Solar Cycle Variability in Tropical Column Ozone
Yung, Liang, Li, Jiang and Camp
Using an empirical orthogonal function (EOF) method (Camp et al. 2003), we analyzed
the Merged Ozone Data (MOD) set from late 1978 to the present. The decadal variability
of column ozone in the tropics follows that of the sun over three solar cycles. The peakto-peak amplitude is about 10 DU (Dobson Units), consistent with the conclusion of
Camp et al. (2003), who analyzed the MOD data up to and including 2000. Previous
attempts to model the amplitude of the observed solar cycle in ozone were unsuccessful,
as models tended to underestimate the solar cycle effect. Using the WACCM (Whole
Atmosphere Community Climate Model) in combination with the latest satellite
measurements of solar variability in the UV (McClintock et al. 2005; Harder et al. 2009),
we report results that simulate the observations correctly for the first time. The
implications for solar forcing on middle atmosphere chemistry are discussed.