@article {silver_spatial_2022,
	title = {Spatial variability of movement, structure, and formation of Warm Core Rings in the Northwest Atlantic Slope Sea},
	journal = {Journal of Geophysical Research - Oceans},
	volume = {127},
	number = {8},
	year = {2022},
	month = {aug},
	pages = {e2022JC018737},
	abstract = {Gulf Stream Warm Core Rings (WCRs) have important influences on the New England Shelf and marine ecosystems. A 10-year (2011{\textendash}2020) WCR dataset that tracks weekly WCR locations and surface areas is used here to identify the rings{\textquoteright} path and characterize their movement between 55 and 75{\textdegree}W. The WCR dataset reveals a very narrow band between 66 and 71{\textdegree}W along which rings travel almost due west along \~{}39{\textdegree}N across isobaths {\textendash} the {\textquotedblleft}Ring Corridor.{\textquotedblright} Then, west of the corridor, the mean path turns southwestward, paralleling the shelfbreak. The average ring translation speed along the mean path is 5.9~cm s-1. Long-lived rings (lifespan >150~days) tend to occupy the region west of the New England Seamount Chain (NESC) whereas short-lived rings (lifespan <150~days) tend to be more broadly distributed. WCR vertical structures, analyzed using available Argo float profiles indicate that rings that are formed to the west of the NESC have shallower thermoclines than those formed to the east. This tendency may be due to different WCR formation processes that are observed to occur along different sections of the Gulf Stream. WCRs formed to the east of the NESC tend to form from a pinch-off mechanism incorporating cores of Sargasso Sea water and a perimeter of Gulf Stream water. WCRs that form to the west of the NESC, form from a process called an aneurysm. WCRs formed through aneurysms comprise water mostly from the northern half of the Gulf Stream and are smaller than the classic pinch-off rings.},
	keywords = {aneurysm, Eddies, Gulf Stream, ring formation, trajectories, warm core rings},
	issn = {2169-9275},
	doi = {10.1029/2022jc018737},
	author = {Silver, Adrienne and Gangopadhyay, Avijit and Gawarkiewicz, Glen and Andres, Magdalena and Flierl, Glenn and Clark, Jenifer}
}
@article {RN201,
	title = {Interannual and seasonal asymmetries in Gulf Stream Ring Formations from 1980 to 2019},
	journal = {Scientific Reports},
	volume = {11},
	number = {1},
	year = {2021},
	pages = {2207},
	type = {Journal Article},
	abstract = {As the Gulf Stream separates from the coast, it sheds both Warm and Cold Core Rings between 75o and 55oW. We present evidence that this ring formation behavior has been asymmetric over both interannual and seasonal time-scales. After a previously reported regime-shift in 2000, 15 more Warm Core Rings have been forming yearly compared to 1980{\textendash}1999. In contrast, there have been no changes in the annual formation rate of the Cold Core Rings. This increase in Warm Core Ring production leads to an excess heat transfer of 0.10 PW to the Slope Sea, amounting to 7.7{\textendash}12.4\% of the total Gulf Stream heat transport, or 5.4{\textendash}7.3\% of the global oceanic heat budget at 30oN. Seasonally, more Cold Core Rings are produced in the winter and spring and more Warm Core Rings are produced in the summer and fall leading to more summertime heat transfer to the north of the Stream. The seasonal cycle of relative ring formation numbers is strongly correlated (r = 0.82) with that of the difference in upper layer temperatures between the Sargasso and Slope seas. This quantification motivates future efforts to understand the recent increasing influence of the Gulf Stream on the circulation and ecosystem in the western North Atlantic.},
	doi = {10.1038/s41598-021-81827-y},
	url = {https://app.dimensions.ai/details/publication/pub.1134854819 https://doi.org/10.1038/s41598-021-81827-y},
	author = {Silver, Adrienne and Gangopadhyay, Avijit and Gawarkiewicz, Glen and Silva, E. Nishchitha S. and Clark, Jenifer}
}
@article {RN167,
	title = {A Census of the Warm Core Rings of the Gulf Stream: 1980-2017},
	journal = {Journal of Geophysical Research Oceans},
	year = {2020},
	type = {Journal Article},
	abstract = {A census of Gulf Stream (GS) warm-core rings (WCRs) is presented based on 38 years (1980{\textendash}2017) of data. The census documents formation and demise times and locations, and formation size for all 961 WCRs formed in the study period that live for a week or more. A clear regime shift was observed around the Year 2000 and was reported by a subset of authors (Gangopadhyay et al., 2019, https://doi.org/10.1038/s41598-019-48661-9). The WCR formation over the whole region (75{\textendash}55{\textdegree}W) increased from an average of 18 per year during Regime 1 (1980{\textendash}1999) to 33 per year during Regime 2 (2000{\textendash}2017). For geographic analysis formation locations were grouped in four 5{\textdegree} zones between 75{\textdegree}W and 55{\textdegree}W. Seasonally, WCR formations show a significant summer maxima and winter minima, a pattern that is consistent through all zones and both temporal regimes. The lifespan and size distribution show progressively more rings with higher longevity and greater size when formed to the east of 70{\textdegree}W. The average lifespan of the WCRs in all four zones decreased by 20{\textendash}40\% depending on zones and/or seasons from Regime 1 to Regime 2, while the size distribution remained unchanged across regimes. The ring footprint index, a first-order signature of impact of the WCRs on the slope, increased significantly (26{\textendash}90\%) for all zones from Regime 1 to Regime 2, with the highest percent increase in Zone 2 (70{\textendash}65{\textdegree}W). This observational study establishes critical statistical and dynamical benchmarks for validating numerical models and highlights the need for further dynamical understanding of the GS-ring formation processes.},
	doi = {10.1029/2019jc016033},
	url = {https://app.dimensions.ai/details/publication/pub.1128843160},
	author = {Gangopadhyay, Avijit and Gawarkiewicz, Glen and Silva, E. Nishchitha S. and Silver, Adrienne M. and Monim, M. and Clark, Jenifer}
}
@article {RN100,
	title = {An Observed Regime Shift in the Formation of Warm Core Rings from the Gulf Stream},
	journal = {Scientific Reports},
	volume = {9},
	number = {1},
	year = {2019},
	pages = {12319},
	type = {Journal Article},
	abstract = {We present observational evidence that a significant regime change occurred around the year 2000 in the formation of Warm Core Rings (WCRs) from the Gulf Stream (GS) between 75{\textdegree} and 55{\textdegree}W. The dataset for this study is a set of synoptic oceanographic charts available over the thirty-eight-year period of 1980{\textendash}2017. The upward regime change shows an increase to 33 WCRs per year during 2000{\textendash}2017 from an average of 18 WCRs during 1980 to 1999. A seasonal analysis confirms May-June-July as the peak time for WCR births in agreement with earlier studies. The westernmost region (75{\textdegree}-70{\textdegree}W) is least ring-productive, while the region from 65{\textdegree}W to 60{\textdegree}W is most productive. This regime shift around 2000 is detected in WCR formation for all of the four 5-degree wide sub-regions and the whole region (75{\textdegree}-55{\textdegree}W). This might be related to a reduction of the deformation radius for ring formation, allowing unstable meanders to shed more frequent rings in recent years. A number of possible factors resulting in such a regime shift related to the possible changes in reduced gravity, instability, transport of the GS, large-scale changes in the wind system and atmospheric fluxes are outlined, which suggest new research directions. The increase in WCRs has likely had an impact on the marine ecosystem since 2000, a topic worthy for future studies.},
	issn = {2045-2322},
	doi = {10.1038/s41598-019-48661-9},
	url = {https://doi.org/10.1038/s41598-019-48661-9},
	author = {Gangopadhyay, Avijit and Gawarkiewicz, Glen and Silva, E. Nishchitha S. and Monim, M. and Clark, Jenifer}
}
