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

Monday 24 August 2015

Arctic Sea Ice Collapse Threatens - Update 6

The image below shows Arctic sea ice extent, with the blue dot indicating that extent for August 22, 2015, was 5.382 million square kilometers. The record 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 could fall dramatically over the next few weeks.

First of all, the situation today is in an even worse condition than one might conclude when looking at sea ice extent alone. The way NSIDC calculates extent is by first dividing the satellite image into a grid and then including each cell in extent that has 15% or more ice. So, if a few small and very thin pieces of ice floating in a cell happen to cover 15% of a cell, it is counted in as "sea ice".

There is quite a difference between the sea ice that was 5 meters thick north of Greenland in 2012 and the ice that is present there now. The image on the right shows the north-east corner of Greenland on the bottom left. There is almost no ice north of this point.

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 20, 2012 (left) with August 20, 2015 (right), from an earlier post.



Furthermore, sea surface temperatures are very high. The North Pacific, on August 23, 2015, was exactly 1°C (1.8°F) warmer than it was compared to the period from 1971 to 2000 (see Climate Reanalyzer image right).

As the image below shows, sea surface temperature anomalies are very high around North America. On August 23, 2015, sea surface temperature anomalies as high as 6.4°C (11.5°F) were recorded in the Bering Strait.

This is where warm waters from the Pacific Ocean are flowing into the Arctic Ocean.


The image below shows sea surface temperatures on August 22, 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. On August 21, 2015, sea surface temperatures near Svalbard were as high as 17°C (62.6°F), a 12°C (21.5°F) anomaly, at the location marked by the green circle on the image below, showing sea surface temperatures in the top panel and sea surface temperature anomalies in the bottom panel.


The image below shows sea surface temperature anomalies in the Arctic as at August 23, 2015.


[ click on image to enlarge ]
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.

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, while storms can also mix warm surface waters all the way down to the seafloor, as discussed in this earlier post. The Climate Reanalyzer forecast for August 26, 2015, on the right shows strong winds both in the Bering Strait and the North Atlantic.

Typhoons increase this danger. The Climate Reanalyzer forecast for August 27, 2015, below shows a typhoon in the Pacific Ocean close to the Arctic Ocean.


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



On August 21, 2015, sea surface temperatures near Svalbard were as high as 17°C (62.6°F), a 12°C (21.5°F) anomaly, at...
Posted by Sam Carana on Monday, August 24, 2015

Tuesday 18 August 2015

Disappearance Of Thick Arctic Sea Ice

[ view full image at facebook ]


Arctic sea ice is in a horrible state. On August 16, 2015, Arctic sea ice extent was 5.786 million square km, the smallest extent on record for this time of year except for the years 2007, 2011 and 2012, as illustrated by the image on the right.

The situation today is even worse than one might conclude when looking at sea ice 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 comparing sea ice thickness on August 16, 2012 (left) with August 16, 2015 (right).


The ice used to be over 4 m thick, or over 13 ft thick, north of Greenland and the Canadian Archipelago. This thick multi-year ice has been a feature of the Arctic sea ice for over 100,000 years. It used to be there all year long, unlike the thinner ice that could melt away entirely during the melting season.

The disappearance of this thick multi-year ice is a major development. Why? 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, and huge amounts of heat that would otherwise go into melting the ice will instead be warming up the Arctic Ocean, further accelerating warming of its waters.

Absence of thick sea ice makes it more prone to collapse, and this raises the question whether the sea ice could collapse soon, even this year. Sea ice works like a mirror. Without sea ice, sunlight that was previously reflected back into space, will instead be absorbed by the Arctic. Albedo changes in the Arctic alone could more than double the net radiative forcing resulting from the emissions caused by all people of the world, as calculated by Prof. Peter Wadhams back in 2012.

Furthermore, there is a danger that loss of the sea ice will weaken the currents that currently cool the bottom of the sea, where huge amounts of methane may be present in the form of free gas or hydrates in sediments. This danger is illustrated by the image below by Reg Morrison, from an earlier post.


Absence of sea ice also goes hand in hand with opportunities for storms to develop over the Arctic Ocean. Such storms could push the remaining sea ice out of the Arctic Ocean. Such storms could also mix surface heat all the way down to the seafloor, where methane could be contained in sediments.

As described in an earlier post, sea surface anomalies of over 5 degrees Celsius were recorded in August 2007 (NOAA image right). Strong polynya activity caused more summertime open water in the Laptev Sea, in turn causing more vertical mixing of the water column during storms in late 2007, as described in this study, and bottom water temperatures on the mid-shelf increased by more than 3 degrees Celsius compared to the long-term mean.

Indeed, the danger is that heat will warm up sediments under the sea, containing methane in hydrates and as free gas, causing large amounts of this methane to escape rather abruptly into the atmosphere.

The image on the right, from a study by Hovland et al., shows that hydrates can exist at the end of conduits in the sediment, formed when methane did escape from such hydrates in the past.

Heat can travel down such conduits relatively fast, warming up the hydrates and destabilizing them in the process, which can result in huge abrupt releases of methane.

Since waters can be very shallow in the Arctic, much of the methane can then rise up through these waters without getting oxidized. As the methane causes further warming in the atmosphere, this will contribute to the danger of even further methane escaping, further accelerating local warming, in a vicious cycle that can lead to catastrophic conditions well beyond the Arctic. For additional feedbacks in the Arctic, see the feedbacks page

At the same time, ocean heat is at a record high and there's an El NiƱo that's still gaining strength. 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. The image below shows sea surface temperatures on August 16, 2015 (left) and anomalies (right).


How warm is the water entering the Arctic Ocean? Merely looking at sea surface temperatures could make one overlook the full extent of the predicament we are in. Ocean heat traveling underneath the sea surface can be even warmer than temperatures showing up at the surface. This is illustrated by the image below indicating that on August 16, 2015, warm water emerged at the sea surface near Svalbard with temperatures as high as 14.9°C or 58.7°F, a 9.5°C or 17.1°F anomaly.


There still is about a month 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.

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, as illustrated by...
Posted by Sam Carana on Tuesday, August 18, 2015

Sunday 16 August 2015

Arctic Sea Ice Collapse Threatens - Update 5

The image below shows sea surface temperatures in the Arctic as at August 15, 2015.



Below a time lapse video, covering the period from May 30 to August 15, 2015, created by Cameron Forge with daily images from NPEO Webcam 1 from the North Pole Environmental Observatory, National Science Foundation. For a drift map of the buoys, also see this page.



Below is an August 14, 2015, satellite image from Arctic.io showing that there is very little sea ice to the north east of Greenland and what is there looks to be very thin as well.


The image below shows Arctic sea ice extent, with the blue dot indicating the extent for August 14, 2015.




More will follow soon.



Sea surface temperatures in the Arctic as at August 15, 2015.http://arctic-news.blogspot.com/2015/08/arctic-sea-ice-collapse-threatens-update-5.html
Posted by Sam Carana on Sunday, August 16, 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

Saturday 25 July 2015

Arctic Ocean Temperatures Keep Rising

People's emissions are causing the planet to heat up and more than 93% of this heat goes into the oceans.

People have measured ocean temperatures for a long time. Reliable records go back to at least 1880. Ever since records began, the oceans were colder than they are now. NOAA analysis shows that, on the Northern Hemisphere, the 20th century average for June is 16.4°C (61.5°F). In June 2015, it was a record 0.87°C (1.57°F) higher.

Back in history, there have been times when it was warmer. The last time when it was warmer than today, during the Eemian Period, peak temperature was only a few tenths of a degree higher than today, according to the IPCC. In those days, there was huge melting, accompanied by extreme storms and sea levels that were 5 to 9 m higher than today.


In many ways, the situation now already looks worse than it was in the Eemian. "The warm Atlantic surface current was weaker in the high latitude during the Eemian than today", says Henning Bauch.

Carbon dioxide levels during the Eemian were well under 300 ppm. So, there could well have been more pronounced seasonal differences then, i.e. colder winters that made that the average ocean temperature didn't rise very much, despite high air temperature in summer. By contrast, today's high greenhouse levels make Earth look set for a strong ocean temperature rise.

As illustrated by above image, contained in ocean temperature data from 1880 for the Northern Hemisphere is a polynomial trendline that points at a rise of almost 2°C by 2030. This indicates that temperatures across the Arctic Ocean could soon be even higher than the peak temperature was back in the Eemian Period. Indeed, the Arctic Ocean temperature is rising at a terrifying pace, the more so given that there seems to be no end in sight soon for this rise. 


This rise of almost 2°C by 2030 is not limited to the month of June. As above image shows, it applies to the 12-months period from July 2014 to June 2015 as well.

In some places, the Arctic Ocean is already very warm. Sea surface temperatures around North America have increased to very high levels and they are threatening to further raise the temperature of the Arctic Ocean.

The Arctic sea ice is on the verge of collapse, as discussed in earlier posts such as this one and this one. 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 screenshot below showing high carbon dioxide concentrations over the Arctic (from NASA video).



    Furthermore, methane levels are very high over the Arctic. An earlier image showed methane levels as high as 2512 parts per billion on July 17, 2015, with high methane levels north of Greenland that also showed up on an earlier image at this post.

  2. High levels of ocean heat in the North Atlantic, 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 sea surface temperatures in the Arctic Ocean, as illustrated by the image below.

  4. High air temperatures over North America and Russia extending over the Arctic Ocean, as illustrated by the image below showing a location well inside the Arctic Circle where temperatures as high as 37.1°C (98.78°F) were recorded on July 2, 2015. (green circle).


  5. Wildfires triggered by these heatwaves resulting in darkening compounds settling on snow and ice, making it more prone to melting, as illustrated by the image below showing smoke reaching high up into the Beaufort Sea on July 22, 2015.


  6. 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 19, 2015. 
The danger is that collapse of the sea ice will further accelerate warming in the Arctic, as sunlight that was previously reflected back into space and heat that previously went into melting then will all be absorbed by the Arctic. Furthermore, more open waters will increase the possibility of storms that can mix surface heat down to the bottom of the seafloor, and destabilize sediments that contain large amounts of methane in hydrates and free gas.

Such feedbacks are further discussed at the feedbacks page, including the danger that further warming of the Arctic Ocean will unleash huge methane eruptions from the Arctic Ocean seafloor, in turn driving temperatures up even higher and causing more intense wildfires, heatwaves and further extreme weather events.

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.



People's emissions are causing the planet to heat up and more than 93% of this heat goes into the oceans. People have...
Posted by Sam Carana on Saturday, July 25, 2015