Stratosphere Troposphere Interactions : An Introduction

Stratospheric processes play a signi?cant role in regulating the weather and c- mate of the Earth system. Solar radiation, which is the primary source of energy for the tropospheric weather systems, is absorbed by ozone when it passes through the stratosphere, thereby modulating the solar-forcing energy reaching into the t- posphere. The concentrations of the radiatively sensitive greenhouse gases present in the lower atmosphere, such as water vapor, carbon dioxide, and ozone, control the radiation balance of the atmosphere by the two-way interaction between the stratosphere and troposphere. The stratosphere is the transition region which interacts with the weather s- tems in the lower atmosphere and the richly ionized upper atmosphere. Therefore, this part of the atmosphere provides a long list of challenging scienti?c problems of basic nature involving its thermal structure, energetics, composition, dynamics, chemistry, and modeling. The lower stratosphere is very much linked dynamically, radiatively,and chemically with the upper troposphere,even though the temperature characteristics of these regions are different. The stratosphere is a region of high stability, rich in ozone and poor in water - por and temperature increases with altitude. The lower stratospheric ozone absorbs the harmful ultraviolet (UV) radiation from the sun and protects life on the Earth. On the other hand, the troposphere has high concentrations of water vapor, is low in ozone, and temperature decreases with altitude. The convective activity is more in the troposphere than in the stratosphere.

K. Mohanakumar is the holder of Masters degree in Meteorology (1979) and Ph. D. degree in Atmospheric Science (1994). In 1995 he joined as Lecturer in Cochin University of Science and Technology (CUSAT), India, for post graduate teaching in Atmospheric Science. He worked as a Visiting Scientist in 1990-1991with the Stratospheric Research Group in Freie University Belin, Germany under the support of EU Commission. At present, he is a Dean of Faculty of Marine Sciences, CUSAT, India.

The author is a member of Interenational Union of Geodesy and Geophysics (IUGG), Interanational Association of Meteorology and Atmospheric Sciences (IAMAS), International Association of Geomagnetism and Aeronomy, Committee on Space Research (COSPAR), Climate and Weather of the Sun Earth System (CAWSES), Solar Terrestrial Energy Program (STEP).