QBO and Annual Cycle Variations in Tropical Lower Stratosphere Trace Gases from HALOE and Aura MLS Observations (Invited Speaker)

We have analyzed thirteen years (1993 to 2005) of HALOE and over two years of EOS MLS observations (Sept. 2004 to Dec. 2006) for QBO and annual cycle trace variations in tropical H2O, HCl, ozone, N2O, CO, HF and CH4. We use these results to develop the theory explaining both Brewer-Dobson circulation (BDC) and QBO driven fluctuations in tropical trace gases. For H2O and CO, tropopause BDC variations drive part of the tropopause annual forcing, and this signal is carried upward by the time mean BDC. For ozone, N2O, HCl and other gases, photochemical processes force fluctuations in the trace gases to be synchronized with annual and QBO variations in the zonal mean residual vertical velocity.