Friday, February 26, 2016

Three kinds of warming in the Arctic

The Arctic is prone to suffer from three kinds of warming. Firstly, the Arctic is hit particularly hard by emissions, as discussed in earlier posts such as this one and this one.

Secondly, warming in the Arctic is accelerating due to feedbacks, as discussed on the feedbacks page. Many such feedbacks are related to decline of the snow and ice cover in the Arctic, which is in turn made worse by emissions such as soot.

Thirdly, the most dangerous feedback is release of methane from the Arctic Ocean seafloor, due to hydrates getting destabilized as heat reaches sediments.


Last year, Arctic sea ice reached its maximum extent on February 25, 2015. This year, there was a lot less sea ice in the Arctic on February 25 than there was last year, as illustrated by above image. The difference is about 300,000 square km, more than the size of the United Kingdom.

The image below shows that global sea ice on February 22, 2016, was only 14.22086 million square km in area. It hasn't been that low since satellite records started to measure the sea ice.


A number of feedbacks are associated with the decline of sea ice, such as more sunlight being absorbed by the water, instead of being reflected back into space as it was previously. Furthermore, there are three kinds of warming active in the Arctic, as described above and as depicted by the image below.


Sea ice can reflect as much as 90% of the sunlight back into space. Once the ice has melted away, however, the water of the ocean reflects only 6% of the incoming solar radiation and absorbs the rest. This is depicted in above image as feedback #1.


As Professor Peter Wadhams once calculated, warming due to Arctic snow and ice loss could more than double the net warming now caused by all emissions by all people of the world.

Professor Peter Wadhams on albedo changes in the Arctic, image from Edge of Extinction
As the sea ice melts, sea surface temperatures will remain at around zero degree Celsius (32°F) for as long as there is ice in the water, since rising ocean heat will first go into melting the ice. Only after the ice has melted will ocean heat start raising the temperature of the water. Sea ice thus acts as a buffer that absorbs heat, preventing water temperatures from rising. As long as sea ice is melting, each gram of ice will take 334 Joule of heat to change into water, while the temperature remains at 0° Celsius or 32° Fahrenheit.

Once all ice has turned into water, all further heat goes into heating up the water. To raise the temperature of one gram of water by one degree Celsius then takes only 4.18 Joule of heat. In other words, melting of the ice absorbs 8 times as much heat as it takes to warm up the same mass of water from zero to 10°C. This is depicted in the image on the right as feedback #14.



Above video, created by Stuart Trupp, shows how added heat at first (A) goes mainly into warming up water that contains ice cubes. From about 38 seconds into the movie, all heat starts going into the transformation of the ice cubes into water, while the temperature of the water doesn't rise (B). More than a minute later, as the ice cubes have melted (C), the temperature of the water starts rising rapidly again.

Methane is a further feedback, depicted as feedback #2 on the image further above. As the water of the Arctic Ocean keeps getting warmer, the danger increases that heat will reach the seafloor where it can trigger release of huge amounts of methane, in an additional feedback loop that will make warming in the Arctic accelerate and escalate into runaway warming.

Sediments underneath the Arctic Ocean hold vast amounts of methane. Just one part of the Arctic Ocean alone, the East Siberian Arctic Shelf (ESAS, see map below), holds up to 1700 Gt of methane. A sudden release of less than 3% of this amount could add 50 Gt of methane to the atmosphere, and experts have warned for many years that they consider such an amount to be ready for release at any time.


Above image gives a simplified picture of the threat, showing that of a total methane burden in the atmosphere of 5 Gt (it is meanwhile higher), 3 Gt that has been added since the 1750s, and this addition is responsible for almost half of all antropogenic global warming. The amount of carbon stored in hydrates globally was in 1992 estimated to be 10,000 Gt (USGS), while a more recent estimate gives a figure of 63,400 Gt (Klauda & Sandler, 2005). Once more, the scary conclusion is that the East Siberian Arctic Shelf (ESAS) alone holds up to 1700 Gt of methane in the form of methane hydrates and free gas contained in sediments, of which 50 Gt is ready for abrupt release at any time.

The warning signs keep getting stronger. Following a peak methane reading of 3096 ppb on February 20, 2016, a reading of 3010 ppb was recorded in the morning of February 25, 2016, at 586 mb (see image below).

Again, this very high level was likely caused by methane originating from the seafloor of the Arctic Ocean, at a location on the Gakkel Ridge just outside the East Siberian Arctic Shelf (ESAS), as discussed in the earlier post. This conclusion is supported by the methane levels at various altitudes over the ESAS, as recorded by both the MetOp-1 and MetOp-2 satellites in the afternoon, as illustrated by the combination image below showing methane levels at 469 mb.


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


Links

- Feedbacks in the Arctic
http://arctic-news.blogspot.com/p/feedbacks.html

- Albedo changes in the Arctic
http://arctic-news.blogspot.com/2012/07/albedo-change-in-arctic.html

- The time has come to spread the message
http://arctic-news.blogspot.com/2013/12/the-time-has-come-to-spread-the-message.html

- Greenhouse gas levels and temperatures keep rising
http://arctic-news.blogspot.com/2016/01/greenhouse-gas-levels-and-temperatures-keep-rising.html

- Arctic sea ice area at record low for time of year
http://arctic-news.blogspot.com/2016/01/arctic-sea-ice-area-at-record-low-for-time-of-year.html

- Has maximum sea ice extent already been reached this year?
http://arctic-news.blogspot.com/2016/02/has-maximum-sea-ice-extent-already-been-reached-this-year.html

- Global sea ice extent record minimum - Arctic Sea Ice Blog
http://neven1.typepad.com/blog/2016/02/global-sea-ice-extent-minimum-record.html

- Warming of the Arctic Fueling Extreme Weather
http://arctic-news.blogspot.com/2014/06/warming-of-the-arctic-fueling-extreme-weather.html

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



Last year, Arctic sea ice reached its maximum extent on February 25, 2015. This year, there's a lot less sea ice in the...
Posted by Sam Carana on Friday, February 26, 2016

Tuesday, February 23, 2016

Arctic Winter Heatwave

The Arctic is experiencing a heatwave in winter, with temperature anomalies on February 23, 2016, averaging 7.84°C or 14.11°F higher than what was common 1979-2000.


The forecast for 6:00 UTC on February 23, 2016, shows an anomaly of 8.17°C or 14.71°F.


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, from an earlier post.

These high temperatures go hand in hand with sea ice extent that is much lower for this time of year than since records started.

As discussed in an earlier post, low sea ice extent is fueling fears that this year's maximum extent was already reached on February 9, 2016.

A much higher ocean temperature is behind both the low sea ice extent and the high temperature anomalies.

Ocean temperatures are particularly high where the Gulf Stream pushes water from Atlantic Ocean into the Arctic Ocean, as illustrated by the image below that compares sea surface temperature anomalies in the Arctic between the years 2015 and 2016 for February 22nd.


This spells bad news for the sea ice in 2016, since El Niño is still going strong and ocean temperature keeps rising, as illustrated by the NOAA global ocean temperature anomalies graph for January below.

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



ARCTIC WINTER HEATWAVE The Arctic is experiencing a heatwave in winter, with temperature anomalies on February 23,...
Posted by Sam Carana on Tuesday, February 23, 2016

Thursday, February 18, 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.


The image below shows that Arctic sea ice extent on February 21, 2016, was only 14.160
million km2 (arrow), further fueling 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, February 15, 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