A new study led by Tandon lab PhD student Siddhant (Sid) Kerhalkar sheds light on the recovery of ocean thermal structures after cyclone passage, a largely unexplored area due to limited direct observations. As part of an international research effort in the Arabian Sea, Sid and his co-authors (including Dr Tandon) analyzed data from the R/V Thompson’s 2023 field campaign to study the aftermath of Cyclone Biparjoy. Their findings reveal that the cyclone’s slow movement, combined with monsoon winds, triggered small-scale oceanic processes that created asymmetrical temperature, salinity, and velocity structures in its wake—marking first such measurements in the region.

These observations were part of the “Enhancing Knowledge of the Arabian Sea Marine Environment through Science and Advanced Training (EKAMSAT)” program, an international collaboration funded by India’s Ministry of Earth Sciences and the U.S. Office of Naval Research. The initiative aims to improve monsoon prediction models by gathering critical oceanographic and atmospheric data in the Arabian Sea, a region that has been anomalously warm in recent years but remains less studied than many of the world’s oceans.

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

The study highlights how oceanic processes influence air-sea heat exchange and climate dynamics, providing valuable insights for improving storm behavior and monsoon predictions, which are crucial for climate forecasting and disaster preparedness affecting nearly a third of the world’s population.

“Siddhant’s research provides new observational evidence that will help refine predictive models for extreme weather events”, said Dr. Tandon.

The paper, titled “Monsoon-Frontal Interactions Drive Cyclone Biparjoy’s Wake Recovery in the Arabian Sea” is published in Geophysical Research Letters and is available at [here].

Fig: Schematic explaining the forcing conditions and the asymmetric response of the cold wake

Congratulations Sid and Dr Tandon!

A recent study led by former post-doctoral fellow Dr. Suraj Singh, in collaboration with Dr. Amit Tandon and former research professor Dr. Christian E. Buckingham, titled ‘On baroclinic instability of curved fronts’, explores how introducing slight curvature to oceanic fronts impacts baroclinic instabilities.
The research extends the classic Eady and Charney models on a cylindrical polar coordinate system by adding a slight curvature to a predominantly zonal flow. Under quasi-geostrophic scaling, the team analyzed the structure and growth rates of the pressure perturbations.
A key finding reveals that while unstable Eady modes remain largely unaffected by curvature, unstable Charney modes deepen owing to the introduction of a depth scale, enhancing vertical buoyancy flux—a phenomenon highlighted in their results (figure below).
The study also acknowledges certain limitations and suggests that understanding curved fronts could improve future parametrization of baroclinic instabilities in ocean models, and eddies which are deeper than the mixed layers. (here)

Fig: Vertical structure of the along-front averaged buoyancy flux for several values of the radius of curvature (Fig 8 of the paper)

In September 2024, Dr. Amit Tandon was felicitated with the title of Commonwealth Professor (here) at UMass Dartmouth, an achievement celebrated on November 4th, 2024, during the Faculty Recognition Ceremony.

Colleagues, students and family gathered on the university’s main campus to honor his contributions to academia.

Congratulations, Dr. Tandon, on this well-earned recognition!

Teledyne Marine, a global leader in developing deep ocean floats, recently highlighted the remarkable work of Dr. Amit Tandon and graduate student Patrick Pasteris in their recent feature.

They worked with four undergraduate engineering students for their capstone projects, with the help from the chief engineer from Teledyne Marine Bob Melvin and capstone instructor Prof. Hamed Samandari. The main objective of the project was to improve the design of the buoyancy engine and make the previous product more energy efficient. The students researched a combination of many components like pumps, motors, bladders, battery chemistries, in different ocean conditions to make the floats “Go-Anywhere”.

“…The students were motivated and talented, working well as a team to engineer and test a concept…I look forward to more capstone opportunities”, said Teledyne chief engineer Bob Melvin.

More information in the article: here and on YouTube: here

Dr. Amit Tandon, along with his colleagues from National Institute of Ocean Technology (NIOT) Chennai and Woods Hole Oceanographic Institute (WHOI), collaborated on the recently published paper: “Performance of Moored Real-Time Ocean Observations During Cyclones in the Bay of Bengal”.

This article provides a detailed explanation of the meteorological conditions, the air-sea flux conditions (measured and derived from COARE), the temperature and salinity depth profiles (and hence the mixed layer conditions) and the ocean current velocity profiles, as measured by the NIOT BD moorings, during Tropical Cyclone (TC) Amphan, which traversed through the Bay of Bengal at May 2020.

The authors highlight the benefits and necessity of maintaining such array of moored buoys in the Northern Indian Ocean, especially with the rise in the number and strength of TCs. They also discuss the challenges faced in data telemetry, mooring design, sensor exposure, etc. during cyclones and briefly outline NIOT’s plans for improving accuracy in generating and providing real-time data.

For more information: here