). or five cycles these To obtain and this r-eq”ires reliable appear of independent lies results, the existence in the there- of a time constant. i“ Figs. 3 (a) through near noon and midnight by day and by night. fn plotting Av typically Profiles with time (Table four, , and n is the number at Millstone, of dens!t y and temperature we have been able to find periods aPPear runs conducted mm r several Steady .State-Velocity-vs By examining of the ions (2kTi/mi) and is comparable of i or 2 hours B. (Z), For speed (13) Similar diagrams, 96 For when the density these periods, of data. diagrams Figure profiles 9(a-b) of w+rti.al presents were comtmc ted the height assigned (z) and 7 (a) through and temperature to each w+loc - examples of for all t!,c peri data point was a TABLE VI PERIODS Date (1969) 16-17 J.snu.a,y EMPLOYED FOR COMPUTING AVERAGE VELOCITY PROFILES Daytime Nighttime (EST) (EST) 1200-14&3 VERTICAL Comments 2200-2330 AWB= +7 m/4ec 0130-0230 As above 10-31 January 5-6 February 1300-1500 2330-0100 As above 12-13 February 1500-1630 2300-0100 As above 26-27 Febr..ary I 330-1530 0000-0200 As above 21-22 March 2300 -OICO ,% above 25-26 March 9-10 AK.ri I 1200-1400 2300-0100 As above 23-24 April 0800-1000 2230-0030 AWB = O 6-7 May 2230-0030 As above 1200-1400 As above 30-3 I May 0930-1030 As above June 1000-1200 As above June 1 I 00-1300 0100-G200 AWB = –7 mjsec July I 130-1300 2330-0030 As above I -2 June 5-4 23-24 I -2 9-10 July 29-30 July 14-15 August — 1000 -I2OO 0000-0130 1000 -1200\1200-1400 As above As obove As above 9-10 September I 330- I 500 23-24 September 0900-11 14-15 October 1300-1500 As above 3-4 November 1400-1530 As above 20-21 November 1330-1530 1030-0230 As above 8-9 December 1300- I 500 ?300-0130 As above As above oil 9030-0300 97 As above ,C+4 / ‘ooor71zEELI ,6-17 JAN!969 2?CU -23,0 Es. -.ln .00 ❑ we o z . : 0 ‘+ I o u MODE OW,. -7WSOC ❑ c .00, A.c=-,om,’,c .m , .~ “,,7,,,, “!,0,,,” _- 1 . B .0.9, 4.,. +7.,,,. m c . . . . ..,. -)0”,,,., 1 1 -4. “,RTI I -a (./..,) -m CAL ,,,.eighted Exmnples of plots of aver.ge height,, matched-filter that takes response echo power vs delay. distribution ob~erved The error bars and serve to indicate nighttime curves these plots signals during the scatter is that introduced where reading. tbe receiver, smaller source arising of this error the echo -power-vs of -delay of the points of error is discussed between and in constructing the input and output of the fall in the applied in the Appendix means, for the daytime encountered difference as a result about their where voltage it is shown to For typical These (14) ‘/s’” DC current read on the transmitter values, Vm = i 00 kV, this by me.ms and the receiver In plotting tests of tests tuning was adjusted gave an estimate meter, and Vm is the transmitter Iav . 3.8 A, Aw -–i in which the transmitter to balance of AW -–10 tbe “elocities in the C-mode the results in the height the varying ccmdition [Fig. 9(a-b)], and a correction interval where of the B-mode a correction 2 rn/sec. signal the power m/see Attempts was leaked observed in the C-mode of –iO m/see for the B-mode the results filter into at the center and a somewhat was applied to all tbe points data was sou~ht by attempting overlap. bank during 98 __ distribution value fm. the B-mode. gathered 3 ,, using deviations in the phase amplifier by the Pulse and measurement. these may be taken as typical A second by the change klystron io81av — ~Vm)3/2 have been made to verify pair of filters. are the rms imposed and (2) the actual computed (A-mode) for periods listed in Table VI, weighting function), were iOO-Psec of the data; The magnitude Iav is the average voltmeter ( 1) the triangular heights for 1969. constructed of Av/=— I weighted velocities ambiguity shown in Fig. 9 (a-b) constructed the pulse. the radar in the preceding at the transmitter be of the order .ertic tito account: (i. e., These ,./,$.1 (b) MGHTT,ME 10) ,,”7,., Fig. 9(a-b). “Em,,, ” This the year. procedure seemed to match justified by . t Tmi@L . “t t I I I J.. I ,,, . . . I I I ,,, .,” I ,“. ,., ,,, I I I I ... ,0” m, ,,, I 969 Fig. 10. Estimates of bias errcms in B-mode results breed on matching velocities t. those .bserved in C-mode in region of oved.p. Estimates have been confined to nighttime, m velocity is then les$ rapidly varying with height. AISO shown (solid line) is correction Iraw finally adopted, Figure finally 10 shows adopted. it difficult to detect be considerably C. Velocity true seasonal from there and diffuse created there upward diffuse variations well above downward is usually line is the correction tbrou ghout the year at low altitudes the day the drift tbe level to lower and are lost via charge upward At night [ Fig. 9 (b)], into the magnetosphere. the drift the magnetosphere below (unless which renders these happen to about 500 km is downward. of peak production altitudes a transition where to upward exchange 53>55 (near chemical drift. Ions created with hydi-ogen at all altitudes. with atomic creates a flux of 0+ ions which diffuse at a rate that just balances down through their the layer rate of arrival peak to levels (at times Between this transition The protons There oxygen readily holds. above atoms. tends to be downward from {80 km) cannot equilibrium which charge -exchange protons removed The solid variation in the drifts Fig. 9(a) that during ions created 500 and 600 km, diffuse in this manner. Results It can be seen level of AWB obtained this has a systematic larger). This is because be lost the values Unfortunately, so is then a. fhx above where when the layer of hmaxF2. This the ions are is stationary and stable ). D. Daytime The plots vertical Flux Results of vertical flux for daytime velocity [e. g., and nighttime the velocity was assumed importance on the interpretation to follow Fig, 9(a-b)] periods have been employed listed the smooth curve of the velocity in Table VI. [ Fig. 9 (a-b]]. results to construct In conr,tr”cting This at the highest places altitudes, graphs these of plots, considerable especially during the daytime. Plots of the daytime The downward flux appears fluxes obtained in this to i-each a maximum 99 manner close are shown in Figs. to the F-1ayer 11 (a) through (t). peak that lies in the range ‘m lmm 16-17 t JAN ,200-,400 1969 EST ~ I ., ,00,0 I ‘:F L L+-_+- ., (.1/..2/,..) (al FLUX . ) ,1 1 ,8 ‘oG). ‘Lu;b~l/cm’/lac) Fig, 11(0-f). Daytime vertical fluxes computed for periods listed in Table VI. AISO shown in some cases cme ‘correcte d,,cuwes which have been obtained in rn.anner outlined in te. t (plus signs indicate upward flux; and minus signs indicate downward %00 . flux). ,,00 ,00 1. 26-27 r- ‘“” - -lima 25-26 FEB 1969 1330-1530 MAR 1969 1200-,400 EST so, EST t I ., ,s3 LWO ‘Lu;d~@/secl LOG,, FLUX (,1/..2 (e) ,000 TIm!EL ,00 I 9-,0 ,,, ,,6, 1200-1400 EST , LO.,. ,,”. (,1/.. %,) (f) Fig, 1I (o-t). i 01 Ccmtinued. J,, -.1 , . MU, suwo o CORRECTED I I ., ,, c) ,0. 1 5-6 JUN 1969 1000-1200 EST ., LO G,, FLUX {.$/< .2,s,.) LOG,. [n] {WC.2A.C1 FLUX (i) Fig. 11 (o-t). Continued. 23.24 WN 1100-1300 ,969 EST 800 ~ 1 1-2 -m 1 -, (,,/..,,, FL”, EST t 1 +, LOG,, WL ,969 1130-1300 -s r am— (k] -imIEL 3-10 AIL 4969 1000-1200 E?,, 600 z ~ : g ! ..0 200 ~‘< o 1 -m [M, m%,d LOG, O FLU, Ii) ,0,0 ., -, ,, -8 ‘Lu:l p/cm’/,ecJ ‘o% F;g. I I (a-t). f 03 Continued, ,. . .. .. .- r ‘“ -E!zml 1000-1200 \ c 14-15 AUG 1969 EST \ > Bce- :,=: : g: .Cc F . MEASURED o CORRECTED =0? ,, I -9 I .. ,, -, 1 ,, , -, LOG N FLU:mV2/OOC ) , I ,, -8 ‘Lu:n~/cm’/5ec) L% ,mu TEEliL o 9-10 SE, ,969 1330-1500 800 – EST o ,. ? : m. — o : q % WC — *W – I -, I I -, I -7 ,0610 ,,”, ,6 (e(,m,,,ed (0) Fig. 11 (a-t). 104 I l— Continued, ,7 , .. . ME AS” FED o CORRECTED t ,~~ 1 . ., Lo,% ‘Lux {cl/cm ‘,. (Q) !., ) — Tmm_ o ,00 I 14-15 OCT 1969 1300-1500 3-4 EST Nov 1969 1400-1530 EST [ — Fig. 11(.-t). Continued, 105 I ,W.3 ,,0 j TmEm 20-21 NOV 1969 ,330 -,?,30 ES, - ,W _ -# 2 : Y 4C0 ,Ca ~ c 1 ., ,ma = m, I 8-9 DEC 4969 1300-1500 EST ~ LO G,, ,,”, ,., /.”,% [1) Fig. 11 (a-t). — Continued The upward 1 to 6 x 109 ellcrnzlsec. flux is usually value in the range 2 x 107 to 2 x iO 8 el/cm2/sec. decrease, atom~.53 pears and this has heen attributed However, in some to be increasing. fn two cases under [Figs. plots examination. These resentative appear to be cases curves considerable have plotted from of daytime variation. (in Fig. i 2 ) the altitude (against flux a scale to vary from day to day in a correlated with respect in others it ap- throughout the altitude range was computed for a are not considered rep- profile two cases analysis. flux [Figs. Ii(a), to see if this exhibits of the transition peak upward of the flux curves vertical with hydrogen while may not be well determined. in which the velocity further In order variation These e.xcbange of altitude, to be downward flux was absent. and have heen excluded The remaining display that the altitude 600 and 750 km at a the 0+ flux often is seen to charge independent the flux appears time late in the day when the escape this level, to the 10SS of 0+ through the flux appears This suggests 1i (c) and (r)], found to peak between Above that imreases between toward fashion, to the abscissa. (b), (d) through any particular upward bottom). (q). and downward These (s): and (t)] regularity, we fluxes two quantities suggesting that there are errors This could be the result and the appear in the location of an additional bias ,00 - 0 PEAK x ,,., UPWARD FLUX ALTITUDE s,,,0, – 800 error Fig. 12. Values of log peak upward flux observed in pl.ts between upward and downward in the velocity outlined above, through vertical through details at all altitudes. as an instrumental motions averaging over Ev=lls several foregoing, effect cycles (e.g., (e. g., of data. in flux above it seems with the observed Indeed, in order postulate an H+ abundance to acmmnt of the order arise altitude casts as chirp), or doubt on the accuracy to compute decrease i970. fn view Of tbe by the accuracy in the 0+ flux, 0+ at 900 km (Ref. 55). of the one is obliged such a large 407 i of the H+ distribution in 0+ flux for 24 March may not be warranted of iO-percent for frequency fields altitude. have attempted for a significant of electric that have not been suppressed This conclusion decrease as a result compensation by TIDs) the transition that this type of calculation results. could improper caused and Holt53 and Schunk and Walker55 that would be consistent ,. Such an em-or of the layer such as the decrease of Fig. 11, and transition FIu. regions. —.—. ,,.—.,...—.,;..— to abundance percentage in cmr reWlt.;7 i 000 km, and hence in the region layer peak should Accordingly, mine all escaping increase Figs. charges will be carried That is,” we propose to a constant by bias errors value, but appears transition altitude by atomic that the upward flux and V* is the bias velocity error well abcwe oxygen and the altitude in the vertical to be absent lies (i.e., as 0+) flux above variations the seen in that have not been remcved. in the velocity curve, then the Ne is the electron against 4 4(g), density. (m), BY plotting and v! (the slope). to vary markeddy the electron dc. exhibit (i5) - F, + iVevV obs as a function Curves Figure of i4-i5 i 3 shows August of “corrected” the corrections flux values of Ne. T“tis has been attempted for the. case large. (n); and (p) irhere upward Fobs with altitude. density to have been extremely curves on the spectrum, the O+/H+ flux is F! (the intercept) plotted positive if Fe is the true escape ward flux appsars pears its effect at Millstone, with height i.atroduced F where that, which we are able to study. Fig. i 1 are chiefly observed could be seen through We conclude in those values constant cases tO deter- where of the ohserved 1969 when the drift. error flux “[Ne(vob~ are largest. that are sensibly it is pOssible the upflux Vt ap- – V’ ) ] are shOwn in It can be seen that the ncorrected” over the altitude range of interest. ,..’. ./ ~~ N, WC.3 Fig. 13. Figure Ne in region of upvard flux for 1000-1200 EST 0. 14-15 August. Slope of line gives magnitude of velocity required to cause flux to be height-independent over this interval. bias v’ i4(a) tion in those cases been reduced from presents be height-independent change Plot of &served in the region where a factor flux our best F vs electron x 105) estimates it was deemed ues of Fig. 14(a) are lower of the upward appropriate. correct, to the flux. Ignoring i 08 of 4. making The assumption in that some 1000 km must take place, limits flux after the above It can be seen that the spread of 10 (Fig. 12) to a factor may not be strictly below density Thus, loss the cases in values has that the flux should of 0+ through it appears correc- charge that the ‘corrected” in which a corrected exval- flux curve ,. has been - obtained, we get an average b, taken as our. best estimate tion heights for these cases proximately to an exospheric value for the escape of the daytime was 600 km. escape Adopting temperature flux of 5 X 107 el/cm2/see, flux during a scale of 1000 K), i 969. height we require The average which maY of the transi- H = 60 km (corresponding the production ap- q at 600 km to be q600 The values quite large, F! ~ . . 8 el/cm3/sec of the peak downward but, flux obtained if the 71corrected’! points I . are shown are ignored 0,$ ERV5D JAN FEB [.-” MAR A,n amounts Here the scatter to a factor mu. I 1 ‘A” ‘UN I I I ‘“L ‘“G ““ 1 I .0. me “ ,,6, (b) Fig. 14(a-b). Values of log peak flux obtained points) or after correction (open points). f 09 from cuwes of Fig. 1 I directly remains of 4, and an ~ 7.721 I I I I -8,, vALUE in Fig. i4(b). again, c,AY,, ME“,.,., ~ ,,0 (i6) . (closed TABLE WI CURVES AVERAGED AND SUMMER TO OBTAIN MEAN WINTER DAYTIME FLUX CURVES Summer Winter 16,-17 January 23-24 April 5-6 February 30-31 May 14-15 October 5-6 June 20-21 November 1-2 July 8-9 December 9-10 July ’00”TmEL r--” WERAGE DAYTIME VERTICAL FLuXES 1969 ) , / /’ / (’ I ‘\ ( / / / / / / /“ ,“M.,, WINTER-, ~ --J-+._ ‘O%. ‘Lux 2“k{cm‘“c) ,! Fig. 15. Averoge flux curves obtained by taking for five days (Table Vll). 10 mean of (uncorrected) curves obtained ave rage value for the peak downward is somewhat variable, the flux should but usually decrease lies in the range linearly over divergence the 300 -km level, we can make an estimate negligible (since should roughly the peak production we estimate lies that the average 3 X 109 el/cm2/sec. Employing While this appears consistent close must commence do not consider curves five and five and the differences flux in winter ing as a result the curves the flux would be -3 E. Nighttime Vertical listed in Table Vf. Except i6(a) rates processes and resembled error pertaining fields). loss (n)], The losses the upward level, i.e., where it reverses bias errors (Fig. i i). Vlf, flUX at about 550 km. sign, in the velocity-vs we different from out for that are presented the estimate to be significant. arrived in at above, The peak downward This is probably By extrapolating summer. -altitude This has been carried with results in summer. during July, of Fig. ‘11 were all cases, of the layer. fluxes a real the linear effect aris - portions of of losses It is clear gravity (which, by 0+ ions of altitude well below over the interval periods and uncertain, these created the O+/H+ Fig. 9(b) that there the drift velocity to decay can be at a rate set by the by the competing by neutral winds and possibly by H+ diffusing downward transition to be small from the protono - and should region. nights give rise The altitude in only three 600 to 800 km for these three at is small. is governed caused will diffuse 400 to 500 km was observed poor F-1ayer in turn, and lifting The 0+ ions so created from where the nighttime of the layer will be offset appear for tbe nighttime the flux was found to be downward at low altitudes we expect under constructed when the results In almost of the flux shown (as a conseqwmce the loss those when the decay . Rather, 58 it is ~ot cases [ Figs. t 6(b ), we obtain an esti- flux of 2 x 407 el/cm2/sec. variation was descending ward motion the region of the large in Table to those the shape diffusion and averaging able to balance we obtain at this level, flux. the 300-km are not considered (n). at the altitude of the flux above The altitude this ap - in both seasons. for 29-30 conditions, mate for this arriving layer above to be little rates similar to a flux that is independent (m), to would be 400 and 500 km down to 300 km we find that in the absence into the ionosphere. variation region were Adopting of losses flux, production through that observed in the nighttime of downward electric sphere some listed the curves through Under steady-state loss if loss Flux Results shown in Figs. considerable heights of the flux curves X i09 el/cm2/sec flux diagrams all altitudes scale appear to be twice of the greater for the escape of F-region the flux curve days fluxes in Fig. i5 between this altitude). 300 km in the absence of 600 km for the upward several between appears this linear there, produc - to be serious. ‘rsummeru’ The peak upward below from exist the log of where (17) to removing (Fig. 9) is to average ‘twintert! Fig. f 5. are . 4.i5 in drawing approach substantially estimates this inconsistency An alternative Extrapolating balance. the peak, . altitude in In (508/8) fn view of the difficulty Above of the peak flux of about 350 to 500 km, of the flux that would Eq. (i 6 ) and allowing to current with the transition 250 to 300 km. region flux through q300 = 508 cl/cm ! the altitude tion and downward preach, The altitude flux is 2.5 X 409 el/cm2/sec. in the remaining of loss), at this time! (despite rate appeared due to an eastward small). electric i.e., plots the flwi from of Fig. !6 suggests that the the magnetosphere was not the fact that the periods An alternative field. fn either explanation case, a large selected for analysis were is that there was a downpart of the fhx observed m 1“0 - 16-17 JAN 2200-2330 800 1969 EST 30-31 JAN 0!30- 0230 1969 EST 400 \ 200 [ I ASYMPTOTIC FLUX (600 = -1S ,.900 X 10’e!lcm21s0c km) , ‘OGIO ‘Lux(o~1cm2fs’c) , ,. (b) 1000 ,m -!18{4 -11 118.2 5-6 FEB 118-2-119711 12-13 1969 2330-0100 FEB 1969 2300-0100 EST EST 800 : 600 k : * 400 ,.20 “L 1 :) ASYMPTOTIC FLUX (500 AsYMPTOTIC i FLUX = -4x107 el/cm2& = -5 X 107dh2/sec t0700km1 t , 150010700km1 LOG,. FLUX (dcf112/9.C) (d) Fig. 16(.-.). Loglo vertical flux .s altitude observed for nighttime t i2 periods listed in Table V1. 1Oca [18-2 21-22 -11913[ MAR1969 2300-0100 EST 8CQ - ~ 600 - ! g : .Ka - ASYMPTOTIC 200 FLUX (500 = -9 x 107el/cm2/, to700km1 t I -,.0 , -7.0 1 - m LOG,O FLUX - I -..0 LOGIO FLUX (CIICMZISEC) [.1 Icm’lsnc) (f) [e] 1000 -tiEEI@ 23-24 APR 1969 2230-0030 EsT 0 *OO ; .00 i ~ : 400 ‘ ?00 ASYMPTOTIC FLUX (600 = -4.’4x 107el\tm’/w< / ,00 ASYMPTOTIC to OOOkml FLUX = -2 (4501 .700 x 107 el/Cm km) t [ I I -,0 , -,.0 I -,.0 LOGIO FLUX (e!/cmz/=C) (h) ! Fig. 16(.-.). . Continued, Z/%eC e< 1000 118-2-119161 23,24 JUN 1969 0100-0200 EST *OO - : ma 0 – : : : 4C0 — I z00 ‘“”~ -,.0 FLUX (500 = 9 X 10”e!/cm 2/w to 800km1 t -8.0 LOG,O ASYMPTOTIC -7.0 ~ -6 {,l/cmz/see) FLUX LOG, O FLUX (,1/..21$,,1 (i) (1] ,030 118-2 -1191s1 6-7 MAY 1969 2230-0030 I 800 o /0 1-2 ,--- JJL 1,69 ,330-0030 E*T / . - ,00 – ‘ z 5 z < EST 600 ; i z : I J x W.3 – 400 ( ,00 200L—____— t ~~ -,.0 .8.0 -7., Lo,,. ,,”. -,.0 -..0 -7.0 -8.0 LOG,O FLUX {,,/,../,.,, [.1 (i) (k) Fig. 16(a-n). ii4 C.ntin.ed. /..2/s..) -6.0 ,000 ‘“””v I 18-2-119181 8-9 DEC 1969 23CQ - 0130 t L 200 t , ~ -9,0 -6,( LOGIO FLuX (., EST /,m2/,,c) LOG,. (n] (ml Fig. 16(a-n). will be caused by the descent be given an eqw.tion of the layer of the form If this is the case, sphere. be carried below out for the altitude to sensible to compute values region it was applied layer was clearly descending cases, plots in only 8ix cases stationary, of the values estimate and appears for the, arriving the results sensible are sufficiently which thereby Since reliable vs IXe. Fobs casting in Table losses the method sensible appeared some to permit However. reaulta firm conclusions listed (i.e., in Table VI lead for nights when the for five of these. linearly doubt on the validity fluxes this must are important. constructed to depend are plotted will the protcnm- does not depend upon the layer VfII is 3 X i 07 el/cmZ/sec. the two methods flux Fobs from flux is fully established fm. which flux diagrams in the light of the escape from Fobs vs Ne for the other nights VfII). VIII) and yielded over of F! listed flux obtained the region of Fobs (Table ( Table this was quite restricted, average by plotting for a fm-thei- seven range v,) so that the observed F, is the true flux arriving in which the protonospheric and above FI from VIII is the height (with velocity of Eq. ( i 5 ) where region) being in Table Ccmfinued, F9 can be recovered the change-exchange Attempts (d /Cm2/SOC) FLUX on Ne. Listed In some of the results. This is close An to our other found in the daytime. The valws in Fig. i7. We do not believe concerning possible that seasonal trends. The failure many cases hence of the method probably the flux errors stem8 of plotting from ) are larger Fobs a number at night, W Ne of camses (2) there ! 1<5 to recover including: a constant flux F, at night in ( i ) the velocity is only a limited errors height interval (and over which TABLE Vlll ESTIMATES Date (1969) OF Nighttime (EST) NIGHTTIME PROTONOSPHERIC Linear R.nge F r (el\cm2\sec) (km) 16-17 January 2200-2330 30-31 January 0130-0230 5-6 February 2330-OIIM -4X 12-13 February 230Q-01 CO -5X107 500-70Q 26-27 February 0000 -G200 21-22 March 2300-0100 –9x 500-700 25-26 March’ 2300-01 9-10 April 23O+3-O1OO 23-24 April 2230-0030 6-7 MJIy 2230-0030 30-31 May” 1-2 June’ 5-6 June* 0100-0200 23-24 June 0100-0200 I-2 July 2330-0030 9-10 July’ 220+3-01 00 29-30 July 0000-0130 14-15 August* 2300-0100 9-10 September” 2300-0100 23-24 September 0030-0200 14-15 Octcber’ 2300 -OILXI M -1.5 XI07 10’ 10’ -3.5X107 –4.4x 500-700 700-900 107 +2X107 -1. lx -9 lo’ XI06 -2.4x107 600-800 450-700 1 3-4 November ?0-21 November 0030-0230 8-9 December 2300-0130 k Day added. Upward f! .x! Poor velocity profile Poor velocity profi 1. 500-900 500-800 500-900 1 -2.4x Comment 600-9LII 2300-0100 ! FLUX 107 1.9 XI07 500-700 450-704J — -,.0 .,., — Q ~,.-7.8— : > : .,., 5 ~ . ~. .7. * — \/ 2 . -,,0 — -,.8 I ! JAN , i , ““l with height, F. and these tionary in those layer). arriving conditions Figs. Similarly, ruary cover (w). VALUE I I ,[? 0., I 1 .0” . . . flux w date for 1969 (Table Vlll). knowledge flux is able to balance of the rate of change tbe loss, of vertical velocity by night than hy day. . -. that the daytime where is not moving this level flux is usually from near vertically. provides is close we conclude estimate were obtained a“terma the vertical a sta- to the value of the that under equilibrium of the flux being exchanged by averaging those by the density by about (indicating the flux at this height Fig. 18, as the redwed to have caused this level Thus, a useful estimates fu13y developed flux is height-independent we have computed The actual has been omitted escape the upward delay and multiplying (Sec. 11-A) appears noisy I 1“, even when the protono8pheric Accordingly, and 5. O-msec J.. in Fig. i 6 the flux observed the flux through 4 8(a) through at 4.5- arriving are smaller cases flux when the layer the protonosphere. J“. CORRECTED 650 km It can be seen in Fig. ii 650 km altitude, I I ..” upon an accurate changes Flux Through 1P* Plot of nighttime depends I I MA. 0+ flux can be expected and (3) the method 1 I e,, 17. Fig. a steady OBSERVED VALUE 0 and plotted the velocities at 650 km. observed The plot for 26-27 gain brought drift velocity with this in about estimates Feb- by the snow to be extremely and unreliable. The most Iisbed striking at sunrise the layer near sunset, may be introduced of Figs. the transition at a time near noon. of TIDs. from Thus, bution too late in the day. was computed [Fig. ii(j) exact flux moved The sunrise times, there onset adjusted ceases from by +i4 minutes fhx estab of many of the fluctuations to downward fluxes On some above days, 650 km, an upward flux is usually (to allow ii? appears in which the daytime to be those to be any escaping of the upward While that a significant and (r)] appear to an altitude 1, so that the transition time at which These i i(c) of the curves. upward flux set up by the decay it is believed the two cases [Figs. downward component is real 52 upward ward at all altitudes ward to upward nature (i) the large (w) are: (2) the large of measurement, of the presence On many days, 18(a) through of the layer, and (3) the oscillatory by errors and a manifestation sunset features by the growth in which to occur flux was found to go downthe vertical velocity the height of the transition e.g., 9 -iO April to a downward well before [Fig. ii(f)], flux in Fig.48 from distridown- 23-24 June may not mark the flux. a readily recognizable for the difference between feature local of the records. and standard time), 16-17 JAN 1969 ‘t “’ma. 1 02.0 I Mcc I 0600 0s00 I IOm ! ,200 1 )... 1( 1,., ),.. 1 zoo. 1 =w 2* EST (.) SUNSET SUNRISE .4 — -, ,m & & & JOO ,:00 ,,100 ,,’00 ,6’00 ,,00 I , ,00, ,,.0 ,4C+ Esl [b) Fig. 18(a-w). in Table V1. Values of log Io (F)65o, i.e., These are thought to be cl-e i48 — flux through 650 km for the days listed to actual pr.ionospheric flux. , ~16-2-11M&-11 P-IQ. , 0 w SUNRISE SUNSET -4 – -, mm ,2100 MOO I .600 08W 1oOO ,2.. 1400 1600 18W 2000 “0° “m EST (c) 2 ~ 12-13 FEE !969 o 00 ; >= ~ -, ~. o =, ~ . ,SUNSET S“NRISE - ,– - , \,oo Im ,4,. \ C6m I .,.0 , Wca ,.00 I 14C0 EST (.51 Fig. 18(.a-w). ii9 I A 1 Continued. , ~600 1 1,,, 1 ,000 , 2,00 MC.? ~ 3 – 25-26 MAR ,96, * - ;0 .\~ < , ~, ., ~ ; > -* — : -3 — .4 - s“.,,,. -, SUNSET I “’o OCO 0,00 1 1111[11, 0400 .,0. t, 08.0 ,000 ,,0, Fig. 18(cJ-w). 420 Moo Continued. ),00 ,800 moo ,*C-O ,,( EST [g) -* ‘1 t -, ,Wo & & 1,,1 SUNSET SUNRISE -, - I 0600 1 CSC4 , 1000 I !200 Fig. 18(0-w). , 1400, Continued. 121 1600 I ,,~ zooO 2200 2w0 0)’ \ \ -3 -4 1 SUNSET SUNRISE -5 - t -e C@. O*OO I,llljsl Mm C6ua O*W 1000 ,.~ ,.~ 1,.. l... ,- 2=-3 2+, EST (1) 00 -8 .OOO I ,,@ I .400 I 06o0 0800 I IO.. IZGO , IMCU EST (1) Fig. 18(0-w). $22 Continued. I,.. IWX ZW5 Z* z40 1 ‘~\r 0 .1 -2 .3 SUNSET ‘U NRISE t I O*CO -50000 I 0.00 , I 060, ,,0, , )00. ,,.. ,4.0 ,.00 ,800 ,.0. ,x.1 ,4( EST (k] 2— 23-24 JUN 1969 fiu Q. A .< < iv -z -,g 5 .,— ~ -3 — SUNSET -+ - ‘ 0000 ‘“’’’’” , 0200 t 0400 I 0,00 I .,00 I !0.0 I )200 I 1400 Es, {11 Fig. 18(a-w). 323 Continued. I 1600 1 leoo 1 200 t I 2200 2.0 , ,8-2-1)98! + ],8-2 .11838-11 39-1o duL 1,69 1- 0 73 .< <. w , “2 1 > “- ,3- s“NRISE 4- ‘0000020. 1, Moo 0600 0,, EST (n] Fig. 18(a-w). Continued. i24 29-30 d“, 1969 2 - ;0 : ,5 . -f “g ; . # .? 0 -3- S“N.ISE .. -, Ocoo , 0200 II 0400 \ 0600 ! ,*OO I ,,.0 ,,00 1 ,.00 , ,,,0 ( !8,0 1 I ,,00 ,,00 240, EsT .4 – SUNSET SWR(SE -5 0 -’0000 0200 , ..00 .,00 , moo , ,,0, I ,.00 ,,0, EST {P] Fig. 18(a-w). 125 Continued. 1 (,,0 I ,,00 moo 1 ,200 MC -5 m+. ozoo 1! ..00 $ I 0600 .s00 400. IZOO I~o. f,.. 1 t,.. II 2000 I 2,00 I 2+~ EST (q) -4 t ‘t‘u”’” ISUNR”E Fig. 18(0-w). C.ntinued. 126 23-24 -mm. SEP !9s9 3 - , — { .; o { ., _ .. : -2 — .3 .. -’0000 moo 0.00 06,, mm ’000 ,,00 ,4.0 ,,.0 ,,,0 moo 2200 2.00 EST (s) , -, t -. SUNSET SUNRISE -, 0... 1 .2.0 I 0400 0600 , 0800 {000 , !200 I !.00 EST (I1 Fig. 18(a-w). Cc.ntinued. 1 ,600 I ,.00 I 2..0 1 2200 Z400 3-4 NOV 4969 # ~ o -, – 0 -z – o 0 -3 – .4 - -, – I “’0.00 .20. 0400 , 0600 0800 1000 , IZOO I f400 ES, (.) , ,, [“1 ( Fig. 18(a-w). i28 !, — Continued. I 1600 ( 1800 2000 2200 ‘“w I 8-9 DEC 4969 I i 1 -. -, ,0000 I,I((IIILI SUNSET SUNRISE 0200 0.00 0600 on.. ,000 s,.. ,4.. s... ~,oo *000 =oo 2“00 EsT (.) Hg. are plotted at o, in Fig. %00, 200, time coincides rise and sunset observed before Ccmtin.ed. they are superimposed on curves and 300 km (Ref. 59) for 4Z” latitude. closely times at sunset the 200-km Fig. 19. i 9 where 18(.-w). with the time of sunrise have been indicated usually begins sunset. The onset It is clear prior It is striking to the sunset of this downward the times of sunrise fFOm tMs PlOt that the Onset at 200 km altitude. in Fig. i 8. 1 to 3 hours indicating Accordingly, that the large time and peaks flu% is thought to be caused tbe 200-km downward flux at or slightly by tbe decay Times of onset of upward flux (F;g. 18) compared with sunrise in ionosphere at different i29 sun- altitudes. of the F -laj-er during to a thermal collapse the downward Large At sunset, the temperature Sometime the two effects 30 of the layer. in the downward nights, that could open the source decreases, to give separate leading peaks in give rise flux (e. g., to the observed rising increases to 5 X i08 el/cmz/see) during winter 36 in Nina, do not appear to occur, thus of this ionization. SUMMARY Incoherent vertical scatter velocity data on F-region have been gathered (42. 60N, 7 i. 50W) approximately the altitude density interval (near a complete modes profile report. Contour density summer year, of April were and stationary (Table flux for these By assuming flux profile was filled to identify times. motions could be obtained, From be 500 el/cm3/sec. in the data, it is difficult and/or were observed and ion temwinter the beginning and of the encountered during the and the valley region be- curves showing instrumental the production 200 km altitude noon when the layer flux that would account The flux through begins for the winter the altitude obtained variation in the results were present. about 700 km, a corrected flux appears to be 5 X rate at 300 km was deduced flux at all altitudes Owing to the greater flux, but the best tbe level sunrise. increases with a appears that large Downward Large to uncertainties estimate 650 km 8hows until late at night. nighttime of near noon suggests above ionospheric to decay appeared biases show a downward the true protonospheric flux. when the F-layer value for the escaping flux, flux curves soon after of the downward (z)], a characteristic precipitation near the peak of the layer. upward after have been described 7(a) through exhibits of many of the curves and an average to establish are established for vs height and time of electron be altitude-independent the downward-going escape fluxes of i 5 km in electron methods near noon and midnight layer flux should to be half that for the daytime for a period span The time resolution the two (in 1969) around and have constructed magnitode) The results upon which of two operating Te [Figs. were and Hill radar in. The character The nighttime peak (of very uncertaim II). parameters. density temperatures periods of the entire that the escape 107 el/cm2/sec. VI), (Table depending temperature of auroral electron i969 the variation between and ion temperatures, at a time at the Millstone and reduction The electron Two cases high F-region We have attempted that significant showing with a rapid transition tween the E- and F-regions stable 30 or 45 minutes, electron (z)]. electron with a height resolution The data-collection (z)], 8(a) through and October. when very vertical approximately, and 75 km in the other cons tructed 3(a) through Ti [ Figs. behavior months V). densities, of 24 hours per month throughout was either (Table 20 diagrams &,e [Figs. perature twice 200 to 900 km, altitude electron for periods the peak of the layer) was employed in a previous exist of the p3asma appear flux. increases leaving Vf. 30 the afternoon. fluxes increases of the F-layer were not seen. *3O ,j — ,.—.......___ .._.. ______ z__=_.=. j_ , APPENDIX I. INTRODUCTION It is possible produce Figure bya A-i cathode impinges by field to calculate from first dinthe LIHF transmitter. shows a section is accelerated on a grounded coils around with distance through through The beam the klystron. alongtbe amplifier. Vvolts value of the frequency Abeam of electrons and then traverses of the beam magnetic is modula.ted RF field field produced by the RF fieJd across in the beam can be excited HEATER SUPPLY giv.m off a drift tube until it by an axial of ‘nbunchingrt of the electrons so that a much larger offset the method, is kept in focus Tbe velocity The degree beam the approximate outline8 tbe klystron a potential collector. tbe gap in the input cavity. principles This Appendix across increases the -P in the ~ CATHODE I . I INPuT cOAxlAL m .P.TCA= 1- ] “y”e m ‘L=” ““cl JEl=”’’’””””’ WATERCOOLED COLLECTOR Fig. A-l. output cavity, the energy being , wed I up heating the water that cools and hence the efficiency H. at Millstone, gained at the exptmse of the beam the collector. .mplifiertuhe. of the energy energy ) The idler in the beam. is extracted cavity serves (In the klystrons and the remainder to improve ends the bunching of the device. PHASE SHIFT fN THE KLYSTRON r required output CaVitie S introduces I Cross section ofklystron only about 30 percent The time interval v a fixed for the electrons phase difference to traverse q between the distance d between input and tbe input and output signals. Hence q =2rfr where f is the radar frequency r = d/ve where a voltage (440 MHz). The time interval T is given by (A-2) sec Ve is the electron through (A-1) rad Vle can compute ~elocity. Ve knowing that the electron has fallen V from electron energy . i/2 me(ve)z . eV (A-3) Combining Eqs. (A-i), (A-2), and (A-3), we have _- ~. Scaling the drawing and rn: = 9.108 JL ‘ad 2rfd % of tbe x626Ac x 10-28 (A-4) ~ we find klystron, d = i08 cm. Since i eV = i.60 X iO -iz ergs g, we have (A-5) where lfI. V is the klystron VOLTAGE Although DROP voltage. DURING the current voltage drop occurring change of applied THE I through during voltage PULSE the klystron a pulse, varies we may assume with the applied voltage that it is constant. V, for the small Hence, the rate of is (A-6) I Here, C is the capacity fa13 in voltage [from during Eq. (A-5)] ,: FREQUENCY A constant tbe pulse causes bank (24 #F) and I is the current the phase shift q during the pulse during to change a pulse. The at a rate given in ~ IV. of the condenser ❑ –2n 80i.7 ~ $ rad/sec of the phase difference (A-7) . SHIFT rate of change mm-responds to a frequency shift Af that is given by Af=;r~ ~Z ~.~ 2 V312 (A-8) .~Hz. 432 8ubstitutimg for dV/dt [Eq. (A-6)], ~f . -400.81 ~$/2 -1.67 we obtain ~z X i07 1 Hz v3/2 (A-9) V. CURRENT READING AS shown in Fig. A-2, only the average Fig. A-3(a) current where the current Iav. t represents through The actual the klystrons current the interpulse waveform period is read by a meter through (i3. O msec for B-mode, which measures. is shown-in 20.0 msec for 1 1 KLYSTRON HIGH- the meter KLYSTRON 4 2 I I VOLTAGE POWER SUPPLY + Fig .A-2. DkJgr.am of power supply cmtpnents. II I I Fig. A-3. C-mode) Waveforms for current and T is the modulator age and peak currents I=FI are related I (b) pulse and VOI toge applied length (i.0 msec to klystrms: (~) current, for C-mode). (b) v.dt~ge. It is clear that the aveI.. through (A-io) av 133 1 where F is a duty factor in the B-mode to keep the average T = 0.61 msec. Thus, the frequency B-, –4.67 VOLTAGE a modulator pulse length C-mode (A-ii) . X i07 F1av (A-i2) ~3/2 READING The voltmeter employed waveform voltage This requires constant. length is adjusted shift may be written M. VI. current pulse Thus, F .18.0 ( The modulator equal to i 8.0 in the C-mode. to measure of the form there will be a voltage the voltage applied As current shown in Fig. A-3(b). drop through to the klystron the tivo resistors (Fig. A-2) is drawn through that connect will havea the klystron, the klystrons to the condenser bank of AVi =22.5 There will bea further ~v 2 FIav voltage . <v XT dt FIav — 24 X 10”6 At the end of the pulse, This will recover with a time volts drop during the pulse of ~olt~ volts the voltmeter to its former (A-43) . . (A-i4) will agati see the fu13 voltage value as it is charged through applied to the condenser the 65- and 6.25 -ohm C. resistors constant ~= (65 + 6.25) C .i.71xi0-3 Thus, the voltmeter reads sec a value (A-i5) . Vm which is less than the voltage V! on the condenser bank by an amount l’! –Vm = ~ IavF [22.5 (T+ 10-4) + 2.o8 X iO T(T+ i.71 X iO-3)] . (A-i6) Hence, VI - (vm)B .3.49 IavF = 62.9 V1 – (Vm)c = 4.05 IavF = 72.9 Iav The voltage bank V applied to the klystrons $v V01t5 Volts during (A-i7a) . the pulse V 1 by an amount ● i 34 (A-i7b) is also less than that on the condenser AV2 V! -V=AVi + ~ = FIav[Z2.5 Vi – VB = 633 Iav volts VI - Vc = 779 la” volts It follows that, during the meter less -5701 the pulse, ~v volts +2.08 X 404T] (A-18) (A-i9a) . (A-i9b) the voltage applied for the B-mode to the klystrons and -700 Iav volts will be the amount in C-mode. given on ThUS, Eq. (A-i3) may be written 3 x ios Iav AfB = (A-20a) (Vm -570 3x4081 AfC = (Vm The corresponding velocity -700 errors I av )siz av ‘z Hz . (A-20b) Iav)3/2 Aw are ios 1=” m/s ‘WB = - (Vm -570 io* ‘Wc = - ec (A-21a) m/s ec (A-2ib) 1=”)3/2 Iav (Vm – 700 ,Iav)3/2 135 A~KNOWLECGMENTS The aufbor is grateful to W. A. Reid, J. H. McNaIly, L. B. Hanson, and others of tie staff of Millstone Hill who gathered data reported here. R. F. Julian and J. K. Upham were responsible for writing the computer programs required to process the data, while Mrs. A. Freeman a“d Mrs. J. LaJoie carried out the work of plotting graphs and performing some calculations by hand. During 1969, the incoherent scatter work at Millstone Hill was supported hy the U.S. Air Force through its program of general research at Lincoln Laboratory. REFERENCES 1. J. V. Evans, Reoort 374, , “Millstone Hill Thomson Staffer Remits for 1964: Technical Laboratory, M. I. T. (15 November 1967), DDC AD-668436. Report 430, Lincoln , “Millstone Hill Thomson Scafter Resdts for 1965: Technical Laboratory, M. L T. *8 December 1969), DDC AD-707501. Report 474, Lincoln , “Millstone HOI Thomson Laboratory, M. L T. Report 481 I Lincoln “Millstone Hill Thomson Staffer Results for 1967; L&oratory, M. 1. T. (22 July 1971), DCC AD-735727. Technical Report 482, Lincoln , “Millstone Hill Thomsm Starter Results for 1963: Technical Laboratory, M. L T. (23 ]amary 1973), DDC AD-767251/2. Report 499, Lincoln 2. 3. 4. 5. 6. , Planet. 7. 8. “Ionospheric %.ckscatfer Observations at Millstone Hill: Technical Lincoln Laboratory, M. I. T. (22 January 1965), DDC AD-616607. Space Sci. . ]. Geopbys. — Res. 1175 (1965), 9. , Ptanet. Space Sci. g, , Planet. Space Sci. M, 11. , J. Atmos. , J. Geophys. 12. Results for 1966: Technical , DDC AD-725742. L3, 1031 (1965), ~, 10. Terr. Staffer EIys. DDC AD-616607. DDC AD-61431O. 1387 (1967). 1225 (1970), Z, DDC AD-716056. 1629 (1970), DDC AD-716057. Re.s. 7&, 4803 and 4815 (1970), DDC AD-714447 and AD-714446, respectively. 13. , Planet. 14. , J. Atmo.. Space Sci. z, Terr. and I.J. Gasfman, 15. 763 (1973). S%YS. %, J. Geophys. Res. 16. R. J. Cicero”e and S. A. SowhiU, Radio Sci. 6, partment of Electrical Engineering, University 17. J.V. Evans and L. P. Cox, J. Geophys. 18. L. P. Cox and J.V. Evans, 19. J.V. 20. Evans, j. Geophys. J. Geophys. Res. DDC AD-772 ~3716. 593 (1973), DDC AD-77 ~877/8. 25, 807 (1970). 159 (1970), Res. X, Res. Z5, 6271 (1970, 17, 2341 (1972), DDC AD-704626. 957 (1971) [ahm Aeronomy Repofl 39. Deof Illinois, Urbana (1 September 1970)1. DDC AD-703492. DDC AD-722911. DDC AD-752948. Scatter Measurements , R. F. Julian and W.A. Reid, “Incoherent Censity, Temperatures, and Verticat Velocity at Millstone Hill: Technical Lincoln Laboratory, M. L T. (6 February 1970), DDC AD-706863. 21. J. P. McClure, H.C. Carlson, (1973). 22. J. E. Salab, PhD Thesis, 23. A. E. Hedin, H.G. Mayr, Res. 29, 215 (1974). of F-Region Report 447? W. B. Hanson, A. F. NagJ, R.]. Cicerone, L. H. Brace, M. E&on, P. L!a.er, J.V. Eva”s, G.N. Taylor and R. F. Wocdman, J. Geophys. Res. 18. 197 “A Study of the Midlatitude Meteorology Department, C.A. Reber, Thermosphere by Incoherent M. I. T. (Augwst 1972). N. W. Spencer i 36 Scatfer and G. R. Carignan, Radar f J. Geophys. y77 — ! 24. H. G. Mayr and H. Volland, J. Geophys. Res. 25. D. Alcayde, 26. J. E. ?.alah, J. V. Evans and R. H. Wand, 27. K.L. 28. P. E!auer and J. Fontanari, Jones, 29. —! T. Tamka 30. J.V. J. Atmos. Terr. Phys. Radio SCL 31. ibid , _., 32. , J. Geophys. 6 _. 843 (1971), R... Res. 29, 629 (1974). Radio Sci. ~, 231 (1974), N, DDC AD-785097/7. 1311 (1971). 609 (1971), 6, 6774 (1972). J. Geophys. ibid 35 1515 (1973). _.! .$ and K. Hirao, J. Atmos. Terr. Evans, 27, Phys. N, 1443 (1973). DDC AD-731927. DDC AD-737929. ~, 4331 (1965), DDC AD-623606. 33. U.S. Department of Commerce, Envirrmmerdal services Administration, - ITS Ionospheric Predictions for January 1969,” TB 11-499-70/TO 31-3 -28-2 (October 196 B). 34. J. A. Klobuchar, J. Aaronsand H. H. Hoseinieh, 35. J. V. Evans, 36. A. V, Mikhaylov, 37. W. B. Hanson and T. N. L. Patterson, 38. T. Yonezawa, J. Geophys. Res. Geomag. ~, J. Geophys. 3489(1968), and Aeron. M, Res. Planet. DDCAD-673605. Space Sci. U, 979(1964). 39. 40. J. E. Geisler, Res.7Z, 7530(1968). 653,(1972). Space Research V, 49(1965). ——— l. E. Geisler and S. A. Bmvhill, Aero”omy Report5, Department ing, Uniyersityof Illinois, Urbana (l January 1965). J. Geophys. X, of Electrical En@neer- 81(1967). 41. V. A. Vasin, 42. G. S. Ivanov-~olodnyy and A. V. MikbaylOv, 43. H. Risbbetb, Terr. 44. P. Y. S. Hsuand S.F. Chii, “Mahttemnceof Nighttime F-Region: Observadonof 8pheric Eledro” Flmat&ecti,” J. Atmos. Terr. Phys. (Lu press, 1975). L. V. Grishkevich J. Atmos. 45. R. Rtister, J. Atmos. Terr. 46. T. E. VanZandt, and V. V. Pisareva, Phys. ~, Pbys. V. L. Peterson 47. C. G. Park, 48. C. G. Park and C. LMeng, J. Geophys. 49. J. E. %.lah and J. V. E“ans, 50. G. Lejeune and G.N. Res. a, El, 473(1970). N, 39(1973). Exo- 765(1969). J. Geophy.s. Res. z, 27 S(1971). 4650(1971). J. Geophys. Res. Space Research Taylor, and Aeron. and Aeron. 1(1972). and A. R. Laird, ~, Geomag. Geomag. Planet. Z@, 8326(1971); also seelg, XIII (.Lkademie-Verlag, Space SCL ~, 3B28 (1973). Berlin, 1973). P. 267. 1061 (1972). 51. [. V. Evans, 52. 1.V. Evans, R. A. Brockehnan, R. F. Julia”, Sci. 5, 27 (1970), DDC AD-704631. 53. [.V. Evans and J. M. Holt, 54. V. W.J. H. Kirchoff and L. A. Carpenter, “Dominance of the Dimmtd Mcde of Horizontal Jrift Velocities at F-Region Heights: J. Atmos. Terr. Phys. (in press, 1975). 55. {. W. Schunk and J. C.G. 56. ‘. E. 3aLah and J. M. HoIt, 57. ‘.L. Massa 58. L Risbbetb and O.K. Garriott, iew York, 1969), pp. 170-171. 59. . . Colin and M. A. Myers, “Computed Times of Smrise L4.SA Technical Memor.md”rn TM X-1233 (April 1966). J. Geophys. (private Res. ~, 2344 (1973), DDC AD-772214/3. W. A. Reid and L. A. Carpenter, Radio Sci. ~, 855 (1971), Watker, Planet. DDC AD-738727. Space Sci. k, Radio Sci. ~, 301 (1974), Radio 855 (1971). DDC AD-7 B5096. communication). Introduction to Ionospheric Physics and Sunset (Academic FTeSS, in the Ionosphere ,“ i 37 ———. UNCLASSIFIED En, ,. . .. <,,.,,-..!.. .. . . . “, . 7., s. ,.,. .-,. ,uf,,... D.,. ——. .— ... .,.. ,,. ..,,, REPORT e,ed) READ 1NSTRUCTIONS PAGE BEFORE COMPLETING FORM 2. GOVT ACCESSIONNO. 3. RECIPIENTS CATALOGNUMBER DOCUMENTATION 1. ,6?ORT .UM8ER ESD-TR-74-234 5. TYPE OF REPORT & PERIOD COVERED i. TITLE !.mi S.h!itte) Tecknical Millstone Hill Thomson Scatter Results 6. PERFORMING ORG. Technical 7. AU THOR(, 8. I Evans, 9. 0RGAN12AT10N Box REPORT NUMBER Report OR GRANT 513 NUMBER(S) F1962 8-73-C-0002 NAME Lincoln Laboratory, P. O. CONTRACT John V. PERFORMING Report for 1969 AND 10. ADDREs5 PROGRAM ELEMENT, AREA & WORK UNIT . PROJECT, NUMBERS TASK M. I. T. 73 7X263304D215 Lexington, MA 02173 11. CONTROLLING OFFICE NAME AND 12. ADDRESS Sallistic Missile Defense Program Office Department of fhe Army 1320 Wilsm Poulevard Arlin@on, VA 22209 14. W3NITOR,NG AGENCY NAME & ADDRESS (({ difie.enl /,0”! DISTRIBUTION STATEMENT Approved (oj,his 13. 18. S“PF’LEMENT.4RY NUM8EROF PAGES 144 15. CO”1,0111T8 o!{i.d SECURITY Uncla 15.I. CLASS. (./ thi, w@) sified DECLASSIFICATION 5CH EDULE DOWNGRADING Re.wrt) for public release; !7. US7R[BUTION s~~i’~.$!mi~(.[ DATE 23 ]Ldy 1974 Electronic Systems Division Hanscom Air Force Sase Sedford, MA 01731 16. REPORT the distrfbutim nbstrcact entered unlimited. in Block 20, i{ di,ffemnt jr.”! Report) NOTES Nom 19, K E“ WORDS (Cm,;,,”< on ,.”.,s. ,(d< ;( ,,ace, smy and ”.. on ,,”,,s. 67 block number) electron den sity ionospheric scatter sea sons 1 variations Millstone radar F-region diurnal variations !0. ABSTR~C7(Co”,, ide,,tijy s,de ;/ ,w<e, sa.y .md ;dent,/y by Mock temperature effecfs spectrum analyzers “u”Ib8r/ report summarizes the results for the electron density distribution, elecfron and ion temperatures This and vertical ionization fluxes in tbe F-regim obtained during 1969 using the Millstone Hill (42. 6“ N, 71. 5“ W) These data, for tie hei$m interval approxim.cely 200 to 900 km Them.sm (incoherent) scatter radar system. were @bered . . . . 24-hour observing periods, roughly twice per calendar month. The time resolution to obtain rcmlts over this emire height imerval was eifher 30 or 45 minutes, depending upon which of two operating modes was employed. The results for the diurnal variation of fhe electron demity and temperature exhibit the characteristic summer and winter p.mterm discussed previously. The transition he fwee” the two takes pbCe in April and . . ,“. ” LJD , ;;N;3 1473 EOITION OF 1 NOV 65 15 OBSOLETE UNCLASSIFIED SECURITY CLAs51FficAT10NOF rH15 PAGE (when O.,O Kn,e, <d) 4 20. (continued) October, TWO cases of overhead auroral precipitation were observed efforts to observe a stable red arc. Other instances of geomagnetkally 1 during the year as a consequence of disturbed behavior were infrequent. Vertical fluxes of ionization were measured, and the flux escaping to the magnetosphere near midday was found to have an averap value of -5 x 107 el/cm2/.sec. NW midrd$n, the magnetosphere appears to ~PPIY tie 10~1 iOnOs@ere witi a flux of atmtt half ttds ~O~t. { i39 * “. ,. .0,,,..,., mrm,ws owl.,: ,975 --60, -,,,..,,