Emine Ceren KALAFATOGLU EYIGULER 1,2
1. Istanbul Technical University, Department of Meteorological Engineering
2. NASA-GSFC, Space Weather Laboratory, Community Coordinated Modeling Center

Why?
Basic Properties of Ionosphere and Thermosphere
Energy Sources and Sinks
Formation Mechanisms
Trends and time scales
Short term- daily
Long term- solar cycle
Global Structure
Coupling and processes within the IT system
Disturbance intervals
Recent research results

Why?
Conductivity
Enhancement
Electric Field
Variations
Absorption,
Reflection
Problems in
Communication:
Radio Blackouts
Heating at thermospheric and ionospheric levels
• Expansion of the atmosphere
• Increased Drag
Shorter lifetime for the affected spacecraft
4

Parameter Provides
Information
About
NmF2 Ionosphere
HmF2 Ionosphere
TEC
NO
O/N2 ratio
Ionosphere
Ionosphere and
Thermosphere
Thermosphere
Why it is important
HF Communication
HF Communication
HF Communication
Communication,
Satellite drag
Atmospheric Tides
Neutral Composition
Satellite Drag Joule Heating:
𝐸 , Σ p
, 𝑈 𝑛
, 𝐵
Neutral
Density: ρ n
Ionosphere
125-140 km altitude
Thermosphere Satellite Drag
[3,4]

STRUCTURE COMPOSITION
TURBOPAUSE
10 2 10 4 10 6
DENSITY (cm -3 )
10 8 10 10
[1,2]

ENERGY SOURCES:
1.
Absorption of Extreme UV radiation (10 -200nm)
2.
Joule heating by electrical currents
3.
Particle precipitation from the magnetosphere
4.
Dissipation of upward propagating waves (tides, planetary waves, gravity waves)
ENERGY SINKS:
1. Thermal conduction into the mesosphere
2.
IR cooling by CO
2
NO, O
3.
Chemical reactions
[5,6,7,8]

1) Photoionization (NO dominant source of D region ionization) –radiowaves-AM signals
2) Charge Transfer O + + H -> H + + O
3) Loss: Recombination NO + + e --> N + O
F layer exists during the night because of O +
Production rate by precipitating electrons >
10* (1) E region-noon
Variability Scales:
• Diurnal and seasonal variations
– Expansion around 5-500 km
• Solar activity variation: sunspots
– F10.7 is a good Proxy
– Now Magnesium index is also of concern
• Geomagnetic activity variation
– Storms-Days Lasting
– Substorms-Hours
• Semi-annual variation
– increased mixing of species due to uneven heating on solstices.

A Solar Min Temperature-B Solar Max Temperature / C Solar Min Density-D Solar Max Density
[7,9]

[10,2]

[11]

[9]
Neutral temperature contours and thermospheric wind at 130 km
[11]
Total Electron Content

Solar EUV Effects
No Magnetic Fields

Neutral wind and neutral temperatures at 130 km
(Kalafatoglu et al., 2013a)

Ionospheric Horizontal Current
Approach
Neutral Wind Parameters Approach
Joule Heating
Neutral Wind
Frame of Reference
Inertial Frame of Reference
(fixed with Earth)
J

2


C
J

 includes the contribution of neutral wind in itself
Resulting Neutral Wind
Contribution
J

2


C
 
P
 
2

P
 
E



U n


B

2

P
 
2

P

 
U n


B
2


2

U n

 
E



B



Estimation of neutral wind contribution by different models
Directional differences and Joule heating contribution
(Kalafatoglu et al., 2013b)

Neutral
Density
Increase
Height Integrated
Joule Heating
Enhancement
Kalafatoglu E.C., Part of the project carried out for TUBITAK in collaboration with the CCMC, 2014-ongoing study

• Thermosphere contracted two to three times greater than normal solar minimum conditions during the 2008-
2009 prolonged minimum (Emmert, 2010).
• Ionospheric electrodynamics play an important role as an effect of solar flares along with the enhanced photoionization(Qian, 2012).
• Lunar tide effects are significantly amplified during stratospheric sudden warmings (Pedatella, 2012c).
• The WAM (Whole Atmosphere Model) simulation shows that there is a substantial increase in the amplitude of the
8-hour ter-diurnal tide in the lower thermosphere dynamo in response to the warming, at the expense of the more typical semi-diurnal tides(Fuller-Rowell, 2011).

[1] Stan Solomon , Thermosphere / Ionosphere Basic Principles. Space Weather Summer School 101
[2] Stan Solomon, Ionosphere’s of Terrestrial Planets, Heliophysics Summer School, 2009.
[3] M.C. Kelley, The Earth’s Ionosphere: Plasma Physics and Electrodynamics, 2nd edn. (Elsevier, Amsterdam, 2009)
[4] H. Kohl, R. Rüster, and K. Schlegel (eds.), Modern Ionospheric Science, European Geophysical Society, Katlenburg-Lindau, Germany.
[5] Delores Knipp, Space Weather in the Thermosphere: Satellite Drag, in Space Weather Training for Mission Operators and Engineers, January 2014
[6 ]Courtesy of ICON
[7] Courtesy of UCAR COMET
[8] Forbes, J. M. (2007), Dynamics of the upper mesosphere and thermosphere, J. Meteorol. Soc. Jpn., 85B, 193–213.
[9] E. A. Araujo Pradere, D. J. Fuller Rowell, R. Redmond, R. A. Viereck, T. J. Fuller Rowell, Comparative Study of the Global Ionospheric Behavior During Solar
Cycles 22-23 and 23-24 Minima
[10] Emmert, J. T., J. L. Lean, and J. M. Picone (2010), Record-low thermospheric density during the 2008 solar minimum, Geophys. Res. Lett., 37, L12102.
[11] Courtesy of A. Burns, T. Killeen and W. Wang at the University of Michigan) http://www.windows2universe.org/spaceweather/images/quiet_ionosphere_animated.gif
[12] Courtesy of UCAR COMET http://www.meted.ucar.edu/hao/aurora
[13] J. Grebowsky, Processes due to Solar EUV effects, Earth’s magnetic field, Solar wind, IMF and Geomagnetic storms
[14] Qian, L., A. B. Burns, S.C. Solomon, and P.C. Chamberlin (2012a), Solar flare impacts on ionospheric electrodynamics, Geophys. Res. Lett., 39, L06101, doi:1019/2012GL051102.
[15] Pedatella, N.M., H.-L. Liu, A.D. Richmond, A. Maute, and T.-W. Fang (2012c), Simulations of solar and lunar tidal variability in the mesosphere and lower thermosphere during sudden stratosphere warmings and their influence on the low-latitude ionosphere, J. Geophys. Res., 117, A08326, doi:10.1029/2012JA017858.
[16]Fuller-Rowell, T., H. Wang, R. Akmaev, F. Wu, T.-W. Fang, M. Iredell, and A. Richmond. 2011: Forecasting the dynamic and electrodynamic response to the
January 2009 sudden stratospheric warming, Geophys. Res. Lett., 38, L13102, doi:10.1029/2011GL047732 .
[17] Heelis, R. A., “ Electrodynamics in the low and middle latitude ionosphere: a tutorial.” Journal ofAtmospheric and Solar-Terrestrial Physics, 2004,66,
825–838.
[18] Ridley, A. J., A. D. Richmond, T. I. Gombosi, D. L. De Zeeuw, and C. R. Clauer, “Ionospheric control of the magnetospheric configuration: Thermospheric neutral winds”, J. Geophys. Res., 2003, 108, 1328, doi:10.1029/2002JA009464, A8.
[19] Buonsanto, M. J., and O. G. Witasse, “An updated climatology of thermospheric neutral winds and F region ion drifts above Millstone Hill”, J.
Geophys. Res., 1999, 104(A11), 24675–24687, doi:10.1029/1999JA900345.
[20] Brum, C. G. M., C. A. Tepley, J. T. Fentzke, E. Robles, P. T. dos Santos, and S. A. Gonzalez,” Long-term changes in the thermospheric neutral winds over
Arecibo: Climatology based on over three decades of Fabry-Perot observations”, J. Geophys. Res., 2012, 117, A00H14, doi:10.1029/2011JA016458.
[21] Thayer, J.P. , “Height-resolved Joule heating rates in the high-latitude E region and the influence of neutral winds”, J. Geophys. Res., 1998, 103, A1, 471-437.
[22] Deng, Y., T. J. Fuller-Rowell, R. A. Akmaev, and A. J. Ridley,” Impact of the altitudinal Joule heating distribution on the thermosphere”, J. Geophys. Res.,
2011, 116, A05313, doi:10.1029/2010JA016019.