Showing posts with label Alaska. Show all posts
Showing posts with label Alaska. Show all posts

Thursday 28 May 2015

Arctic Sea Ice in Uncharted Territory

On May 27, 2015, Arctic sea ice extent was merely 11.973 million square kilometers, a record low for the time of the year since satellite started measurements in 1979.


This fall in sea ice extent follows heat waves in Alaska and the north of Canada, as illustrated by the image below.

Temperature in Alaska on the afternoon of May 23, 2015, when a temperature of 91°F (32.78°C) was recorded in Eagle
High temperatures extended over the Beaufort Sea and Chukchi Sea. The image below shows the difference in sea surface temperatures between May 13, 2015, and May 23, 2015.


The large amounts of meltwater flowing into Beaufort Sea and the Chukchi Sea is illustrated by the image below, showing the difference in sea surface salinity between May 17, 2015, and May 24, 2015.


Sea ice has retreated dramatically in the Chukchi Sea and the Beaufort Sea, and in Baffin Bay, with high sea surface temperature showing up where rivers flow into the Arctic Ocean and where the Gulf Stream carries warm water from the Atlantic Ocean into the Arctic Ocean.

The size-reduced navy.mil animations below show the fall in sea surface salinity (left) and the fall in sea ice thickness (right) in the Beaufort Sea, from May 3, 2015, to June 2, 2015 (run May 27, 2015).

Sea surface salinity Beaufort Sea
Sea ice thickness Beaufort Sea
   
The image below shows sea surface temperature anomalies on May 27, 2015.


For reference, the animation below, from the Naval Research Laboratory, shows sea ice thickness over a 30-day period, including a forecast up to June 4, 2015.


Update: here's an image showing Arctic sea ice extent up to May 28, 2015, highlighting that sea ice extent is now well outside 2 standard deviations.



The situation is dire and calls for comprehensive and effective action as discussed at the Climate Plan.



Arctic Sea Ice in Uncharted Territory Sea ice has retreated dramatically in the Chukchi Sea and the Beaufort Sea, and...
Posted by Sam Carana on Thursday, May 28, 2015

Monday 25 May 2015

Sleeping Giant in the Arctic



Huge amounts of carbon are contained in sediments, soils and vegetation in the Arctic. Rising temperatures in the Arctic threaten to cause much of this carbon to be released to the atmosphere.

On May 23, 2015, temperatures in Alaska were as high as 91°F (32.78°C), as illustrated by the image below.

[ image credit: US National Weather Service Alaska ]
High temperatures were reached at the city of Eagle, located on the southern bank of the Yukon River, at an elevation of 853 ft (260 m). High temperatures at such a location will cause meltwater, aggravating the situation well beyond the local area.
A bank of permafrost thaws near the Kolyma
River in Siberia. Credit: University of Georgia

Carbon contained in soils will thus become increasingly exposed under the combined impact of rising temperatures and the associated growing amounts of meltwater. The meltwater can additionally cause erosion further downstream, thus making carbon at many locations become more prone to be consumed by microbes and released into the atmosphere in the form of carbon dioxide and methane.

A recent study found that, at a location where the Kolyma river in Siberia carved into the permafrost and exposed the carbon, microbes converted 60% of the carbon into carbon dioxide in two weeks time.

Gary Houser, who recently launched the movie Sleeping Giant in the Arctic, elaborates on the threat of emissions from thawing permafrost:
This immense release would likely feed on itself, raising temperatures that continue melting more and more permafrost in a vicious, frightening, and unstoppable cycle. A tipping point could well be crossed, at which time human intervention is no longer possible. Temperatures across the planet could soar, setting in motion catastrophic levels of drought and food shortage. All life support systems on earth and life forms themselves could be placed under severe stress.

The colossal scale of the danger - and the observation of those factors lining up that could trigger it - demand that humanity exercise the precautionary principle. All political decision-making related to carbon emissions must be based on the understanding that a catastrophic consequence is looming, and the window of time for prevention quickly diminishing.
SLEEPING GIANT IN THE ARCTIC:
Can Thawing Permafrost Cause Runaway Global Heating?
by Gary Houser



Sources: 

US National Weather Service Alaska

University of Georgia

Sleeping Giant in the Arctic


Sleeping Giant in the Arctic http://arctic-news.blogspot.com/2015/05/sleeping-giant-in-the-arctic.html

Posted by Sam Carana on Monday, May 25, 2015

Thursday 21 May 2015

Arctic Sea Ice At Historic Low

On May 20, 2015, Arctic sea ice extent was only 12.425 million square km, a record low for the time of the year since satellite measurements began in 1979.


As the Arctic Sea Ice is at a historic low, Alaska faces temperatures as high as 31°C (87.8°F), as illustrated by the image below.



How is it possible for temperatures to get so high at locations so close to the North Pole?

Typhoon Dolphin
Dr. Michael Ventrice, Operational Scientist at The Weather Channel Professional Division points at two typhoons, Noul and Dolphin, that recently hit the western Pacific Ocean.

These typhoons do have some impact. Importantly, global warming is increasing the strength of cyclones. In other words, a greater impact of cyclones on the jet stream can be expected as a feedback of global warming.

Furthermore, global warming is directly changing the path followed by the North Polar Jet Stream, from a relatively straight path at a latitude of 60°N to a wildly meandering path that at some places merges with the Subtropical Jet Stream and reaching speeds as high as 267 km/h (166 mph) and that at other places moves high into the Arctic and reaches speeds as high as 170 km/h (106 mph).



On above image, part of the jet stream even moves right across the pole. Such changes to the jet stream constitute one out of numerous feedbacks of global warming, as discussed at the feedbacks page. Decline of the snow cover and sea ice in the Arctic is another such feedback.

As discussed in earlier posts, heat waves at high latitudes cause thawing of frozen soil and melting of glaciers and snow cover, This results in large amounts of water draining into rivers that end up in the Arctic Ocean. At the same time, heat waves also raise the temperature of the water in these rivers. The larger amounts of warmer water result in additional sea ice decline and warming of the Arctic Ocean seabed.

Such heat waves also set the scene for wildfires that emit not only greenhouse gases such as carbon dioxide and methane, but also pollutants such as carbon monoxide (that depletes hydroxyl that could otherwise break down methane) and black carbon (that when settling on ice causes it to absorb more sunlight).


Above image shows how much warmer the water in the Arctic Ocean is compared to what it used to be, with high anomalies where rivers flow into the Arctic Ocean and where the Gulf Stream carries warm water from the Atlantic Ocean into the Arctic Ocean.

The situation looks set to get worse, as the frequency and intensity of heat waves in North America and Siberia increases as temperature at high latitudes are rising rapidly. Furthermore, warm water is lining up along the path of the Gulf Stream, with sea surface temperature anomalies as high as 10.3°C (18.54°F) recorded off the coast of North America on May 20, 2015, as illustrated by the image below.

Green circle shows a 10.3°C (18.54°F) sea surface temperature anomaly from daily average (1981-2011)

Meanwhile, a very high methane reading was recorded at Barrow, Alaska (hourly average, in situ measurement), as illustrated by the image below.


The big danger is that the combined impact of these feedbacks will accelerate warming in the Arctic to a point where huge amounts of methane will erupt abruptly from the seafloor of the Arctic Ocean.

The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan page.



As the Arctic Sea Ice is at a historic low, Alaska faces temperatures as high as 31°C (87.8°F). From the post: Arctic...
Posted by Sam Carana on Thursday, May 21, 2015

Saturday 30 August 2014

Ring Of Ice



Prominence of earthquakes in North America and around Greenland has prompted a team of researchers led by Arctic-news blog editor Sam Carana to coin the phrase “Ring Of Ice” to describe what they see happening in the Arctic.

“Melting of ice in north Canada and on Greenland is causing pressure changes, resulting in seismic activity”, explains Sam Carana.

Heavy seismic activity is ocurring along the faultlines that constitute the border of the North American Plate, similar to the the heavy activity along the Ring Of Fire around the Pacific Ocean.

Seismic activity roughly follows the borders of the North American Plate, which includes Greenland. However, where the major fault bends away to the west following the Aleutian Islands, seismic activity continues north through Alaska along a line that extends over the North Pole toward Svalbard.

This northward path through Alaska is illustrated by the earthquakes on the image below.


“Earthquakes are prominent along the entire border of the North American Plate”, Sam Carana adds, “but they increasingly appear to be taking this shortcut through Alaska and the underlying cause of this is melting of ice in north Canada and on Greenland”.

“This Ring Of Ice spells danger, just like the name Ring Of Fire indicates danger”, Sam Carana concludes. “The name Ring Of Fire warns about possible volcanoes, earthquakes, landslides and tsunamis. The Ring Of Ice seems even more dangerous, since seismic activity could destabilize methane hydrates contained in sediments under the Arctic Ocean, and could trigger huge methane eruptions. The fault line running from Greenland to Siberia is the most dangerous area on Earth in that respect”.

From the earlier post High Methane Levels over Laptev Sea