Showing posts with label wind. Show all posts
Showing posts with label wind. Show all posts

Friday, August 19, 2016

Storms over Arctic Ocean


Winds over the Arctic Ocean reached speeds of up to 32 mph or 52 km/h on August 19, 2016. The image below shows the Jet Stream crossing Arctic Ocean on August 19, 2016 (see map on above image for geographic reference).


The Naval Research Lab image on the right shows a forecast for sea ice speed and drift run on August 15, 2016, and valid for August 17, 2016.

These storms come at a time when the sea ice has become extremely thin, as illustrated by the Naval Research Lab sea ice thickness animation below, covering a 30-day period run on August 17, 2016, with a forecast through to August 25, 2016. The animation shows that the multi-year sea ice has now virtually disappeared.

With the sea ice in such a bad shape, strong winds can cause a rapid drop in sea ice extent, at a time when the Arctic still has quite a bit of insolation. At the North Pole, insolation will come down to zero at the time of the September 2016 Equinox.


Even more terrifying is the Naval Research Lab's Arctic sea ice thickness forecast for August 25, 2016, run on August 17, 2016, using a new Hycom model, as shown on the right.

With the thicker multi-year sea ice now virtually gone, the remaining sea ice is prone to fracture and to become slushy, which also makes it darker in color and thus prone to absorb more sunlight.

Furthermore, if strong winds keep hitting the Arctic Ocean over the next few weeks, this could push much of the sea ice out of the Arctic Ocean, along the edges of Greenland and into the Atlantic Ocean.
Strong winds are forecast to keep hitting the Arctic Ocean hard for the next week, as illustrated by the image on the right showing a forecast for August 24, 2016.

As sea ice extent falls, less sunlight gets reflected back into space and is instead absorbed by the Arctic. Once the sea ice is gone, this can contribute to a rapid rise in temperature of the surface waters.

The video below shows cci-reanalyzer.org wind speed at 10 meters forecasts from August 25, 2016 1800 UTC to September 2, 2016 0300 UTC.


The left panel on the image below shows winds (surface) reaching speeds as high as 61 km/h or 38 mph over the Arctic Ocean (green circle), while the right panel shows winds at 250 hPa (jet stream).


As the Arctic warms faster than the rest of the world, the temperature difference between the Equator and the Arctic decreases, slowing down the speed at which the Northern Polar Jet Stream circumnavigates Earth, and making it wavier.

As a result, the Jet Stream can extend far over North America and Eurasia, enabling cold air to move more easily out of the Arctic (e.g. deep into Siberia) and at the same time enabling warm air to move more easily into the Arctic (e.g. from the Pacific Ocean). Such changes to the jet stream also enable strong winds to cross East Siberia more easily and cause stormy weather over the Arctic Ocean.

This is illustrated by the image below. The left panel shows the jet stream crossing East Siberia at speeds as high as 277 km/h or 172 mph on August 27, 2016, while at surface level cyclonic winds occurring over the Arctic ocean reached speeds as high as 78 km/h or 48 mph that day.

The right panel shows that, on that day, cold air moved deep into Central Siberia, resulting in temperatures as lows as -15.9°C or 3.5°F in Central Siberia and temperatures that were higher than they used to be over the Arctic Ocean.


[ click on image to enlarge ]
The image on the right shows surface winds (top) and winds at 250 hPa (i.e. jet stream, bottom) over the Arctic Ocean causing snow (blue) and rain (green) to fall north of Greenland (center).

Rain can have a devastating impact on the sea ice, due to kinetic energy breaking up the ice as it gets hit.

This can fragment the ice, resulting in water that is warmer than the ice to melt it both at the top and at the sides, in addition to melting that occurs at the bottom due to ocean heat warming the ice from below and melting that occurs at the top due to sunlight warming the ice from above.

Furthermore, where the rainwater stays on top of the sea ice, pools of water will form, fed by rainwater and meltwater. This will darken the surface. Melting sea ice is also darker in color and, where sea ice melts away altogether, even darker water will emerge. As a result, less sunlight is getting reflected back into space and more sunlight is instead absorbed.

The image below shows Arctic sea ice thickness (in m, nowcast, run on August 27, 2016, valid for August 28, 2016, panel left) and Arctic sea ice speed and drift (in cm per second, nowcast, run on August 27, 2016, valid for August 28, 2016, panel right).


The danger is that such storms, especially at this time of year, can push much sea ice out of the Arctic Ocean, along the edges of Greenland, into the Atlantic Ocean.


This danger grows as the sea ice gets thinner. Above image shows ice thickness (in m) nowcasts, run on August 30 and valid for August 31, for each year from 2012 to 2016.


Next to loss of snow and ice cover, another big danger in the Arctic is methane releases.

Above image shows methane levels as high as 2454 ppb on August 25, 2016 (top panel), strong releases from Alaska to Greenland on August 26, 2016 (middle panel), and mean methane levels as high as 1862 ppb on August 27, 2016 (bottom panel).

The image on the right shows high methane levels recorded at Barrow, Alaska, up to August 30, 2016.

The image below shows cyclonic winds (center left) over the Arctic Ocean on August 22, 2016.


The image below shows how little sea ice was left at locations close to the North Pole on August 25, 2016.


[ click on images to enlarge ]
The image on the right shows that Arctic sea ice extent was 4.8 million square km on August 27, 2016, according to the NSIDC.

NOAA data show that the July 2016 global land and ocean temperature was 16.67°C or 62.01°F, the highest temperature for any month on record.

The image below on the right shows July sea surface temperature anomalies (compared to the 20th century average) on the Northern Hemisphere.

This ocean heat is now being carried by the Gulf Stream toward to Arctic Ocean.

Meanwhile, the cold sea surface area that was so pronounced over the North Atlantic in 2015, is getting overwhelmed by ocean heat.

This is illustrated by the image below showing sea surface temperature anomalies on August 27, 2015 (left panel) and on August 27, 2016 (right panel).


The image below shows sea surface temperature anomalies in the Arctic (latitude 60°N-90°N) compared to 1961-1990.


The Climate Reanalyzer image below also shows sea surface temperature anomalies August 16, 2016, this time compared to 1979-2000.


The image below, from an earlier post, shows sea surface temperature anomalies on August 12, 2016, in the left-hand panel, and sea surface temperature anomalies in the right-hand panel.

Sea surface temperature and anomaly. Anomalies from +1 to +2 degrees C are red, above that they turn yellow and white
Above image also shows that on August 12, 2016, sea surface temperatures near Svalbard (at the location marked by the green circle) were as high as 18.9°C or 65.9°F, an anomaly of 13.6°C or 24.4°F.

As said above, changes to the Jet Stream enable warm air to move more easily into the Arctic Ocean and cold air to move more easily out of the Arctic Ocean. Where seas are shallow, a surface temperature rise can quickly warm up water all the way down to the Arctic ocean seafloor, where it can destabilize methane hydrates contained in sediments.

This could make that huge amounts of methane get released from the seafloor. Given that many of the seas in Arctic are very shallow, much of this methane can enter the atmosphere without getting broken down in the water, resulting in huge additional warming, especially over the Arctic. As discussed in an earlier post, this could contribute to a global temperature rise of over 10°C or 18°F by the year 2026.

One of the people who has been warning about these dangers for many years is Professor Peter Wadhams, whose new book A Farewell to Ice was recently launched (256 pages, published September 1, 2016).

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


Links

 Wildfires in Russia's Far East
http://arctic-news.blogspot.com/2016/08/wildfires-in-russias-far-east.html

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

 Rain Storms Devastate Arctic Ice And Glaciers 
http://arctic-news.blogspot.com/2015/01/rain-storms-devastate-arctic-ice-and-glaciers.html

 High Temperatures in the Arctic
http://arctic-news.blogspot.com/2015/06/high-temperatures-in-the-arctic.html

 Arctic Sea Ice Getting Terribly Thin
http://arctic-news.blogspot.com/2016/08/arctic-sea-ice-getting-terribly-thin.html

 A Global Temperature Rise Of More than Ten Degrees Celsius By 2026?
http://arctic-news.blogspot.com/2016/07/a-global-temperature-rise-of-more-than-ten-degrees-celsius-by-2026.html

 A Farewell to Ice, by Peter Wadhams
https://www.penguin.co.uk/books/273799/a-farewell-to-ice/9780241009420



Thursday, October 1, 2015

Cyclones continue to hit Northern Hemisphere

As the 2015 El Niño gets stronger, the Northern Hemisphere continues to get hit by strong winds and cyclones. The image below shows strong winds over the Arctic Ocean, as hurricane Joaquin approaches the coast of North America.



On above image, hurricane Joaquin is clocked at a speed of 79 mph (127 km/h) on October 1, 2015. NOAA warned that on that day the maximum sustained wind speed had increased to near 120 mph (195 km/h) with higher gusts.

For reference, NOAA uses four categories:
D: Tropical Depression – wind speed less than 39 mph (63 km/h)
S: Tropical Storm – wind speed between 39 mph and 73 mph (63 km/h - 118 km/h)
H: Hurricane – wind speed between 74 mph and 110 mph (118 km/h - 177 km/h)
M: Major Hurricane – wind speed greater than 110 mph (over 177 km/h)

NOAA issued the image below on September 30, 2015, warning that Hurricane Joaquin is likely to cause wind damage across a large part of the eastern coast of North America.


The NOAA animation below gives an idea of the strength of hurricane Joaquin.

[ click on image to enlarge, note that this is a 1.4 MB file that may take some time to fully load ]

Meanwhile, sea surface temperatures off the North American coast, as well as in the Arctic Ocean, are very high, as illustrated with the image on the right.

In the Arctic Ocean, the sea ice in many places is now less thick than it was in 2012, as illustrated by the image further below, showing sea ice thickness on October 7, 2012 (panel left) and a forecast for October 7, 2015 (panel right).

The water in the Arctic Ocean was already very warm this year. The main factor causing both these strong winds and the dramatic decrease in thickness of the multi-year sea ice is ocean heat, as also illustrated by the image below, showing high sea surface temperature anomalies in the Arctic as at September 30, 2015.


As the image below shows, nearly all the thick (over 3 m) multi-year sea ice has now disappeared, setting up a dangerous situation for the future that is much more dangerous than the situation was back in 2012. The thicker sea ice used to act as a buffer, consuming ocean heat in the melting process. Without thicker sea ice, ocean heat threatens to melt the sea ice from below right up to the surface, causing the entire sea ice to collapse as more open water will go hand in hand with stronger winds and waves. In case of such a collapse, sunlight that was previously reflected back into space will instead be absorbed by the water, causing rapid rise of the temperature of the water. In places such as the East Siberian Arctic Shelf, the water is on a average only 50 m deep, so warmer water is able to reach the seafloor more easily there.


The water of the Arctic Ocean is very warm, not only at the surface, but even more so underneath the surface. The danger is that strong winds will mix warm water all the way down to the seafloor, where it could destabilize sediments that can contain huge amounts of methane in the form of hydrates and free gas.

[ click on image to enlarge ]
The image on the right illustrates the impact of winds over the East Siberian Arctic Shelf on September 26, 2015.

NSIDC specialist Julienne Stroeve recently warned"In 2007 more than 3m of bottom melt was recorded by [an] ice mass balance buoy in the region, which was primarily attributed to earlier development of open water that allowed for warming of the ocean mixed layer. But perhaps some of this is also a result of ocean mixing."

As discussed in an earlier post, sea surface anomalies of over 5°C were recorded in August 2007 in the Arctic Ocean. 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 and bottom water temperatures on the mid-shelf increased by more than 3 degrees Celsius compared to the long-term mean.

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



As the 2015 El Niño gets stronger, the Northern Hemisphere continues to get hit by strong winds and cyclones. The image...
Posted by Sam Carana on Thursday, October 1, 2015

Friday, July 24, 2015

Thick Sea Ice Dislodged

As the comparison image below shows, the last bit of thick sea ice has become dislodged from its location in the Canadian Archipelago and is forecast to be floating along with the sea ice in the Arctic Ocean. The left panel shows the situation on July 19, 2015, while the right panel shows a forecast for July 31, 2015, run on July 23, 2015.


One reason for this development is of course the heavy melting that has taken place in this area. But what has made this thick sea ice move so strongly? The reason for this is a combination of wind, sea currents and meltwater running off the coasts of North America and Greenland. This has been persistently pushing this thick ice in this direction, as illustrated by the Naval Research Laboratory animation below.


The Naval Research Laboratory animation below shows sea ice thickness over a 30-day timespan, including a forecast up to 31 July, 2015, run July 23, 2015.


The screenshot below from arctic-io shows the sea ice on July 23, 2015, with an inset showing a rotated outcut from a Naval Research Laboratory ice thickness map for that date.
[ click on image to enlarge ]
The animation below shows a 5-day forecast of ice speed and drift up to July 27, 2015, starting from and run on July 23, 2015.


Furthermore, there has been a lot of smoke from wildfires in North America for some time. The image below shows smoke reaching far into the Beaufort Sea on July 22, 2015.



When smoke settles on snow and ice, it decreases albedo and makes it more prone to melting.

Seismic activity could also have contributed to this development. As the snow and ice cover on land disappears, isostatic rebound occurs, i.e. the land moves upward. Furthermore, an earthquake with a magnitude of 3.6 on the Richter scale was registered in Baffin Bay on July 22, 2015.


Above animation shows the last bit of thick sea ice becoming dislodged from its location in the Canadian Archipelago, from July 21, 2015, through to July 24, 2015.


Albert Kallio comments: "The more ice moves, the more heat it can pick up from the ocean - and melt. Also, the overturning of sea water in the ocean increases in the increasingly open sea areas - bringing heat up to the surface - and into contact with ice that then melts faster."

[ hat tip to Patrick McNulty for contributions to this post ] 



The last bit of thick sea ice has become dislodged from its location in the Canadian Archipelago and is forecast to be...
Posted by Sam Carana on Friday, July 24, 2015

Friday, March 6, 2015

March 4, 2015 - Arctic Sea Ice Extent Hits Record Low

Sea surface temperature anomalies as high as 12°C (21.6°F) recorded off the east coast of North America have been described earlier, in he post 'Watch where the wind blows'. The Jet Stream reaching high speeds has also been described earlier, in the post 'Climate Changed'.


As feared, this is pushing warm water, water vapor and air from the North Atlantic into the Arctic Ocean. The three images below show forecasts for March 8, 2015, of - from top to bottom - the jet stream, surface winds and temperature anomalies.





Above image shows that the Arctic is forecast to reach a temperature anomaly of more than +4 degrees Celsius (more than +7 degrees Fahrenheit) on March 8, 2015, with temperature anomalies at the top end of the scale forecast for most of the Arctic Ocean.

On March 4, 2015, Arctic sea ice extent hit a record low for the time of the year, as illustrated by the image below.


As the March 5, 2015, Naval Research Laboratory image on the right illustrates, there is little scope for Arctic sea ice extent to grow over the next few weeks, since the only areas where it could possibly expand would be the Pacific and the North Atlantic, the very areas that are under pressure from ocean heat and high surface temperatures.

In other words, the situation looks set to deteriorate further.

Huge amounts of heat are still going into melting the sea ice. Furthermore, the sea ice is still able to reflect a lot of sunlight back into space. With continued demise of the snow and ice cover, more and more heat will be absorbed in the Arctic.

The big danger is that warm water will trigger further releases of methane from the seafloor of the Arctic Ocean. Peak daily methane levels recorded in early 2015 averaged a very high 2372 parts per billion, as illustrated by the image below.


Methane extent has been especially high over the Arctic Ocean. The images below are from the earlier post 'Temperature Rise'. The post added that, as the Gulf Stream keeps carrying ever warmer water into the Arctic Ocean, methane gets released in large quantities, as illustrated by the images below showing high methane levels over the East Siberian Arctic Shelf (red oval left) and over Baffin Bay (red oval right) with concentrations as high as 2619 ppb.

click on image to enlarge
The images below show methane levels on Jan 25 (top), and Jan 26, 2015 (bottom).


Update:
Meanwhile, Arctic sea ice extent as reported by NSIDC.org reached a new record low for the time of the year with 14.358 million square km on March 4, 2015, and another record low with 14.308 million square km on March 7, 2015.

Temperature anomaly for the Arctic on March 8, 2015 (daily average) was even higher tha forecast, at +4.26 degrees Celsius, with peaks at +4.37 degrees Celsius.



High waves were registered in the North Atlantic on March 7, 2015, moving into the Arctic Ocean and causing waves more than 4 m high close to the edge of the sea ice on March 8, 2015.



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


Tuesday, February 3, 2015

Watch where the wind blows

The Arctic looks set to be pummeled by strong winds on February 5, 2015, as shown by the Climate Reanalyzer forecast below.


The video below, based on Climate Reanalyzer images, watch the situation unfold over a period of 9 days



Strong winds can increase the transport of warm water into the Arctic Ocean by the Gulf Stream. The video shows strong winds repeatedly developing off the North American east coast and moving along the path of the Gulf Stream, all the way into the Arctic Ocean, all in a matter of days.

Emissions are causing greater warming of the Gulf Stream and the Arctic. As a result, there is less temperature difference between the equator and the Arctic, slowing down the speed at which the jet streams circumnavigate the globe, while the jets can also become wavier, which in turn can cause extreme weather events.

In this case, what fuels these winds is the temperature difference between an area off the east coast of North America where temperatures are much higher than they used to be on the one hand, and an area in Siberia where temperatures are extremely low on the other hand. Wind flows from a warm area to a cold area, and the greater the temperature difference, the stronger the wind will blow.

The image below shows that, on February 3rd, 2015, a sea surface temperature of 21°C (69.8°F) was recorded off the east coast of North America (green circle), which constitutes a 12°C (21.6°F) anomaly. Anomalies as high as 12°C were also recorded on February 4, 2015.

click on image to enlarge
Changes to the jet streams can thus fuel strong winds, and such winds can bring warmer air into the atmosphere over the Arctic Ocean. On February 5, 2015, surface temperatures over a large part of the Arctic Ocean were more than 20°C (36°F) warmer compared to what they were from 1985 to 1996.


Extreme weather events, as a result of changes to the jet streams and polar vortex, are depicted as feedback #19 in the diagram below, while storms that bring warmer air into the atmosphere over the Arctic Ocean are depicted as feedback #5,

Besides increasing the transport of warm water into the Arctic Ocean and bringing warmer air into the atmosphere over the Arctic Ocean, strong winds can also break up the sea ice by sheer brute force of the waves caused by the wind.

Waves as high as 10.61 m (34.81 ft) were recorded south of Greenland on February 4, 2015, while waves as high as 7.05 m (23.13 ft) were recorded on the edge of the Arctic sea ice (east of Svalbard) on February 5, 2015, as shown on the combination image below.



Waves that break up the sea ice into smaller pieces can speed up melting, especially in summer. More wind also means more water evaporation, and warmer air holds more water vapor, so this can result in huge rainstorms that can rapidly devastate the integrity of the ice. Strong winds thus constitute a feedback that can result in more open waters in the Arctic Ocean (feedback #6 on the diagram below).

Furthermore, strong winds can speed up the currents that will eventually move sea ice out of the Arctic Ocean into the Atlantic Ocean (feedback #7). Wavy waters catch more sunlight than still water (feedback #8). Decline of the Arctic snow and ice cover results in more sunlight being absorbed by the Arctic, thus further heating up the water of the Arctic ocean (feedback #1).

The dual image below, with images from Climate Reanalyzer, shows high sea surface temperatures around North America and at the edges of the Arctic sea ice. This contributes to surface temperatures that are 20°C (36 °F) higher than what they used to be in Eastern Siberia. At the same time, temperatures on land elsewhere in Siberia, on the North Pole and in parts of Canada and Greenland can go down to 40 degrees below zero.



Accelerated warming of the Arctic is changing the jet streams, in turn contributing to the likelyhood that such strong winds will hit the Arctic. The high temperature difference between the hot spot off the North American east coast and the cold spot over Siberia fuels such strong winds. The dual images below show the jet stream's elongated path over Greenland. Accordingly, temperature anomalies in Greenland are reaching the top end of the scale.



The big danger is that such strong winds will warm up the Arctic Ocean and cause huge amounts of methane to erupt from its seafloor.

The image below shows that methane levels as high as 2503 ppb were recorded on January 31, 2015.



Such methane eruptions constitute yet another feedback that further contributes to warming in the Arctic. For more feedbacks, see the image below.

from:  climateplan.blogspot.com/p/feedbacks.html

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