A STUDY ON THE RESPONSE OF TROPICAL STRATOSPHERE TO THE SOLAR-ACTIVITY IN 11-YEAR CYCLE

An investigation on the influence of solar activity in the 11-year cyc le on temperature changes in the tropical stratosphere, based on M-100 and M-100 B rocket observations over Thumba for a period of two decad es, has been made. It has been noted that the temperature in the tropi cal stratosphere show an out-of-phase variation with the changes in so lar activity. The stratosphere cools during the period of high solar a ctivity and warms during the period of low solar activity. The negativ e response of solar activity in the 11-year cycle on temperature is fo und to be higher in the upper part of the stratosphere, and it decreas es as the height decreases. The role of QBO on solar activity induced changes in the tropical stratosphere seems to be comparatively lower t han that observed from the middle and high latitudes. In tropics, the upper stratosphere shows a better out-of-phase relation with solar act ivity during summer, and the middle stratosphere exhibits higher inver se association during winter.