Dr. Priyanka Ghosh (IAP) will talk about "Gravity waves studies in the troposphere and lower stratosphere" in the IAP colloquium on 16th Dec 2021 at 10:00 am.
The troposphere is the lowermost layer of the atmosphere, which is influenced by the weather phenomena like cyclones and thunderstorms, topography, and human activities. Thus, it acts as a primary source region for the generation of the spectrum of atmospheric waves ranging from a few minutes to several days. These waves transport the energy and momentum from the lower atmosphere to the middle and upper atmosphere leads to the short and long-term variabilities in those regions. The upper troposphere and lower stratosphere (UTLS) region is the transition zone between the troposphere and stratosphere which is roughly 5 km around the tropopause. The tropopause is one of the coldest regions in the earth’s atmosphere which is at the altitude of ~10 km in the extratropics. The tropical UTLS is influenced by the radiative-convective processes whereas the extratropical UTLS is dominated by the baroclinic wave dynamics. UTLS portray as a gateway not only to the tropospheric originated waves but also a source region for the secondary waves generation. Thus, the dynamical processes in UTLS affect both the lower and middle atmosphere and contribute to the dynamical coupling processes. Therefore, understanding the characteristics of the waves in the atmosphere is essential for better weather and climate forecasting.
One of the important tasks is to understand the plausible mechanisms responsible for the generation of gravity waves (GWs) in the tropical and extratropical UTLS. The present talk gives an insight on the various mechanisms responsible for the generation of GWs in the UTLS over a tropical region Gadanki, India, and the altitudinal, seasonal, and inter-annual variation of GWs frequency power spectra in the extratropical (Andøya) location using high-resolution wind measurements from mesosphere-stratosphere-troposphere radar.