On March 27, 2024, the Inter-campus Marine Science (IMS) of University of Massachusetts (UMass) hosted an symposium at the School for Marine Science and Technology (SMAST). The event brought together students and faculties from various UMass campuses to showcase their latest findings and innovations in marine science. One of the highlights of the symposium was Sid Kerhalkar (a 5^th year PhD candidate in the Tandon Lab), who was invited as a plenary speaker. Sid captivated the audience with his talk on the physics of hurricanes, drawing on insights from our recently concluded field trip to the Arabian Sea where we sampled the ocean post-hurricane (read more about the field campaign here).

Sid Kerhalkar presenting a plenary talk

Debarshi Sarkar (1^st year PhD student) presented his research on biases in reanalysis fluxes in the Arabian Sea through a compelling poster and a lightning talk. His work with Sid and Dr. Tandon as co-authors shed light on the biases in the Arabian Sea meteorological and flux variables.

Debarshi Sarkar presenting a lightning talk on his research

In addition to his plenary talk, Sid was voted with the best “Marine-Science” themed photo award in the symposium’s photo contest. Sid’s winning photograph captured the most essential instrument associated with oceanography, the CTD rosette. Overall, the UMass IMS symposium proved to be a fruitful gathering for the Tandon lab members.

Sid’s photo contest winning picture!

Members of Tandon lab and Mahadevan lab after the group meeting at SMAST

On March 15, 2024, Tandon Lab welcomed members from the Mahadevan Lab (Drs Amala Mahadevan, Alex Kinsella and Nihar Paul) for a collaborative group meeting. The session proved to be a melting pot of expertise, with members engaging in lively discussions spanning a broad spectrum of research areas. From the intricacies of clouds and atmospheric convection to the dynamics of air-sea interaction and ocean transport, every facet of ocean and atmospheric science found representation. The dialogue extended to topics as diverse as hurricane wakes, mooring designs for right whale monitoring, and beyond. This convergence of minds highlighted the commitment to interdisciplinary collaboration, laying the groundwork for future projects, innovations in understanding and addressing complex issues in ocean research.

In February 2024, the vibrant city of New Orleans became the focal point of ocean, atmosphere and marine biosphere research as Dr. Tandon and Sid (a PhD candidate in Tandon Lab)  participated in the prestigious Ocean Sciences Meeting. This gathering, organized by AGU, ASLO and TOS, and renowned for its interdisciplinary approach to marine research, provided a platform for scientists and scholars to share insights and innovations shaping the future of oceanography.

Dr Amit Tandon and Sid Kerhalkar at OSM 2024

Dr. Tandon presented a poster on reanalysis flux biases in the Arabian Sea. Drawing on research conducted by his PhD student, Debarshi (who could not attend due to class schedules), Dr. Tandon shed light on the biases in the Arabian Sea meteorological and flux variables, which could play a significant role in the forecasting errors in sub-seasonal to seasonal weather over Indian subcontinent. The poster sparked discussions and offered valuable perspectives for identifying and addressing biases in reanalysis fluxes, a critical aspect of understanding air-sea coupling. Dr Tandon was also a co-author on 6 other presentations/posters.

Dr Amit Tandon explaining the poster

Sid Kerhalkar presenting a talk

One of those included Sid, who talked about Hurricane wake recovery in the Arabian Sea. His presentation highlighted one-of-a-kind observational field campaign, which braved high waves to sample the hurricane wake and showcase the role of wind and density gradients coupling to drive lateral  processes to recover the wake. Sid’s insights stirred up an interesting conversation among experts, who initially believed that surface forcing was the only important process in the recovery of the wake.

The Ocean Sciences Meeting served as a melting pot of ideas and collaborations, where Dr. Tandon, Sid, and countless other researchers (including former members and collaborators of Tandon Lab) exchanged knowledge and forged partnerships for future research in marine science.

Dr Tandon and his extended group consisting of collaborators, students, former students and post-docs.

Dr Tandon with some of EKAMSAT Team

In a pioneering mission, a group of researchers (including Dr Amit Tandon) participating the Monsoon Intra-Seasonal Oscillations in the Bay of Bengal (MISO-BOB) field campaign, funded by the US Office of Naval Research, has provided groundbreaking insights into the tropical supercluster dynamics over the equatorial Indian Ocean.

In a study led by Dr Phadtare from University of Notre Dame, observations were collected using a WC-130J aircraft operated by Air Force’s 53rd Weather Reconnaissance Squadron, which delved into the heart of the action during the summer monsoon seasons of 2018 . Dropsonde observations revealed a captivating variance of zonal winds within the supercluster. The upper troposphere favored easterlies, while the lower troposphere exhibited prevailing westerlies, creating a unique atmospheric stratification just below the 0°C level.

Of particular interest was the cold pool at the center of the supercluster. It maintained a consistent easterly component, with the coldest temperatures registering a 2.5°C drop at the center. The depth of the cold pool varied, reaching its deepest at the rear/western end and shallower at the front/eastern end, measuring at around 300 meters. A key revelation was the identification of the level of free convection (LFC) at the front end. On the eastern flank, researchers observed zonal convergence between the westerlies within the supercluster and ambient easterlies at lower tropospheric levels. This suggested the uplifting of conditionally unstable air parcels above LFC due to convergence, rather than the influence of the cold pool.

Conversely, the western flank exhibited low-level zonal divergence, further supporting the concept of ‘self-similarity’ between mesoscale convective systems and large-scale waves.

The MISO-BOB campaign’s findings provide a leap forward in our understanding of monsoon intra-seasonal oscillations. The data obtained from these aircraft observations holds promise for refining climate models and advancing our ability to predict tropical weather patterns, contributing to more effective global weather predictions in the future.

More information about this article can be found here. Congratulations Dr Phadtare and team!

A schematic of the observations taken by the WC130J aircraft in the supercluster. (Adapted from Figure 10 of Phadtare et al. 2024)

Sid with his poster

Dr. Amit Tandon and PhD students, Siddhant (Sid) Kerhalkar and Debarshi Sarkar, recently participated in the ‘Geophysical Flows: From the Field to the Lab- Workshop and Discussion Meeting’  at Chennai, India from January 05 to 09, 2024 (workshop) and January 10 to 12, 2024 (discussion meeting). This workshop and discussion meeting aimed to achieve two objectives: providing an improved understanding of the climate dynamics relevant to the Indian subcontinent to the scientific community actively engaged by the Geophysical Flows Lab at IIT Madras; and to train young scientists and researchers from across the globe, mentored by Indian and foreign researchers.

Debarshi with his poster

Sid and Dr. Tandon contributed to the discussion meeting with a presentation titled “Observations of Cyclone Biparjoy’s cold wake recovery”. Alongside participating in discussions, Sid and Debarshi presented posters on their research topics. Sid’s poster focused on “Lateral Gradients in Diurnal Warm Layers in the Bay of Bengal”, while Debarshi presented on “Air-Sea Reanalysis Flux Biases in the Arabian Sea: A Case Study from 2017-2018”. Additionally, both Sid and Debarshi were involved in group projects as a part of the workshop assigned by the group leaders and organizers. Sid worked on “Near-inertial Oscillations in the North Indian Ocean: A case study”, and Debarshi focused on “Evolution of SST Across Arabian Sea During May-June 2020”.

Sid and Debarshi are grateful to the workshop organizers for this opportunity. Their travel to attend this workshop were additionally funded by the various UMass Dartmouth travel grants as well as ONR.

We are thrilled to announce that Patrick Pasteris, a Master’s student in Tandon Lab, defended his master’s thesis on November 10, 2023. He worked on the Aurelia Upper Ocean Profiler (UOP), a revolutionary solution to the financial constraints plaguing upper ocean observations, for his thesis. Inspired by the Aurelia jellyfish genus, the Aurelia UOP is engineered for upper-ocean profiling within the top 200 meters, utilizing a unique buoyancy engine mechanism and integrating wireless connectivity.

Patrick’s journey with this profiler began with a 2016 Senior Capstone project, which saw the evolution of a groundbreaking idea into the Aurelia UOP. Mentoring five multidisciplinary Capstone teams and guided by Dr. Amit Tandon, Professor of Mechanical Engineering, alongside committee members Dr. Alice Pietri and Dr. John Buck, Pasteris successfully navigated the challenges of developing this affordable and user-friendly oceanic research device.

The Aurelia UOP Lite, the culmination of Patrick’s thesis research which involved a series of tank and ocean tests, is a compact 10lb device capable of reaching depths of 50m. This innovation not only signifies a significant milestone in oceanic research but also holds the promise of advancing weather forecasting and enhancing maritime safety through cost-effective upper ocean monitoring. The Aurelia UOP Lite stands as a testament to the power of interdisciplinary collaboration and ingenuity, paving the way for a new era in scientific exploration.

Congratulations Patrick!

Patrick (left) with his thesis committee members: Dr Amit Tandon (first from right), Dr John Buck (second from right) and Dr Alice Pietri (virtual)

Dr. Filipe Pereira was recently featured in the Feature stories section of UMassD. Find more about his motivating academic journey so far, which had its own challenges, as well as what the future holds for him here (including his upcoming appointment in Scripps Institution of Oceanography as a UC president’s fellow!).

Congratulations Filipe!

One of the Lab Alumni, Viktoriya Balabanova, recently spoke in an event to welcome 2023 ACCOMPLISH Scholarship Awardees and talk about the Scholarship. The ACCOMPLISH program from UMassD, funded by NSF, aims to provide a multi-faceted financial and social support and contextualized computing-centered educational framework for eligible STEM students to propel them into the nation’s high-quality STEM workforce. In her talk (video at the end of this article) , Vicky talks about how this award helped her to be inspired towards the importance of computational knowledge, work on such projects in Physics (including her BS thesis work in Tandon lab as a part of WHOI-UMassD Blue Economy internship) and graduate sooner. Vicky also talks about the procedure to apply for this scholarship. More about the program can be found here

(L-R) Sid Kerhalkar, Prof. Amit Tandon and Debarshi Sarkar with the R/V Roger Revelle docked in the Mormugao port.

Professor Amit Tandon, Siddhant (Sid) Kerhalkar (PhD candidate) and Debarshi Sarkar (incoming PhD student) were aboard the US research vessel Roger Revelle for the pilot cruise of EKAMSAT (Enhancing Knowledge of the Arabian Sea Marine Environment through Science and Advanced Training) in the Arabian Sea, June 09-26, 2023. EKAMSAT is a USA-India international collaboration. The USA team is funded by the US Office of Naval Research for the air-sea interaction, marine meteorology, and physical oceanography components, and the Indian team is funded by the Indian Ministry of Earth Sciences (MoES). During the pilot, the two teams worked collaboratively to understand the evolution of the mini-warm pool in the Arabian Sea and its connection to the Indian Summer Monsoon. In addition, three NASA-funded scientists also joined this cruise to examine the ocean ecosystem during this cruise.

After reaching Goa during the first week of June, the three of them were joined onboard by 20 other scientists from institutions such as the University of Washington, Scripps Institution of Oceanography, Woods Hole Oceanographic Institution, Columbia University, University of Notre Dame, Consiglio Nazionale delle Ricerche (Italy), NOAA Center for Weather and Climate Prediction, Penn State University, Whatcom Community College and Indian institutions  INCOIS, NIOT, NCMRWF, and IITM-Pune. The ship made port calls in Goa, India for this experiment, with Prof. Craig Lee from U of Washington as the chief scientist of the cruise. The ship left the Mormugao port on the night of June 08. 2023, while the Arabian sea was  being churned by cyclone Biparjoy resulting in a very high wave and wind state. To commemorate the beginning of the pilot cruise and the project, the ship was virtually flagged by the MoES secretary. Due to the passage of Tropical cyclone Biparjoy, the team shifted its target station southward from 14.6 N, 69 E (NIOT AD07 mooring) to 12.06 N, 67.75 E (100 km offshore of AD 08 mooring). This meant that the ship had a longer transit time, which was made tougher due to rough waves from the cyclone, making most of the members sea-sick for the initial few days.

Virtual flag-off of EKAMSAT cruises (Source: INCOIS Twitter)

In addition to learning how to operate out of Goa, the scientific goals of the pilot cruise were focused on understanding the processes that governed the evolution of stratification around the target station (one-dimensional versus the lateral processes) before obtaining clean simultaneous measurements of atmospheric variables and vertical ocean profiles to measure accurate air-sea fluxes, including the importance of waves and swell for these fluxes. In order to obtain clean atmospheric measurements, the ship needs to point into the wind. The passage of the cyclone also inspired secondary goals of understanding the role of waves in driving the mixing and sampling across the cyclone wake to unearth the processes behind restratifying the cold dense wake created by the cyclone .

Cruise Map of EKAMSAT Pilot 2023

(Clockwise from Top Left): A pretty sunset in Arabian Sea, Prof Tandon and Sid during the watch, CTD rosette underwater, CTD rosette being deployed, Science discussions in the hope of a rain event, uCTD probe underwater

This cruise was a major learning experience for the participating student members of Tandon lab: Sid and Debarshi. In addition to both of them participating in uCTD watches and helping with typical deployment-recovery of other gear when needed,  Sid was mostly in charge of preliminary processing and visualization of the ship through-flow, lower atmospheric variables, and wave data. Debarshi, who was participating in his first scientific cruise, was tasked to process and plot the profiles from the CTD casts. The data and ideas from this experiment will eventually be used for parts of their respective dissertations. Along with serving on watches, Professor Tandon provided overall guidance, as well as conceptual inputs to the cruise along with senior scientist Professor Janet Sprintall and Chief scientist Professor Craig Lee.

EKAMSAT Pilot Cruise 2023 Science Team

Sid also documented some of the science activities on the cruise using his action camera (see the video above). Overall, the cruise was very successful and the team members are now looking forward to analyzing the dataset and working on the science further.

Sid was recently featured in the Feature stories section of UMassD. Find more about his motivation for pursuing his doctoral dissertation in the Tandon Lab, his research interests, his participation in research cruises and his favorite things about the lab and UMassD in the article here.

Congratulations Sid!