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North Atlantic jet stream



  Impact on hole in North Atlantic stream
Iceberg ice in Sea Labrador south of Greenland. Credit: Melissa Gervais / Penn State

The North Atlantic heated hole (NAWH), a region of reduced heating located in the North Atlantic Ocean, has a major impact on the North Atlantic stream in future climate simulations, according to a team of researchers.

Global climate temperatures (SST) in most global oceans are expected to increase as a result of global climate change. However, within an area of ​​rotating ocean currents just south of Greenland there is an anomaly where colder temperatures on the sea surface were recorded in both global climate projections and opinions.

"It is called a hole because there is a lack of heating," said Melissa Gervais, assistant meteorological and atmospheric science professor, Penn State, who used the CESM model to investigate the impact of NAWH. atmospheric circulation and medium jets. "We found that this region of the ocean is a very important place for the implementation of the jet stream that passes over the North Atlantic."

The researchers published their findings in Journal of Climate . [1

9659005] The development of the NAWH is linked to a slowdown in Atlantic Atlantic Behavior Circulation, a large system of ocean currents which transports hot water from the tropics north into the North Atlantic, and is thought to be an influx of fresh water from Art sea ice. melt.

  Influence of the hole on the North Atlantic ocean
A floating iceberg in the Labrador Sea south of Greenland. Credit: Melissa Gervais / Penn State

Previous research by Gervais and her team showed that this increase in fresh water changes to the ocean patterns of circulation and surface cooling.

"With more ice melting in the Arctic, more fresh water flows into the Labrador Sea, deep convection is reduced," said Gervais, an Institute is also for cybersecure hire. " allow it to cool in that region south of Greenland. "

This cooling pattern, relative to the average global increase of RSS, is predicted to be more and more pronounced when compared to the internal variation of the ocean as the 21st

"These changes in RSS patterns occur as a result of changes in the circulation of the oceans and could have a significant impact on the future circulation of the atmosphere and the North Atlantic storm track," said Gervais. [19659005] Jet streams, high wind currents flowing over the Earth, carrying air masses and driving weather patterns. and complex jet streams and understanding of the potential impact of climate change on jet streams is critical to understanding changes in weather patterns and storm tracks.

  The impact of the burrows on the stream from the North Atlantic
from the research vessel Knorr WHOI. Credit: Melissa Gervais / Penn State

"With climate change we have some ideas about how the jets will change. In general, we expect to see the change and extension east of the jet," said Gervais. "Right now, it is a type of war tug between the effects of the tropics and the effects of the Arctic. So both of these are competing to change the position of the jet." The transformation is going to change but there is a lot of change in the Atlantic predictions, Gervais said.

To investigate how NAWH development affects the jet stream, the team made a series of atmospheric model-ense experiments in CESM with SST ice and sea ordered levels over three different time periods

"We ran three simulations," said Gervais. "One with existing heating conditions; one where the temperature of the ocean was increased to fill the warming; and one containing twice as deeper to simulate more freshwater from melted ice sheets."

Their findings show that the NAWH plays an important role in central atmospheric circles that change the model's future climate simulations.

"We found that it is very important for that region," Gervais said. "The NAWH seems to be separating the jet longer and moving it north. Instead of thinking about how the tropics and the arctic amplification affect the jet, we now need to think about how These local changes in the North Atlantic jet are as great as the overall response to climate change in the region, indicating that the North Atlantic heated hole could be an important additional factor in war diving. on circulation circulation, that he received little attention. "


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More information:
Melissa Gervais et al, North Atlantic Heating Holes Impacts in Future Climate Projections: The Atmospheric Middle Circulation and North Atlantic Jet, Journal of Climate (2019). DOI: 10.1175 / JCLI-D-18-0647.1

Available at
Pennsylvania State University




Lua :
North Atlantic jet stream (2019, 15 April)
recovered 15 April 2019
from https://phys.org/news/2019-04-north-atlantic-hole-impacts-jet.html

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