Showing posts with label extent. Show all posts
Showing posts with label extent. 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 Niño 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

Sunday 31 January 2016

Arctic sea ice area at record low for time of year

Arctic sea ice area on January 28, 2016, was only 12.17902 million square km. At this time of year, sea ice area hasn't been as low as this for at least since satellite records started in 1979, as illustrated by the image below.

based on image from: arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html
Furthermore, on January 29, 2016, Arctic sea ice reached its second lowest extent since the satellite records began, as the image below shows.

based on image from: nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph

Why is sea ice at record low?

The sea ice is in a bad shape due to very high temperatures. A forecast for January 30, 2016, shows surface temperatures over the Arctic that are 2.7°C (4.86°F) warmer than they were in 1979-2000. The image below further illustrates this, showing temperature anomalies at the top end of the scale, i.e. 20°C (36°F) above 1979-2000, in many places in the Arctic.


At this time of year, there is very little sunshine in the Arctic. Therefore, these anomalies are caused by sea water that is warmer than it used to be. The image below shows that on January 24, 2016, sea surface temperature was 12.3°C (54.2°F) at a location near Svalbard marked by the green circle, a 10.4°C (18.7°F) anomaly.


Such anomalies are in turned caused by water that is much warmer than it used to be, and that is being carried by the Gulf Stream all the way into the Arctic Ocean.

Water much warmer off the North American coast

The water off the coast of North America is much warmer than it used to be due to emissions that extend from North America over the Atlantic Ocean due to the Coriolis effect. The image below, from an earlier post, shows carbon dioxide levels as high as 511 ppm over New York on November 5, 2015, and as high as 500 ppm over the water off the coast of coast of New Jersey on November 2, 2015.

from the post: 2015 warmest year on record
As discussed at an earlier post, also relevant are other emissions such as carbon monoxide that depletes hydroxyl, making it harder for methane to be oxidized. Below is an update on carbon monoxide levels.


These emissions heat up the Gulf Stream and make that ever warmer water is carried underneath the sea surface all the way into the Arctic Ocean, while little heat transfer occurs from ocean to atmosphere, due to the cold freshwater lid on the North Atlantic.

Arctic sea ice in uncharted territory

Update 1: For the time of the year, Arctic sea ice is now 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 1, 2016, when area was 12.27298 million square km.

based on image from: arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html
The image below shows Arctic sea ice extent up to February 2, 2016, when extent was 13.932 million square km.

based on image from: nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph
Update 2: For the time of the 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 4, 2016, when area was 12.30656 million square km.

[ click on image to enlarge ]
Comprehensive and effective action is needed

This situation spells bad news for what will happen later in 2016, also given the current El Niño. Less sea ice means that less sunlight is reflected back into space, resulting in more heat being absorbed by the Arctic Ocean.

As more heat reaches the bottom of the Arctic Ocean, the risk increases that heat will penetrate and destabilize sediments containing methane hydrates. Methane escaping from hydrates could strongly accelerate warming in the Arctic, causing further melting of the sea ice, in a spiral of warming that could escalate into runaway warming.

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


Related posts

- Why America should lead on climate
arctic-news.blogspot.com/2016/01/why-america-should-lead-on-climate.html

- Sea surface warmest on record
arctic-news.blogspot.com/2015/10/september-2015-sea-surface-warmest-on-record.html

- Climate Plan
arctic-news.blogspot.com/p/plan.html

- 2015 warmest year on record
arctic-news.blogspot.com/2015/12/2015-warmest-year-on-record.html

Arctic sea ice area on January 28, 2016, was only 12.17902 million square km. At this time of year, sea ice area hasn't...
Posted by Sam Carana on Sunday, January 31, 2016

Tuesday 5 January 2016

Arctic Sea Ice At Record Low

Arctic sea ice extent on January 4, 2016, was at a record low for the time of the year, as illustrated by the image below.


Arctic sea ice will typically reach its maximum extent in March. In 2015, sea ice extent was very low in March (see blue line in above image), and the outlook for this year is even more grim, as oceans get warmer and El Niño is still gaining in strength.

Below is a comparison of sea ice thickness (in m) on January 4th for the years 2012, 2015 and 2016.


Below is an update showing Arctic sea ice extent as on January 6, 2016, at the bottom left corner, marked with the red dot.



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



Arctic sea ice extent on January 4, 2016, was at a record low for the time of the year. Arctic Sea Ice At Record Lowhttp://arctic-news.blogspot.com/2016/01/arctic-sea-ice-at-record-low.html
Posted by Sam Carana on Tuesday, January 5, 2016

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

Friday 18 September 2015

Arctic Sea Ice Collapse Threatens - Update 9

The image below shows that Arctic sea ice had reached a level of 4.45 million square kilometers on September 16, 2015 (end of dark blue line at center of image).


NSIDC has meanwhile called the 2015 minimum, but the first sentence of their post hastens to add that on September 11, Arctic sea ice reached its likely minimum for 2015,  at 4.41 million square kilometers (1.70 million square miles), putting 2015 in the fourth lowest place since satellite records began. Arctic sea ice minimum was lower only in 2012 (dotted line), 2007 (light blue line) and 2011 (orange line). Sea ice extent was 4.413 million square kilometers both on September 9, 2015, as well as on September 10 and 11, 2015.

September 9 would be early for the sea ice to reach its minimum, as a comparison with earlier years on above image illustrates. The dark blue line on above image shows that sea ice extent fell slightly on September 16, compared to the day before, and is now below the 2011 extent (orange line) for this time of the year. Over the next few days, sea ice extent may well fall somewhat further, and reach a level below the 2011 minimum, thus reaching the third lowest minimum extent since record began. This could eventuate due to winds compacting the sea ice.

More importantly, sea ice thickness is still falling, as illustrated by the image below showing the sea ice thickness on September 9 in the left panel and a forecast for thickness on September 24 in the right panel.


The image below compares sea ice thickness between September 24, 2012 (left panel) with that forecast for September 24, 2015 (right panel).


Above image illustrates why the situation in 2015 is even more threatening than it was in 2012. Only the ice that is colored light green, yellow and red is more than 3 meters thick. In 2015, ocean heat has been melting the sea ice from underneath. So, even while the currently lower temperatures of the air may have resulted in a slight increase in extent over the past week, the added ice is very thin. Ocean heat first of all goes into melting the thickest sea ice, i.e. the parts that are meters below the surface. This because the water at surface level is colder than the water underneath the surface. This explains why much of the water surface will remain covered by (very thin) ice as air temperatures are now falling (compared to air temperatures over the past few months).

The image below shows sea surface temperatures as at September 17, 2015.


In conclusion, while the sea ice appears to have survived the 2015 melting season without collapsing, the threat that this will occur in the coming years is ominous. Lack of multi-year sea ice makes that sea ice is in a very vulnerable situation. Total collapse of sea ice is therefore more likely to happen in the coming years. Every time ocean heat will arrive in the Arctic Ocean at its fullest strength in future, this heat will no longer be able to be fully absorbed by the process of melting thick sea ice, so what's left of the sea ice will melt very quickly.

There is a strengthening El Niño, while more open water increases the chance that storms will develop that will push the last remnants of the sea ice out of the Arctic Ocean, as discussed in earlier posts such as this one. Storms can also mix warm surface waters all the way down to the seafloor, as discussed in this earlier post. Cyclones that emerge with greater force due to high sea surface temperatures further increase this danger.

The big danger is that ocean heat will cause methane contained in sediments on the Arctic Ocean seafloor to be released abruptly in large quantities, triggering further methane releases spiraling into runaway warming.

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


Below is a text-only version of this post for radio.




Sea ice thickness on September 24, 2012 (left panel) compared to a forecast for September 24, 2015 (right panel). This...
Posted by Sam Carana on Friday, September 18, 2015

Tuesday 1 September 2015

Arctic Sea Ice Collapse Threatens - Update 7

The image below shows Arctic sea ice extent, with the blue dot indicating that extent for August 30, 2015, was 4.804 million square kilometers. Satellite records shows that, at this time of the year, extent was only lower in 2007, 2011 and 2012.


There are a number of reasons why sea ice looks set to decrease dramatically over the next few weeks. On above image, extent for 2015 looks set to soon cross the lines for the years 2007 and 2011, while the sea ice today is in an even worse condition than one might conclude when looking at extent alone.

Thick sea ice is virtually absent compared to the situation in the year 2012 around this time of year, as illustrated by the image below that compares sea ice thickness on August 30, 2012 (left) with August 30, 2015 (right).


Furthermore, sea surface temperatures are very high. The North Pacific, on August 31, 2015, was about 1°C (1.8°F) warmer than it was compared to the period from 1971 to 2000, as illustrated by the Climate Reanalyzer image on the right.

As the image below shows, sea surface temperature anomalies are very high around North America, both in the Pacific Ocean and in the Atlantic Ocean.

The image below shows sea surface temperatures on August 30, 2015, indicating that a huge amount of ocean heat has accumulated in the Atlantic Ocean off the coast of North America.


The Gulf Stream is carrying much of this warm water toward the Arctic Ocean. Additionally, warm water from the Pacific Ocean is entering the Arctic Ocean through the Bering Strait.


Above image below shows sea surface temperature anomalies in the Arctic as at August 31, 2015.




There still are a few weeks to go before sea ice can be expected to reach its minimum, at around half September 2015, while sea currents will continue to carry warmer water into the Arctic Ocean for months to come.

There is a strengthening El Niño, while more open water increases the chance that storms will develop that will push the last remnants of the sea ice out of the Arctic Ocean, as discussed in earlier posts such as this one. Storms can also mix warm surface waters all the way down to the seafloor, as discussed in this earlier post. Typhoons increase this danger. The above image show three typhoons in the Pacific Ocean on 30 August, 2015, and the Climate Reanalyzer image on the right shows them on September 1, 2015.

These typhoons are headed in the direction of the Arctic. The Climate Reanalyzer forecast for September 8, 2015, below shows typhoons in the Pacific Ocean close to the Arctic Ocean, as well as strong wind over the Arctic Ocean.


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

Thick sea ice is virtually absent compared to the situation in the year 2012 around this time of year....
Posted by Sam Carana on Tuesday, September 1, 2015