Middle Atmosphere Sensitivity to SSI Solar Cycle Variations
William H. Swartz1 [Bill.Swartz@jhuapl.edu], R. S. Stolarski2,3, L. D. Oman3, E. L.
Fleming3, and C. H. Jackman3
1
Johns Hopkins University, Applied Physics Laboratory, Laurel, Maryland
Johns Hopkins University, Laurel, Maryland
3
NASA Goddard Space Flight Center, Greenbelt, Maryland
2
Variation of the solar spectral irradiance (SSI) with solar cycle impacts the composition
and temperature of the atmosphere. Stratosphere ozone and temperature, for example,
respond through both direct solar heating and photolysis. We have implemented an 11-year
solar cycle in the Goddard Earth Observing System Chemistry–Climate Model (GEOS
CCM). Simulations based on a multi-decadal historical reconstruction derived from
contemporary observations of solar irradiance and historical proxies for solar activity (Lean
SSI) and a reconstruction from the SORCE dataset are compared and contrasted. We find
that the magnitude and morphology of the atmospheric response is highly dependent on the
spectral characteristics of the SSI dataset used, and we examine the sensitivity of the
atmospheric response to both the relative and absolute variations of the solar spectrum
represented by the two datasets. The model output is also compared with observations in
order to test the validity of the results.