With severe impacts on human health and agricultural output (crop damage in India upto 3.5 million tonnes a year, tropospheric ozone is a prominent air pollutant and greenhouse gas in spite of being only 10% of total column amount.

However, Ozone is not only a greenhouse gas and biological irritant but also an atmospheric cleansing agent which rids the atmosphere off hazardous gases through production of hydroxyl radicals and is beneficial if it is present in the stratosphere in abundant amount as it prevents harmful sun rays from penetrating through the troposphere to the Earth’s surface. Ozone exerts considerable radiative forcing too with recent estimate being 360 mW/m2 which is 25% of the same exerted by CO2.

Climate variabilities ranging from interannual to decadal scales like El Niño and the Southern Oscillation (ENSO), Pacific–North American teleconnection (PNA), North Atlantic Oscillation (NAO), Antarctic Oscillation (AAO), Pacific Decadal Oscillation (PDO) etc. has been reported to influence the tropospheric ozone at remote locations.

Despite of having tremendous climatic, agricultural, compositional and health repercussions, variability of ozone (tropospheric in particular) vis-a-vis circulation changes (due to climate change and stratospheric ozone hole recovery) is still poorly understood.

Given this background, it is imperative to ask the following relevant questions:

o How is the ozone in the Antarctic distributed both vertically and spatially?

o Is the ozone hole in the stratosphere healing? If yes, how confident are we about our analysis showing the recovery trends?

o Is there any evidence of recovery in atmospheric layers which experience near complete destruction of ozone i.e. ozone loss saturation layers?

o How is the recovery affecting the tropospheric ozone trends?

o How do O3 profiles cluster for various regions, each of which are known to exhibit differing O 3 distributions?

o What are the links among the O3 profile clusters, meteorology, and chemistry, and how do they depend on latitude or region?

o How do the ozone recovery in the stratosphere and trends in tropospheric ozone affect the surface climate in the Antarctic and how is it correlated with the increasing greenhouse gases?

I’ll be using state of the art Physical models and Causal Discovery and Inference methods based on Artificial Intelligence to answer these questions.