Climatological Upper Atmospheric Data Assimilation from Multiple Missions and Instruments

Abstract:

The most up-to-date multi-mission, multi-instrument climatological data summary of Earth’s upper atmospheric composition comes from the series of empirical reference models known as Mass Spectrometer and Incoherent Scatter (MSIS^®). Derived from over forty years of NASA satellite mission data, sounding rockets, and non-NASA ground-based measurements, MSIS has long provided a statistical data summary of upper atmosphere neutral temperature, total mass density, and the individual species concentrations of O, O2, N, N2, He, H, and Ar. These specifications are a function of day-of- year, solar local time, latitude, longitude, altitude, solar-flux, and geomagnetic activity and are obtained via an approach that uses an optimal error-weighted multi-variant non-linear least-squares parameter estimation procedure; i.e. upper atmospheric data assimilation. While MSIS continues to provide a convenient and generally reliable functional representational of historical upper atmospheric observational mission datasets, the most recent upgrade (NRLMSISE-00) was in 2001 and consequently does not include any data from the NASA Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) mission which began in 2002. Furthermore, this new generation of data has identified critical deficiencies in MSIS reference in the MLT region. Another drawback of the present MSIS is the lack of simultaneous uncertainty estimates as part of the standard model output. This presentation describes recent efforts to updated MSIS from the mesosphere to the exobase (60-500 km) based predominately upon TIMED SABER data but also utilizing other relevant satellite and ground- based datasets.

This work sponsored by the Office of Naval Research.