URI oceanographers reveal links between migrating Gulf Stream and warming ocean waters

UNIVERSITY OF RHODE ISLAND

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IMAGE
IMAGE: AN ANIMATED MAP AND TIME SERIES (SAME COLOR CONVENTION) OF THE 2008 TEMPERATURE ANOMALY ON THE NORTHWEST ATLANTIC SHELF, HIGHLIGHTING THE RAPID WARMING IN THE MOST RECENT DECADE. view more CREDIT: (ANIMATION BY AFONSO GONÇALVES NETO)

KINGSTON, R.I., — April 20, 2021 — The Northwest Atlantic Shelf is one of the fastest-changing regions in the global ocean, and is currently experiencing marine heat waves, altered fisheries and a surge in sea level rise along the North American east coast. A new paper, “Changes in the Gulf Stream preceded rapid warming of the Northwest Atlantic Shelf,” published in Communications Earth & Environment by recent URI Graduate School of Oceanography graduate Afonso Gonçalves Neto reveals the causes, potential predictability and historical context for these types of rapid changes.

“We used satellite data to show that when the Gulf Stream migrates closer to the underwater plateau known as the Grand Banks of Newfoundland, as it did after 2008, it blocks the southwestward transport of the Labrador Current that would otherwise provide cold, fresh, oxygen-rich water to the North American shelf,” said lead author Gonçalves Neto. This mechanism explains why the most recent decade has been the hottest on record at the edge of the Northeast United States and Canada, as the delivery system of cold water to the region got choked off by the presence of the Gulf Stream.

The URI research team noted the importance of finding that the satellite-observed signature of the Gulf Stream’s position relative to the Grand Banks precedes subsurface shelf warming by over a year. “By monitoring satellite observations for changes near the Grand Banks, we can predict changes coming to the Northeast U.S. shelf with potentially enough lead time to inform fishery management decision-making,” said GSO graduate student and co-author Joe Langan.

The Grand Banks of Newfoundland is hardly a stranger to attention. It was near this feature that an iceberg sank the R.M.S. Titanic, one impetus for creation of the International Ice Patrol. The Ice Patrol has been collecting oceanographic data in this region for over a century, allowing the URI team to put recent satellite observations in a much longer-term context. Though the 2008 shift at the edge of the Grand Banks created warmer and saltier conditions than ever recorded since 1930, there was a similar shift in the 1970s relative to the decades preceding it. Thus, the circulation change directly observed by satellites might have had a precedent about 50 years ago.

Jaime Palter, GSO associate professor of oceanography and co-author of the study, marveled at the long record, and what remains unknown. “We still don’t know what caused the abrupt shift of the circulation near the Grand Banks inferred in the 1970s and observed in 2008, or whether this is the new normal for the circulation and the temperatures of the northeast shelf,” said Palter. “There are modeling studies that suggest that a slowdown of the Atlantic Meridional Overturning Circulation can cause the types of changes we observed, but the connection remains to be made in the observational record.”

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The Atlantic Meridional Overturning Circulation or AMOC is a system of currents that delivers warm ocean waters to northern regions, contributing to the warm climate of Scandinavia and influencing a broad array of northern hemisphere weather phenomena. Climate models show the AMOC circulation slowing if greenhouse gas emissions continue unabated, which–if the link is proven–would continue altering the Northeast U.S. and Canadian shelf waters and impacting fisheries in the future.

From EurekAlert!

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April 20, 2021 2:10 pm

I read several papers, AMOC is stable within minor variability contradicting the Rahmstorf papers showing always slowing AMOC

garboard
April 20, 2021 2:23 pm

why would a weaker/ slower amoc cause it to expand vis a vis the Labrador current ? seems like if it were weaker then the Labrador current would push it more south and east ?

garboard
Reply to  garboard
April 21, 2021 5:19 am

maybe the Labrador current weakened ?

ATheoK
April 20, 2021 2:35 pm

“We used satellite data to show that when the Gulf Stream migrates closer to the underwater plateau known as the Grand Banks of Newfoundland, as it did after 2008, it blocks the southwestward transport of the Labrador Current that would otherwise provide cold, fresh, oxygen-rich water to the North American shelf,” said lead author Gonçalves Neto.”

One group of loudmouth alarmists claim the Gulf Stream is rapidly weakening.

These alarmists claim that the Gulf Stream’s strength blocks the Labrador Current.

They should reconcile their own contradictions.

“We used satellite data to show”

Jaime Palter, GSO associate professor of oceanography and co-author of the study, marveled at the long record”

1979 to the present is a long record?
Allegedly, it takes thirty years for a minimal basic climate signal. It can take centuries to understand the cycles and their amplitude involved.
This apparently biased researcher is a co-author…

Richard M
April 20, 2021 3:10 pm

warmer and saltier conditions

The saltier conditions will lead to warmer water. It’s another one of those two way causal links that climate cultists ignore, They just assume warming can cause saltier.

Retired_Engineer_Jim
April 20, 2021 3:36 pm

“Climate models show the AMOC circulation slowing if greenhouse gas emissions continue unabated, which–if the link is proven” Oh my goodnees. Is that a hint of uncertainty?

sailor76
April 20, 2021 4:14 pm

Warmer, Hottest? What are they talking about, 1F, 5F, 10F higher the in 1930? Quantify what you are claiming, otherwise it is just vague fear mongering, which it probably is anyways.
Send more grant money, so we can dig deeper!

Joel O'Bryan
April 20, 2021 5:14 pm

Though the 2008 shift at the edge of the Grand Banks created warmer and saltier conditions than ever recorded since 1930, there was a similar shift in the 1970s relative to the decades preceding it. Thus, the circulation change directly observed by satellites might have had a precedent about 50 years ago.”

We still don’t know what caused the abrupt shift of the circulation near the Grand Banks inferred in the 1970s and observed in 2008, or whether this is the new normal for the circulation and the temperatures of the northeast shelf,” said Palter.

Well Duh.

AMO-w4trees.jpg
Last edited 3 months ago by joelobryan
Abolition Man
Reply to  Joel O'Bryan
April 20, 2021 5:59 pm

Thanks, Joel!
That looks suspiciously like a fifty to sixty year cycle! Too bad we don’t have accurate data going back a few millennia to see if there is anything new under the sun!

H. D. Hoese
Reply to  Abolition Man
April 20, 2021 6:20 pm

I worked on the outer Virginia coast in 1959-61 winters, saw a lobster caught in a crab trap, large herring gill net offshore catches, report of something sounded like a seal from a WWII coast guardsman. Also ice once so thick it muted the relatively large tides. “…if the link is proven…” OK let’s check in a few years.

fred250
Reply to  Abolition Man
April 20, 2021 11:22 pm

Actually, the AMO shows up reasonably clearly in Iceland sea ice records.

comment image

Reply to  Joel O'Bryan
April 22, 2021 3:43 am

Joel
As Levitus et al published in 2009, upper 150m water temperature in the Barents sea correlates exactly with the AMO.
This confirms that warm water inflow to the Arctic oscillates with the AMO – in fact the AMO is essentially an oscillation in the strength of the AMOC.

Barents Sea multidecadal variability (wiley.com)

Levitus 2009 Barents-AMO fig2.PNG
Ulric Lyons
April 20, 2021 6:07 pm

If it happened in 1930, that was also during a warm AMO phase, which is negative NAO driven, and is normal at least during each centennial solar minimum.
Rising CO2 forcing should increase positive NAO, that should be associated with a colder AMO.
https://archive.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-3-5-6.html

Redge
April 20, 2021 11:49 pm

From the paper:

In this region, some of the longest continuous records of ocean temperature and salinity have been collected, several dating to before the turn of the 20th century. More than 50 years ago, these records had already revealed that the sea surface temperature could fluctuate by up to 2 °C on a decadal timescale over a region extending at least from the coast of New Jersey, US to Halifax, Canada. Subsequent research linked these temperature fluctuations to ripples through the food web and fisheries and showed that one of their drivers may be a modulation in the westward transport of the Labrador Current south of the shallow underwater plateau known as the Grand Banks of Newfoundland

…..

Additionally, our analysis of nearly a century of hydrographic data suggests that a similar shift toward more subtropical water at the TGB was linked to shelf warming at the end of the 1960s, from which the system had never fully recovered.

…..

The recent subsurface warming of the Northwest Atlantic Shelf, associated with a dynamic change at the TGB, coincides with unprecedented surface warming, salinification, and severe marine heat waves that have likely contributed to long-noted trends in fisheries.

Are the authors trying to be subtle to retain their funding and say this warming is not climate change?

Stu-in-Flag
April 21, 2021 5:58 am

Possibly my browser, but the animated map isn’t animated.

beng135
Reply to  Stu-in-Flag
April 23, 2021 10:52 am

Doesn’t work for me on Firefox either, tho I have a number of tracker-blocks.

Last edited 3 months ago by beng135
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