# JB2008

### The Jacchia-Bowman 2008 Empirical Thermospheric Density Model

JB2008 is based on Jacchia’s diffusion equations. Driving solar indices are computed from space-based sensor data, which provide the solar irradiances in the extreme through far ultraviolet, including x-ray and Lyman-α wavelengths. Exospheric temperature equations represent the thermospheric EUV and FUV heating. Semiannual density equations based on multiple 81-day average solar indices represent the variations in the semiannual density cycle that result from EUV heating. Geomagnetic storm effects are modeled using the Dst index as the driver of global density changes. Extensive model validation was performed by Bowman et al. [2008], which includes comparisons with accurate daily density drag data previously computed for numerous satellites in the altitude range of 175 to 1000 km, model comparisons between JB2008, JB2006, Jacchia 1970, and NRLMSIS-00 models, and comparisons to accelerometer measurements from the CHAMP and GRACE satellites.

## Indices and Code Access

The JB2008 empirical thermospheric density model code is provided, as well as historical space weather indices with a 45-day lag.

### Access JB2008 model code and historical indices

SET offers current epoch and forecast operational indices to the community through the Unified Data Library (UDL). Whether for research or operational use, please visit the Unified Data Library site to request a subscription.

## Figures

Figure 2. Density percentage errors (1 standard deviation) from model density values at 400 km altitude compared to HASDM density values.

Figure 3. The amplitude function F(z) for three different years (1990, 1993, 2002), with semiannual amplitudes plotted for each satellite for each year. The constant F(z) function from Jacchia is also plotted.

Figure 4. A multiple storm during 2004, showing the different storm events.

Figure 5. Major 2004 storms with Dst, ap (left scale) , and density (Rho) ratios displayed. The density ratios are based on orbit averaged model density values / GRACE 2004 density average.

Figure 6. Major 2003 storms with Dst, ap (left scale), and density (Rho) ratios displayed. The density ratios are based on orbit averaged model density values / CHAMP 2003 density average.

Figure 7. Model density 1-standard deviation errors as a function of ap ranges representing storm magnitudes. Values are based on orbit averaged percent density differences between the calibrated accelerometer data, from both CHAMP and GRACE, and the different model values. JB2006 uses the same geomagnetic storm modeling as J70.

## Publications, License, and Acknowledgement

### Publications

**A description of indices used in the JB2008 Thermospheric Model.**- COSPAR CIRA Draft, chapter 4, 2008
- Tobiska, et. al.
- JB2008_solar_geomag_indices-2.pdf

**The solar and geomagnetic inputs into the JB2008 thermospheric density model for use by CIRA08 and ISO 14222**- CIRA08 and ISO 14222, JB2008 Proxy indices
- Tobiska
- C01-0003-10.ppt.pdf

**A New Empirical Thermospheric Density Model**

JB2008 Using New Solar and Geomagnetic Indices- JB2008 model using new indices
- Bowman et al.
- AIAA_2008-6438_JB2008_Model.pdf

**The thermospheric semiannual density response**

to solar EUV heating- Thermospheric semiannual variations
- Bowman et al.
- JASTP_Semi_Dens_Resp_2008.pdf

**The development of new solar indices for use in thermospheric density modeling**- JB2006 indices
- Tobiska et. al.
- JB2006_JASTP_2008_803.pdf

**The JB2006 empirical thermospheric density model**- JB2006 model
- Bowman et. al.
- JASTP_Bowman_JB2006_2008.pdf

**Accuracy of Earth’s Thermospheric Neutral Density Models**- 2006 6167 Model Comparisons
- Marcos et. al.
- JB2006_AIAA_2006-6167.pdf

**The development of new solar indices for use in thermospheric density modeling**- 2006_6165_Development of New Solar Indices for thermospheric modeling
- Tobiska et. al.
- SET_AIAA_2006_revD.pdf

**COSPAR 2006 Session C4.1 Paper COSPAR2006-A-01661**- New solar indices for improved thermospheric densities
- Kent Tobiska
- COSPAR2006-A-01661.pdf

**New Satellite Drag Modeling Capabilities**- 2006_470_Satellite_Drag _Modeling Capabilities
- Marcos
- JB2006_AIAA_2006_470.pdf

**Improvements in Modeling Thermospheric Densities Using New EUV and FUV Solar Indices**- 2006_237_Density_Improvements
- Bowman, Tobiska
- JB2006_AAS_2006_237.pdf

**Solar and Geomagnetic Space Environment Specification for Operations**- 2006_471_Solar_Geomagnetic _Specification_for_Ops
- Tobiska, Fry
- JB2006_AIAA_2006_471.pdf

**Advances in Solar Inputs for Precision Orbit Determination**- 2005_252_Solar_Inputs
- Tobiska
- JB2006_AAS_2005_252.pdf

**The Semiannual Thermospheric Density Variation at Altitudes of 160-300 km**- 2005_254_Semiannual_Density
- Bowman
- JB2006_AAS_2005_254.pdf

**Drag Coefficient Variability at 175-500 km from the Orbit Decay Analyses of Spheres**- 2005_257_Drag_Coef_Variability
- Bowman, Moe
- JB2006_AAS_2005_257.pdf

**The Effects of Surface Composition and Treatment on Drag Coefficients of Spherical Satellites**- 2005_258_Surface_Effects_on _CD_of_Spheres
- Moe, Bowman
- JB2006_AAS_2005_258.pdf

**The Semiannual Thermospheric Density Variation From 1970 to 2002 Between 200-1100 km**- 2004_174_Semiannual_Density _Between_200_1100_km
- Bowman
- JB2006_AAS_2004_174.pdf

**A Method For Computing Accurate Daily Atmospheric Density Values From Satellite Drag Data**- 2004_173_AAS_EDR_Method
- Bowman et. al.
- JB2006_AAS_2004_173.pdf

**High Accuracy Satellite Drag Model (HASDM) Review**- 2003_625_HASDM_Review
- Bowman, Strorz
- JB2006_AAS_2003_625.pdf

**High Accuracy Satellite Drag Model (HASDM)**- 2002_4886_HASDM
- Storz et. al.
- JB2006_AIAA_2002_4886.pdf

**HASDM Validation Tool Using Energy Dissipation Rates**- 2002_4889_HASDM_Tool_Using _Energy Dissipation_Rates
- Storz
- JB2006_AIAA_2002_4889.pdf

**True Satellite Ballistic Coefficient Determination for HASDM**- 2002_4887_True_B
- Bowman
- JB2006_AIAA_2002_4887.pdf

**Atmospheric Density Variations at 1500-4000 km Height Determined from Long Term Orbit Perturbation Analysis**- 2001_132 Den_Var _1500-4000km
- Bowman
- JB2006_AAS_2001_132.pdf

**Orbit Perturbation Analysis of West Ford Needles Clusters**- 2000_4236_Needles_Perts
- Bowman
- JB2006_AIAA_2000_4236.pdf

## SOFTWARE LICENSE AND WARRANTY AGREEMENT Software License and Warranty Agreement,

JB2006 and JB2008 Empirical Thermospheric Density Models

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## Acknowledgement

When using JB2008 indices or other data from this website in a publication or conference paper, please acknowledge use of the data as: “The JB2008 solar and geomagnetic indices are provided for scientific use courtesy of Space Environment Technologies.”