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]

Arctic cyclone warning for September 7

By Paul Beckwith, 
edited by Sam Carana

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

Paul Beckwith warns that another cyclone is forecast to develop in the Arctic by September 7th, 2012, pointing at the image below, from the Naval Research Laboratory.

“This will cause lots of sea ice breakup in the Arctic if it develops and persists”, Paul says.  “The sea ice now is thinner than in August, so the potential for severe damage to ice exists. On the other hand, however, the August cyclone lasted for a week, while this one looks like a 2 to 3 day event.”

Paul also points at the image further below, from weather.unisys.com/gfsx, showing a 9 day GFSx model for Arctic region; on the website you can select single day panels.

“Most scientists think that the massacre of Arctic sea ice will stop on/or around September 15th which is the 'normal' date at which ice formation is due, as the decrease of solar insolation at the pole will cause the area of the sea ice to start increasing", Paul says, adding however that “a minority of us think that the melt will continue beyond this date by several weeks, due to the warmness of the sea water both beside and below the very thin sea ice.”

Paul continues: “In fact, I predicted on August 10th that at the end of the melt season there would be virtually no sea ice left; this was predicated on there being a few more cyclones of equal intensity to that of the August 2nd to August 10th cyclone that eliminated around 0.8 million square kilometers of sea ice area (equivalent to about 20% of the ice remaining in 2007, the previous worst year in terms of ice melt). Thankfully, my prediction looks to be wrong, but we are not out of the woods yet. It appears that a strong cyclone will be attacking the sea ice in a few days, with the peak churning occurring on September 7th.”

The 500mb/SLP chart shows the 500 mb height (in color contours), and the sea level pressure in mb (black lines).

The image below, also from the Naval Research Laboratory, is an animation showing sea ice speed and drift over 30 days, from early August up to September 9, and including the forecast cyclone event.

PIOMAS data confirm exponential trend

The Applied Physics Laboratory/Polar Science Center at the University of Washington has issued an extra release of Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) data.

Sea ice volume on August 25th, 2012, was 3500 km³, or about 500 km³ less than the prior minimum, reached on September 10th, 2011.

The image below shows that recent data for 2012 appear to match almost perfectly the expected values based on exponential trends added by Wipneus.

The image below, again based on PIOMAS data, shows trends added by Wipneus for each month of the year. The black line shows the average for the month September, pointing at zero a bit into the year 2015, while the average for August and October (the overlapping red and dark blue lines, appearing as a single purple line) point at zero before the start of the year 2016.

In conclusion, it looks like there will be no sea ice from August 2015 through to October 2015, while a further three months look set to reach zero in 2017, 2018 and 2019 (respectively July, November and June). Before the start of the year 2020, in other words, there will be zero sea ice for the six months from June through to November.

And, events may unfold even more rapidly, as discussed earlier at Getting the picture.

The image below, from the Naval Research Laboratory, shows the dramatic decline of sea ice thickness over the last 30 days.