A study led by UMass Dartmouth School for Marine Science & Technology (SMAST) Ph.D. student Siddhant Kerhalkar sheds new light on the recovery of ocean thermal structures following cyclone passage—an area of oceanography that has remained largely unexplored due to the scarcity of direct shipboard observations. This research enhances our understanding of how the ocean recovers after cyclones, which is essential for improving climate models and predicting extreme weather events.

The study appears in the journal Geophysical Research Letters.

As part of an international research collaboration in the Arabian Sea, Kerhalkar and his co-authors Ankitha Kannad, Alex Kinsella, Amit Tandon, Janet Sprintall, and Craig M. Lee utilized data collected from the R/V Thompson during a 2023 field campaign to investigate the aftermath of Cyclone Biparjoy.

Their findings reveal that the slow movement of the cyclone, coupled with monsoon winds, triggered small-scale oceanic processes that created asymmetrical temperature, salinity, and velocity structures within the cyclone’s wake. This is the first time such measurements have been made in the Arabian Sea, which—while being anomalously warm in recent years—remains less studied than many of the world’s oceans.

These observations were made as part of the program “Enhancing Knowledge of the Arabian Sea Marine environment through Science and Advanced Training (EKAMSAT),” focused on the acquisition of contemporary oceanographic and atmospheric datasets deemed critical for improving the predictive skills of operational monsoon models, and to addressing the safety of ships at sea.

“Our research shows that these small-scale ocean processes, typically referred to as submesoscale processes, play a critical role in accelerating the recovery of the ocean’s thermal structure after a cyclone,” said Kerhalkar. “This has major implications for ocean heat transport, nutrient distribution, and weather predictability, particularly for monsoon forecasts.”

The study highlights how these oceanic processes could potentially influence air-sea heat exchange and overall climate dynamics, providing valuable insights for improving predictions of storm behavior and monsoon variability. The Indian monsoon directly affects nearly a third of the world’s population, so this research underscores the importance of understanding these mechanisms for climate forecasting and disaster preparedness.

“This work contributes to our growing knowledge of ocean-atmosphere interactions, particularly in regions impacted by strong tropical systems,” said Amit Tandon, co-author and professor of mechanical engineering and estuarine and ocean sciences at UMass Dartmouth. “Siddhant’s research provides new observational evidence that will help refine predictive models for extreme weather events.”