Dear Dr Hoeksema: In response to the message concerning the WSO data just received as part of the AGU SPA Newsletter, I am attaching for your reference a paper that acknowledges scientific use of the WSO data, as emphasised in your message. The data were used to provide background material that underpinned the interpretation of Cassini IMF data obtained during the approach to Saturn, as is indicated in the paper. We would wish to make similar use of the data in future as the Cassini mission unfolds into the rising phase of the next solar cycle. May I take the opportunity of thanking you once again for the help you gave in providing these data to us. Regards, Stan Cowley -------------------------------------------------------------------- Prof Stanley W H Cowley Head, Radio & Space Plasma Physics Group Department of Physics & Astronomy Tel: +44-116-223-1331 University of Leicester, Leicester LE1 7RH Fax: +44-116-252-3555 United Kingdom Sec: +44-116-252-3563 To Whom It May Concern: I frequently use the data products of the Wilcox Solar Observatory in my research and strongly urge that the program continue. The coronal magnetic field maps at the source surface are particularly useful for relating solar wind features to the heliospheric current sheet, and several have appeared in my publications, most recently in Crooker and Webb (2006). This publication also features a section from one of the large-scale photospheric field maps. Sincerely, Nancy Crooker crooker@bu.edu
Crooker, N. U., and D. F. Webb (2006), Remote sensing of the solar site of interchange reconnection associated with the May 1997 magnetic cloud, J. Geophys. Res., in press. The data from WSO are the "gold" standard for the long-term assessment of the large-scale solar magnetic field. The accurate determination of the zero-level is unique to WSO. WSO polar fields have been (and will be for cycle 24) important for the prediction of solar cycle strength [e.g. Svalgaard

et al. (2004) Geophysical Research Letters, Volume 32, Issue 1, CiteID L01104]. The mean field signal is still not well understood, but its long-term behavior is probably important for the understanding of the sources of the IMF [e.g. Kotov et al. Solar Physics, v. 209, Issue 2, p. 233-245 (2002)]. The "saturation" factor problem is also unresolved: The magnetic fields measured at each observatory are all different, but for each observatory a factor (or function) exists to make all measurements agree. The cause of this is unknown. It is important to let WSO operate at least until the end of cycle 24. At that time, we may have enough data overlapping with SOLIS that we can properly interprete the legacy of WSO data back to 1976. The value of long-term data is often degraded by termination of the observations without sufficient overlap with newer data. The Greenwich sunspot areas come to mind. ACRIM solar irradiance is another example. -- Leif Svalgaard leif@leif.org
Date: Tue, 30 May 2006 11:39:34 -0700 (PDT) From: Janet Luhmann Reply-To: Janet Luhmann Subject: CISM use of WSO To: wso@solar.stanford.edu
Cc: nick.arge@hanscom.af.mil
, pete.riley@saic.com
, yliu@solar.stanford.edu
, yanli@ssl.berkeley.edu
, hughes@bu.edu
, jmquinn@bu.edu
, todd.hoeksema@solar.stanford.edu
Re: Response to SPA news item on uses of WSO WSO is one of the primary solar magnetogram providers for our solar/heliosphere modeling activities within CISM (the Center for Integrated Space Weather Modeling)- an NSF Science and Technology Center led by Jeff Hughes at Boston U. MHD models of the solar corona, including those of CISM, are just coming of age in terms of regular use and practical applications. Simulations of the solar wind are coupled to these coronal models, and depend on their accuracy. Full-disk solar magnetograms from WSO have been one of the main sources of the critical synoptic map boundary conditions used in CISM models. In particular, they are an option in the CORHEL community user-oriented version of the CISM corona and solar wind model which is archived and provided for general users at the CCMC (Community Coordinated Modeling Center) at Goddard Space Flight Center. The NOAA SEC (Space Environment

Center) also uses CISM models for assessing upgrades to their space weather prediction capabilities. STEREO mission, to launch this year, will make heavy use of the magnetograph-based models for its multipoint data interpretation. While there are a few other sources of magnetograph-derived synoptic maps, WSO is one of the longest-lived and most consistent providers. These data can be used for a host of solar cycle studies of the corona and solar wind, as well as providing the basis for calibrating newer magnetographs, such as the SOLIS instruments at NSO and the upgraded GONG instruments. The WSO staff does an exceptional job of generating and providing, via website, useful products relating to everything from the latest heliospheric current sheet geometry to the ongoing solar cycle changes in the solar polar fields. To lose this stable and reliable solar magnetograph resource would be akin to losing something like the GOES spacecraft series- it is something we have all grown to use and depend on, and is irreplaceable in terms of its benefit to current modeling efforts. We hope that you will find a way to maintain the WSO magnetograph facility and continue support for its operation and data provisions. It would be a shame to lose its benefits at a time when it is becoming more and more widely used and exploited given the high level of activity in the solar and heliosphere modeling and space weather communities, including CISM. Sincerely, Janet Luhmann, on behalf of CISM solar modeling members Yes, we do use WSO observations in our work. We use them to compare with MWO and NSO observations. Over the years, one of the observatories occasionally has a problem. We use them for long-term consistency. Here, spatial resolution is not a factor. The important quantity is consistency for comparing the fields of one cycle with another. We also use the mean field observations, again looking for the long-term variation. As we get into more sunspot cycle studies and studies of the dynamo, the WSO observations will be increasingly important. I could go on, but I will let my colleague Yi-Ming continue... Sincerely, Neil Sheeley Hi -- I am writing in support of continuing the Wilcox Solar Observatory synoptic program. WSO observations were integral to my thesis work, and the citations listed below directly or indirectly depended on these data. Despite the fact that there are current and pending magnetic field

observations available which have higher spatial resolution and better time coverage, there remains a set of important scientific questions regarding the large-scale, slowly-changing Sun for which WSO data are ideal. WSO provides a continuity of data which is essential to understanding solar changes on time scales on the order of solar cycles. Having used WSO data while just starting out as a graduate student, I can also testify to the ease of use of the data: the spherical harmonic coefficients were particularly useful data products for me. So, please don't turn it off! cheers, Sarah S. E. Gibson, Global solar wind structure from solar minimum to solar maximum: Sources and evolution , invited review paper for Proc. of the 34th ESLAB symposium, ESA publications (refereed), 2000. S. E. Gibson, D. Biesecker, M. Guhathakurta, J. T. Hoeksema, A. J. Lazarus, J. Linker, Z. Mikic, Y. Pisanko, P. Riley, J. Steinberg, L. Strachan, A. Szabo, and B. J. Thompson, The Three Dimensional Coronal Magnetic Field During Whole Sun Month, ApJ, 520, 871, 1999. S. E. Gibson and P. Charbonneau, Empirical modeling of the solar corona using genetic algorithms, JGR, 103, 14511, 1998. S. Gibson and P. Scherrer, Supergranule power leakage through an observing mask, in IAU Symp. 181: Sounding solar and stellar interiors (Poster volume, eds. J. Provost & F.-X. Schmider, 1998). S. E. Gibson , F. Bagenal, D. Biesecker, M. Guhathakurta, J. T. Hoeksema, and B. J. Thompson, Modeling a simple coronal streamer during Whole Sun Month, Proc. of the Fifth SOHO WORKSHOP, ESA SP-404, 319, 1997. S. E. Gibson, F. Bagenal, and B. C. Low, Current sheets in the solar minimum corona, JGR, 101, 4813, 1996. S. E. Gibson and F. Bagenal, Large-scale magnetic field and density distribution in the solar minimum corona, JGR, 100, 198651, 1995. F. Bagenal and S. Gibson, Modeling the large-scale structure of the solar corona, JGR, 96, 17663, 1991. Dear Todd et al.: The WSO data continue to be of great use in my research. A recent example is the use in the paper by Bemporad et al. (2003). However, this does not reflect our continuous use of the data on a regular basis as an aid to interpretation of the state of the large scale corona. There is no similar data set for us. Our use of the data includes the source surface models and, more recently, use of the source surface coefficients in a developing study. The utility of the data includes: (1) Its continuity over a very long interval. (2) Its coverage of the entire Sun, in a synoptic data set. (3) The ease of access, with no additional manipulation being required. I expect to utilize the WSO data in the coming several years as an important piece of information for developing a 'reference heliosphere' at the time of the Voyagers' encounter with the heliosheath.

Related data sets from SOHO, the upcoming Solar-B mission, and SDO to be launched in 2008 do not meet the same requirements. Those data are focused on high resolution and fine scale structure studies. They do not easily address the large-scale corona and the state of the heliosphere over multi-solar cycle intervals. The WSO data thus continues to be of value to a large community. - Steve Suess Bemporad, A., G. Poletto, S. T. Suess, Y. K. Ko, S, Parenti, P. Riley, M. Romoli, and T. Z. Zurbuchen, Temporal evolution of a streamer complex: coronal and in situ plasma parameters, Astrophys. J., v593, 1146-1163, 2003. -- -------------------------------- Steven T. Suess ( Steven.T.Suess@nasa.gov
) NASA Marshall Space Flight Center National Space Science & Technology Center / Solar Physics Mail Code XD12 Huntsville, Alabama 35812-9999 USA ph. 256-961-7611, fax 256-961-7216 Hello Todd, I found the Wilcox solar data very useful in compiling an analysis of the effects of differential rotation on the solar magnetic field -- reference: @Article{bergerruzmaikin00, author = "Berger, M. A. and Ruzmaikin, A.", title = " Magnetic helicity production by differential rotation", journal = jgr, year = 2000, volume = 105, pages = "10481--10490", annote = " " } I would hope sometime in the future to extend the analysis to the most recent cycle. Very best Wishes Mitch Professor Mitchell Berger Gower Street London WC1E 6BT
Mathematics, University College London +44 (0) 20 7679 2835

United Kingdom +44 (0) 20 7679 2839
Hi Todd,
I don't know the cost of continuing the Stanford Wilcox observations, but I and many others regard the PFSS synoptic maps as a highly valuable asset, with the long-term continuity being an important factor here. In some ways this is like the valuable archival data base compiled by IMP-8, which was enough to find ways to keep it operating in a limited capacity long after its nominal lifetime. As you know, Nancy Crooker and I have found the Stanford SS maps very valuable in our work where we look for changes in the 1 AU inward/outward field polarities to compare with the solar-wind heat flux signatures for magnetic topologies. We hope to do more work with Nariaka Nitta to trace SS fields down to their photospheric origins for long-lived and transient structures. Then of course there are the important solar wind predictions using the nonradial expansion of open field models from the SS maps, of great value to the space weather community. I am not knowledgeable about the big question of inter-observatory field calibrations, but maybe the Wilcox observations play an important role there, as well. Maybe the Wilcox 3-arc min data are not really needed for the SS maps, but if not, then we would want to know what new magnetograph data are replacing them and how that impacts the SS maps. The Wilcox observations will be terminated at some future time, we suppose, but it would be good to know just what data sets will replace them and what the implications are for continuing the SS maps. I am concerned, but the uncertainty of the consequences leaves me somewhat ambivalent here. I hope this is useful for you in making the case (or not) for continued Wilcox observations. Regards, Steve Kahler Dear Todd, This e-mail is in support of the continuation of WSO observing program. About a month ago, or so, I began to use WSO data, more specifically, the coronal maps (WSO-R250*gif) computed from the WSO magnetic field maps. There is no publication yet since this is a new study in progress and about 26 WSO magnetograms-coronal images pairs (all are gifs) are used so far to study orientations of the magnetic fields in the CME source region, coronal and interplanetary ejecta. I did not yet notify you about the data usage as the WSO Data Policy requires, mainly because, again, this is a work in progress. I'll most certainly send you a copy of a study report and include a proper credit

in a publication. If you would like to know more details on what I do, please, let me know I'd be happy to show you preliminary results and figures. On June 23 I'll be visiting HEPL for one day to attend the calibration review meeting and if it is convenient for you, I'd be happy to talk to you about this during this visit. Best, Vasyl -- Vasyl Yurchyshyn Big Bear Solar Observatory 40386 North Shore Lane Big Bear City, CA 92314-9672 909.866.5791 x 35 909.866.4240 FAX vayur@bbso.njit.edu
www.bbso.njit.edu/~vayur Hi Todd et al, I would like to add a little weight to the argument for keeping WSO running if possible. We have found it very valuable for comparing with interplanetary scintillation measurements because it gives a reliable indication of the location of the neutral sheet a the source surface. This has become more important to us as we try to compensate for the line of sight integration in the IPS observations by modeling the full line of sight. The model requires the electron density, not the magnetic field, but the WSO neutral sheet defines the average location of the highest density slow wind as well as does a WLC. So we find it very valuable to have both. The Lasco coronagraphs have greatly improved the density measurements but there has not been a corresponding improvement in the magnetic neutral line estimate. Although I have not been doing as much IPS recently, this work has been continued by the group at Aberystwyth in Wales, involving Andy Breen, Richard Fallows and others. They continue to use the modeling techniques that we developed and they find WSO data very useful. Bill Coles

Coles, Grall, Klinglesmith and Bourgois, JGR 100, 17069, 1995 Coles, Sp.Sc.Rev. 72, 211, 1995 Grall, Coles, Klinglesmith, Breen, Williams, Markkanen, and Esser, Nature 379, 429, 1996 Coles, Astrophys and Space Sc. 243, 87, 1996 Response to the question on continuation of WSO synoptic program. As a user (see for example the paper Ruzmaikin, J. Feynman, M. Neugebauer and E. Smith, Preferred solar longitudes with signatures in the solar wind, J. Geophys. Res, vol 106, 8363, 2001) I vote for continuation of the WSO Program. The availability of higher resolution solar magnetic observations, does not jeopardize the usefulness of continuing the Wilcox Solar Observatory synoptic program. First, there are applications, which do not require fine resolution but rather global averaged maps, similar to the fact that many engineering applications do well with Newton laws and do not need relativity. Second, in addition to the direct data, the WSO provides a valuable amount of processes data, such as harmonic coefficients and coronal filed extensions, which are extremely useful in doing research. Alexander Ruzmaikin Principal Scientist at Jet Propulsion Laboratory California Institute of Technology. Dear Todd and Colleagues, I am sorry to hear that Wilcox is in danger of being shut down. There may indeed be reduced need for low spatial resolution magnetograms with new instruments coming online. However, in at least one respect Wilcox data are invaluable, namely to help determine long-term trends and to constrain models of the evolution of the magnetic field, e.g., the total magnetic flux determined at low resolution (in particular its secular evolution, which is central for producing secular trends in irradiance and other quantities that may affect our climate). Unfortunately, neither Kitt Peak nor Mt Wilson data appear to have the stability to give reliable results on their own and Wilcox data are quite indispensable. Now, the Kitt Peak SPM may be more stable than the old 512-channel magnetograph, but the large gap between the end of data taking by this instrument and the time at which SOLIS data started being regularly recorded has once again demonstrated the importance of Wilcox data. I would strongly urge you to continue gathering data at WSO until it is clear that SOLIS is providing stable results for the total magnetic flux. Maybe the maximum of the next cycle may be a better time to reconsider the future of WSO (HMI

will be running and SOLIS should have provided enough data to get an idea if there are any drifts), although I would urge you to run WSO for an even longer time. There have been too many examples of long term solar records being stopped at highly inopportune times (Greenwich observatory's end of the sunspot program in 1976 being a particularly sad example). Unfortunately, space missions cannot replace the ground-based instruments due to the limited lifetime of the former. We have recently submitted a paper (Wentzler, T., Solanki, S.K., Krivova, N.A., Froehlich, C., 2006, Astron. Astrophys. submitted) in which Wilcox data play an important role (for exactly the reason outlined above). Similarly, Wilcox data are also used to constrain models of the total and open magnetic flux and irradiance in a paper that we are currently writing and hope to submit within the next month or two (Balmaceda, L., Krivova, N.A., Solanki, S.K., Schuessler, M., 2006, Astron. Astrophys. to be submitted). We plan to use WSO data for further such analyses in the near future. Best wishes, Sami Reply on the question: Continuation of Wilcox Solar Observatory Program ? (SolarNews, Volume 2006 Number 12)/ Dr. Mikhaylutsa V.P. Dear Dr. Todd Hoeksema! I should like to state my point of view on such old and important question as: Are the solar large-scale observational data important today for investigation of solar behavior? My 30-year experience as solar researcher has given me the understanding of importance of such kind of solar observations. Really, from common physical point of view, the formation and evolution of large-scale characteristics of nonlinear dynamical system are determined by small-scale ones if the energy of system is transported strongly from the small-scales to the large-scales. I believe that for the Sun it is the open question up today. Not concerning unconditional importance of these observations for tracking the evolution of the Sun's polar and large-scale photospheric field, routinely and reliably modeling the coronal magnetic field at the source surface, forecasting solar wind conditions etc., I specify the following example: Who knows, what is the origin of the sectoral-hemispherical asymmetry in solar behavior? This surprising phenomenon appears only in large-scale distributions of facular points on the quiet solar photosphere...(Solar Phys. 2001, Vol.199, pp.13-21). Thank you for attention, Sincerely,

Dr. Mikhaylutsa V.P. Hi Todd, This email is in response to the question about WSO continuation. I may not have fully acknowledged the usefulness of WSO and staff, although I hope I have, in a number of papers (which are really helpful to NASA), in making long term predictions of the solar cycle (and updates I supply to NASA at Goddard), based primarily upon WSO observations. I shall put some of the references below, but I know the list is not complete as I have not updated my vita recently, etc... I know though that I, and recently Svalgaard, used WSO observations to help predict the next cycle's activity levels. WSO may not have the smallest observing window, however, I find that the stability of the observations is vastly superior to other observatories where there is more noise in the data, through numerous "upgrades", (which really represent changes to their system, and make their data less reliable for long-term studies.. .such as solar activity prediction than the WSO data.) The WSO staff are excellent researchers and their instrument is world class, so I think it should be continued for the next few years, certainly until the next solar maximum. I cannot think of a more valuable resource to the community than WSO ($ for $), not only with the raw observatory data, but also the fine Work that Hoeksema, Scherrer, and others do in studies of coronal fields, and the interaction of the Sun with the Earth, which is what the Living with a Star program should be about. At Stanford, they also help train future generations of students on the value of solar research, as students often operate the telescope, etc., so there are many side benefits that do not come out in "publication lists." Below are a small sample of papers where i have used WSO data. I know I used them for each cycle, back to '78 when we started making forecasts of solar activity (from WSO, where the methods originated). The WSO has a long record of drawing together excellent solar researchers who wish to work with their staff. Kenneth Schatten kenneth.schatten@ai-solutions.com
Senior Scientist a.i. solutions, Inc 10001 Derekwood Lane, suite 215 Lanham, MD 20706 USA main phone 301 949-7855 *2 cell phone: 301 221-8107 123. "Panel Achieves Consensus Prediction of Solar Cycle 23" by Jo Ann Joselyn, et al. , EOS Transactions, AGU, Vol. 78, no. 20, pgs. 205, 211-212, . 124. "Forecast Update for Activity Cycle 23 from a Dynamo-Based Method”, S. Sofia, P. Fox, K. Schatten , Geophys. Res. Lett. , VOL. 25, NO. 22, PAGES 4149-4152, 1998. 125. “Coronal and Interplanetary Magnetic Field Models: A Critical Commentary,” Schatten, K. H., AGU Monograph of Yosemite conference proceedings, 1999. 126. “Coronal and Interplanetary Magnetic Field Models”, Schatten, K. H, Solar Wind 9 conference proceedings, Nantucket, MA., 1999. 127. “Coronal and Interplanetary Magnetic Fields: Streak lines ”, Schatten, K. H., J. Geophys. Res. , Vol. 106 , No. A8 , p. 15,833 (2000JA000102).

128. “Solar activity prediction: Timing predictors and cycle 24”, Schatten, Kenneth JGR – Space Physics, 10.1029/2002JA009404, . 129. “Solar Activity and the Solar Cycle” presented at COSPAR, session D - D1.1-0001, accepted for publication in “Advances in Space Research” ASR, 2003. 130. Schatten, K., Correction to “Solar activity prediction: Timing predictors and cycle 24” JGR – Space Phys., 2003JA009843, 2003. 131. Schatten, K., “Fair Space Weather for solar cycle 24”, GRL vol 32, L21106, 2005. My group at SAIC uses WSO synoptic maps as boundary conditions for modeling the large-scale corona. I strongly believe that WSO observations should continue through the coming cycle, because they represent a continuous, WELL-CALIBRATED data set over the greatest # solar cycles of any observatory. The emphasis on calibration is important. For example, in trying to model the time-period 1980-2000, we found changes in the properties of our solutions that corresponded with instrument changes at other observatories, and did not appear when we used Wilcox data. While we certainly take advantage of higher resolution maps from other observatories in studying individual time periods, at the present time WSO maps are the best resource for studies over a number of cycles. I might add that the Stanford staff is always very helpful for working with WSO data (or MDI, for that matter). Sincerely, Jon Linker Dear Colleagues, I regularly use the data from WSO in my research. I have cited and acknowledged the WSO data in my papers. Most of these papers were sent to you (see the list below). I would like to comment on the usefulness of the WSO data. The Wilcox Solar Observatory provides for scientific community data which represent large-scale properties of solar magnetism. Large-scale patterns in solar magnetic fields appear clearly in the WSO magnetograms at moderate resolution. The procedure of extrapolation of solar magnetic field at the source surface reveals the heliospheric current sheet, its sector structure. The time-series of the Sun-as-a-star magnetic field measurements quantify the global magnetic field of the Sun. This dataset is useful to compare its changes with the Total Solar Irradiance to study the relation between magnetic and radiative indices of the Sun. This is also of interest to compare the cyclic behavior of the Sun with sun like stars. The synoptic maps of the photospheric magnetic fields as well as the synoptic maps of the computed coronal magnetic field characterize large-scale patterns in magnetic activity of the Sun and the temporal

behavior of the opened magnetic field. The fast rearrangements of large-scale magnetic field sometimes result in dramatic changes in space weather. The data from WSO complement high resolution magnetograms in a non-redundant way. The high-precision WSO measurements provide an independent scale to estimate long-term changes in solar and heliospheric magnetic field which possibly affect the Earth environment. A. V. Mordvinov and L. A. Plyusnina, Cyclic Changes in Solar Rotation Inferred from Temporal Changes in the Mean Magnetic Field, Solar Phys. V. 197, 1, 2000. A. V. Mordvinov et al. The Topology of Background Magnetic Fields and Solar Flare Activity, Solar Phys. V. 211, 241, 2002. A. V. Mordvinov and R.C. Willson, Effect of Large-Scale Magnetic Fields on Total Solar Irradiance, Solar Phys. V. 215, 5, 2003. A. V. Mordvinov and L. A. Plyusnina, Coherent Structures in the Dynamics of the Large-Scale Solar Magnetic Field, Astron. Reports, V. 45, 652, 2001. A. V. Mordvinov and L. L. Kitchatinov, Active Longitudes and North-South Asymmetry of the Activity the Sun as Manifestations of Its Relic Magnetic Field, Astron. Reports, V. 48, 254, 2004. Thank you very much and hope for your successful future work! Alexander Mordvinov Institute of Solar-Terrestrial Physics PO Box 4026 126 Lermontov str., Irkutsk, 664033 Russia Dear Drs Hoeksema and Kosovichev, On the request of Dr Kosovichev I am sending you a file of my recent paper on the kinetic models of the solar wind with magnetic field. This (very short because of the page limit) paper is submitted for publication in the Proc. of the IAU Symp. 233. In this work, I used data from the Wilcox Solar Observatory. If you are interested in kinetic solar wind models I'll be very glad to collaborate. With very best wishes, Natalia Minkova Tomsk State University, FTF Lenin Ave., 36 Tomsk, 634050 Russia

nminkova@ftf.tsu.ru
nminko@mail.tomsknet.ru
2006.06.06 Response to the request for opinions about continuing the collection of synoptic magnetic field data by the Wilcox Observatory: I would strongly recommend continuing the synoptic magnetic field measurements by the Wilcox Solar Observatory. I would also recommend that an additional program be initiated for which those data of 1 arcmin (44 Mm) resolution may be exceptionally useful. Consider the following possibility. Put a latitude and longitude grid over a computer model of the sun such that the grid partitions the surface of the sun into equal area boxes. Let each segment of the grid (e.g. a latitude segment between adjacent meridians, or a meridian segment between adjacent parallels of latitude) be considered an electrically conducting line element. Assume that all surface electric currents occur only on line segments of the grid and nowhere else. The problem is to use the magnetograph data to solve for the electric currents of the solar surface grid. This is an inverse problem that can be tried for different grid resolutions. The goal is to plot and predict the growth of mid-scale active regions. Line-of_sight magnetic data should be re-scaled to eliminate the fictitious magnetic monopole contribution from the data before the inverse calculation to solve for the currents is attempted. This is a simple procedure. Also each node of the surface grid should have as much current leaving as entering. The usefulness of the grid-current calculation should be as follows: It should allow early correlation of harmonic components of the solar magnetic field with specific surface locations of active regions (photospheric electric currents). Whereas the complexity of the photospheric field and its gradients might delay detection of a new active region pattern until it is highly developed, the grid-current model provides another visual pattern to supplement that of the photospheric magnetic field. Specifically, it should distinguish between latitudinal currents (that create the dipole component of the quiet years) with the longitudinal currents (that signal large active regions). It should provide information as to whether active regions correlate temporally over distant regions of the sun, and if so, exactly how. There is much that can be done with synoptic data of the quality obtained by the Wilcox Solar Observatory. It should be used aggressively for prediction not only of the near-

earth domain but also for the detection and prediction of large-scale solar magnetic patterns. Sincerely yours, Martin D. Altschuler June, 7, 2006 Dr. Todd Hoeksema Senior Scientist Hansen Experimental Physics Laboratory Stanford University Stanford, CA Dear Todd, As you probably know, I am currently the P.I. of the COSPIN Consortium experiment on Ulysses, which provides measurements of cosmic rays and other high energy charged particles in the inner heliosphere between the orbits of Earth and Jupiter and up to heliographic latitudes of 80° in both the northern and southern hemispheres. I constantly use the global magnetic field measurements from the WSO to provide context for Ulysses and IMP-8 measurements of the modulation and spatial gradients of cosmic rays as they vary through the solar cycle. In probably the majority of the papers I have published on these subjects in recent years, at least one figure has included a plot of the solar polar magnetic fields and/or the tilt of the current sheet as computed by the WSO. I attach a list of recent papers and talks in which I have made use of data provided on the WSO web page. While I clearly recognize and celebrate the marvelous new capabilities for high resolution solar magnetic field studies, there remains the old problem of the forest and the trees. With ever increasing resolution, the tendency is to focus on the detail, the trees and even perhaps the branches and leaves, while for cosmic ray studies, and I would venture for heliospheric studies in general, it is the global structure of the Sun's magnetic field, the forest, that is most significant. WSO has been doing a first-rate job for many years in providing a global overview of solar magnetic structure, and I have come to depend on it for this information. I strongly endorse continuing support of WSO to provide these measurements. The value of a long-running, continuous, and consistently produced data set for studies of heliospheric variations on multi-decadal time scales cannot be overstated. With best regards, R. Bruce McKibben Research Professor Dept. of Physics and SSC/EOS

University of New Hampshire R.B. McKibben Recent Papers and Talks Based on Ulysses Cosmic Ray Measurements That Incorporate WSO Observations Ulysses COSPIN high energy telescope observations of cosmic ray and solar energetic particle intensities since its distant Jupiter flyby in 2004 R.B. McKibben, J.J. Connell, and C. Lopate Geophys. Res. Abs., 8, Abst. EGU06-A-05301, 2006. Cosmic-ray diffusion in the inner heliosphere, R.B. McKibben Adv. Sp. Research, 35, 518-531, 2005. The modulated intensities of cosmic rays during Ulysses' return to the ecliptic: Ulysses HET and IMP-8 CRNC observations R.B. McKibben, C. Lopate, and M. Zhang Geophys. Res. Abst., 6, Abstract EGU04-A-05176, 2004. Ulysses COSPIN Observations of Cosmic Rays and Solar Energetic Particles from the South Pole to the North Pole of the Sun during Solar Maximum R.B. McKibben, J.J. Connell, C. Lopate, M. Zhang, J.D. Anglin, A. Balogh, S. Dalla, T.R. Sanderson, R.G. Marsden, M.Y. Hofer, H. Kunow, A. Posner, and B. Heber Ann. Geophys., 21, 1217-1228, 2003 Cosmic Ray and Solar Energetic Particle Observations in the 3-D Heliosphere near Solar Maximum R.B. McKibben, J.J. Connell, and R.B. McKibben Geophys. Res. Abs., 4, Abst. EGS02-A-01043, 2002 Modulation Near Solar Maximum and High Solar Latitudes: Observations from the Ulysses COSPIN High Energy Telescope R.B. McKibben, C. Lopate, and M. Zhang Sp. Sci. Rev., 97, 367-371, 2001 Cosmic Rays at All Latitudes in the Inner Heliosphere R.B. McKibben in “The Heliosphere Near Solar Minimum: The Ulysses Perspectives, (R.G. Marsden, A. Balogh, and E.J. Smith, editors), Wiley-Praxis, pp. 327-371, 2001 These maps are extremely useful to our solar wind studies. They enable us to relate solar wind speed studies to coronal holes and active regions. See Neugebauer et al. for many references. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 103, NO. A7, PAGES 14,587–14,600, 1998 Sorry, I know this is important, but I have run out of time. The WSO maps are a fundamental building block for understanding the fields on the sun. It would be criminal to shut it down, in my opinion.

-- Alan Lazarus Room 37-687, MIT, 77 Mass. Ave., Cambridge, MA 02139 Phone: 617-253-4284; fax: 617-253-0861; Email: ajl@space.mit.edu
08 June, 2006 Research & Scientific Support Dept. of ESA Solar System Missions Division Dr. J. T. Hoeksema H.E.P.L. Annex B213 Stanford University Stanford CA 94305-4085 USA Dear Dr. Hoeksema, I am writing in my capacity as Ulysses Mission Manager in response to the item that appeared recently in AGU’s SPA Newsletter concerning the future of the Wilcox Solar Observatory synoptic program. As you are aware, WSO data products are widely used by the Ulysses community, in particular the source surface synoptic charts and heliospheric current sheet (HCS) tilt data. These data will be especially important as a reference now that Ulysses is starting its third set of polar passes. For example, one of the key scientific objectives of the mission during 2007/2008 will be to look for N-S asymmetries of the kind found during the so-called "fast latitude scan" in 1994/95. At that time, the Ulysses cosmic ray observations showed that the HCS was offset by ~10º to the south. The synoptic data from WSO, together with in-situ magnetic field observations from the Ulysses and Wind spacecraft, were crucial in confirming this effect. A similar comparison in 2007 will reveal whether or not this offset is once again present. Another obvious area where WSO data will make an important contribution to the interpretation of Ulysses measurements in 2007/2008 is the study of cosmic ray latitudinal gradients. In contrast to the situation at the previous solar minimum in 1994/95, and as a result of the polarity reversal of the Sun’s magnetic field in 2000/2001, Ulysses is expected to find negative latitudinal gradients for positively charged particles. In all such studies, the HCS tilt angle is a much-used input parameter in modeling the transport of galactic and anomalous cosmic rays in the heliospheric magnetic fields. Indeed, the availability of a self-consistent synoptic data set covering multiple solar cycles is of great value in the study of cosmic ray modulation, and will continue to be

important in the future. I have forwarded your request for input to the Ulysses co-investigators, and am confident that they will provide even more examples of the usefulness of the WSO synoptic observations in the interpretation of their data. In summary, then, I fully support the continuation of the WSO synoptic program and consider it to play an important role in providing context data for the Ulysses mission. Yours sincerely, Richard G. Marsden
I was shocked to learn that regular observations of the solar magnetic field at WSO might be stopped. It sounds as if someone would suggest stopping Wolf number determinations and measurements of the solar integral radio flux. For many years, I have been using your data both in my research work and in daily forecasts. The corresponding references are given in my publications. A few other research teams at our Institute are conducting similar work. As Vice-Chairman of the Russian Scientific Council on Solar-Terrestrial Physics, I can contend that the WSO data are also widely used at the Institute of space research and Institute of Applied Geophysics (Moscow), Institute of Solar-Terrestrial Physics (Irkutsk), Astronomical Observatories and Institutes at Ussuriisk, Yakutsk, Odessa, Kiev, Tashkent, and Alma-Ata. Moreover I know that your data are used many groups in USA, France, Germany, Japan and China. I suppose that this problem is a topic for discussion in International Counsel of Scientific Unions, especially IAU and SCOSTEP. So I am sending the copy of the message to S.T. Wu and Dave Webb. The appearance of new, higher-resolution observations cannot be an excuse for ceasing the classical WSO observations. Firstly, their task is quite different (analysis of the inner structure of the particular active features) and secondly, reducing data from different observatories to a single format would present a significant difficulty.

I very much hope that the decision of closing these observations will not be taken. V.N.Obridko
The synoptic WSO data have an advantage that the new, higher resolution data do not, namely, continuity over three solar cycles. Four cycles would be especially desirable, and more for future generations. My collaborators and I have used these, especially the different synoptic map sets for a number of purposes. The main one has been principal components analysis and independent components analysis. These involve finding recurrent modes in the magnetic field distributions and the ways they come and go with the solar cycle. The relatively low resolution form of the WSO data actually is a plus in these calculations. I strongly urge that the WSO program be continued. John Lawrence John K Lawrence 3380 Country Club Dr Glendale, CA 91208 -or- Physics & Astronomy, CSUN, Northridge, CA 91330-8268 Tel 818-541-0649 Fax 818-541-0663
We are carrying out wavelet analysis and neural network modeling of solar magnetic field time series. For that it is totally crucial to have continuous data of highest accuracy. WSO at Stanford has produced such data since May 1975. We are therefore very much appreciating the availability of that data. We have published several articles using that data and have several new articles in progress. We have taught neural networks to predict solar wind velocity from the photospheric and computed coronal magnetic field, observed at WSO (Wintoft and Lundstedt, 1999). With the availability of high resolution magnetic field data from MDI onboard we have

compared that data with WSO data. Since WSO has produced data over three solar cycles we may even make predictions using MDI data that has only been available during one cycle. In Boberg et al., (2002) we were capable to find in mean field data, observed with WSO, the very important 1.3 year periodicity at tachocline (Howe et al., 2001). Since WSO has produced data for over three cycles we could study that periodicity over three cycles. Most recent we have studied synoptic solar magnetic fields, both using WSO and MDI data. The first results of wavelet studies have been presented by Lundstedt at (AGU, 2005, SCOSTEP, 2006 and EGU 2006). The goal is to develop a neural network dynamo model. This model is expected not only to improve our understanding of solar magnetic activity but also to offer predictions of next solar cycle (24). We have already used WSO polar magnetic field data to predict next solar cycle. Again, without continuous WSO data these results should not have possible to obtain. However, WSO has not only produced data over several cycles but also very accurate data. Actually the best in the world. We therefore really hope that there will be possibilities to continue the observations. Dr. Henrik Lundstedt Head of the Solar and Space weather group in Lund Deputy Director, ISES Swedish Institute of Space Physics Scheelev. 17, SE-223 70 Lund, Sweden Phone: +46-46-2862120 Fax: +46-46-129879 Web: http://www.lund.irf.se e.mail: henrik@lund.irf.se hlundstedt@solar.stanford.edu
References:
Boberg, F., Lundstedt, H., Hoeksema, J.T., Scherrer, P.H., and W. Lui, Solar mean magnetic field variability: A wavelet approach to WSO and SOHO/MDI observations, J. Geophys. Res., 107, 15-1--17-7, 2002. Howe, R., Christensen-Dalsgaard, J., Hill. F., Komm, R.W., Larsen, R.M., Schou, J., Thompson,M.J., and Tomre, J., in Helio- and Ateroseismology at the Dawn of the Millennium: Proc. SOHO 10/GONG 2000 Workshop, ed A. Wilson, ESA SP-464 (ESA Publication Division, Noordwijk, The Netherlands), 19, 2001. Wintoft, P. and H. Lundstedt, A Neural Network Study of the Mapping from Solar Magnetic Fields to the Daily Average Solar Wind Velocity, J. Geophys. Res., Vol. 104, No A4, 6729-6736, April, 1999. Lundstedt, H., Multiresolution Analysis of Solar Synoptic Magnetic Fields, presented at AGU meeting, San Francisco, California, USA, 5 December 2005.

Lundstedt, H., Wavelet reconstruction of solar magnetic activity, presented at 11th Quadrennial Solar Terrestrial Physics Symposium Sun, Space Physics and Climate, Rio de Janerio, Brazil 6-10 March 2006. Lundstedt, H., Reconstruction of solar magnetic activity using wavelets, presented at EGU General Assembly meeting, Vienna 2-7 April 2006. WSO is internationally famous for its magnetic field measurements. They are literally used worldwide. No other instrument in the world performs this type of measurement and provides analysis methods for producing three dimensional models of the magnetic field from the photosphere into the high corona. I just finished refereeing an excellent paper submitted to Solar Physics comparing Fe XIV emission in the corona with magnetic field measurements from WSO. Exciting new work is taking place inferring how and under what conditions the magnetic field in the corona controls the properties of the corona. Only the WSO measurements could have provided this opportunity. To discontinue these observations now would be a great blow to our ability to understand the physics of the sun and make use of such understanding to predict the increasingly-important effects of the sun on the earth. -- DR. RICHARD C. ALTROCK, DR-IV (GS-15), Principal Astrophysicist Air Force Research Laboratory, Space Weather Center of Excellence AFRL/VSBXS, National Solar Observatory at Sacramento Peak 3004 Solar Physics Dr., P. O. Box 62, Sunspot, NM 88349-0062 (505)434-7016; DSN 572-7542, ext. 7016; fax (505)434-7029 or 7079 Air Force email: Richard.Altrock@hanscom.af.mil
Internet email: altrock@nso.edu
June 16, 2006 Florence, Italy Dear Colleagues, I would like to express my strong support in favor of the observations of photospheric magnetic field performed by Wilcox Solar Observatory since 1976. I should stress that the WSO data are the longest sets of high quality data which permit to perform the study of the topology and dynamics of the magnetic field and the origin of variability of the Sun through cycles of activity. The use of the WSO data permits to get lots of the important results. To prove my statement I include the drafts of two new papers 100% based on the WSO data related to the study of the latitudinal, longitudinal structures and rotation rate of the photospheric field and their variability during last 30 years and to the study of the relationship between the basic topology of the photospheric magnetic field with the heliospheric characteristics such as interplanetary field, solar wind and geomagnetic perturbations.

Additionally I got very important results related to the longitudinal structure reconstructed in the system rotating with such a velocity which corresponds to the real rotational rate (found without any a priory assumptions) of the level where the longitudinal structure is originated from. This important result I plan to publish in the nearest time, and to present in IAU Assembly in August 2006. These studies were possible only due to the opportunity to use long data sets of such good quality as the WSO observations. Please find enclosed the titles of my recent presentations (7 contributions) in the IAU 233 Meeting in Cairo, in March 2006, and in SOHO 17 Congress in Sicily, in May, 2006, 5 contributions submitted to the IAU General Assembly, in Prague, 2006, two recent publications and drafts of two new papers prepared for publication. One more extremely important point is an open character of the data usage policy of the WSO team, very friendly and intelligent way to access the data which permits to proceed quickly to the analysis and helps to reveal scientifically significant results. I am sure that solar community should be deeply grateful to the WSO team, and particularly to Prof. Ph.Scherrer and T. Hoeksema for their great contribution to the one of the most important goals of the research in solar physics related to the study of the origin of solar dynamics and activity. It should be clearly realized that these observations of the photospheric magnetic field have great importance for the understanding of the dynamics of the Sun, heliospheric structure and geomagnetic perturbations which play a key role for the predictions of the space weather. Which best wishes, Deeply grateful, Dr. Elena Gavryuseva, Arcetri Astrophysical Observatory, Largo Enrico Fermi, 5, Florence, 50125, Italy Tel. 39 055 2752 225 FAX: 39 055 2752 292 elena@arcetri.astro.it
elena.gavryuseva@gmail.com