The Jacchia-Bowman 2008 Empirical Thermospheric Density Model

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Dear Colleague,

Welcome to the JB2008 empirical thermospheric density model website. Please contact us at if you desire to be notified about updates to the JB2008 model, and the availability of forecasts.

Thank you,

Space Environment Technologies

NOTICE April 15, 2017: To address non-Y2K issues with the former JB08DRV.for program and the DTCFILE.TXT data file, the former Fortran program JB08DRV.for file has been updated to JB08DRVY2K.for, and now uses the 4-digit year (simply download JB08DRV.for.txt and remove the .txt extension).

NOTICE March 27, 2017: On March 27, 2017 the JB2008 indices were updated to v5.3g as part of an annual review of these indices. Included in this update are corrections to the S10 index during 2016 and 2017 resulting from calibration changes in the SDO/EVE data that are used to create S10. In addition, improvements to both the solar cycle 23 minimum (2008-2009) S10 values and the rise to solar cycle 24 maximum (2010-2014) were made. The updated indices were validated against 3 LEO debris objects whose ballistic coefficients are very well known.SET now produces an improved version of the JB2008 solar indices (SOLFSMY.TXT) and geomagnetic storm indices (DTCFILE.TXT) which are updated daily.

NOTICE May 11, 2016: On May 11, 2016 the JB2008 indices were updated to v4.2g. Included in this update are corrections to the S10 index due to degradations in TIMED/SEE and SDO/EVE data that were used to create S10 from 2010 to date. The S10 values starting on January 1, 2010 are now different than the previous version. The S10 index in the 2008-2009 time frame also continues to include an empirical correction that reduces the amount of energy coming into the thermosphere. This correction, though not a solar effect, was required to produce solar minimum thermosphere densities that matched what calibration satellites experienced. The M10, Y10, and F10 indices are unchanged.

Notice: During 2008 - 2012, JB2008 operations were upgraded, and there were significant code and data changes. Note that most of these data released for public use will have an approximately 40-day lag from the current date. Contact SET for information regarding realtime/forecast indices. A number of significant improvements have been made to the JB2008 indices, which have been validated with 2001 and 2005 solar/geomagnetic data. For more information, contact with "JB2008" in the subject line.

It is recommended that all users upgrade all JB2008 code and data from the Indices and Code web pages.

Last Website Update: 28 Apr 2017

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