Huge pool of Arctic fresh water could cool Europe

Jan 23, 2012 By Tamera Jones
Huge pool of Arctic fresh water could cool Europe
The North Atlantic and Arctic Oceans are critical components of the ocean-climate system.

British scientists have discovered an enormous dome of fresh water in the western Arctic Ocean. They think it may result from strong Arctic winds accelerating a great clockwise ocean circulation called the Beaufort Gyre, causing the sea surface to bulge upwards.

The researchers made their discovery using (ESA) satellites ERS-2 and Envisat. They measured height over the western Arctic over a 15-year period, from 1995 to 2010.

Using these measurements, they calculate that since 2002 the sea surface in the western Arctic has risen by around 15cm, and the volume of fresh water has swollen by roughly 8000 cubic kilometres. This is around ten per cent of all the fresh water in the Arctic Ocean.

This video is not supported by your browser at this time.
The Beaufort Gyre is a great clockwise ocean circulation in the western Arctic Ocean. Accelerated by strong Arctic winds, the sea surface bulges upwards. Measurements from ESA’s ERS and Envisat missions show that, since 2002, the surface has risen by about 15 cm and the volume of fresh water has swollen by approximately 8000 cubic km - around 10% of all the fresh water in the Arctic Ocean. Credits: CPOM/UCL/ESA/Planetary Visions

If the wind changes direction, as happened between the mid-1980s and mid-1990s, the water could spill out into the rest of the Arctic and then perhaps even the north Atlantic. This could cool Europe by slowing down a key ocean current derived from the Gulf Stream, which keeps the continent relatively mild compared with countries at similar latitudes.

The forms part of a larger movement of water called the ocean conveyor belt, which is itself one component of the global system of .

Arctic Ocean mean sea-surface with respect to the geoid for the past 15 years of satellite radar altimetry data. The Beaufort Gyre is the yellow/orange dome in the Western Arctic. Credits: CPOM/UCL/ESA/Planetary Visions

"Satellite data has shown us that a dome of fresh water has been building up in the western Arctic over the past 15 years, due to the wind. Our findings suggest that a reversal of the wind could result in the release of this fresh water to the rest of the Arctic Ocean and even beyond," says Dr. Katharine Giles from the Centre for Polar Observation and Modelling (CPOM) at University College London, lead author of the study, published in Nature Geoscience.

Earlier studies from ships, submarines, and instruments on moored had pointed to increasing volumes of fresh water in the Arctic over the last few decades, especially in the western Arctic. Not only that, but other studies had found that less reached the Atlantic than expected over the same period of time. These findings suggest the water is concentrated in the Beaufort Gyre, and can't spill out into the Atlantic.

But all of these studies relied on limited observations, so scientists weren't sure exactly what was driving the changes.

Climate models had suggested that the action of the wind on the sea surface could cause a raised dome to form in the middle of the Beaufort Gyre. But until now, there had been no continuous observations of sea-surface height to demonstrate this categorically.

Now, using from 1995 to 2010, Giles and colleagues from the National Oceanography Centre (NOC) have found that the height of the sea surface in the middle of the Beaufort Gyre has increased substantially since 2002.

This is a mosaic of Envisat radar images acquired between 9 and 11 September 2011 over the Arctic Ocean. The sea ice extent highlighted in blue corresponds to the areas where more than 80% of the sea surface is covered by ice (from an analysis performed by the US National Ice Center). The Arctic is one of the most inaccessible regions on Earth, so obtaining measurements of sea ice was difficult before the advent of satellites. Credits: ESA/DMI/NIC

"We were surprised to find that our results also suggested that something else was going on,' says Giles. 'When we looked at our data on a year-to-year basis we noticed that the changes in the sea surface height did not always follow what the wind was doing so we thought about reasons why this might happen. One idea is that sea ice forms a barrier between the atmosphere and the ocean. So, as the sea-ice cover changes, the effect of the wind on the ocean might also change."

"Our next step is to look into how changes in the sea-ice cover might affect the coupling between the atmosphere and the ocean in more detail to see if we can confirm this idea,' she adds.

"Satellites have been measuring how the ice is changing for many years but we now have the tools to monitor how the underneath the ice is changing. These techniques can also be used with the recently launched CryoSat-2 satellite to measure changes over the whole basin,' says Dr. Seymour Laxon, director of CPOM and co-author of the study.

Explore further: Better forecasts for sea ice under climate change

More information: Katharine A. Giles, et al. (2012), Western Arctic Ocean freshwater storage increased by wind-driven spin-up of the Beaufort Gyre, Nature Geoscience, doi: 10.1038/NGEO1379, published online on 22 January 2012

Related Stories

New fresh water in Arctic could shift Gulf Stream

Apr 05, 2011

Scientists are monitoring a massive pool of fresh water in the Arctic Ocean that could spill into the Atlantic and potentially alter the key ocean currents that give Western Europe its moderate climate.

Arctic Ocean waters warm suddenly

Oct 07, 2005

Water flowing from the North Atlantic Ocean into the Arctic provides evidence that the Arctic Ocean is warming, according to U.S. and European researchers.

Arctic sea ice thinning at record rate

Oct 28, 2008

(PhysOrg.com) -- The thickness of sea ice in large parts of the Arctic declined by as much as 19% last winter compared to the previous five winters, according to data from ESA's Envisat satellite.

CryoSat-2 ice mission ready for launch

Mar 30, 2010

(PhysOrg.com) -- A UK-led CryoSat-2 satellite designed to monitor changes in ice cover at the poles will launch at 13:57 UK time on 8 April 2010 from the Baikonur cosmodrome in Kazakhstan.

Recommended for you

Better forecasts for sea ice under climate change

2 hours ago

University of Adelaide-led research will help pinpoint the impact of waves on sea ice, which is vulnerable to climate change, particularly in the Arctic where it is rapidly retreating.

"Ferrari of space' yields best map of ocean currents

10 hours ago

A satellite dubbed the "Ferrari of space" has yielded the most accurate model of ocean circulation yet, boosting understanding of the seas and a key impact of global warming, scientists said Tuesday.

Researcher studies deformation of tectonic plates

13 hours ago

Sean Bemis put his hands together side by side to demonstrate two plates of the earth's crust with a smooth boundary running between them. But that boundary is not always smooth and those plates do not always ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

NotParker
1.7 / 5 (13) Jan 23, 2012
Yup. What goes around, comes around.

Cycles exist. They change direction.

Co2 doesn't cause cycles, conmen blame natural cycle changes on CO2.
rubberman
4.4 / 5 (13) Jan 23, 2012
Yup. What goes around, comes around.

Cycles exist. They change direction.

Co2 doesn't cause cycles, conmen blame natural cycle changes on CO2.


What natural cycle is this one? The semi bidecadal arctic oscillation reversal cycle?
Also, these conmen, do you mean those dirty climate grifters that are trying to dupe us into cleaner forms of energy production, those shameful eco-nazi's that are vying for a minimal environmental impact where mankind is concerned?

sons of bitches
rwinners
1 / 5 (3) Jan 23, 2012
This article is far to secular to be of value.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.