Subscribe free to our newsletters via your
. Earth Science News .

Subscribe free to our newsletters via your

Northwest Atlantic Ocean may get warmer, sooner
by Staff Writers
Woods Hole MA (SPX) Jan 15, 2016

Over the past ten years, the Gulf of Maine has warmed faster than 99% of the global ocean. Recent studies indicate that the enhanced warming is associated with a northerly shift in the Gulf Stream.

A new study by NOAA researchers suggests future warming of ocean waters off the Northeastern U.S. may be greater and occur at an even faster rate than previously projected.

Their findings, based on output from four global climate models of varying ocean and atmospheric resolution, indicate that ocean temperature in the U.S. Northeast Shelf is projected to warm twice as fast as previously projected and almost three times faster than the global average. The models were developed at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL) in Princeton, New Jersey.

"We looked at four GFDL models and compared their output to ocean observations in the region. The highest resolution GFDL model, CM2.6, matched the Northwest Atlantic circulation and water mass distribution most accurately," said Vincent Saba, a NOAA fisheries scientist and lead author of the study. "Prior climate change projections for the region may be far too conservative."

Over the past ten years, the Gulf of Maine has warmed faster than 99% of the global ocean. Recent studies indicate that the enhanced warming is associated with a northerly shift in the Gulf Stream. Changes in the distribution and species composition are already evident, but existing climate change projections are based on warming scenarios from coarse resolution models. Warming of 3 to 4 degrees C (as much as 5.4 to 7.2 degrees F), projected by NOAA GFDL's CM2.6, will likely cause more extreme effects on the ecosystem.

Global climate models used to project global and regional climate change generally have coarse ocean and atmospheric resolution. The higher resolution model better reflects the ocean circulation and sea floor bathymetry in smaller, complex areas like the Gulf of Maine and the U.S. Northeast Shelf. According to the study, the models project that ocean warming will be even more pronounced than suggested by coarser models under increasing concentrations of atmospheric CO2.

The global climate models assessed by the Intergovernmental Panel on Climate Change (IPCC), which are used to project global and regional climate change, are coarse resolution models based on a roughly 100-kilometer or 62-mile grid, to simulate ocean and atmospheric dynamics. NOAA GFDL's CM2.6 offers ten times more resolution by using a roughly 10-kilometer or 6.2-mile ocean grid.

"It is like comparing an old standard definition television screen to today's ultra high definition screens," said Saba, a member of the Northeast Fisheries Science Center's Ecosystem Assessment Program who works at GFDL. "There aren't many high resolution global climate models available due to their prohibitive cost.

For much of the global ocean the coarser resolution is okay, but when you are studying a unique location like the Gulf of Maine, with its complex bathymetry of deep basins, channels, and shallow banks combined with its location near the intersection of two major ocean current systems, the output from the coarser models can be misleading."

A warm bias in sea surface temperature in most global climate models is due to a misrepresentation of the coastal separation position of the Gulf Stream, which extends too far north of Cape Hatteras, North Carolina. The model bias, known as the "Gulf Stream separation problem," is a result of the models' coarse resolution.

As a consequence of that bias, existing climate change projections for the Northeast U.S. Shelf and the Gulf of Maine are based on unrealistic regional ocean circulation patterns. NOAA GFDL's highest resolution model, CM2.6, significantly reduces that bias.

The study also found that the warming of the upper 300 meters (roughly 1,000 feet) of the Northwest Atlantic increases salinity due to a change in water mass distribution related to a retreat of the colder, fresher Labrador Current and a northerly shift of the warmer, saltier Gulf Stream.

Observations and the high-resolution climate model CM2.6 show a strong relationship between a weakening Atlantic Meridional Overturning Circulation (AMOC) and an increase in the proportion of warm-temperate slope water entering the U.S. Northeast Continental Shelf, primarily through the Gulf of Maine's Northeast Channel.

"These results show the need to improve simulations of basin and regional-scale ocean circulation," said Saba, who will use the CM2.6 model findings for a variety of climate studies on living marine resources in the ecosystem.

In addition to Saba and Jonathan Hare from NOAA Fisheries' Northeast Fisheries Science Center, other study authors are affiliated with NOAA's Geophysical Fluid Dynamics Laboratory and the Earth System Research Laboratory in Boulder, Colorado. The study appears in the Journal of Geophysical Research - Oceans, published by the American Geophysical Union.


Related Links
NOAA Northeast Fisheries Science Center
Water News - Science, Technology and Politics

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Previous Report
Ocean current in Gulf of Mexico linked to red tide
Miami FL (SPX) Jan 13, 2016
A new study found that a major ocean current in the Gulf of Mexico plays an important role in sustaining Florida red tide blooms. The University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science research team suggest that the position of the Loop Current can serve as an indicator of whether the algal bloom will be sustained, and provide warning of possible hazardous red tide cond ... read more

MH370 search finds new shipwreck, but no plane

Six years on, quake-devastated Haiti mourns its dead

Snow makes migrants' journey through Europe even harder

Guatemalan ex-dictator set for genocide retrial

New twists in the diffraction of intense laser light

A new way to print 3-D metals and alloys

How seashells get their strength

China chemical giant to acquire Germany's KraussMaffei

Northern methane has a watery source

Robotic vehicles offer a new tool in study of shark behavior

Tough times for the tree of life on coral reefs

U.S. patent granted for novel wastewater treatment system

Ice sheets may be hiding vast reservoirs of powerful greenhouse gas

World's largest canyon could be hidden under Antarctic ice sheet

Mountains west of Boulder continue to lose ice as climate warms

Greenland ice sheet melts more when it's cloudy

Grazing towards sustainability

Researchers work on lowering greenhouse gas emissions from poultry houses

De-mystifying the study of volatile organic plant compounds

Backyard chickens harbor many parasites

Evidence aids tsunami hazard assessments from Alaska to Hawaii

UK Environment Agency boss quits after flood response criticism

Redirected flood waters lead to unintended consequences

Greek dig reveals past glories of Europe's oldest city

China's imports from Africa plummet in 2015: officials

Niger holds 13 over failed December coup

Mali extends state of emergency until March 31

Mali pro-govt armed group accuses France of killing 4 fighters

Decision making in action

Brain monitoring takes a leap out of the lab

Britain's Pompeii: Bronze Age stilt houses found in English quarry

Research suggests morality can survive without religion

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.