Neutral Atmospheric Influences from Solar Proton Events
            Dr. Charles Jackman
         Laboratory for Atmospheres
               NASA/GSFC

ABSTRACT

Solar Proton Events (SPEs) can cause changes in constituents 
in the Earth's middle atmosphere.  The highly energetic protons 
cause ionizations, excitations, dissociations, and dissociative
ionizations of the background constituents, N2 and O2.  
Complicated ion chemistry leads to HOx (H, OH, HO2) production 
and dissociation of N2 leads to NOy (N, NO, NO2, HNO3, HO2NO2, 
ClONO2, N2O5) production.  Both the HOx and NOy increases can 
result in changes to ozone in the stratosphere and mesosphere 
(~12 to 90 km).  The HOx increases lead to short-lived ozone 
decreases in the mesosphere and upper stratosphere due to the 
short lifetimes of the HOx constituents.  The NOy increases lead 
to long-lived stratospheric ozone because of the long lifetime 
of NOy constituents in this region, especially in the polar winter.  
An overview of the present understanding of SPEs and their 
influence on the Earth's middle atmosphere will be given in 
this talk.