Showing posts with label collapse. Show all posts
Showing posts with label collapse. Show all posts

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

Friday 14 August 2015

Arctic Sea Ice Collapse Threatens - Update 4


On August 12, 2015, Arctic sea ice extent was 6.043 million square km. For this date, the only years on record that sea ice extent was smaller were 2007, 2011 and 2012, as illustrated by above image.

Similarly, on August 11, 2015, Arctic sea ice area on August 11, 2015, was 3.67025 million square km (bottom end yellow line). For this date, the only years on record that sea ice area was smaller were 2007, 2011 and 2012.

So, will Arctic sea ice reach a record low this year? The situation is actually a lot worse than it appears when just looking at sea ice extent and area up until now. 

In fact, sea ice is in a horrible state. One indication of this is the almost complete absence of thick sea ice on August 12, 2015, which becomes even more clear when compared with the situation in 2012 for the same date, as illustrated by the image below. 

The absence of thick sea ice means that, in terms of volume, there is very little sea ice left to melt until the minimum volume will be reached around half September. In other words, the remaining sea ice could melt rather quickly. 


Also note the presence of water on the image below, from Web Cam 1, from the North Pole Environmental Observatory, National Science Foundation. For a drift map of the buoys, also see this page.


The image below shows sea surface temperature anomalies in the Arctic on August 13, 2015.


As discussed earlier, Greenland's dramatic losses of ice mass over the past few years and the subsequent large volumes of meltwater have affected sea surface temperatures in the North Atlantic and have caused the sea ice to be larger than it would otherwise have been in terms of extent and area.

Nonetheless, this has not halted the overall rise of ocean heat and the subsequent decline of Arctic sea ice, as illustrated by the discussion further above on sea ice thickness. Thick sea ice is shattered if not absent altogether in many places. 

Until now, the thicker multi-year sea ice used to survive the melting season, giving the sea ice strength for the next year, by acting as a buffer to absorb heat that would otherwise melt away the thinner ice. Without multi-year sea ice, the Arctic will be in a bad shape in coming years. Absence of thick sea ice makes it more prone to collapse, and this raises the question whether a collapse could occur not merely some years from now, but even this year.

Meanwhile, ocean heat is at a record high and there's an El Nino that's still gaining strength. The image below illustrates that a huge amount of ocean heat has been piling up in the Atlantic Ocean, ready to be carried into the Arctic Ocean, while large amounts of heat are also entering the Arctic Ocean from the Pacific Ocean through  the Bering Strait.

Sea surface temperatures around North America - note that the top end of the scale is 35°C or 95°F 

This ocean heat is likely to reach the Arctic Ocean in full strength by October 2015, at a time when sea ice may still be at its minimum. Absence of sea ice goes hand in hand with opportunities for storms to develop over the Arctic Ocean, which could mix surface heat all the way down to the seafloor, where methane could be contained in sediments. 

The methane situation is already very dangerous, given mean methane levels that recently reached levels as high as 1840 ppb, while much higher peak levels can occur locally, as illustrated by the image below. 
Methane levels appear to be rising by over 10 parts per billion a year at Barrow, Alaska. Worryingly, high peaks have been showing up there recently.

In conclusion, Arctic sea ice looks set to take a further battering over the next few weeks and could end up at a record low around half September 2015. If things get really bad, sea ice collapse could occur and the remaining pieces of sea ice could be driven out of the Arctic Ocean altogether by storms, resulting in a blue ocean event as early as September this year.

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



On August 11, 2015, Arctic sea ice area on August 11, 2015, was 3.67025 million square km (bottom end yellow line). For...
Posted by Sam Carana on Friday, August 14, 2015

Sunday 9 August 2015

The Methane Monster


At no time in the past did humans exist under conditions that we are facing now, no matter how far back you go in history.

Global mean methane levels as high as 1840 parts per billion were recorded on August 4, 2015. This is the highest mean level since records began and this new record is likely to be superseded by even higher levels soon.

The carbon dioxide that is released now will only reach its peak impact a decade from now. Methane's high immediate impact makes it more important than carbon dioxide emissions in driving the rate of global warming over the coming decade.

The Pacific Ocean is very warm at the moment. Warm water flows from the Pacific Ocean through the Bering Strait into the Arctic Ocean. Sea surface temperatures in the Bering Strait were as high as 20.5°C (or 69.1°F) on August 4, 2015. That is 8.7°C (or 15.6°F) warmer than the water used to be. Sea surface temperatures as high as 11.8°C (53.2°F) were recorded in between Greenland and Svalbard on August 7, 2015, an anomaly of 8.5°C (15.3°F).

[ click on image to enlarge ]
The danger is that further warming will cause collapse of the sea ice, which in turn will lead to even more rapid warming of the Arctic Ocean, while the presence of more open water will also increase the opportunity for powerful storms to develop that can mix high sea surface temperatures all the way down to the seafloor, resulting in destabilization of sediments and triggering releases of methane that can be contained in such sediments in huge amounts.

Methane releases from the seafloor of the Arctic ocean threaten to cause rapid local warming that in turn will trigger further methane releases, in a vicious cycle of runway warming that could destroy habitat for humans within decades.

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


References

-  Sea surface temperatures in the Bering Strait on August 4, 2015. 

- Sea surface temperatures in between Greenland and Svalbard on August 7, 2015.
http://earth.nullschool.net/#2015/08/07/0000Z/ocean/surface/currents/overlay=sea_surface_temp_anomaly/orthographic=18.75,79.02,3000

- Maximum warming occurs about one decade after a carbon dioxide emission, by Katharine L Ricke and Ken Caldeira (2014)
http://iopscience.iop.org/1748-9326/9/12/124002/article

- Methane's Global Warming Potential
http://arctic-news.blogspot.com/p/faq.html#13



THE METHANE MONSTER - by Sam Carana At no time in the past did humans exist under conditions that we are facing now,...
Posted by Sam Carana on Sunday, August 9, 2015

Monday 3 August 2015

Arctic Sea Ice Collapse Threatens - Update 3

The image below is based on a nullschool.net forecast for August 6, 2015, run on August 2, 2015. It shows temperatures as high as 26.4°C (or 79.4°F) in the north of Canada (green circle). The inset, based on a Climate Reanalyzer forecast for that date, shows that this is as much as 20°C (or 36°F) higher than temperatures that were common in the area only recently, i.e. from 1979-2000.


The satellite image below, captured on August 2, 2015, shows a close-up of the area, with the green circle in the same location as on above image.


Above image shows that there still is some solid ice present to the right of the green circle. This ice may not be able to survive such high temperatures for long. Furthermore, above image shows what looks like smoke plumes from wildfires to the left of the green circle, another sign of the high temperatures in the area and another feedback that will accelerate decline of the snow and ice cover.

Disappearance of sea ice thicker than 4 meters is now taking place north of Canada and Greenland. It looks set to virtually disappear soon, as shown by the 30-day Naval Research Laboratory animation below, ending with a forecast up to August 10, 2015.


In my experience, sea ice thickness hasn't looked this bad for this time of the year since records began, especially when taking the loss of multi-year ice into account. Until now, the thicker multi-year sea ice used to survive the melting season, giving the sea ice strength for the next year, by acting as a buffer to absorb heat that would otherwise melt away the thinner ice. Without multi-year sea ice, the Arctic will be in a bad shape in coming years. Absence of thick sea ice makes it more prone to collapse, and this raises the question whether a collapse could occur not merely some years from now, but even this year.


Above image below shows sea surface temperature anomalies in the Arctic on August 2, 2015.

Greenland's dramatic loss of ice mass over the past few years and the subsequent meltwater may have caused the sea ice to be larger than it would otherwise have been.

Nonetheless, this has not halted the overall decline of the sea ice. As the image on the right shows, sea ice area now is about as low for the time of the year as it was for the three lowest years on record. Furthermore, thick sea ice is shattered if not gone altogether in many places. Meanwhile, ocean heat is at a record high and there's an El Nino that's still gaining strength.

In conclusion, Arctic sea ice looks set to take a further battering over the next few weeks and could end up at a record low around half September 2015. If things get really bad, sea ice collapse could occur and the remaining pieces of sea ice could be driven out of the Arctic Ocean altogether by storms, resulting in a blue ocean event as early as September this year.

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



Arctic sea ice area on July 31, 2015.
Posted by Sam Carana on Sunday, August 2, 2015

Tuesday 21 July 2015

Ocean Temperatures At Record High

Of all the excess heat that results from people's emissions, 93.4% goes into oceans. Accordingly, ocean heat has strongly increased over the years.

NOAA analysis shows that, for the oceans on the Northern Hemisphere, the June 2015 sea surface temperature was at a record high 0.87°C (1.57°F) above the 20th century average of 16.4°C (61.5°F), as also illustrated by the graph below.


The most recent 12-month period, July 2014–June 2015, also broke the record (set just last month) for the all-time warmest 12-month period in the 135-year period of record. 


As the above image shows, sea surface temperature anomalies around North America are very high, threatening to further raise temperatures of the Arctic Ocean, which already has very high sea surface temperatures, as also illustrated by the image below. 


As the image below shows, sea surface temperatures as high as 19°C (66.2°F) were recorded in the Bering Strait on July 19, 2015.



The snow depth comparison below shows the situation on July 20, 2015, on the left and a forecast for July 27, 2015, on the right. The green lines indicate areas where sea ice is at melting point. Note the decline of snow cover on Greenland and the Himalayas.


As the continued snow decline on Greenland also illustrates, high temperatures can be expected to keep causing further decline of the snow and ice cover for many weeks to come, given that the minimum sea ice extent is typically reached about half September.

As the image below shows, sea surface temperatures as high as 10.1°C (50.1°F) were recorded in Baffin Bay, off the west coast of Greenland, on July 20, 2015.


On July 21, 2015, temperatures as high as 14°C (57.1°F) were recorded east of Svalbard, an anomaly of 9.7°C (17.4°F), as illustrated by the image below, created with nullschool.net images.


The danger is that warm water will enter the Arctic Ocean and cause the Arctic sea ice to collapse, which could make the Arctic Ocean absorb even more heat. This could unleash huge methane eruptions from the Arctic Ocean's seafloor, in turn driving temperatures up even higher and causing more extreme weather events, wildfires, etc.

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



For the oceans on the Northern Hemisphere, the June 2015 sea surface temperature was at a record high 0.87°C (1.57°F)...
Posted by Sam Carana on Tuesday, July 21, 2015

Sunday 19 July 2015

Arctic Sea Ice Collapse Threatens - Update 1

The image below compares the Arctic sea ice thickness (in m) on July 15, for the years from 2012 (left panel) to 2015 (right panel), using Naval Research Laboratory images.

Click on image to enlarge
The image below compares the Arctic sea ice concentration (in %) on July 18, for the years from 2012 (left panel) to 2015 (right panel), using Naval Research Laboratory images.


Above images show the dramatic decline of the sea ice in 2015, both in thickness and in concentration.

In terms of thickness, sea ice has been reduced by more than one meter in many places, such as north of Greenland and the Canadian Archipelago, all in the time span of just one month.

The dramatic fall in sea ice concentration also becomes apparent when comparing recent sea ice concentration (July 18, 2015, above right) with sea ice concentration back in May 2015 (image right, May 1, 2015).

This dramatic decline of the sea ice in 2015 is the result of a combination of factors, including:

  1. High levels of greenhouse gases over the Arctic Ocean, as illustrated by the image below, showing that on July 17, 2015 (pm), levels as high as 2512 parts per billion were recorded at 6,041 m (19,820 ft) altitude, while mean methane levels were 1830 parts per billion at this altitude.
  2. High levels of ocean heat, as illustrated by the image below showing high sea surface temperatures off the east coast of North America; much of this ocean heat will be carried by the Gulf Stream into the Arctic Ocean over the next few months.
  3. High air temperatures over North America and Siberia extending over the Arctic Ocean, as illustrated by the image below showing a temperature of 23.1°C (73.7°F), recorded on July 19, 2015, at Banks Island, in the Canadian Archipelago (green circle).
  4. Wildfires triggered by these heatwaves resulting in darkening compounds settling on snow and ice, as illustrated by the image below showing smoke covering a wide area on July 19, 2015, from the east Siberia over North America to the southern tip of Greenland.
  5. Very warm river water running into the Arctic Ocean, as illustrated by the image below, showing sea surface temperatures as high as 19°C (66.2°F) off the coast of Alaska on July 12-15, 2015.
The image below shows the already very high sea surface temperature anomalies as at July 18, 2015.

The Climate Reanalyzer image below shows the high sea surface temperature anomalies in the Pacific Ocean, and where water enter the Arctic Ocean through the Bering Strait, on July 19, 2015.



With still two months of melting to go before the sea ice can be expected to reach its minimum for 2015, the threat of sea ice collapse is ominous. The Arctic-News Blog has been warning for years about the growing chance of a collapse of the sea ice, in which case huge amounts of sunlight that previously were reflected back into space, as well as heat that previously went into melting the ice, will then instead have to be absorbed by the water, resulting in a dramatic rise of sea surface temperatures.

More open water will then come with an increased chance of storms that can cause high sea surface temperatures to be mixed down all the way to seafloor of the Arctic Ocean, which in many cases is less than 50 m (164 ft) deep. This is the case for the East Siberian Arctic Shelf, where experts estimate that huge amounts of methane are contained in subsea sediments. Already now, sea surface temperatures as high as 10°C (~50°F) are recorded there, as illustrated by the image below.


Massive amounts of ocean heat will be carried by the Gulf Stream into the Arctic Ocean over the next few months. The combined result of high sea surface temperatures being mixed down to the seafloor and the ocean heat entering the Arctic Ocean from the Atlantic and Pacific Oceans can be expected to result in dramatic methane eruptions from the Arctic Ocean seafloor by October 2015.

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



Arctic sea ice thickness on July 15, compared over the years 2012 through to 2015. Already virtually all the thick sea...

Posted by Sam Carana on Thursday, July 16, 2015

Friday 4 July 2014

The Threat of Storms Wreaking Havoc in the Arctic Ocean

Arctic sea ice extent is close to a record low for the time of the year, as the image below shows.


Furthermore, the current decline in sea ice extent is much steeper than it used to be for this time of the year, raising the specter of sea ice hitting an absolute record low later this year. Moreover, a total collapse of sea ice may occur if storms continue to develop that push the remaining ice out of the Arctic Ocean into the Atlantic Ocean.


The threat posed by storms is illustrated by the track projected to be followed by Hurricane Arthur (above NOAA image, July 4), renamed as Post-Tropical Cyclone Arthur (NOAA image below, July 5).



The path followed by Arthur is influenced by the current shape of the jet stream. As the animation below illustrates, the jet stream looks set to prevent Hurrican Arthur from moving to the east and instead make it move into the Labrador Sea to the west of Greenland and - partly due to the high mountains on Greenland - continue to wreak havoc in Baffin Bay further north.

[ Note: this animation is a 1.87 MB file that may take some time to fully load ]
As described in an earlier post, post-tropical cyclone Leslie made landfall with hurricane-force winds in Newfoundland in September 2012. The large extratropical low pressure system continued to move rapidly northeastward across eastern Newfoundland at a forward speed of near 45 kt, and merged with a much larger extratropical low over the Labrador Sea.

Recent research by NOAA-affiliated scientists suggests that - over the years - the latitude where hurricanes, typhoons, and cyclones reach their maximum intensity on the Northern Hemisphere has shifted closer to the North Pole.

Such storms can bring lots of heat and moisture into the Arctic, and they can also increase the height of waves. All this can have devastating impact on the sea ice. The many ways in which storms can increase the dangerous situation in the Arctic is described in the post Feedbacks in the Arctic.

Last month, the June heat record broke in Greenland. Very high temperatures are currently recorded all over North America, as the image below shows.


Furthermore, sea surface temperature anomalies in the Arctic are currently very high, as the image below shows.


Additionally, the sea ice is currently very thin, as shown by the Naval Research Laboratory animation below.


The above animation further shows that there now is very little sea ice left in Baffin Bay, making it easier for storms to cause very high waves that could enter the Arctic Ocean and break the sea ice north of Greenland and Canada.

Arctic sea ice volume minimum is typically reached around halfway into September. This is still months away, but the prospect of an El Niño event striking this year now is 90%, according to predictions by the European Centre for Medium-range Weather Forecasts.

All this combines into a growing threat that hydrates contained in sediments will destabilize and that huge quantities of methane will be released abruptly from the seafloor of the Arctic Ocean. The risk that this will eventuate is intolerable and calls for parallel lines of action as pictured in the image below.

Climate Plan, July 7, 2014 version, as discussed at this Climate Plan post and at the Climate Plan blog

Related

- Storm enters Arctic region
arctic-news.blogspot.com/2012/09/storm-enters-arctic-region.html

- Huge cyclone batters Arctic sea ice
arctic-news.blogspot.com/2012/08/huge-cyclone-batters-arctic-sea-ice.html

- Hurricane Sandy moving inland
http://arctic-news.blogspot.com/2012/10/hurricane-sandy-moving-inland.html

- Feedbacks in the Arctic
http://arctic-news.blogspot.com/2014/03/feedbacks-in-the-artcic.html