Variation in Thermospheric Neutral Density
Stan Solomon and Liying Qian
High Altitude Observatory
National Center for Atmospheric Research
CISM All-Hands Meeting
•
Boulder, Colorado
•
15 September 2008
1
Time Scales for Forcing of the Terrestrial Upper Atmosphere
Geological
Solar
Cycle
Solar Evolution
Solar
Rotation
Geomagnetic
Seasonal
Earth
Solar Cycle Variation??
Rotation
Orbital
Biogenic
Anthropogenic
Flares
101 102 103 104
105
106
107
108
109
1010 1011 1012 1013 1014 1015 1016 1017
Seconds
2
Start with the Flares — Are They Really Important?
3
Flare Spectrum Inferred using Rodgers & Bailey Method
The method of Rodgers and Bailey (R&B) [Rodgers et al., JGR, 2005] obtains
a differential emission measure that best fits signals observed by the multiple
bandpasses of XPS diodes on TIMED/SEE or SORCE, and uses the Warren
et al. [1998, 2001] model to produce a flare spectrum.
Flare spectrum on 10/28/03 at 11:12 UT obtained using the R&B analysis method
4
SEE Flare Spectra Combined with R&B Method in the XUV
Combined TIMED/SEE and SORCE spectra for 10/28/03
using the R&B method.
5
Energy Deposition in the Upper Atmosphere — Pre-Flare
6
Energy Deposition in the Upper Atmosphere — During Flare
7
Estimate of the Time Dependence
EUV Data from TIMED/SEE (linear interpolation)
XUV Data from SORCE/XPS (R&B method scaled w. GOES)
X-ray Data from GOES X-ray monitor
8
NCAR TIE-GCM Simulation for the 10/28/03 Flare
E-region electron density (~115 km)
F-region electron density (~350 km)
9
NCAR TIE-GCM Simulation for the 10/28/03 Flare
Neutral temperature at ~350 km
Height of the +2 pressure surface
10
Comparison of Observations to Model for 10/28/03 Flare
Neutral Density
Measurements
from
accelerometers
on CHAMP
and GRACE
satellites
TIE-GCM
Simulations
at same
altitude and
local time
11
Total Electron Content Measurement and Model
Total Electron Content increases on
10/28/03 from GPS observations
[Tsurutani et al., 2004].
Total Electron Content increases simulated
using the NCAR TIE-GCM
12
TIE-GCM Simulation of the 10/28/03 Flare and Storm
13
Thermospheric Variability on (Slightly) Longer Time Scales
14
Taifun-1 Radar Calibration Satellites
NORAD Catalog Number
Name
Launch Date
07337
COSMOS 660
1974-06-18
08744
COSMOS 807
1976-03-12
12138
COSMOS 1238
1981-01-16
12388
COSMOS 1263
1981-04-09
14483
COSMOS 1508
1983-11-11
15
COSMOS 1508 gets its 15 Minutes of Fame
“On a September 15
EVA Solovyov and
Avdeyev retrieved solar
cell and materials
samples and moved the
Kurs rendezvous
antenna on Kristall so it
could be used by Soyuz
TM-16. The
cosmonauts released
the 16.5-kg MAK-2
satellite from the Mir
base blocks
experiment airlock on
November 20. Its
purpose was to study
Earths ionosphere. The
derelict 550-kg Cosmos
1508 satellite, launched
by the Soviet Union in
1983, passed within
300 meters of Mir on
November 8.”
16
Orbital Characteristics of Satellite Drag Measurements
17
Model-Data Comparison for 2003
18
Model-Data Comparison for 2003
07337
08744
12138
12388
14483
19
Average Model-to-Data Ratio for 2003
MSIS-00
TIE-GCM
Mean
1.03
0.99
Std. Dev.
0.20
0.14
20
Model & Measurement of Thermosphere Solar Cycle Variation
21
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