Vertical profiles of ozone and trace gases using Rocket and Balloon

To study the distribution of trace gases (especially CFCs) in the stratosphere, we have conducted high altitude balloon flights from Hyderabad, India. The initial three flights were in collaboration with Max Planck Institute, Germany, the first one launched in 1985. Later, a indigenous cryogenic air sampler was developed jointly with ISRO and flown successfully in 1994 and 1998. Profiles of a large number of trace gases including CFCs, SF6, CH3Br etc. have been observed from Hy- derabad. Total Cl loading has also been calculated from these measurements.

Modelling trace gases in stratosphere

The observed trace gases have been compared with simulations from a 2-D chemical trasport model from MPIC, Mainz (Germany) and now with us at PRL. SF6 is a useful tracer and was included in the 2-D model to validate the vertical transport mechanism of the model. Sharp gradient above 15 km and extremely weak gradient above 25 km in the observations from Hyderabad are due to dynamical effects.