How does the Sun drive the dynamics of Earth’s thermosphere and ionosphere Wenbin Wang, Alan...
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How does the Sun drive the dynamics of Earth’s thermosphere and ionosphere Wenbin Wang, Alan Burns, Liying Qian and Stan Solomon High Altitude Observatory National Center for Atmospheric Research Boulder, USA
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Transcript of How does the Sun drive the dynamics of Earth’s thermosphere and ionosphere Wenbin Wang, Alan...
How does the Sun drive the dynamics of Earth’s thermosphere and ionosphere
Wenbin Wang, Alan Burns, Liying Qian and Stan Solomon
High Altitude ObservatoryNational Center for Atmospheric
ResearchBoulder, USA
Outline
Earth’s thermosphere and ionosphere
Energy and momentum inputs to the thermosphere and ionosphere
Thermospheric response to geomagnetic activity
Simulation of the thermosphere and ionosphere response to a CIR event
The Thermosphere-Ionosphere System
http://en.wikipedia.org/wiki/Ionosphere
Major Species Density Structure of the Atmosphere
Diffusively Separating
Fully Mixed
OO2 N2
Total Density
MSIS empirical model atmosphere
mid-daymid-latitude
5
MSIS/IRI
mid-daymid-latitude
Thermosphere-Ionosphere Variability
Living with a Star Targeted Research and Technology program:“Plasma–Neutral Gas Coupling in the Chromosphere and Ionosphere”
Leake et al., Ionized Plasma and Neutral Gas Coupling in the Sun’s Chromosphere and Earth’s Ionosphere/Thermosphere, Space Sci. Rev., Doi:10.1007/s11214-014-0103-1, in press, 2014.
Chromosphere Thermosphere
Neutral Gas
Plasma
Thermosphere-Ionosphere System: an Externally Driven System
Sun Magnetosphere
ThermosphereIonosphere
Solar WindIMF
Ultravioletand
X-rays
Tides andPlanetary
Waves
Turbulenceand
Convection
Auroral Currents
Energetic Particles
Heliosphere
Lower & MiddleAtmosphere
Knipp et al., Solar Physics, 2004, 224: 495-505
Global Energy Input to the Thermosphere-Ionosphere System
Geomagnetic Forcing on the T-I system
Enhanced Electric Field and Ion Drag Enhanced Auroral Precipitationand Ionospheric Conductivity
Dynamics Explorer Stan Solomon
Joule Heating
Ion Drag
Thermospheric Temperature Response to Geomagnetic Forcing
F107: 190UT:1200DOY: 356HT: ~300km
Quiet
Storm
National Center for Atmospheric Research-Thermosphere ionosphere Electrodynamics Global Circulations Model (TIEGCM)
Neutral Winds in Quiet and Active Conditions
Quiet
Storm
Thayer and Killeen, 1993
Prolss (1981, 2011)
Thermospheric Composition Response to Geomagnetic Forcing
Thermospheric N2 perturbation
TIEGCM
Superposed epoch results of solar wind speed, IMF Bz, Dst, AE and ap indicies for 79 CIR events.
Corotating Interaction Regions (CIRs)
March, 2004 CIR Event
Neutral Temperature: : TIEGCM Simulations
Zonal Winds
O/N2
How is the electron density determined?
Transport: Electric Fields, Neutral Winds and Ambipolar Diffusion
Composition: O/N2 in the F-region
F2 Peak Densities
O/N2
F2 Peak Densities
Summary
1. Earth’s thermosphere and ionosphere system is strongly driven by the energy and momentum input from the Sun.
2. Thermospheric temperature, winds, and composition show global changes during storm events.
3. During a CIR event of 2004, these changes occur over the entire period of the event and do not recover one day after the event.
4. Ionospheric F-region density changes during this CIR event appear to be mostly related to thermospheric composition variations.
2004
Neutral Temperature
Zonal Winds
O/N2
8 min
hours-16 days
SunCMECIR
Magnetosphere
Thermosphere-Ionosphere: An Externally Driven System
EUV and UV
Radiation
Lower and Middle Atmosphere
Thermosphere-Ionosphere
2-10 days
Leake et al., Ionized Plasma and Neutral Gas Coupling in the Sun’s Chromosphere and Earth’s Ionosphere/Thermosphere, Space Sci. Rev., Doi:10.1007/s11214-014-0103-1, 2014.
Conductivity
Chromosphere Thermosphere
