An empirical model of the thermospheric mass density derived from CHAMP satellite
In this study, we present an empirical model, named CH-Therm-2018, of the thermospheric mass density derived from 9-year (from August 2000 to July 2009) accelerometer measurements from the CHAllenging Mini-satellite Payload (CHAMP) satellite at altitudes from 460 to 310 km. The CHAMP dataset is divi...
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Published in | Annales geophysicae (1988) Vol. 36; no. 4; pp. 1141 - 1152 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Katlenburg-Lindau
Copernicus GmbH
24.08.2018
Copernicus Publications |
Subjects | |
Online Access | Get full text |
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Summary: | In this study, we present an empirical model, named CH-Therm-2018, of the
thermospheric mass density derived from 9-year (from August 2000 to
July 2009) accelerometer measurements from the CHAllenging
Mini-satellite Payload (CHAMP)
satellite at altitudes from 460 to 310 km. The CHAMP dataset is divided into
two 5-year periods with 1-year overlap (from August 2000 to July 2005 and
from August 2004 to July 2009) to represent the high-to-moderate and
moderate-to-low solar activity conditions, respectively. The CH-Therm-2018
model describes the thermospheric density as a function of seven key
parameters, namely the height, solar flux index, season (day of year),
magnetic local time, geographic latitude and longitude, as well as magnetic
activity represented by the solar wind merging electric field. Predictions of
the CH-Therm-2018 model agree well with CHAMP observations (within 20 %)
and show different features of thermospheric mass density during the two
solar activity levels, e.g., the March–September equinox asymmetry and the
longitudinal wave pattern. From the analysis of satellite laser ranging (SLR)
observations of the ANDE-Pollux satellite during August–September 2009, we
estimate 6 h scaling factors of the thermospheric mass density provided by
our model and obtain the median value equal to 1.267±0.60. Subsequently,
we scale up our CH-Therm-2018 mass density predictions by a scale factor of
1.267. We further compare the CH-Therm-2018 predictions with the Naval
Research Laboratory Mass Spectrometer Incoherent Scatter Radar Extended
(NRLMSISE-00) model. The result shows that our model better predicts the
density evolution during the last solar minimum (2008–2009) than the
NRLMSISE-00 model. |
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ISSN: | 1432-0576 0992-7689 1432-0576 |
DOI: | 10.5194/angeo-36-1141-2018 |