Temperature Trends in the Tropical Lower Stratosphere

In this paper, we will discuss the long-term trends in temperature in the tropical lower stratosphere, emphasizing recent anomalous variations. These trends have important implications for the minor constituent compositions of the stratosphere, and in particular, water vapor. A drop in near tropopause temperature in the tropics, and a concomitant drop in stratosphere water vapor is noted at the end of 2000. This feature has no parallel in earlier periods; at least since regular radiosonde measurements of tropical stratospheric temperatures began in the 1950s. A possible link to variations in the sea surface temperature in the western tropical Pacific will be examined and discussed.