We usually think of the protective ozone shield as a high-altitude layer that stretches across the Earth’s atmosphere, absorbing the harmful UV rays. Scientists in India recently discovered an unusual phenomenon: a thicker and lower-than-normal pocket of ozone above the North Bay of Bengal.
The American Geophysical Union published this discovery in Earth and Space Science, giving researchers new insights into the way air currents move ozone in the Stratosphere and the reasons why the atmosphere in India behaves so surprisingly.
Normaly, the peak of ozone occurs at an altitude between 25-30km.
Scientists found a thicker ozone between 21-23 km over the Bay of Bengal during NetRAD, a national campaign.
It was obvious that the abnormality in ozone levels had occurred: partial pressures were more than 50 nbar over the median climatological level for this latitude, and formed a 7 km-thick layer between an altitude of at least 2.1 kilometers to 2.4km. It lasted for more than 24 hours without changing during the night and day.
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It was not a temporary glitch. All three confirmed that the sporadic structure of ozone was not a temporary glitch.
This campaign involved a large collaboration involving weather balloons, radars, Aura MLS, INSAT-3DR, as well as radars in Nainital and Haringhata.
Central to the effort was one of India’s biggest indigenously developed radars, the Backscatter VHF Radar (BVHF), or Stratosphere-Troposphere Radar, at the Aryabhatta Research Institute for Observational Sciences (ARIES), Nainital, providing high-temporal-resolution vertical air-motion profile data.
The peculiar enhancement of ozone was attributed to two main atmospheric processes. The lower Stratosphere was characterized by downward air movement that compressed the ozone rich air into a thin layer. Advection, also called transport, caused further enhancement during this time. These mechanisms combined to produce the anomaly that was observed, namely a persistent partial pressure with a high level of ozone and cycles day-night.
Antarctica’s ozone cloud reached maximum extent in 2021
The ozone shield protects life on Earth from harmful ultraviolet rays. Scientists will be able to better understand the impact of climate change on ozone distribution by examining how its density and shape changes in unanticipated regions.
The insights gained from these studies also improve models of stratospheric dynamics and chemistry, and they strengthen the global monitoring of ozone.
Researchers Manish Naja, Dr. Samaresh Bhattacharjee, and ARIES played crucial roles in this study. They emphasize that the results are quantitative experimental evidence for ozone distribution in subtropical India, which they had suspected, but not captured as clearly.
The coordinated effort of Indian scientists is evident in this finding. Researchers observed an atmospheric anomaly using data collected from satellites and radars.
This also shows the importance of domestic technology. It was ARIES’ radar- and balloon measurements that were crucial in detecting this anomaly. This shows how India can contribute to global atmospheric research through its scientific infrastructure.
The ozone in lower latitudes does not recover despite the Antarctic ozone holes healing
This pocket of ozone in the Bay of Bengal area is not a mere curiosity.
This pocket of ozone is a constant reminder that Earth’s atmospheric layers and motion are constantly changing. Scientists are creating a UV-reflective protective layer over our planet by revealing these hidden matrices. They also expand the exploration of invisible processes which determine what happens to our skies.
Journal Reference
- Siddharth Shankar Das, N. Poddar, A. K. Ghosh, M.
V. Ratnam et al. Unusual Enhancement of Stratospheric Oxygen Observed over the North Bay of Bengal : Results Inferred from NetRAD-ASMA campaigns-2024. Earth and Space Science. DOI: 10.1029/2025EA004791
