Storm enters Arctic region

Tropical Storm Leslie hit Newfoundland on September 11, 2012. Leslie was discussed in the earlier post by Paul Beckwith. The NOAA image below gives a 5-day forecast of Leslie's continued path along the coasts of Greenland and Iceland.

That may keep Leslie just out of the Arctic Circle, but this path does make it enter the Arctic Region, i.e. the area where temperatures in the warmest month used to remain under 10°C, or 50°F, as illustrated by the map below.

The image below shows how Leslie's impact on air pressure. The image below is part of a series of images showing how Leslie causes a low pressure area (compressed isobars) that then propagates over the Arctic ocean region. See further images at the Polar Meteorology Group at Ohio State University.

This low pressure region can also be tracked in the 9-panel GFSx forecast below, from Unisys Weather.

Storms are important to the Arctic, they can cause high waves and changes in wave direction, as illustrated by the combined images below from OceanWeather Inc. 

Storms can cause decline of Arctic sea ice and bring warm water and air into the Arctic. The Diagram of Doom, discussed in more details in an earlier post, pictures ten feedbacks that can cause warming in the Arctic to accelerate. Storms are a factor in many of these feedbacks. 

As illustrated by the NOAA image below, accelerated warming results in high temperature anomalies, increasing the danger of methane releases from sediments under the water.

Paul Beckwith comments that in this case “Greenland acts as a barrier to the storm entering the Arctic due to its 3 km ice cap (note also that the thickness of the troposphere is only about 7 km high in the Arctic, meaning that Greenland extends up in altitude to cover >40% of the atmosphere in which weather occurs). What this means is that the storm will be diverted from directly crossing Greenland.”

Paul adds a warning: “In this case we are lucky in that the storm passes below and to the right of Greenland and then heads past Iceland on its way to north of Scotland. A worse scenario for the Arctic and the sea ice there would be if the storm stalled of the western coast of Greenland and slowly tracked up north through the Davis Strait and across the Canadian archipelago and then directly into the Arctic to the west of Greenland. Such a storm would have devastating consequences to the Arctic and the sea ice (not to mention Greenland, mostly on the coasts). Lots of heat and moisture would be transferred into the Arctic by such a storm.”

High September 2012 methane levels

An earlier post reported average hourly methane measurements as high as 2500 ppb recorded at Barrow, Alaska. Sadly, hardly any further in situ measurements have been publicly released from Barrow since, as illustrated by the image below.

Flask measurements continue to be available and the five most recent measurements show levels well over 2000 ppb.

The image below shows methane levels over a period of three years, from August 1, 2008, to August 1, 2011.

The image below shows methane levels over a period of a more recent year, from August 1, 2011, to August 1, 2012. There is a marked increase of methane at higher latitudes, compared to the earlier three years.

The image below shows methane levels in August 2012, with high levels showing up at many places. 

The image below shows the most recent methane level measurements available, from September 1, 2012, to September 7, 2012. High levels of methane show up at even more places, such as in the Arctic to the north of North America.

Around this time of year, there will typically be a lot of methane at many locations on the Northern Hemisphere. The image below allows a comparison of the 2012 period with the same period last year. In early September 2011, there was not quite as much methane as there now is north of Alaska, in Greenland and along the Siberian coast. There was a lot of methane in China last year in this period in 2011, though, and the situation appears to have improved somewhat this year.

To compare things further, an image is added below showing methane levels during the same period in 2010.

Below are added images produced by Dr. Leonid Yurganov from IASA data. Note that the scales are slightly different. The images confirm the presence of high levels of methane in the Arctic Ocean north of Siberia. Further below a combination picture showing the significant rise of methane levels in that area between October 2008 and October 2011.

[click to enlarge]

The images highlight a number of concerns:

1. Methane levels are rising over the years; 
2. Methane levels are particularly high in the Arctic;  
3. Very high levels of methane are recorded in the Arctic in the months September and October, the very period when Arctic sea ice is at its lowest; 
4. Incidental measurements, such as at Barrow, add to concerns that levels can rise abruptly with significant amounts. 

Methane is more than 100 times as potent as a greenhouse gas as carbon dioxide over 20 years, and even more potent over shorter periods. This makes methane a very powerful warming factor in the Arctic. While the Arctic is already warming more than three times as fast as the rest of the world, the sea ice still acts as a buffer to prevent even more acceleration of warming in the Arctic, but this situation will deteriorate dramatically as the sea ice disappears, as Professor Peter Wadhams recently described.

The big danger is that ferocious warming in the Arctic will trigger methane releases from hydrates and from free gas in sediments, which will further accelerate warming in the Arctic and further trigger methane releases, in a vicious circle set to spiral into runaway global warming unless action is taken to reduce the danger.

Two important images

As Arctic sea ice continues to decline, breaking one record after the other, one wonders what more can be said to capture the significance of what is happening. Two images spring to mind.

The image below, from The Cryosphere Today, shows that Arctic sea ice has shrunk in area by 11.41475 million square km from March 28, 2012, to September 6, 2012, a fall of about 83¼ percent in 162 days.

The image below illustrates the dramatic drop in sea ice volume over the years. The image is based on data calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) developed at the Applied Physics Laboratory/Polar Science Center at the University of Washington.

The PIOMAS data for the annual minimum values are the black dots. The trend (in red) is added by Wipneus and points at the start of the year 2015 as the moment when ice volume will first reach zero. The red point indicates the most recent value for 2012 volume, noting of course that this value may still come down further as the year progresses.

This image is further discussed in the post Getting the picture.

Update on September Arctic cyclone

By Paul Beckwith, 
edited by Sam Carana

The loss of Arctic sea ice appears to be flattening out at the moment. The above image shows Arctic sea ice extent (total area of at least 15% ice concentration) for the last 7 years, compared to the average 1972-2011, as calculated by the Polar View team at the University of Bremen, Germany.

Paul Beckwith, B.Eng, M.Sc. (Physics),
Ph. D. student (Climatology) and
Part-time Professor, University of Ottawa 

However, Paul Beckwith warns that Hurricane Leslie looks set to capture Hurricane Michael just off the Canadian maritimes and strongly impact Nova Scotia and Newfoundland (large hurricane), to then continue northward and start to affect Arctic climate by compressing isobars creating large pressure gradients and thus high winds.

Paul points at the image below, from weather.unisys.com/gfsx, showing a 9 day GFSx model for Arctic region.

The model shows that an Arctic cyclone is amplified as a result of Leslie and a strong high pressure ridge is also generated over the Beaufort Sea. As the Arctic cyclone decreases in strength a strong cyclone is generated over Alaska.

“Needless to say this scenario would be very destructive to Arctic sea ice if it plays out,” Paul adds.  “Also, there is no apparent decrease in Arctic sea surface temperatures in projections out to September 12th, and no apparent salinity change. I will be amazed if this melt season does not last until the end of September or even into early October.”

View Paul Beckwith's September 8 presentation by clicking on the following link:
https://docs.google.com/file/d/0ByLujhsHsxP7QndrZjdKX2szTHM/edit


Or, view the presentation in the window below (it may take some time for the file to fully load).