Tuesday, December 10, 2013

Noctilucent clouds: further confirmation of large methane releases

Back in September 2013, extremely high methane readings were recorded over the heights of Antarctica, as illustrated by the image below.



These high methane readings over Antarctica have not been discussed much among climate scientists, let alone in the media. Yet, large methane releases can contribute significantly to climate change, given methane's high potency as a greenhouse gas. Furthermore, the vast amounts of methane contained in the permafrost comes with the danger that, as global warming continues, such releases could increase in a non-linear way.

Noctilucent clouds could confirm that such emissions have indeed taken place from Antarctica. Methane will rise in the atmosphere, turning into water vapor as it rises up in the sky, and form ice crystals around meteor smoke at 83 kilometers altitude, showing up as noctilucent clouds.











































 Noctilucent Clouds over the Southern Hemisphere from November 21, 2013, to December 17, 2013.
Click on each image to view enlarged versions.

It takes a while for methane to rise up to such altitudes, making it hard to pinpoint which methane releases are responsible for these noctilucent clouds. As methane rises, it tends to move closer to the equator, which is another reason to conclude that these noctilucent clouds are the result of large amounts of methane that have been released from the heights of Antarctica earlier in 2013.

As such high methane concentrations transform into water vapor and carbon dioxide, they may no longer register as methane on satellite measurements, yet they will continue to contribute to global warming. Therefore, large methane releases should be closely monitored, even if they do not appear to immediately translate into mean global methane level rises.

The question remains what caused such huge releases from the heights of Antarctica in the first place. The graph below may provide some of the answers. Look at the sharp temperature anomaly rise of 6 degrees Celsius over Antarctica in September 2013, preceded by a -3 anomaly. That's a difference of about 9 degrees Celsius. As temperature differences increase, there will be greater pressure changes, in line with compacting, expanding, tearing and other movements of the ice. Furthermore, more snowfall followed by more melting and vice versa will come with increased differences in weight. These two forces combined could be destabilizing the permafrost and the hydrates and free gas it contains.

Diagram showing area weighted Antarctic (70-90oS) monthly surface air temperature anomalies (HadCRUT4) since January 2000, in relation to the WMO normal period 1961-1990.  The thin blue line shows the monthly temperature anomaly, while the thicker red line shows the running 37 month (c.3 yr) average. Last month shown: September 2013. Last diagram update: 17 November 2013. From: http://www.climate4you.com/Polar%20temperatures.htm
The temperature differences more striking when looking at individual days in September 2013. The NOAA images below show a difference of well over 20°C over a few days in September 2013.


Temperature anomalies can be even more striking when looking at specific areas on specific days, such as on August 9th, 2013, as on the image below.



As said on the image, such anomalies (well over 20°C, in this case) can be masked when averaged out over longer periods and over a larger area, such as an area covering latitudes from 60S to 90S for all longitudes.

Recent research findings show that, as weight is lost due to melting, West Antarctica becomes more vulnerable to pressure from East Antarctica, which is pushing West Antarctic bedrock westward at rates up to about twelve millimeters—about half an inch—per year. This finding further confirms crustal motions that could destabilize methane hydrates contained in the permafrost.

The occurence of large temperature differences spells bad news, as they can trigger methane releases, the more so as wide and rapid temperature changes on Antarctica look set to become even more frequent and intense with further global warming.

Finally, the NASA video below gives more background details on noctilucent clouds.




References

- Is Global Warming breaking up the Integrity of the Permafrost?
http://methane-hydrates.blogspot.com/2013/05/is-global-warming-breaking-up-the-integrity-of-the-permafrost.html

- Noctilucent clouds indicate more methane in upper atmosphere
http://arctic-news.blogspot.com/2012/09/noctilucent-clouds-indicate-more-methane-in-upper-atmosphere.html

- Noctilucent Clouds Get an Early Start

- Aeronomy of Ice in the Mesosphere (AIM) satellite, exploring Polar Mesospheric Clouds (PMCs), also called noctilucent clouds




5 comments:

  1. http://www.climate4you.com/Polar%20temperatures.htm Thanks for this link Sam some great data here you can see the trends in the Arctic and Antarctica . the temp analogy in the southern hemisphere seems to happen at the same time as the CH4 bloom on methane tracker. incredible!!

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  2. Www.lasthours.org explains it all quite well, the scary part is that Methane release of any kind is associated with temperature increase No Ice = Methane release, but what most people tend to forget is that there are over 50 large deposits of Methane Hydrates around the globe, these deposits are also driven by temperature it takes just 1° degree change at depth in the Ocean to release these Hydrates, what I'm eluding to is things like El Ninjo not to mention that the water around the last Philippines Typhoon was 5° degree's warmer.. We got ask the question.? Is it possible that Methane has actually been the main driver of climate change for more than 10 years.. As it's hard to catch it in the act let alone the fact that it has not been on the agenda.? And if the IPCC is still putting it to Cow's & Pigs, as they can't really see it in there report system which in 2007 stated that sea ice would be gone in 2100 = ice = no Methane where the fact now is that the Ice is gone by 2015 a scary fact which has just been swept under the carpet ..!

    Could unchecked Methane be the real climate driver the answer is yes, why there is 1800 billion tons of it lying in wait for us, or 200 times our combined emissions including future reserves of Coal, Oil and Gas or just 1° hereof being released would equal our combined emissions over 200 years.!

    And whilst we are focusing on Oil, Coal and Gas which is not wrong, where fact is that we are letting the real killer of the Hook as it darfs all other reporting and the people who created these reports claiming to be climate scientists, it is much like in the dark days of of modern medicine, by that I mean the 1800`s where doctor's refused to wash there hands killing thousands of women while giving birth as they just minutes before had cut up a dead body.. But these doctor's where the heads and leaders of science and medicin at that time, which is exactly where we are right now, so yes the people that say the climate scientific community is a hoax might not be that far of from the truth .?

    Right.!

    How could anyone miss 1800 billion tons of Methane, when fact is that this Gas alone has caused all 5 mas extinction on this planet all due to one thing increase of temperature.?

    Www.lasthours.org

    Best

    Jorn Winkler

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  3. Actually jorn 1800 gtons is pretty much the shallow methane of the east siberian arctic shelf alone. The deep sea hydrates are estimated in one study at 5500 gtons and another at 78000 gtons. Losing the constant replenishment of -1.8c water on the ocean floor from arctic overturning is going to get us a deep seafloor clathrate horror show. Especially since there hasn't been the geography to allow anywhere near as much seafloor clathrate in at least 500 million years.

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  4. Those cental antarctic methane spikes are scary. The truth is that the ice buildup on central antarctica over the last thirty odd million years has pushed the sedimentary layers from 600 million years of a biologically productive antarctic continent several km downward into the geothermal heat of the deeper crust. This will have baked methane out that has risen through the ice from the zero c base to a clathrate stability zone where the temperature is much lower near the surface. Say the ice layers near the surface are in the region of -50c. That means the temperature gradient goes from 0c at bedrock to -50 near the surface through the several km thick ice sheet. The rise of winter mean temps by near 20c over the area means that gradient might have changed to 0c at bedrock to -30 surface. This would destabilise substantial clathrate deposits that have already migrated upwards in the last deglaciation and migrate them upwards into the fractured and permeable surface ice layers. From where they seem to be being released now. Its particularly alarming when you consider that central antarctic weather is comprised of deep dry cold downwelling air and strong katabatic outflow off the icesheet to the coast. So a short residence time for local releases like this is indicated. Meaning that the total methane output is likely pretty large.

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  5. Again, great article, although I had to laugh (ruefully...) at the optimism/neutrality in the NASA presenters voice...

    Also, great comments from those above. Often one can learn more from the comments than the articles, especially where science is being discussed.

    I am inclined to agree that it is quite possible, given how difficult it is to quantify methane release, that methane may well be the driving force behind the current AGW... Study of the past MEE's are showing us that CH4 was a major driving factor... I see no reason to deny that this is likely the case in the current MEE.

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