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Upcoming Seminar/Colloqium

Topic:

Exploring the dynamics of an intense pre-monsoon deep convective system using Stratosphere Troposphere Radar

Speaker : Aditya Jaiswal
Affiliation : ARIES
Date & Time :
Venue : Auditorium and zoom
Abstract :

Mountain regions modulates the dynamics of the lower and middle atmosphere due to their complex orography. Vertical ascents induced by the mountains cause variances in the temperature and moisture of the region assisting the development of mesoscale flows and convective cells. Deep convective processes transports the heat, mass and moisture throughout the atmosphere thereby affecting the dynamics and energetics of the large scale atmospheric system. It is the primary mechanism for enhancing the upper tropospheric and lower stratospheric humidity levels, thus affecting the climate by modifying the radiative budget at these altitudes. VHF radars possess the unique capability to simultaneous detect the ‘clear air’ echoes from the temperature and humidity fluctuations as well as echoes due to hydrometeors motion. Hence they had been an indispensable tool to study the mesoscale convective systems.

In this context, we have used the ARIES Stratosphere Troposphere radar system to explore dynamic evolution of an intense pre-monsoon deep convective storm was observed during its overpass. Synoptic analysis of the event by satellite and reanalysis dataset has led to the inference that it was initiated by the transport of large amounts of moisture by the western disturbance in the lower and mid-tropospheric levels. During the event, vigorous updrafts and downdrafts of magnitudes reaching up to 16 m/s were observed. Updrafts observed to be extending well beyond the tropopause into the lower stratosphere region. A clear demarcation between the updrafts and downdrafts regions were observed due to the veering of the wind. Changes the momentum flux during the event was also estimated. The study is the beginning of the attempts to probe the dynamical features and improve the understanding of the developing mesoscale convective systems over Himalayan regions.

About Speaker :

Aditya Jaiswal is a Ph.D. student at ARIES. This seminar forms a part of his annual review.