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).

Noctilucent clouds indicate more methane in upper atmosphere

Noctilucent clouds [credit: NASA]

The inner solar system is littered with meteoroids of all shapes and sizes—from asteroid-sized chunks of rock to microscopic specks of dust. Every day Earth scoops up tons of the material, mostly the small stuff. When meteoroids hit our atmosphere and burn up, they leave behind a haze of tiny particles suspended 70 km to 100 km above Earth's surface.

Inside the meteor smoke zone, at a height of 83 km, so-called noctilucent clouds can occur, describes a NASA article. Meteor dust is the nucleating agent around which such clouds form. Specks of meteor smoke act as gathering points where water molecules can assemble themselves and grow into ice crystals to sizes ranging from 20 to 70 nanometers.

While noctilucent clouds appear most often at Arctic latitudes, they have been sighted in recent years as far south as Colorado, Utah and Nebraska. Question is: Why are the clouds brightening and spreading?

Prof. James Russell of Hampton University believes that more in methane in the atmosphere is causing this. Russell explains: "When methane makes its way into the upper atmosphere, it is oxidized by a complex series of reactions to form water vapor. This extra water vapor is then available to grow ice crystals for noctilucent clouds."

In conclusion, this greater occurrence of octilucent clouds is an indication that more methane is escaping into the upper atmosphere.

Graphic prepared by Prof. James Russell of Hampton University showing how methane, a    
greenhouse gas, boosts the abundance of water at the top of Earth's atmosphere. This water
then freezes around "meteor smoke" to form icy noctilucent clouds.              [Credit:  NASA] 

Below, a new ScienceCast video explains how "meteor smoke" seeds noctilucent clouds.

Arctic sea ice loss is effectively doubling mankind's contribution to global warming

Loss of Arctic sea ice is effectively doubling mankind's contribution to global warming. Increased absorption of the sun's rays is "the equivalent of about 20 years of additional CO2 being added by man", Professor Peter Wadhams said in the BBC article: Arctic ice melt 'like adding 20 years of CO2 emissions', by Susan Watts, September 5, 2012.

For more details on Professor Wadhams' calculations, see the earlier post Albedo change in the Arctic.

Arctic sea ice area fell by 11.33629 million square km from March 28, 2012, to September 1, 2012, as shown on the image below, edited from The Cryosphere Today. That's an 82.7 percent fall in 157 days. 

The image below 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.

There still are quite a few days to go in the melting season, so the fall could be even more dramatic.

Peter Wadhams adds:  “The point about summer conditions is that as long as there is SOME ice present on the sea surface, however thin the layer, then the ocean temperature below it is held to 0 degrees Celsius because the absorbed solar radiation melts the ice rather than warming the water. Also the atmospheric temperature is held to close to 0 degrees Celsius because warmer air melts the surface snow layer on top of the ice and is thereby cooled. The sea ice, even when thinned, continues to act with 100% efficiency as an air conditioning system for ocean and atmosphere alike.”

“BUT”, Prof Wadhams continues, “as soon as the sea ice layer goes, this process ceases and the sea can warm up rapidly (to typically 7 degrees Celsius by the end of summer - which is not much colder than the North Sea), as can the atmosphere (which speeds up Greenland ice sheet melt when that warmed air passes over Greenland). Latent heat is an enormously powerful buffer - the amount of heat that you have to pump in to melt 1 kg of ice will subsequently heat that same amount of melted water to 80 degrees Celsius. So once the ice goes away entirely there is a big jump in temperatures in the upper ocean and atmosphere (with dire consequences for permafrost), and it is very difficult to see how one can ever go back to an ice-covered summer ocean once this has happened.”

In the August 27, 2012, BBC article Arctic sea ice reaches record low, Nasa says, by Roger Harrabin, Professor Peter Wadhams said: “Implications are serious: the increased open water lowers the average albedo [reflectivity] of the planet, accelerating global warming; and we are also finding the open water causing seabed permafrost to melt, releasing large amounts of methane, a powerful greenhouse gas, to the atmosphere.”

Indeed, 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.

The image below, from a study by Polyakov et al., shows temperature differences in the vertical water column at selected stretches of water in the Arctic over the years.

[click images to enlarge]