@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}
}
