Showing posts with label storms. Show all posts
Showing posts with label storms. Show all posts

Friday, October 28, 2016

Arctic sea ice extent again at record low for time of year

For some time, Arctic sea ice extent has again been at a record low for the time of the year. The image below shows Arctic sea ice extent on October 26, 2016, when extent was only 6.801 million km².


One reason for the low sea ice extent is the high and rising temperature of the Arctic Ocean. On October 27, 2016, the Arctic Ocean was as warm as 14.8°C or 58.6°F (green circle near Svalbard), 12.1°C or 21.7°F warmer than 1981-2011, as the image below shows.


On October 29, 2016, the Arctic Ocean was as warm as 14.9°C or 58.8°F (green circle near Svalbard), 12.1°C or 21.8°F warmer than 1981-2011, as the image below shows.


As the sea ice shrinks, less sunlight gets reflected back into space, while more open water and higher sea surface temperatures also cause storms and cyclones to become stronger. Stronger cyclones also cause greater amounts of water vapor to move up the Pacific Ocean and the Atlantic Ocean toward the Arctic.

[ click on image to enlarge ]
[ click on image to enlarge ]
Less Arctic sea ice and a warmer Arctic Ocean make that more heat and water vapor gets transferred from the Arctic Ocean to the atmosphere. The two above images show temperature forecasts for November 1 & 2, 2016. In both cases, temperatures over the Arctic as a whole are forecast to be as much as 6.40°C higher than 1979-2000.

As these images show, temperature anomalies in many places are at the top end of the scale, i.e. +20°C or +36°F.


Above combination image shows record low Arctic sea ice for the time of the year (left) and near record low Antarctic sea ice for the time of the year (right), with a combined sea ice extent of only 23.751 million km² on October 28, 2016. In other words, the world is now absorbing a lot of sunlight that was previously reflected back into space.

Below are two further temperature forecast:

Above image shows forecasts for October 31, 2016. The Arctic is forecast to be 6.07°C warmer than 1979-2000, while the Antarctic is forecast to be 4.56°C warmer than 1979-2000.

Above image shows forecasts for November 1, 2016. The Arctic is forecast to be 6.42°C warer than 1979-2000, while the Antarctic is forecast to be 3.70°C warmer than 1979-2000.

Rising temperatures over the Arctic further contribute to a rise in the amount of water vapor in the air over the Arctic at a rate of 7% more water vapor for every 1°C warming. Since water vapor is a potent greenhouse gas, more water vapor further accelerates warming in the Arctic.

The Climate Reanalyzer image below shows the temperature rise in the Arctic over time.


In the video below, Dr. Walt Meier of NASA Goddard Space Flight Center describes how the Arctic has been losing its thicker and older sea ice over the years (1991 to September 2016).


The Naval Research Lab 30-day thickness animation below (up to October 28, 2016, with forecasts up to November 5, 2016) further shows minimal recent growth of the Arctic sea ice, especially in terms of the ice with a thickness of 1m or above.



As the Arctic Ocean gets warmer, the danger grows that large amounts of methane will erupt from destabilizing hydrates at its seafloor. Ominously, high methane levels are visible over the Arctic on the image below, showing methane levels as high as 2424 ppb on October 24, 2016.

The animation below, made with images from another satellite (and a different scale), shows high methane levels over th Arctic Ocean from October 26 to 28, 2016.


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


Monday, September 7, 2015

Arctic Sea Ice Collapse Threatens - Update 8

The image below, from Arctic-roos.org, shows Arctic sea ice extent up to September 6, 2015.
Editorial note: The dramatic drop in sea ice extent shown on the image below turns out to be an error. The website at Arctic-roos.org is being updated and will show the correct extent soon.
The image shows a recent drop in sea ice extent that is so dramatic (red line, i.e. extent for the year 2015) that some think that it must be a glitch in the system. Even so, it should act as a warning about deterioration of the sea ice in the Arctic.

As discussed in earlier posts, the sea ice today is in a terrible condition. 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 September 5, 2012 (left panel) with September 5, 2015 (right panel).


Furthermore, sea surface temperatures are very high. The North Pacific, on September 3, 2015, was more than 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.

Sea surface temperature are very high around North America, both in the Pacific Ocean and in the Atlantic Ocean. The image below shows sea surface temperatures on September 4, 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 pushing 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 September 6, 2015. 

As the Arctic warms up faster than the rest of the world, the jet stream becomes ever more destabilized, as illustrated by the image below


The image on the right, from the Naval Research Laboratory, shows sea ice speed and drift as forecast on September 5, 2015, for September 6, 2015. 

The situation looks set to get worse. Warm oceans increase the chance that strong winds will emerge that can have a devastating impact on the remaining sea ice in the Arctic.

As the September 7, 2015, image below right shows, cyclones are lining up in the Pacific Ocean, with their strongest impact yet to hit the Arctic Ocean. 

There still is some time 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. Cyclones increase this danger.

These cyclones are headed in the direction of the Arctic. The Climate Reanalyzer forecast for September 14, 2015, below shows strong winds over the Pacific Ocean close to the Arctic Ocean, as well as over the Arctic Ocean and the North Atlantic.


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



Sea surface temperature anomalies in the Arctic as at September 6, 2015. From 'Arctic Sea Ice Collapse Threatens -...
Posted by Sam Carana on Monday, September 7, 2015

Monday, August 24, 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, August 18, 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 Niño 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

Tuesday, July 28, 2015

Storms Over Arctic Ocean

The image below shows sea surface temperature anomalies over the Arctic on July 27, 2015.

departure from 1961-1990 temperatures, click on image to enlarge ]
The image below shows sea surface temperature anomalies on July 28, 2015.

[ departure from 1971-2000 temperatures, click on image to enlarge ]

There is a growing chance that the sea ice will collapse over the next few weeks, due to heavy melting and storms speeding up the flow of sea ice out of the Arctic Ocean into the Atlantic Ocean.

An example of such storms is shown on the animation below. This is a forecast for July 31, 2015, showing cyclonic winds at the center of the Arctic Ocean, with strong winds moving sea ice down Fram Strait.


The above situation alone is not likely to trigger sea ice collapse. It is more likely to be short-lived. However, there is a growing possibility for such storms to emerge and drive the melting sea ice out of the Arctic Ocean into the Atlantic Ocean.

As the situation in the Arctic further deteriorates, feedbacks can be expected to kick in with growing strength.

One of these feedbacks is the growing amount of heat (due to both latent heat and albedo changes) that will have to be absorbed by the Arctic Ocean as the sea ice disappears, and that will accelerate warming of the water of the Arctic Ocean.

Another feedback is a changing jet stream, as illustrated in above animation. This, in combination with the presence of more open water, can be expected to cause increasingly intense storms over the Arctic to emerge. Such storms can bring more heat into the Arctic Ocean, especially during heatwaves over North America and Russia. Such heatwaves can further cause surface heat to be mixed down to the seafloor, especially in the many places where the Arctic Ocean is very shallow. This can in turn cause destabilization of hydrates, resulting in huge amounts of methane to be abruptly released from the seafloor.

Methane itself is yet another feedback that will accelerate warming in the Arctic, in turn threatening to trigger further methane releases in a spiral of self-reinforcing positive feedback loops.

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



Sea surface temperatures over the Arctic on July 27, 2015. There is a growing chance that the sea ice will collapse over...
Posted by Sam Carana on Tuesday, July 28, 2015

Friday, July 4, 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