Towards an Improved Understanding and Representation of the Effects of Gravity Waves on Climate

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Prof. Aditi Sheshadri
Department of Earth System Science
Stanford University
Monday April 4, 2022, 2 PM ET

Abstract:

Atmospheric gravity waves (GWs) are ubiquitously excited on the Earth and are critical drivers of the atmospheric circulation, however, they present a challenge to climate prediction: waves on scales of 102-105m can neither be systematically measured with conventional observational systems, nor properly resolved in atmospheric models. I will describe collaborative efforts aimed at developing an observationally constrained, physically meaningful representation of the effects of GWs on the resolved flow for use in global climate models. a) We have leveraged high-resolution data from balloon flights launched by Loon LLC, originally deployed for internet access. The opportunistic Loon dataset, though not from a scientific campaign, gives us access to tens of thousands of balloon flights with high-resolution measurements of position, pressure, and temperature from which we have inferred statistics of gravity wave motions in the lower stratosphere. b) We have developed a machine learning GW parameterization, coupled it to a global climate model, and showed that it is stable and accurate when run online, and that it reproduces features of the climate that depend critically on GWs. c) I will also describe uncertainty quantification of a popular gravity wave parameterization.

Biosketch:

Aditi Sheshadri is an assistant professor in the Department of Earth System Science of Stanford University. She is also affiliated with Stanford Woods Institute for the Environment and is a center fellow. She was a Junior Fellow of the Simons Foundation in New York, and a postdoctoral research scientist at Columbia University’s Department of Applied Physics and Applied Math the Lamont-Doherty Earth Observatory, hosted by Lorenzo M. Polvani. She received the Ph.D. in Atmospheric Science at MIT’s Department of Earth, Atmospheric, and Planetary Sciences, in the Program for Atmospheres, Oceans, and Climate, where she worked with R. Alan Plumb. Prof. Sheshadri is broadly interested in atmosphere and ocean dynamics, climate variability, and general circulation, particularly in fundamental questions in atmospheric dynamics. She tackles these topics using a combination of theory, observations, and both idealized and comprehensive numerical experiments. Current areas of focus include the dynamics, variability, and change of the mid-latitude jets and storm tracks and the stratospheric polar vortex.

Webinar:
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Webinar number: 2622 938 5403
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