Showing posts with label ice. Show all posts
Showing posts with label ice. Show all posts

Thursday 18 February 2016

Has maximum sea ice extent already been reached this year?

An earlier post wondered whether maximum extent for this year had already been reached, i.e. on February 9, 2016, when sea ice extent was 14.214 million km2.

As illustrated by the image below, extent since has been lower, including on the two most recent days on the image, i.e. on February 16 and 17, 2016, when extent was respectively 14.208 and 14.203 million km2.



Last year (2015), maximum sea ice extent was reached on February 25. That's close to the most recent date on the image of February 17, so with El Nino still going strong, it may well be that the maximum in 2016 will be reached early.

On the other hand, strong winds could spread out the sea ice and speed up its drift out of the Arctic Ocean, which may result in a larger extent, but which won't do much to strengthen the sea ice.

UPDATES: On February 18, 2016 (arrow), Arctic sea ice extent was 14.186 million square km, i.e. less than it was on February 9. In fact, sea ice extent hasn't been higher on any day since February 9, 2016. So, the question is, has this year's maximum extent already passed us by (i.e. on February 9)?

The image below shows the heat is having a huge impact on the sea ice, with some areas (black) showing sea surface temperature anomalies above 8°C (or above 14.4°F).


Ominously, sea surface off the North American east coast was as much as 11.8°C or 21.3°F warmer on February 19, 2016, than it was in 1981-2011 (at the location marked by the green circle in the image below).


Temperatures over the Arctic Ocean are forecast to remain extremely high for the next five days, with anomalies in a large part of the Arctic Ocean at the top end of the scale, i.e. 20°C or 36°F.


As the image below shows, Arctic sea ice area was at a record low for the time of year on February 18, 2016.



The image below shows that Arctic sea ice extent on February 20, 2016, was only 14.166
million km2 (arrow), adding to fears that this year's maximum was already reached on February 9.



Meanwhile, very high methane levels, as high as 3096 parts per billion, were recorded on February 20, 2016, as shown by the image below.


Further analysis indicates that these high levels likely originated from destabilizing methane hydrates in sediments, from a location about latitude 85°North and longitude +105° (East), on the Gakkel Ridge, just outside the East Siberian Arctic Shelf, at the location of the red marker on the map below.

Below is a comparison map, from grida.no
for large-size image, go to grida.no
Below is a map with sea surface temperature anomalies on February 20, 2016. The green circle marks the likely location of sediment destabilization and subsequent methane plume, at about latitude 85°North and longitude +105° (East), on the Gakkel Ridge, just outside the East Siberian Arctic Shelf.

zoom in and out at nullschool.net
If you like, you can discuss this further at the Arctic News group or below.


On February 18, 2016 (arrow), Arctic sea ice extent was 14.186 million square km, i.e. less than it was on February 9....
Posted by Sam Carana on Friday, February 19, 2016

Monday 15 February 2016

Arctic sea ice remains at a record low for time of year

For the time of year, Arctic sea ice remains at a record low since satellite records started in 1979, both for area and extent. The image below shows Arctic sea ice area up to February 12, 2016, when area was 12.49061 million square km.


The image below shows Arctic sea ice extent up to February 12, 2016, when extent was 14.186 million square km.


The reason for the record low sea ice is that there is more ocean heat than there used to be. The image below shows that on February 12, 2016, the Arctic Ocean sea surface temperature was as warm as 11.3°C (52.4°F) at a location near Svalbard marked by the green circle, a 10.4°C (18.7°F) anomaly.


The reason for this is that the water off the east coast of North America is much warmer than it used to be.

The Gulf Stream is pushing heat all the way into the Arctic Ocean.

The image below shows that on February 14, 2016, sea surface temperature anomalies (compared to 1981-2011) off the east coast of North America were was as high as 10.1°C or 18.1°F (at the location marked by the green circle).

While sea surface looks cooler (compared to 1981-2011) over a large part of the North Atlantic, an increasing amount of ocean heat appears to be traveling underneath the sea surface all the way into the Arctic Ocean, as discussed at this earlier post.

This spells bad news for the sea ice in 2016, since El NiƱo is still going strong. Temperatures in January 2016 over the Arctic Ocean were 7.3°C (13.1°F) higher than in 1951-1980, according to NASA data, as illustrated by the graph on the right.

See the Controversy page for discussion
A polynomial trend added to the January land temperature anomaly on the Northern Hemisphere since 1880 shows that a 10°C (18°F) rise could eventuate by the year 2044, as illustrated by the graph on the right. Over the Arctic Ocean, the rise can be expected to be even more dramatic.

As the NASA map below illustrates, the global January 2016 land-ocean temperature anomaly from 1951-1980 was 1.13°C (or over 2°F) and the heat did hit the Arctic Ocean stronger than elsewhere.

In January 2016, it was 1.92°C (3.46°F) warmer on land than in January 1890-1910. Before 1900, temperature had already risen by ~0.3°C (0.54°F), which makes it a joint 2.22°C (4°F) rise. On the Northern Hemisphere, the rise on land was the most profound, with over 10°C (18°F) warming occurring at the highest latitudes.


Meanwhile, methane levels as high as 2539 parts per billion (ppb) were recorded on February 13, 2016, as illustrated by the image below.


The danger is that, as the Arctic Ocean keeps warming, huge amounts of methane will erupt abruptly from its seafloor.

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

Update: Arctic sea ice extent keeps falling. Last year (2015), maximum sea ice extent was reached on February 25. Could it be that maximum extent for this year was already reached on February 9, 2016? The image below illustrates this question. discussed further at the Arctic News group.

discuss this further at the Arctic News group



Arctic sea ice extent keeps falling. Last year (2015), maximum sea ice extent was reached on February 25. Could it be...
Posted by Sam Carana on Monday, February 15, 2016

Monday 23 November 2015

Arctic Ocean Shows New Record Low Sea Ice

by Albert Kallio


Both the sea ice thickness and sea ice area have fallen to new record lows for this time of the year (22.11.2015), even surpassing all of the worst previous years.

From Naval Research Laboratory image - view animation
Immense thrust of fast moving sea ice is pushing through at the full width of the Fram Strait between Norway and Greenland. This amounts to huge transport of latent coldness out of the Arctic Ocean to North Atlantic, while the constantly forming new sea ice (as temperatures are below 0°C) is generating heat to keep the surface air temperatures higher across the Arctic Ocean. Thus, heat is constantly being added to the Arctic Ocean while heat is taken away from the North Atlantic Ocean.


The normal sea ice area for this time of year is 9,625,000 km2, whereas the sea ice covers currently just 8,415,890 km2,, which makes that 1,209,120 km2 sea ice is missing from the normal (22.11) sea ice area.



The combination image below shows the jet stream (November 23, 2015, left panel) and surface wind (November 24, 2015, right panel).


Jet stream is wavy and strong, showing speeds as high as 219 mph or 352 km/h (at location marked by the green circle). Right panel shows cyclonic winds between Norway and Greenland speeding up movement of sea ice into the North Atlantic.

Forecasts indicate that conditions could continue. The 5-day forecast on the right shows strong winds in the North Atlantic. Note also the cyclonic winds outside the Bering Strait.

Temperatures over the Arctic are forecast to remain much higher than they used to be, with anomalies at the far end of the scale over a large part of the Arctic Ocean showing up on the 5-day temperature anomaly forecast below.




[ further updates will follow ]

Saturday 10 October 2015

Arctic Sea Ice 2015 - update 11

Arctic sea ice extent has been growing rapidly recently. The image below shows extent up to October 9, 2015 (marked by red dot).


Below is a comparison of sea ice thickness as on October 6, for the years (from left to right) 2012, 2013, 2014 and 2015. The comparison shows that decline has been strongest where sea ice used to be the thickest, i.e. over 3 meters thick.


One of the reasons why the thickest Arctic sea ice has declined so dramatically over the years is the rising ocean heat that is melting the sea ice from underneath. The image below illustrates the situation on October 5, 2015, when sea surface temperature anomalies were as high as 6.4°C, 7.4°C and 7.3°C (11.5°F 13.2°F and 13.1°F) off the North American coast, and as high as 9.4°C (16.8°F) near Svalbard.


Water temperatures are very high in the Arctic, as further illustrated by the image below showing Arctic sea surface temperature anomalies as at October 9, 2015.



Rising ocean heat is further illustrated by the graph below, showing August sea surface temperature anomalies on the Northern Hemisphere over the years.
The situation is very dangerous, due to feedbacks and their interaction. The thicker sea ice used to act as a buffer, consuming ocean heat in the melting process. Without thicker sea ice, ocean heat threatens to melt the sea ice from below right up to the surface, causing the entire sea ice to collapse. As the sea ice declines, more open water will give rise to stronger winds and waves.

Furthermore, sunlight that was previously reflected back into space will instead be absorbed by the water, causing rapid rise of the temperature of the water. In places such as the East Siberian Arctic Shelf, the water is on a average only 50 m deep, so warmer water is able to reach the seafloor more easily there. As ocean heat keeps rising, there's a growing risk that heat will reach the Arctic Ocean seafloor and destabilize methane hydrates in sediments at the Arctic Ocean seafloor.

The image below shows a non-linear trend that is contained in the temperature data that NASA has gathered over the years, as described in an earlier post. A polynomial trendline points at global temperature anomalies of over 4°C by 2060. Even worse, a polynomial trend for the Arctic shows temperature anomalies of over 4°C by 2020, 6°C by 2030 and 15°C by 2050, threatening to cause major feedbacks to kick in, including albedo changes and methane releases that will trigger runaway global warming that looks set to eventually catch up with accelerated warming in the Arctic and result in global temperature anomalies of 16°C by 2052.

[ click on image to enlarge ]
The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan.

Comparison of sea ice thickness on October 6, for the years (from left to right) 2012, 2013, 2014 and 2015, shows that...

Posted by Sam Carana on Saturday, October 10, 2015

Tuesday 22 September 2015

Arctic Sea Ice 2015 - Update 10

It looks like sea ice has passed its minimum extent for the year 2015, as illustrated by the image below.


There are some differences between the various websites measuring extent, such as to whether the 2015 low was the third or fourth lowest. Japanese measurements show that sea ice extent was 4.26 million square km on September 14, 2015, i.e. lower than the 2011 minimum of 4.27 million square km, as illustrated by the image below.


Meanwhile, the Polar Science Center at the University of Washington has announced that Arctic sea ice volume minimum was reached on September 12, 2015, with a total volume of 5,670 cubic km. The image below shows a polynomial trendline based on their annual Arctic sea ice volume minima, including this volume for 2015.


Importantly, the sea ice in many places is now less thick than it was in 2012, as illustrated by the image below, showing sea ice thickness on September 27, 2012 (panel left) and a forecast for September 27, 2015 (panel right).


The reason for the dramatic decrease in thickness of the multi-year sea ice is ocean heat, as illustrated by the image below, showing sea surface temperature anomalies in the Arctic as at September 21, 2015.


The water of the Arctic Ocean is very warm, not only at the surface, but even more so underneath the surface. What has contributed to this situation is described by the image below. From 2012, huge amounts of fresh water have run off Greenland, with the accumulated fresh water now covering a huge part of the North Atlantic.

Since it's fresh water that is now covering a large part of the surface of the North Atlantic, it will not easily sink in the very salty water that was already there. The water in the North Atlantic was very salty due to the high evaporation, which was in turn due to high temperatures and strong winds and currents. As said, fresh water tends to stay on top of more salty water, even though the temperature of the fresh water is low, which makes this water more dense. The result of this stratification is less evaporation in the North Atlantic, and less transfer of ocean heat to the atmosphere, and thus lower air temperatures than would have been the case without this colder surface water.


Meanwhile, global warming continues to heat up the oceans, while less of this ocean heat can now be transferred from the water to the atmosphere in the North Atlantic, since the fresh water is acting like a lid.

The danger is thus that warmer water will be pushed into the Arctic Ocean at lower depth, and that it will reach the seafloor of the Arctic Ocean where huge amounts of methane are contained in sediments. Ice acts like a glue, holding these sediments together and preventing destabilization of methane hydrates. Warmer water reaching these sediments can penetrate them by traveling down cracks and fractures in the sediments, and reach the hydrates.

The big melt in Greenland and the Arctic in general is causing further problems. Isostatic adjustment following melting can contribute to seismic events such as earthquakes, shockwaves and landslides that can destabilize methane hydrates contained in sediments on the Arctic Ocean seafloor.

In the video below, by Nick Breeze, Professor Peter Wadhams discusses the situation.



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


The water of the Arctic Ocean is very warm, not only at the surface, but even more so underneath the surface. What has...
Posted by Sam Carana on Tuesday, September 22, 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

Friday 15 August 2014

Heatwave to hit Greenland

A heatwave with temperature anomalies exceeding 36°F (20°C) is expected to hit Greenland between August 16 and 22, 2014, as illustrated by the image on the left and the animation on the right. 

Such heatwaves can be expected to hit the Arctic more frequently and with greater intensity, as temperatures in the Arctic are rising faster than elsewhere on Earth.

Such heatwaves can result in massive melting on Greenland, as persistent heat changes the texture of the snow and ice cover, in turn reducing its reflectivity. This makes that less sunlight is reflected back into space and is instead absorbed. 

The image below illustrates what a difference the presence of sea ice can make.
from: Arctic Warming due to Snow and Ice Demise
As the NSIDC/NOAA graphs below shows, melting on Greenland has been relatively modest this year when compared to the situation in 2012. By July 12, 2012, 97% of the ice sheet surface had thawed, according to this NASA analysis and this NOAA Arctic Report Card.


Melting on Greenland directly affects sea level rise, and melting on Greenland is accelerating due to a number of factors.

Projections of melting on Greenland have long been based on a warming atmosphere only, ignoring the warmer waters that lubricate glaciers and that warm Greenland's bedrock canyons that sit well below sea level.

Furthermore, there are growing quantities of black carbon deposits as a result of burning of fossil fuel and biomass. High temperatures have recently caused ferocious wildfires in Canada that have in turn caused a lot of black carbon to go up high into the atmosphere.

And of course, the atmosphere over the Arctic is warming up much faster than most models had projected. This in turn causes triggers further feebacks, including more extreme weather events such as heatwaves and rain storms that can be expected to hit Greenland with ever more frequency and ferocity. Further feedbacks include methane eruptions from the heights of Greenland, as discussed at the Arctic Feedbacks Page.

When also taking into account the accelerating impact of such factors on melting in Greenland, sea levels could rise much faster than anticipated, as illustrated by the image below.

from: more than 2.5m sea level rise by 2040? 

Note that sea level rise is only one of the many dangers of global warming, as discussed in the 2007 post Ten Dangers of Global Warming.

The image on the right shows a temperature forecast for August 16, 2014, with parts of Greenland changing in color from blue into green, i.e. above the melting point for snow and ice.

Such high temperatures are now hitting locations close to the North Pole ever more frequently, due to the many feedbacks that are accelerating warming in the Arctic, as discussed at this Feedbacks page.

One of the most dangerous feedbacks is a sudden eruption of huge quantities of methane from the seafloor of the Arctic Ocean, as discussed in a recent post.

The impact of such feedbacks can be accumulative and interactive, resulting in self-reinforcing feedbacks loops that can escalate into runaway warming.

Below is another forecast by ClimateReanalyzer for August 16, 2014, showing the remarkable ‘greening’ of Greenland, as well as the very high temperatures reaching the higher latitudes of North America.


Also see the very high sea surface temperatures around Greenland on the image below, created with ClimateReanalyzer.

Sea surface temperature anomalies on August 15, 2014. 
In conclusion, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog