MIDDLE ATMOSPHERE COOLING TREND IN HISTORICAL ROCKETSONDE DATA

Data from the historical rocketsonde network demonstrate that signific ant cooling of the upper stratosphere and fewer mesosphere (similar to 30-60 km) occurred in northern midlatitudes of the western hemisphere and in the tropics during 1962-1991. The downward trend of temperatur e averaged over this layer was about -1.7 K/decade and temperatures we re apparently modulated by the solar cycle with amplitude similar to 1 .1 K. The trend was a function of height and somewhat larger in the lo wer mesosphere relative to the middle and upper stratosphere.