Showing posts with label drift. Show all posts
Showing posts with label drift. 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



Monday, August 12, 2013

Cyclone raging on Thin Ice

Another cyclone is raging over the Arctic Ocean. The Naval Research Laboratory image below shows the speed and drift of the sea ice.

[ click on image to enlarge ]
Last time a cyclone hit the Arctic, this resulted in a temporary increase in area covered by sea ice, as shown on the Cryosphere Today image below. The cyclone pushed down on the sea ice, flattening it and pushing it sideways. 


Note that area as measured by the Cryosphere Today includes all spots that have a 15% or higher concentration of ice. This way of measuring area ignores the fact that the cyclone reduced the sea ice concentration in many spots, from a high sea ice concentration (around 90%) to a lower concentration (less than 80%), as shown on the Naval Research Laboratory image below. 


Furthermore, sea ice has since dropped in thickness, as illustrated by the Naval Research Laboratory image below. 

Much of the ice is now less than one meter thick, while some areas close to the North Pole have ice that is only between zero and half a meter thick.

The cyclone is raging most fiercely in those areas and much of the ice is drifting out into the Atlantic Ocean.

Neven mentioned at the Arctic Sea Ice Blog that average thickness (crudely calculated by dividing PIOMAS (PI) volume numbers with Cryosphere Today (CT) sea ice area numbers, see image below) had a very steep drop in July, similar to the drop in 2010. This year's trend line is now lowest, probably signifying that the ice pack is spread out and thin at the edges (read: melting potential).

[ click on image to enlarge ]
The image below, from the University of Bremen, Germany, shows sea ice concentration on August 11, 2013.



Sunday, July 21, 2013

The Great Arctic Flush

By Paul Beckwith

A massive cyclone is forecast to develop in the Arctic, as shown on the image below, from the Naval Research Laboratory.

Within 2 weeks the Arctic Ocean will be completely transformed. The cyclone that appears 6 days out on both the US and European ten day forecasts will massacre the sea ice in what I call "The Great Arctic flush".

The image below is a forecast for Arctic sea ice speed and drift on July 27, 2013. More images, including animations, on Arctic sea ice can be viewed at http://www7320.nrlssc.navy.mil/hycomARC/arctic.html 


Last August, a massive cyclone formed over the Arctic Ocean and destroyed 800,000 square km of ice in about a week. The predicted cyclone looks to be as strong as the one in early August, 2012. Problem is, the ice is much weaker, thinner and fractured this year; including all the ice just north of the Canadian Arctic Archipelago that is 4 or 5 meters thick; this ice is mobile, broken, fractured ice piled up into ridges; it is not multiyear ice (MYI) at all.

Above image, from the Naval Research Laboratory is a prediction of ice speed and drift a week from now, showing the motion of the ice, the darker and redder the faster, the ice is being set in motion by the cyclone above. Since the Coriolis force flings things to the right, the ice is all sent to the outside of the rotation, into the warmer surrounding water as well as the Atlantic Ocean. The storm surge of a foot or two over the entire basin (highest near the cyclone eye) will draw in warm water from the Pacific via the Bering Strait and from the Atlantic via the Fram Strait. It will also mix the fresh water on the surface from melting ice with warmer saltier water from below. It will also generate lots of churning and grinding of the ice and waves several meters high. Warm and smoky air that is filled with ash and black carbon from burning fires in the far north will drop the albedo of the ice and increase the solar absorption. 

When I forecast zero sea ice at the end of the melt season this summer, I fully expected at least one or more of these massive cyclonic storms. Last year it occurred in early August, and lasted for about 8 days. In the rest of the melt season last year no other huge cyclone developed, although several small ones did. Perhaps the cyclone disturbed the ocean conditions enough to prevent subsequent ones occurring. We shall see this year...

edited screenshot from animation at weather-forecast.com


Paul Beckwith is a part-time professor with the laboratory for paleoclimatology and climatology, department of geography, University of Ottawa. He teaches second year climatology/meteorology. His PhD research topic is “Abrupt climate change in the past and present.” He holds an M.Sc. in laser physics and a B.Eng. in engineering physics and reached the rank of chess master in a previous life.

Friday, July 19, 2013

Arctic Ocean Events - Videos by Paul Beckwith

by Paul Beckwith


Massive Arctic cyclone effect on sea ice in August 2012
Part 1: August 1st to 16th, 2012
http://www.youtube.com/watch?v=nli47-9dT5o

Arctic sea ice motion (speed and direction) is compared to sea ice thickness from August 1st to August 16th, 2012. Sea ice motion is then compared to meteorology (500 mb pressure heights and 200 mb vector winds).




Massive Arctic cyclone effect on sea ice in August 2012
Part 2: August 1st to 16th, 2012
http://www.youtube.com/watch?v=WqwIVEpSg3w

Northern hemisphere meteorology (500mb pressure heights) and Arctic sea ice concentration compared to SST (sea surface temperatures) are examined from August 1st to August 16th, 2012 encompassing the mass persistent cyclone.




Massive Arctic cyclone effect on sea ice in August 2012
Part 3: August 1st to 16th, 2012
http://www.youtube.com/watch?v=HjYxRV0fzz4

Arctic basin SSS (sea surface salinity) is compared to SSH (sea surface height) during the period August 1st to August 16th, 2012 which encompassed a massive persistent cyclone. Detailed meteorology is also examined (tropopause temperature + pressure, surface precipitable water + pressure). Also examined is ocean profile salinity and temperature from an ice tethered buoy.




Massive Arctic cyclone effect on sea ice in August 2012
Part 4:  August 1st to 16th, 2012
http://www.youtube.com/watch?v=aAJRIV8YITY

The jet streams in the Arctic ocean basin are shown (200mb vector winds) from NOAA/ESRL daily data, as well as from 4 times daily data from SFSU. The data is given from August 1st to August 16th, 2012 which encompasses the massive Arctic cyclone.




2013

Arctic sea ice thickness + motion
May 14th to June 10th, 2013
http://www.youtube.com/watch?v=5ljHI0VITgk

Arctic sea ice data from May 14 to June 10, 2013
Left pane shows Arctic sea ice thickness; right pane shows sea ice motion (direction and speed).




Arctic sea ice thickness + motion
July 1st to 17th 2013
http://www.youtube.com/watch?v=cUZr51_yW5s

Arctic sea ice data from July 1st to July 17th, 2013. Left pane shows the Arctic sea ice thickness; right pane shows sea ice motion (direction and speed).




Sea ice concentration, temperature, salinity, and height;
July 1st to 18th, 2013
http://www.youtube.com/watch?v=icUtGqpkFx8

Arctic ocean data from US Navy for
1) sea ice concentration,
2) sea surface temperature (SST),
3) sea surface salinity (SSS), and
4) sea surface height (SSH)




Jet streams
July 1st to July 17th 2013
http://www.youtube.com/watch?v=IFbJCFVSiPI

Northern hemisphere (NH) jet streams are shown from two sources:
1) NOAA/ESRL data collected daily, and
2) SFSU data collect every 6 hours. Data is given for the time period from July 1st to July 17th, 2013.




Meteorology
July 1st to 18th 2013
http://www.youtube.com/watch?v=LONJT8JbM7I

The following meteorology plots are shown for time period July 1st to July 18th, 2013 over the Arctic Ocean between 60 degrees N and 90 degrees N:
1) 500mb pressure levels,
2) 200mb vector winds (jet streams),
3) precipitable water, and
4) tropopause temperatures.