Interannual and Solar-Cycle Terms in Middle Atmospheric Temperature Time Series from HALOE

Temperature versus pressure or T(p) time series from the Halogen Occultation Experiment (HALOE) have been generated and analyzed for the period of 1991-2004 and for the mesosphere and upper stratosphere at latitude zones from 40N to 40S. Multiple linear regression (MLR) techniques were used for the analysis of the seasonal and the significant interannual, 11-yr solar cycle, and/or decadal-scale dynamical terms. Both sub-biennial (688-dy) and QBO-like (800-dy) terms are resolved for the upper stratosphere along with a 13.5-yr term due to their predicted modulation. A solar cycle (SC) term emerges for the tropical stratopause region, but its amplitude is only about half that predicted from most models. The SC terms for the middle to upper mesosphere have amplitudes that agree will with model predictions. At northern hemisphere middle latitudes there is some lag for the apparent SC response in the mid mesosphere, possibly due to interference from the effects of wintertime wave activity. SC amplitudes from the MLR models are somewhat weaker but in-phase for the southern hemisphere latitudes, and may be more representative of the true solar cycle forcing effects.