Dr. Amit Tandon, along with Tandon Lab members Debarshi Sarkar and Parth Sastry, and former PhD student Dr. Siddhant Kerhalkar, attended the third EKAMSAT (Enhancing Knowledge of the Arabian Sea Marine Environment through Science and Advanced Technology) update meeting on September 10-11, 2025. The meeting, hosted by the Office of Naval Research (ONR), was held at the ProteQ facility in Herndon, Virginia.

The two-day program featured a series of back-to-back sessions, where researchers from collaborating universities and institutes shared progress on topics ranging from basin-scale modeling and process studies to insights gained from the 2023, 2024, and most recent 2025 field campaigns.

Debarshi delivered a 12-minute presentation on the causes of spatial variability in air-sea heat and momentum fluxes, drawing on observations from the 2024 and 2025 campaigns. Parth presented his analysis of horizontal stirring along isopycnals using Argo float data in the Bay of Bengal. Dr. Kerhalkar, now a postdoctoral researcher at the University of Hawai‘i, presented part of his doctoral work on the influence of salinity stratification on diurnal warm layers, as well as plans for his upcoming postdoctoral research aimed at improving wave-based bulk formulations.

Parth presenting his work in the EKAMSAT-DRI meeting.

Debarshi presenting his work in the EKAMSAT-DRI meeting.

Dr. Kerhalkar presenting his work in the EKAMSAT-DRI meeting.

We are glad to announce that Ersen’s Joseph, a master’s student in the Tandon lab, successfully defended his master’s thesis on September 18, 2025. Ersen’s has been with the group since his undergraduate years and continued working with Dr. Tandon for his master’s degree. He took an appointment as a Mechanical Engineer in Dr. Tom Farrar’s group at Woods Hole Oceanographic Institution (WHOI) in May 2023, while continuing to work on his master’s thesis.

Ersen’s thesis explores how to mitigate vibrations caused by the shedding of vortices as fluid flows past a rigid object. His work specifically focuses on how the addition of spiral grooves to stretch hoses – used by engineers at WHOI to maintain ‘quiet’ conditions for underwater acoustics via subsurface hydrophones –  can reduce the low-frequency noise contamination caused by vortex-induced-vibration (VIV).

Ersen’s performed an extensive suite of 2D and 3D Computational Fluid Dynamics (CFD) simulations using ANSYS Fluent to test the impact that various combinations of groove depths and helical pitches would have on the oscillatory (quantified by the RMS lift coefficient) and drag (quantified by the drag coefficient) forces. Guided by his advisor – Dr. Amit Tandon – and his committee, Dr. Hangjian Ling from the Mechanical Engineering Department at UMass Dartmouth and Dr. Tom Farrar, Senior Scientist at WHOI, his study provides crucial insight into VIV mitigation techniques, which is important in ensuring structural integrity in marine environments and accuracy of acoustic measurements.

Congratulations Ersen’s! We wish you luck in your work at WHOI and beyond!

Ersen’s (second from right) with his committee – Dr. Amit Tandon (first from right), Dr. Hangjian Ling (first from left) and Dr. Tom Farrar (second from left)

From August 11 to 15, 2025, PhD students Parth Sastry and Debarshi Sarkar from the Tandon Lab participated in the Ocean Acoustics Summer in School (OASiS) Bootcamp at Stony Brook University, Long Island, NY. The weeklong program provided hands-on training in designing and conducting underwater acoustics experiments.

The bootcamp gathered graduate students, teaching assistants (returning graduate students and postdocs), and five faculty mentors, including Dr. John Buck, Professor of Electrical Engineering at UMass Dartmouth.

Fig 1: The entire team (missing Dr. Grant Deane). Debarshi stands third from left with Parth right behind him.

The central goals of the bootcamp were to:

1. Transmit signals using either a circular acoustic source (direction-independent) or a directional sound source from one boat.

2. Design and deploy an array of hydrophones to receive transmitted signals at a known distance, from another boat.

3. Analyze the recorded data to calculate the time and direction of arrival of the sound waves.

The program followed a progressive, hands-on structure:

• • Day 1: Teams split into two groups — one focused on building and testing the circuit for the acoustic source in a water-filled tub, while the other designed a cube-shaped hydrophone array.

  • Day 2: Experiments moved to a large water tank at the Marine Science campus, testing single and double hydrophone configurations on wooden mounts.

  • Day 3: The team conducted experiments from two piers in the campus harbor, testing the system in realistic coastal conditions for the first time.

  • Day 4: Full-scale field experiments were conducted in Shinnecock Bay. One group operated the source boat, transmitting acoustic signals from different locations, while the receiver boat remained fixed to capture the signals.

Each evening, participants collaborated at the dorm lobby to analyze the day’s data, calculating arrival times and angles of the received signals. While all students contributed across activities, Parth played a key role in writing data-processing scripts, while Debarshi worked extensively on developing the source signal and circuit system.

The figure below captured throughout the week highlight their active participation on the pier and in the bay.

It was a fantastic opportunity to blend learning, research, and teamwork!

More about the workshop can be found <here>

We are excited to announce that Dr. Siddhant Kerhalkar successfully defended his Ph.D. thesis titled “Salinity Stratification and Lateral Variability in the Northern Indian Ocean: From Calm Diurnal Cycles to Cyclone-Induced Recovery” on July 28, 2025.

The thesis was defended in front of a public audience including Dr. Kerhalkar’s distinguished committee members, who have been instrumental in his research. We thank them for their attendance –

– Prof. Amit Tandon (Advisor, Commonwealth Professor, DEOS, UMassD)
– Prof. Miles A Sundermeyer (Professor, DEOS, UMassD)
– Prof. Steven Lohrenz (Professor, DEOS, UMassD)
– Dr. J Thomas Farrar (Senior Scientist, WHOI)
– Dr. Kenneth Hughes (Senior Lecturer, University of Waikato, Hamilton, New Zealand)

Following the public session at SMAST, there was a private session with only Sid and his committee.

We also thank the several attendees, both in person in SMAST and online over zoom, of which there were several.

Dr. Siddhant Kerhalkar now starts as a postdoctoral investigator in Dr. Hyodae Seo’s lab at the University of Hawaiʻi at Mānoa in September. We wish him luck on this new journey!

Congratulations, Dr. Sid!

Dr. Siddhant Kerhalkar (second from left) with his committee members after his successful defense! (From L to R – Prof. Miles A Sundermeyer, Dr. Siddhant Kerhalkar, Dr. Kenneth Hughes (on screen), Dr. J. Thomas Farrar, Prof. Amit Tandon, Prof. Steven Lohrenz)

On July 8, 2025, Dr. Christian Buckingham, a scientist from the National Oceanography Centre (NOC), Southampton, and former Assistant Research Professor at UMass Dartmouth (SMAST), visited the Tandon Lab. The visit brought together a range of expertise, sparking engaging discussions across diverse research areas. Dr. Buckingham presented his recent work on the development of reflectometry-based remote sensing devices, and members of the Tandon Lab shared their ongoing research, spanning observational and modeling studies in the Indian and Pacific Oceans, as well as more fundamental theoretical work.

After offering insightful suggestions on the graduate students’ research, Dr. Tandon, Dr. Buckingham, and Dr. Patibandla (Postdoctoral Researcher at the Tandon Lab) spent additional time exploring new frontiers in oceanographic science and discussing opportunities for future collaboration between Dr. Buckingham and the Tandon Lab.

It was a day well spent!

(From left) High school intern Lia Huang, Debarshi Sarkar, Siddhant Kerhalkar, Parth Sastry, Dr. Amit Tandon, Dr. Christian Buckingham and Dr. Ramana Patibandla, in front of SMAST-East (@photo by Adriano Giangiardi)

Lia Huang, a junior at John L. Miller Great Neck North High School, is a summer intern in the Tandon Lab. Her work contributes to a larger project focused on developing acoustic sensors on global drifters to measure precipitation, led by Dr. Tandon in collaboration with Dr. John Buck from the Electrical Engineering Department. She plans to finally submit her work to the Regeneron Science Talent Search competition.

Lia visited the Tandon Lab during the week of July 7 and participated in a coastal mooring retrieval and redeployment cruise with Dr. Buck on July 9, which lasted about six hours. The experience provided valuable exposure to oceanographic fieldwork and the practical aspects of conducting research at sea.

Mooring turnaround cruise on July 9: Lia Huang and Dr. John Buck (from left) on Fairhaven harbor after the cruise.

To better understand how air-sea interactions over the Indian Ocean influence monsoon dynamics, Debarshi Sarkar (PhD candidate from the Tandon Lab) and Ersen’S Joseph (full-time engineer at WHOI and master’s student in the Tandon Lab) participated in the third cruise of the ASTraL (Air-Sea Transition Layers) /EKAMSAT (Enhancing Knowledge of the Arabian Sea Marine Environment through Science and Advanced Training) field program.

Research Vessel Thomas G. Thompson

This expedition was conducted in two legs: the first (Leg-1) from May 3 to May 15, and Leg-2 (which recently ended) from May 19 to June 19, with additional time allotted for mobilization and demobilization. Debarshi and Ersen’S was part of Leg-1, and for both legs, the R/V Thomas G. Thompson (R/V TGT) departed from the deep-sea port at Phuket, Thailand. The leg-1 focused on a region spanning latitudes 11°N to 15°N and extending longitudinally from 85.5°E to the edge of India’s Exclusive Economic Zone (EEZ).

Track of R/V TGT for Leg-1 ASTraL/EKAMSAT 2025

The key objective of Leg-1 was to locate a ‘mini warm pool’ in the Bay of Bengal (A region with warming temperatures) using satellite data. This would serve as the focal point for the field experiment. This region would need to be in a zone of weak current and away from the EEZ to minimize the drift of the OARBITER buoy, which was scheduled for deployment by NRL during Leg 2.

The science crew (from left): Orson Hyde (engineer from University of Notre Dame), Charlotte Begouen Demeaux (PhD student from University of Maine), Carlyn Schmidgall (PhD student from University of Washington, Seattle), Chief Scientist Dr. J. Thomas Farrar (Woods Hole Oceanographic Institute), Dr. Laurent Grare (Engineer from Scripps Insititute of Oceanography), Ersen’S Joseph & Debarshi Sarkar

During Leg-1. We deployed 3 sea gliders and 4 wave gliders to collect high-resolution upper-ocean data. Drifters, which were capable of measuring winds, waves, and SST, were released across a wide area to ensure a large spatial distribution. Apart from the drifting assets, R/V TGT was equipped with a flux tower for measuring meteorological conditions, a ceilometer for cloud and aerosol properties, a LIDAR for vertically profiling wind structure, an ADCP for subsurface currents, and a thermosalinograph for temperature and salinity at a single depth. These instruments were kept on throughout the time we were outside international waters. The science team also took turns operating the Underway CTD (UCTD) system to measure the vertical profiles of temperature and salinity along the cruise track. The second objective of the cruise was to calibrate NASA’s PACE satellite measurements using in-situ data radiometry, optical, flow cytometry, and pySAS data.

Wave Glider Ida right after deployment

Chief Scientist Dr. J. Tom Farrar inspects a sea glider moments before deployment.

Sunset over the Bay of Bengal, with wave gliders ready on deck the evening before deployment.

The Leg-1 experienced calm ocean surface conditions (characterized by swells and weak wind waves) and mild atmospheric conditions (with weak winds and patchy non-convective cumulus clouds). Aside from a few brief convective downpours, the overall sea state remained favorable, enabling smoother operations and more consistent data collection.

Dr. Laurent Grare demonstrates to the science crew how to remotely operate the wave gliders.

Being the smaller science team, each member juggled multiple responsibilities. UCTD schedulers made a concerted effort to ensure everyone got time to rest. Debarshi’s primary roles included overseeing data from the ship’s sensors, wave gliders, and UCTD operations. In addition, he processed satellite winds, SST and sea level data to assist the chief scientist in optimizing UCTD deployment waypoints. Ersen’S assisted Dr. Laurent Grare on the engineering side, helping to assemble and ensure the smooth operation of the wave gliders during the cruise.

Debarshi and Dr. Laurent Grare on deck manually operating an underway CTD profiler during their shift.

Looking Ahead

This cruise was made possible through the collaborative efforts of a broad team of scientists from the U.S. and India, whose intellectual contributions helped shape EKAMSAT’s scientific vision. Special thanks go to the captain, crew, and port staff of the R/V TGT for their professionalism and support. Observations from both legs of the campaign will be crucial for understanding how air-sea coupling influences the formation, evolution, and eventual dissipation of the Indian Ocean mini warm pool, a poorly sampled and less understood oceanic feature that is thought to influence the Indian Monsoon season.

From June 7 to June 13, the Gordon Research Conference and Seminar on Coastal Ocean Dynamics was held at Colby-Sawyer College in New London, New Hampshire. This conference brought together scientists from around the world to explore pressing questions in oceanography, spanning topics from the physics and biology of tidally governed estuaries and lagoons to the processes controlling glacier and sea ice melt in high-latitude regions.

Debarshi and Parth, both PhD candidates from the Tandon Lab at UMass Dartmouth, participated in the conference, presenting posters based on their ongoing research. Debarshi presented “On the Accuracy of Air-Sea Heat Fluxes in the Arabian Sea Using OMNI Moorings,” while Parth showcased his work titled “Trans-Isthmic Jets and Eddy Evolution in the Eastern Tropical Pacific.” Their presentations sparked insightful discussions and received valuable feedback from the broader ocean science community.

Parth in front of his poster at GRC-2025

Debarshi in front of his poster at GRC-2025

From posters and sessions on cutting-edge ocean instrumentation to the complexities of upper ocean instabilities leading to turbulence, the conference provided a vibrant platform for learning and collaboration. For Debarshi and Parth, the week proved to be both productive and informative, deepening their understanding of the latest developments in coastal ocean dynamics and expanding their professional network.

For this academic year, the mechanical engineering (MNE) and Electrical and Computer Engineering (ECE) department joined their capstone programs. The capstone program brings together the technical and interpersonal skills needed for a student, in a team environment, to successfully plan, complete, and deliver a significant engineering project to a real customer. The culmination of this was the ECE and MNE Joint Senior Design Presentation Day held on May 1, 2025.

Team Aurelia, advised by Prof. Amit Tandon and Patrick Pasteris, and comprised of undergraduate students Ben Claxton, Eli Kroll, Shane Mercuri, and Jacob Tavares, with team lead James Bonnell bagged third place at the event. Their project involved improving the existing drive system on the Aurelia Upper Ocean Profiler – improving the depth capability and increasing operational life. They worked on testing out different motors for their power consumption and on designing a parking brake to install the profiler at depth without requiring active power. They also designed a variable gearbox to improve torque from the piston and increase the depth capability of the profiler.

Congratulations on this achievement to everyone involved!

[Left to Right – Eli Kroll (ECE), Jacob Tavares (ECE), James Bonnel (MNE; team lead), Shane Mercuri (MNE), and Ben Claxton(MNE)] standing next to their poster

On the day of the 3MT thesis competition finale (April 10, 2025), Prof. Tandon was awarded with the ‘2025 Outstanding Graduate Faculty Research Mentor‘ prize for his commitment to working with graduate students in research, knowledge creation and scholarship.

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

Congratulations Dr. Tandon!

(From Left) Dr. Ramana Patibandla, Debarshi Sarkar, Dr. Yanlai Chen, Dr. Amit Tandon, Siddhant Kerhalkar, Dr. Agata Piffer-Braga & Parth Sastry