2021 2021: Researchers shed light on the effects of ring formation
Researchers shed light on the effects of ring formation

A new study explores how the formation of cold core rings and warm core rings from the Gulf Stream has changed over the last 40 years and might have long-term effects on the ecosystem.

Core rings courtesy of Adrienne Silver
Interannual variability of the Warm Core Ring and Cold Core Ring formation between 1980 and 2019. The regime shift (denoted by the split in the red solid line) for the Warm Core Rings is significant at the turn of the century. Note the phase change from “More Cold Core Rings—Fewer Warm Core Rings” to “More Warm Core Rings—Fewer Cold Core Rings” after the year 2000. The average formation rates for different time-periods are indicated within the figure (image courtesy of Adrienne Silver).

A recent study conducted by researchers at UMass Dartmouth explores the formation rates of cold core rings vs. warm core rings in the Gulf Stream based on temporal and geographical patterns over last 40 years. The study examines how the seasonal and interannual patterns of the formation of these rings are asymmetric, which resulted in excess heat input to the continental shelf and slope waters in the northeast US and Canada. This excess heat transfer might have lasting effects on the ecosystem and storms, including the impact on fisheries, weather, and climate.

Dr. Avijit Gangopadhyay, Professor of Estuarine and Ocean Sciences at UMass Dartmouth’s School for Marine Science & Technology, co-authored the study with Senior Scientist Glen Gawarkiewicz of the Woods Hole Oceanographic Institution along with SMAST PhD student Adrienne Silver, who is the lead author. Other authors are E. Nishchitha S. Silva (from Boston University), and Jenifer Clark (Gulf Stream Analyst). Their research delves into understanding the seasonal and inter-annual variability of Gulf Stream warm core rings for nearly four decades, from 1980-2019.

Finding results involved developing a database based on Gulf Stream charts as well as documenting their own observations, observations by previous analysts, and applying survival analysis technique (a method employed in medical statistics). Read the full scope of the study titled “Interannual and seasonal asymmetries in Gulf Stream Ring Formations from 1980 to 2019,” in Nature Scientific Reports.