Sea Level Variability, Marine Extreme Events & Climate Model Diagnostics at AER–JANUS Research Group

As a Senior Research Associate I at Atmospheric and Environmental Research (AER), now a business unit within the JANUS Research Group, I conducted oceanographic research across multiple fronts funded by the National Science Foundation (NSF), the National Oceanic and Atmospheric Administration (NOAA), and the National Aeronautics and Space Administration (NASA). AER is a world-class research and development organization founded in 1977 whose scientists support agencies including NOAA, NASA, and the Department of Defense, as well as major insurance, investment, and energy firms in understanding, forecasting, and managing weather and climate-related risks.

Sea Level Variability in the Pacific Ocean

A central focus of my work at AER was investigating the physical processes driving low-frequency sea level variability in the Pacific Ocean. Using multi-decadal reanalysis datasets, output from the ECCO (Estimating the Circulation and Climate of the Ocean) ocean circulation model, and long-term tide-gauge observations, I analyzed the large-scale ocean and climate interactions that governed coastal sea level on seasonal-to-decadal timescales. This work contributed to an NSF-funded project aimed at identifying the processes controlling the representation of coastal sea level in climate models — with direct implications for coastal flood risk assessment and infrastructure planning. A companion NOAA-funded project examined how ocean model resolution influenced seasonal-to-annual U.S. coastal sea level forecasts, where my expertise in Gulf Stream dynamics and Warm Core Ring propagation was central to understanding how these features were represented — and misrepresented — across different model configurations.

In parallel, I analyzed ocean bottom pressure variability in NASA’s GRACE (Gravity Recovery and Climate Experiment) satellite gravity datasets alongside ECCO model outputs, characterizing mass redistribution signals in the ocean that were linked to sea level change and coastal hazard exposure. This work also contributed to a pan-Pacific study on low-frequency modes of sea level and climate variability, published in Science Advances (2025).

NOAA Model Diagnostics Task Force (MDTF) Framework

I led AER’s efforts to develop and implement a suite of sea level process-oriented diagnostics within the NOAA Model Diagnostics Task Force (MDTF) framework — a collaborative infrastructure used for the assessment of NOAA’s research and operational climate models. This work involved full-stack development in Python across multiple programming contexts: understanding the framework’s backend architecture, building and testing new diagnostic modules, and debugging alongside MDTF developers at NOAA. My expertise was later extended to a second MDTF project within AER’s Modeling and Advanced Remote Sensing Group on low-level jet diagnostics, demonstrating the cross-disciplinary transferability of this model evaluation work.

Marine Extreme Events — Predictability, Consequences & NASA PACE

I led research proposal development at AER on two emerging fronts. The first focused on marine extreme events — specifically Marine Heatwaves (MHWs), their formation mechanisms, ecological and economic consequences, and the degree to which they were predictable on seasonal-to-decadal timescales. This built directly on my doctoral work linking the Kuroshio Extension to Northeast Pacific MHW formation. The second involved leveraging data from NASA’s PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) mission — a recently launched ocean color satellite — to provide high-resolution snapshots of marine primary productivity as a monitoring tool during heat extremes, offering a new observational window into the ecosystem consequences of ocean warming.

Kuroshio Extension, North Pacific Atmosphere & Northeast Pacific Marine Heatwaves

My doctoral dissertation research at Boston University investigated how the Kuroshio Extension (KE) — the North Pacific’s western boundary current — influences large-scale atmospheric circulation and drives extreme marine events. Using high-resolution sea surface temperature data (OSTIA SST), atmospheric reanalysis (ERA5, NCEP/NCAR), and empirical methods including EOF analysis, spatial filtering, lead-lag regression, and Granger causality analysis, I discovered that it is the second mode of large-scale KE variability — a meridional sea surface temperature gradient across the KE region — that sets up the north-south phase of the Pacific Decadal Precession (PDP), a quasi-decadal counterclockwise progression of atmospheric pressure anomalies over the North Pacific. This KE-driven atmospheric pattern further intensifies the subtropical jet stream and modifies downstream stationary wave propagation, giving rise to the east-west phase of the PDP — with downstream consequences including droughts in the Northwest U.S., temperature extremes across North America, and marine heatwaves along both U.S. coasts.

Building on this, I demonstrated that the same large-scale KE variability is linked to the formation of Marine Heatwaves (MHWs) in the Northeast Pacific through an atmospheric teleconnection — with the KE modifying sea-level pressure, wind stress, and mixed layer depth in the Gulf of Alaska region. This work provided the first causal explanation connecting the Kuroshio Extension to the 2013–2015 Northeast Pacific Marine Heatwave (“The Blob”), a catastrophic event that caused over $800M in direct economic losses to fisheries, aquaculture, and coastal industries across the U.S. West Coast. The link extends further into marine biogeochemistry, with KE variability shown to suppress nutrient flux and primary productivity in the region during warming events.

In the final chapter of my dissertation, conducted in collaboration with NCAR’s Climate and Global Dynamics Lab during my NCAR Earth System Science Internship, I investigated how these KE–PDP–MHW links evolve in a changing climate using the high-resolution Community Earth System Model (CESM1.3-HR) under pre-industrial, historical, and RCP8.5 future emission scenarios on NCAR’s Linux supercomputing infrastructure. The model successfully reproduces the observed KE–PDP coupling, and future simulations suggest a diminished KE influence on MHW formation in the Northeast Pacific under continued warming — with important implications for long-range climate hazard projections.

Gulf Stream Warm Core Rings — Regime Shifts, Variability, and Survival

My M.S. thesis research at UMass Dartmouth produced the first-ever comprehensive 38-year census of Gulf Stream Warm Core Rings (WCRs) — mesoscale ocean eddies that pinch off from the Gulf Stream north of the current’s path and play a critical role in heat and salt transport, nutrient cycling, and the marine ecosystem of the U.S. Northeast shelf. Using GIS-based analysis of nearly four decades of NOAA synoptic Gulf Stream charts, I digitized and geo-coded the formation dates, demise dates, locations, and sizes of every WCR from 1980 to 2017 — a dataset that has since become a foundational resource for subsequent research programs at NOAA and WHOI.

From this dataset I discovered a striking regime shift around the year 2000: the average annual formation of Warm Core Rings nearly doubled, from ~18 rings per year (1980–1999) to ~33 rings per year (2000–2017). This finding, published in Scientific Reports, has been cited over 111 times and highlighted in NOAA’s Northeast Fisheries Science Center State of the Ecosystem reports for five consecutive years (2020–2024), directly informing fisheries management policy for the U.S. East Coast. The regime shift has since been linked by other researchers to elevated salinity intrusions on the Northeast U.S. shelf, shifts in commercial fish habitat, and intensified coastal warming — with coverage in the Washington Post and USA Today.

I also pioneered the application of survival analysis — a statistical method widely used in medical research — to quantify ocean eddy lifespan as a function of formation zone, season, latitude, and proximity to the New England Seamount Chain. This cross-domain methodological innovation has been adopted in NOAA National Marine Fisheries Service stock assessments for the northern shortfin squid fishery, which generates over $21.9M in direct income and ~$243M in total economic output annually for New England and Mid-Atlantic states.

Dugong and Seagrass Conservation in the Gulf of Mannar

As a consultant with the IUCN Sri Lanka Office, I contributed to a cross-national Dugong and Seagrass Conservation project in the Indian Ocean. I developed and supplied spatial and ecological inputs for the designation of a new marine protected area (MPA) in the Gulf of Mannar, and designed and executed a structured community survey across Gulf of Mannar and Palk Bay fishing communities to quantify attitudes toward conservation — translating field data into formal policy inputs submitted to the IUCN Sri Lanka Office.

Multi-Purpose Water Infrastructure Management in Central Asia

As part of my work with the International Water Management Institute (IWMI), I developed a structured repository of multi-purpose water infrastructure case studies for use as inputs to a policy model for reservoir management in Kazakhstan. This work involved synthesizing diverse field evidence into a standardized, decision-maker-ready format to support integrated water resource governance across the region.

Water Resources Management in South Asia and East Africa

At IWMI Sri Lanka, I analyzed hydrological datasets across ten climate change scenarios generated from a SWAT (Soil and Water Assessment Tool) model to assess the impacts of future climate change on water availability in the Tana River basin, Kenya — contributing to IWMI Working Paper No. 178. I also assessed the potential for conjunctive use of groundwater and surface water for irrigation in an agricultural development scheme in North-Central Sri Lanka, and built and processed a geo-coded agro-well database to calculate potential cropping intensities across the region. In parallel, I contributed to a case study on the ecological impacts of small-scale hydropower development on mountain stream ecosystems in Sri Lanka, work that informed a published handbook on small hydropower and environmental management.