Research Themes – Ke Chen

The Coastal Ocean and Global Climate

Recent studies suggest that extreme climate events in the climate system are increasing globally, and the coastal ocean is not an exception. An unprecedented extreme warm anomaly (later also known as Marine Heatwaves) in 2012 on the Northwest Atlantic shelf resulted in major impacts to the marine ecosystem and commercial fisheries and garnered attention from academia, government agencies, the fishing industry and the general public. With global climate change, there is a growing need to understand better climate problems in the coastal ocean, which is directly relevant to society.

Selected Publications:

Chen, K., G. G. Gawarkiewicz, S. J. Lentz, and J. M. Bane, 2014a: Diagnosing the warming of the Northeastern U.S. Coastal Ocean in 2012: A linkage between the atmospheric jet stream variability and ocean response. Journal of Geophysical Research: Oceans, 119, 218-227.

Chen, K., G. Gawarkiewicz, Y.-O. Kwon, and W. G. Zhang, 2015: The role of atmospheric forcing versus ocean advection during the extreme warming of the Northeast U.S. continental shelf in 2012. Journal of Geophysical Research: Oceans, 120, 4324-4339.

Chen, K., Y.-O. Kwon, and G. Gawarkiewicz, 2016: Interannual variability of winter-spring temperature in the Middle Atlantic Bight: Relative contributions of atmospheric and oceanic processes. Journal of Geophysical Research: Oceans, 121, 4209-4227.

Chen, K., and Y.-O. Kwon, 2018: Does Pacific Variability Influence the Northwest Atlantic Shelf Temperature? Journal of Geophysical Research: Oceans, 123, 4110-4131.

Gawarkiewicz, G., K. Chen, J. Forsyth, F. Bahr, A. M. Mercer, A. Ellertson, P. Fratantoni, H. Seim, S. Haines, and L. Han, 2019: Characteristics of an advective marine heatwave in the Middle Atlantic Bight in early 2017. Frontiers in Marine Science, 6, 712.

Schlegel, R. W., E. C. J. Oliver, and K. Chen, 2021: Drivers of Marine Heatwaves in the Northwest Atlantic: The Role of Air-Sea Interaction During Onset and Decline. Frontiers in Marine Science, 8.

Chen, K., G. Gawarkiewicz, and J. Yang, 2022: Mesoscale and Submesoscale Shelf-Ocean Exchanges Initialize an Advective Marine Heatwave. Journal of Geophysical Research: Oceans, 127, e2021JC017927.

Shelf Circulation and Shelfbreak Exchange

The exchange of waters between the coastal and open ocean at the shelfbreak has been one of the most important topics in coastal oceanography and my own research portfolio. We have worked on shelfbreak circulation dynamics and related shelf-slope exchange in the coastal ocean of the Northwest Atlantic, with a focus on the Middle Atlantic Bight (MAB) shelfbreak region. This is an area where the shelfbreak front and jet exert a strong influence on the transport and exchange of water masses between the coastal and open ocean.

Selected Publications:

Chen, K., and R. He, 2010: Numerical Investigation of the Middle Atlantic Bight Shelfbreak Frontal Circulation Using a High-Resolution Ocean Hindcast Model. Journal of Physical Oceanography, 40, 949-964.

Chen, K., and R. He, 2015: Mean circulation in the coastal ocean off northeastern North America from a regional-scale ocean model. Ocean Sci., 11, 503-517.

Chen, K., G. Gawarkiewicz, and J. Yang, 2022: Mesoscale and Submesoscale Shelf-Ocean Exchanges Initialize an Advective Marine Heatwave. Journal of Geophysical Research: Oceans, 127, e2021JC017927.

Chen, K., and J. Yang, 2024: What Drives the Mean Along-shelf Flow in the Northwest Atlantic Coastal Ocean, Journal of Geophysical Research: Oceans, 129, e2024JC021079.

Chen, K., 2024: A Hotspot and Mechanism for Enhanced Bottom Intrusion on the Southern New England Shelf, Environmental Research Communications, 6, 071008.

Mesoscale Eddies and the Shelf-Slope Environment

Ocean mesoscale processes and their impact on the physical environment and ecosystem are an important topic. In the Northwest Atlantic, large and energetic mesoscale eddies called warm-core rings (WCRs) are shed from the Gulf Stream and interact with the slope and shelf circulation. These eddies can significantly alter the physical and biogeochemical environment from the open ocean to the shelf.

Selected Publications:

Chen, K., R. He, B. S. Powell, G. G. Gawarkiewicz, A. M. Moore, and H. G. Arango, 2014b: Data assimilative modeling investigation of Gulf Stream Warm Core Ring interaction with continental shelf and slope circulation. Journal of Geophysical Research: Oceans, 119, 5968-5991.

Chen, K., G. Gawarkiewicz, and A. J. Plueddemann, 2018: Atmospheric and offshore forcing of temperature variability at the shelf break: Observations from the OOI Pioneer Array. Oceanography, 31, 72-79.

Chen, K., P. Gaube, and E. Pallàs-Sanz, 2020: On the Vertical Velocity and Nutrient Delivery in Warm Core Rings. Journal of Physical Oceanography, 10.1175/jpo-d-1119-0239.1171.

Shelf-Slope Interdisciplinary Processes

Many oceanographic topics are interdisciplinary in nature and that examining the same phenomenon from different angles will help develop a more comprehensive understanding. This is particularly the case for the coastal ocean, where many physical processes are closely coupled with biological and biogeochemical processes.

Selected Publications:

He, R., K. Chen, T. Moore, and M. Li, 2010: Mesoscale variations of sea surface temperature and ocean color patterns at the Mid-Atlantic Bight shelfbreak. Geophysical Research Letters, 37, doi:10.1029/2010gl042658.

He, R., K. Chen, K. Fennel, G. G. Gawarkiewicz, and D. J. McGillicuddy Jr, 2011: Seasonal and interannual variability of physical and biological dynamics at the shelfbreak front of the Middle Atlantic Bight: nutrient supply mechanisms. Biogeosciences, 8, 2935-2946.

Ning, J., K. Chen, and P. Gaube, 2021: Diverse Variability of Surface Chlorophyll During the Evolution of Gulf Stream Rings. Geophysical Research Letters, 48, e2020GL091461.