Mission Name Medium Energy Particle Precipitation Effects on the Mesosphere and Lower Thermosphere Not Applicable Not Applicable LASP Instruments Not Applicable Destination Not Applicable Launch Date Not Applicable Launch Location Not Applicable Launch Vehicle Not Applicable Mission Duration Not Applicable Mission Description/ LASP involvement Not Applicable LASP Divisions Involved Science LASP Mission Web Page   Official Mission Web Page

LASP Research Associate Frank Eparvier, in collaboration with M.V. Codrescu of NOAA-CIRES, Scott Bailey of Hampton U., and D.E. Siskind of NRL, has been developing a climatology of ionization rates in the upper atmosphere caused by precipitating medium energy (>30keV) electrons. Medium energy electrons penetrate deeper into the atmosphere than the lower energy auroral electrons, becoming a source of energy input to the mesosphere and lower thermosphere at high latitudes that is not captured by most atmospheric models which only include auroral precipitation. The climatology being developed uses the medium energy electron precipitation patterns developed from the NOAA-TIROS MEPED observations and the GLOW electron transport model to generate three dimensional ionization rates for O2, N2, and O. Studies are underway using the NRL two-dimensional CHEM2D model and the NCAR three-dimensional TIME-GCM to determine the effects of the additional source of ionization on the chemistry of the mesosphere and thermosphere, in particular, the effects on odd nitrogen.

Not Applicable