Physical Oceanographer

See my full cv <here>.

about me

I am a physical oceanographer with a keen interest in studying ocean circulation, vertical stratification, mixing, coupling between ocean, atmosphere and sea ice, upper ocean temperature and salinity distribution, and their control on earth's past, present and future climate, its variations and predictions. I want to use in situ and remote observations along with coupled Earth System Model (ESM) simulations to improve our understanding of the climate system.

My Engineering Bachelor’s degree in Computer Science has immensely contributed to my personal and professional development by giving me opportunities to work on advanced research problems. During my undergraduate degree in engineering, I got interested in numerical modeling, which led me to the exciting field of physical oceanography. After receiving my Bachelors degree, I joined the Indian Institute of Science (IISc) in India to work as a Project Assistant at the Center for Atmospheric and Oceanic Sciences (CAOS) to gain knowledge and experience in the fascinating field of Oceanography. I chose to shift to a completely new field because Oceanography combines my two favorite subjects, applied physics and numerical modeling to study fascinating and important mathematical problems in Earth’s climate system. I worked on a project to study the diurnal to inter-annual variability of the Indian Summer Monsoon. I also gained sea going experience with this project on the O.R.V. Sagar Kanya, a deep-sea ocean research vessel, as part of a multi-year study of response of the upper ocean to tropical cyclones in the Bay of Bengal.

These experiences led me to get a Masters degree in Physical Oceanography from Memorial University in Newfoundland, Canada. I got the opportunity to study the largest ocean waves in the world called internal waves. They are named so because they occur in the interior of the ocean, invisible to the naked eye and are responsible for transferring heat, salt and nutrients around the ocean. My masters research was on understanding the energy flux of internal wave reflecting off continental shelf topography with my supervisor, Dr. James Munroe.

After getting my Masters I moved to the US where I received my PhD in Physical Oceanography at Texas A&M University under the supervision of Dr. Achim Stössel aiming to improve the representation of the high-latitude Southern Ocean in Coupled Earth System Models (CESM) by studying the formation mechanism of open ocean polynyas in the Weddell Sea.

I worked as a postdoc at the Center for Nonlinear Studies (CNLS) at the Los Alamos National Laboratory (LANL). I worked on projects studying a) Bjerknes compensation in a changing climate, b) Bathymetric effects on Southern Ocean convection and on bottom water in E3SM and c) Open ocean polynyas in the Southern Ocean and its impact on the deep ocean. Most recently, my research activities were highlighted in an atmospheric, oceanic, hydrologic research issue of a science communication publication, Scientia (https://doi.org/10.33548/SCIENTIA808).

I recently started a new position at Johns Hopkins University as the Dr. George S. Benton Postdoctoral Fellow in the Department of Earth and Planetary Sciences where I will be working with Thomas Haine and Anand Gnanadesikan to study and quantify the effects of antropogenic warming on the polar oceans.

@ Los Alamos national laboratory

Research: Bjerknes compensation (BjC) on decadal to longer timescales across the Coupled Model Intercomparison Project Phase 6 (CMIP6) experiments to identify critical processes contributing to the inter-model spread of BJC and the role of sea ice and cloud feedbacks in the Arctic Ocean

The term BJC is used to describe the hypothesis that atmospheric and oceanic heat transport variations balance each other, given that the fluxes at the top of the atmosphere and ocean heat content remain approximately constant. BJC on decadal to longer timescales is present across multiple simulations in the piControl experiment (with preindustrial forcing) as seen through significant anti-correlation between atmospheric and oceanic heat transport across 65°N. I am currently in the process of submitting a manuscript summarizing my research on understanding the mechanisms of Arctic Bjerknes Compensation in (CMIP6) 'pre-industrial' experiment. I developed analysis metrics to understand how sea ice and clouds uniquely modify the radiative balance of the polar atmosphere and their opposing impacts on longwave and shortwave radiation budgets. Bjerknes compensation is significantly reduced in the 21st century, as seen across simulations in the historical and abrupt-4XCO2 experiments (CO2 is abruptly quadrupled and then held constant). Subsequently, I am also studying the mechanisms responsible for weakening Bjerknes compensation in the Arctic (in the historical and abrupt-4×CO2 experiments) and formulating a second manuscript is also a major focus over the next few months.

As a polar oceanographer, I believe the work of climate scientists is two-fold, one, studying a changing climate, and two, effectively communicating them to the public. Strong communication improves understanding and enables scientists to communicate complex results, which can significantly increase the impact of our science. I was part of a project to highlight the role of polynyas in modulating the earth's mesoscale motions using high-resolution simulations. The resulting narrated animation and the conference paper were submitted to Scientific Visualization and Data Analytics Showcase (https://sc21.supercomputing.org/proceedings/sci_viz/sci_viz_pages/svs106.html).

@ texas a&M university

research: Processes responsible for preconditioning and triggering open ocean deep convection in Community earth system models

My advisor Dr. Achim Stossel and I worked with the Climate Ocean Sea Ice Modeling (COSIM) group at Los Alamos National Laboratory (LANL) to study processes associated with open ocean polynya and their representation in ocean models by analyzing ocean, sea-ice, atmosphere fields from a high-resolution eddy-resolving fully-coupled (ocean-sea ice-atmosphere-land) CESM simulation.

Open-Ocean Polynyas (OOPs) in the Southern Ocean are sea-ice free areas within the winter ice pack that are associated with deep convection, potentially contributing to the formation of Antarctic Bottom Water. It has been speculated that such formed intermittently before the 1970’s, when the atmospheric CO2 concentration was lower than today. While fully-coupled simulations with coarse-resolution versions of the Community Earth System Model (CESM) show no signs of OOP formation, realistic OOPs emerge in high-resolution CESM simulations.

My focus was on understanding the role of poleward shifting westerlies on the circulation and stratification of the Southern Ocean influencing polynya formation, deep convection, and mixing (Kurtakoti et al. 2018, 2021). I studied the interaction between small-scale dynamics and large-scale features of the ocean circulation, such as Taylor cap dynamics in the Weddell Sea, and their role in the Southern Ocean ventilation, ocean mixing, and deep convection. We found, while the formation of Maud Rise Polynyas (MRPs; open ocean polynyas associated with a prominent seamount in the eastern Weddell Sea) requires high resolution to simulate the detailed flow around Maud Rise, a realistic simulation of large Weddell Sea Polynyas (WSPs) requires the ability of a model to produce MRPs.

@ Memorial University of Newfoundland

Research : Understanding the energy flux of internal waves reflecting  off continental shelf topography

My masters research was on studying internal gravity waves with my supervisor, Dr. James Munroe. The time I spent here was what made me go for a PhD. Working in a fluids lab is so much fun !!

1. I used Python for all the scientific calculations and data analysis purposes. The early models of the wave generator were built using LEGOs :P We also designed and built the tank ourselves..! and stress tested it using SOLIDWORKS to make sure we wouldn't flood the building. The python package to perform Synthetic Schlieren was also homegrown since we couldn't pay for the commercial software !!!

2. To understand mechanisms involved in the evolution and interaction of internal waves with sloping topography (subcritical,critical and supercritical), we performed a series (LOTS and LOTS!) of laboratory experiments to study the energy flux of internal waves in a continuously stratified salt water fluid.

   • The internal waves were generated by a wave generator that is capable of producing monochromatic, vertically trapped waves (L. Gostiaux, H. Didelle, S. Mercier, and T. Dauxois (2007)). The wave generator consists of a series of vertically stacked plates which are controlled by a camshaft and the camshaft can be precisely controlled to rotate at different frequencies generating internal waves of different modes.

   • These internal waves propagate along the length of the tank (~5m) and reflect off a sloping boundary wall. The slope of the boundary can be critical, subcritical or super critical.

   • The structure and amplitude of the internal waves are measured using a non intrusive flow visualization technique called ‘Synthetic Schlieren’ that enables us to measure the amplitude and energy of the waves (B. R. Sutherland, S. B. Dalziel, G. O. Hughes and P. F. Linden (1999)). We measured the vertical displacement amplitude and energy flux of the internal waves varying independently the frequency of the wave generator, stratification of the fluid and angle of the sloping boundary wall.

   • Using Hilbert transform we separated the generated waves and the reflected waves to estimate energy from the incoming waves is present in the reflected internal waves (M. J. Mercier, N. B. Garnier, and T. Dauxois (2008)). The analysis of the energy flux of the internal waves during propagation and reflection using the Hilbert transform is helpful as it brings insight into phenomena that are difficult to observe during field studies.

   • I presented the preliminary findings at the 66th Annual Meeting of the American Physical Society's Division of Fluid Dynamics held in Pittsburgh, USA from Nov 24 -26, 2013 (http://meetings.aps.org/Meeting/DFD13/Session/G1.9). Our paper on the research done here is in preparation.

Teaching

Graduate Teaching Assistant                                                   

1. OCNG 252: Introduction to Oceanography LAB (Fall 2015; Fall 2016; Spring 2017; Spring 2019)

   Department of Oceanography, Texas A&M University, USA

2. GEOS 405: Environmental Geosciences (Fall 2018)

   Department of Oceanography, Texas A&M University, USA

3. Physics 1051 − General Physics Laboratory (Fall 2011 - 2014)

   Department of Physics, Memorial University of Newfoundland, Canada

4. Physics 1020 − General Physics Laboratory (Fall 2011 - 2014)

   Department of Physics, Memorial University of Newfoundland, Canada

Journal Publications

1. Kurtakoti, P, Veneziani, M, Stoessel, A,Weijer, W, Maltrud, M. “On the Generation of Weddell Sea Polynyas in a High-Resolution Earth System Model." Journal of Climate 34.7 (2021): 2491-2510

2. Kurtakoti, P., Veneziani, M., Stössel, A., & Weijer, W. (2018). “Preconditioning and Formation of Maud Rise Polynyas in a High-Resolution Earth System Model”. Journal of Climate, 31(23), 9659-9678. https://doi.org/10.1175/JCLI-D-18-0392.1

3. Pandey, V. K., & Kurtakoti, P. (2014). “Evaluation of GODAS Using RAMA Mooring Observations from the Indian Ocean”. Marine Geodesy, 37(1), 14-31. https://doi.org/10.1080/01490419.2013.859642

4. Weijer, W, Haine, T.W.N. Siddiqui, A.H, Cheng, W, Veneziani, M, Kurtakoti,P. “Interactions between the Arctic and the AMOC: A Review." Oceanography 35.3/4 (2022): 118-127. https://www.jstor.org/stable/27182704

5. Kurtakoti, P., Weijer, W., Veneziani, M., Rasch, P., Verma, T. “Compensation between Poleward Atmospheric and Oceanic Heat Transports in CMIP6 Climate Simulations" Journal of Climate, In Revision (2023).