The Thermospheric Density Model JB2008 using New EUV Solar and Geomagnetic Indices
Abstract
A new empirical atmospheric density model, Jacchia-Bowman 2008, is developed as an improved revision to the Jacchia-Bowman 2006 model, which was previously developed based on the CIRA72 model diffusion equations. New solar indices computed from on-orbit sensor data are used for the solar irradiances in the extreme through far ultraviolet, including x-ray and Lyman-alpha wavelengths. New exospheric temperature equations are used to represent the thermospheric EUV heating. New semiannual density equations based on multiple 81-day average solar indices are used to represent the variations in the semiannual density cycle, which are shown to result from EUV heating. The geomagnetic storm effects are modeled using the Dst index to represent global density changes during storm times. The new model is validated through comparisons with accurate daily density drag data previously computed for numerous satellites in the altitude range of 175 to 1000 km. Model comparisons are computed for the JB2008, JB2006, Jacchia 1970, and NRLMSIS 2000 models. Additionally, CHAMP and GRACE accelerometer density data are used to validate the new geomagnetic storm equations.
- Publication:
-
37th COSPAR Scientific Assembly
- Pub Date:
- 2008
- Bibcode:
- 2008cosp...37..367B