Gravity Wave Variance in LIMS Temperatures. Part I: Variability and Comparison with Background Winds

Abstract Small-scale features in temperature data from the Limb Infrared Monitor of the Stratosphere satellite experiment are isolated by subtracting profiles of globally mapped temperatures (containing zonal waves 0—6) from inverted temperature profiles. These features are interpreted as internal gravity waves. The preponderance of the variance is associated with the longest wavelengths, corresponding to the lowest frequencies (inertio-gravity waves). The data include approximately 2000 daily soundings between late October 1978 and late May 1979, all longitudes, latitudes from about 65°S to 85°N, and altitudes from the tropopause to the middle mesosphere (pressures from 100 to 0.1 mb). Zonal-mean gravity wave variance is compared with background winds, and variance maps are presented for five one-week periods: early November, early January, early February, late March, and early May. Time-height plots of zonal mean wave variance and background winds in the latitude bands 45°–55°S, 5°S–5°N, and 45°–55°N ar...