Saturday, June 22, 2013

Open Water In Areas Around North Pole

In some areas around the North Pole, thickness of the sea ice has declined to virtually zero, i.e. open water.


What could have caused this open water? Let's go through some of the background.

North Hemisphere snow cover has been low for some time. Snow cover in May 2013 was the lowest on record for Eurasia. There now is very little snow left, as shown on the image right, adapted from the National Ice Center.

Low snow cover is causing more sunlight to be absorbed, rather than reflected back into space. As can be expected, there now are high surface temperatures in many areas, as illustrated by the NOAA image below. Anomalies can be very high in specific cases. Zyryanka, Siberia, recently recorded a high of 37.4 C, against normal high temperatures of 20 C to 21 C for this time of year. Heat wave conditions were also recorded in Alaska recently (satellite image of Alaska below).

NASA image June 17, 2013, credit: NASA/Jeff Schmaltz, LANCE MODIS Rapid Response Team, NASA GSFC - from caption by Adam Voiland: "Talkeetna, a town about 100 miles north of Anchorage, saw temperatures reach 96°F (36°C) on June 17. Other towns in southern Alaska set all-time record highs, including Cordova, Valez, and Seward. The high temperatures also helped fuel wildfires and hastened the breakup of sea ice in the Chukchi Sea."
Accordingly, a large amount of relatively warm water from rivers has flowed into the Arctic Ocean, in addition to warm water from the Atlantic and Pacific Oceans.


Sea surface temperatures have been anomalously high in many places around the edges of the sea ice, as also shown on the NOAA image below.


Nonetheless, as the above images also make clear, sea surface temperatures closer to the North Pole have until now remained at or below zero degrees Celsius, with sea ice cover appearing to remain in place. The webcam below from the North Pole Environmental Observatory shows that there still is a lot of ice, at least in some parts around the North Pole.

Webcam #2 of the North Pole Environmental Observatory monitoring UPMC's Atmospheric Buoy, June 21, 2013
So, what could have caused the sea ice to experience such a dramatic thickness decline in some areas close to the North Pole?

Firstly, as discussed in earlier posts, there has been strong cyclonic activity over the Arctic Ocean (see also Arctic Sea Ice blog post). This has made the sea ice more prone and vulnerable to the rapid decline that is now taking place in many areas.

Furthermore, Arctic sea ice thickness is very low, as illustrated by the image below.

Arctic sea ice volume/extent ratio, adapted by Sam Carana from an image by Neven (click to enlarge)
Finally, there has been a lot of sunshine at the North Pole. At this time of year, insolation in the Arctic is at its highest. Solstice (June 20 or June 21, 2013, depending on time zone) is the day when the Arctic receives the most hours of sunlight, as Earth reaches its maximum axial tilt toward the sun of 23° 26'. In fact, insolation during the months June and July is higher in the Arctic than anywhere else on Earth, as shown on the image below.

Monthly insolation for selected latitudes -  adapted from Pidwirny, M. (2006), in "Earth-Sun Relationships and Insolation",  Fundamentals of Physical Geography, 2nd Edition
In conclusion, the current rapid sea ice thickness decline close to the North Pole is mostly due to a combination of earlier cyclonic activity and lots of sunlight, while the sea ice was already very thin to start with. The cyclone broke up the sea ice at the center of the Arctic Ocean, which is turn made it more prone to melting rapidly. The cyclone did more, though, as contributor to the Arctic-news blog Veli Albert Kallio explains:
"The ocean surface freezes if the temperature falls below -2.5C. The reason for the negative melting point is the presence of 4-5% of sea salt. Only in the polar regions does the sea surface cool sufficiently for sea ice to form during winters.

The sea ice cover is currently thinning near the North Pole between 80-90 degrees north. This part of the ocean is very deep. It receives heat of the Gulf Stream from the south: as the warm water vapourises, its salt content to water increases. This densifies the Gulf Stream which then falls onto the sea floor where it dissipates its heat to the overlying water column. The deep basin of the Arctic Ocean is now getting sufficiently warmed for the thin sea ice cover to thin on top of it. The transportation of heat to the icy surface is combined with the winds that push cold surface water down while rising heat to surface."
Indeed, vertical mixing of the water column was enhanced due to cyclonic activity, and this occurred especially in the parts of the Arctic Ocean that also are the deepest, as illustrated by the animation below.
Legend right: Ice thickness in m from Naval Research Laboratory
Legend bottom: Sea depth (blue) and land height (brown/green)
in m from NIBCAO Arctic map at NOAA
The compilation of images below shows how the decline of sea ice has taken place in a matter of weeks.

[ click to enlarge ]
This spells bad news for the future. It confirms earlier analyses (see links below) that the sea ice will disappear altogether within years. It shows that the sea ice is capable of breaking up abruptly, not only at the outer edges, but also at the center of the Arctic Ocean. As the Arctic sea ice keeps declining in thickness, it does indeed look set to break up and disappear abruptly across most of the Arctic Ocean within a few years. Models that are based on sea ice merely shrinking slowly from the outer edges inward should reconsider their projections accordingly.

Related

- Getting the Picture
http://arctic-news.blogspot.com/2012/08/getting-the-picture.html

- Supplementary evidence by Prof. Peter Wadhams
http://arctic-news.blogspot.com/2012/04/supplementary-evidence-by-prof-peter.html

Thursday, June 20, 2013

Extreme weather becomes the norm - what can you do?

. . a sky that has turned red due to greenhouse gases, while the land is flooded. The handful of
people who survived are standing by helplessly on higher grounds, in despair and without hope,
while one figure turns to me in panic and pain, uttering nothing but a silent scream . . .
(comment by Sam Carana, March 8, 2012, on auction of the Scream, by Edvard Munch)

Symptoms

Torrential rains in some regions are causing massive floods while in other locales record droughts are occurring with higher frequency and severity and areal extent around the globe. Global food production is being hit hard, leading to large price increases and political instability. Areas under drought are experiencing numerous massive forest fires of incredible ferocity.

Causes

The statistics of extreme weather events have changed for the worst due to changes in the location, speed, and waviness of the jet streams which guide weather patterns and separate cold and dry northern air from warm and moist southern air. The jet streams have changed since the equator to north-pole temperature difference has decreased due to the huge temperature rise in the Arctic.

The huge temperature rise in the Arctic is due to a collapse in the area of highly reflective snow and ice, which is caused by melting. The melting is from warming from the increase of greenhouse gases from fossil fuel burning. The Arctic sea ice and spring snow cover will vanish within a few years and the weather extremes will increase at least 10x.

What can you do?

Go talk to you politicians and friends about climate change and the need to slash fossil fuel emissions. Immediately. Cut and paste my comments above and post them on facebook, send them to newspapers, and educate yourself on the science behind all the above linkages. Leave my name on or take it off and plagiarize all you want, just get this knowledge out there...

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

originally posted as a comment under the CBCnews post:
Calgary braces for flooding, orders communities evacuated 

Related

- The Tornado Connection to Climate Change
- President Obama, here's a climate plan!
- Diagram of Doom
- Polar jet stream appears hugely deformed
Ten Dangers of Global Warming (originally posted March 8, 2007)

Tuesday, June 18, 2013

Mean Methane Levels reach 1800 ppb

On May 9, the daily mean concentration of carbon dioxide in the atmosphere of Mauna Loa, Hawaii, surpassed 400 parts per million (ppm) for the first time since measurements began in 1958. This is 120 ppm higher than pre-industrial peak levels. This unfortunate milestone was widely reported in the media.

There's another milestone that looks even more threatening than the above one. On the morning of June 16, 2013, methane levels reached an average mean of 1800 parts per billion (ppb). This is more than 1100 ppb higher than levels reached in pre-industrial times (see graph further below).
NOAA image
Vostok ice core analysis shows that temperatures and levels of carbon dioxide and methane have all moved within narrow bands while remaining in sync with each other over the past 400,000 years. Carbon dioxide moved within a band with lower and upper boundaries of respectively 200 and 280 ppm. Methane moved within lower and upper boundaries of respectively 400 and 800 ppb.
Temperatures moved within lower and upper boundaries of respectively -8 and 2 degrees Celsius.

From a historic perspective, greenhouse gas levels have risen abruptly to unprecedented levels. While already at a historic peak, humans have caused emissions of additional greenhouse gases. There's no doubt that such greenhouse gas levels will lead to huge rises in temperatures. The question is how long it will take for temperatures to catch up and rise.


Below is another way of looking at the hockey stick. And of course, further emissions could be added as well, such as nitrous oxide and soot.



Large releases of methane must have taken place numerous times in history, as evidenced by numerous pockmarks, as large as 11 km (6.8 mi) wide.

Importantly, large methane releases in the past did not result in runaway global warming for a number of reasons:
  • methane release typically took place gradually over many years, each time allowing a large release of methane to be broken down naturally over the years before another one occurred. 
  • Where high levels of methane in the atmosphere persisted and caused a lot of heat to be trapped, this heat could still be coped with due to greater presence of ice acting as a buffer and consuming the heat before it could escalate into runaway temperature rises.
Wikipedia image
Veli Albert Kallio comments:

The problem with ice cores is that if there is too sudden methane surge, then the climate warms very rapidly. This then results the glacier surfaces melting away and the ice core begins to loose regressively surface data if there is too much methane in the air.

Because of this, there has been previous occurrences of high methane, and these were instrumental to bring the ice ages ice sheets to end (Euan Nisbet's Royal Society paper). The key to this is to look at some key anomalies and devise the right experiments to test the hypothesis for methane eruptions as the period to ice ages.

Thus, the current methane melting and 1800 ppm rise is nothing new except that there are no huge Pleistocene glaciers to cool the Arctic Ocean if methane goes to overdrive this time. In fact methane may have been many times higher than that but all surface ice kept melting away and staying regressive until cold water and ice from destabilised ice sheets stopped the supply of methane (it decays fast if supply is cut and temperatures fall back rapidly when seas rose).

The Laurentide Ice Sheet alone was equivalent of 25 Greenland Ice Sheets and the Weischelian and other sheets on top of that. So, the glaciers do not act the same way as fireman to extinguish methane. Runaway global warming is now possibility if the Arctic loses its methane holding capability due to warming.

Further discussion is invited on the following points:
  • The large carbon-12 emission anomalies in East Asian historical objects that are dateable by historical knowledge. Discussion about the explanations concocted and why methane emission from permafrost soils and sea beds must be the answer; 
  • the much overlooked fact that if there were ever very highly elevated concentrations of air in the Arctic, this would induce strong melting of glaciers which then lack those surface depositions where the air were most CH4 and CO2 laden. Even moderate levels of temperature rise damaged Larsen A, Larsen B, Petermann and Ellesmere glaciers. If huge runaway outgassing came out when Beringia flipped into soil warming, then methane came out really large amounts with CO2.
  • Discussion of the experiments how to compensate for the possible lack of "time" in methane elevated periods in the ice cores by alternative experiments to obtain daily, weekly, monthly and yearly emission rates of CH4 and CO2 from the Last Glacial Maximum to the Holocene Thermal Maximum (as daily, weekly, monthly, and yearly sampling of air).

Editor's update: Methane levels go up and down with the seasons, and differ by altitude. As above post shows, mean levels reached 1800 ppb in May 2013 at 586 mb, according to MetOp-2 data. Note that IPCC AR5 gives levels of 1798 ppb in 2010 and 1803 ppb in 2011, as further discussed in later posts such as this one. Also, see historic data as supplied by NOAA below.




Sunday, June 16, 2013

Arctic Sea Ice September 2013 Projections

What will the Arctic Sea Ice look like in September 2013?

Several projections for Arctic sea ice extent are being discussed at places such as ARCUS (Arctic Research Consortium of the United States) and the Arctic Sea Ice Blog. The image below, from ARCUS, shows various projections of September 2013 arctic sea extent (defined as the monthly average for September) with a median value of 4.1 million square kilometers, with quartiles of 3.8 and 4.4 million square kilometers.


Note that sea ice extent in the above projections is defined as area of ocean with at least 15% ice, in line with the way the NSIDC calculates extent. By contrast, the Danish Meteorological Institute includes areas with ice concentration higher than 30% to calculate ice extent.

Rather than looking at the projected average for September, one could also project the minimum value for September 2013. And rather than looking at sea ice extent, one could also look at sea ice area, which differs from sea ice extent as the NSIDC FAQ page describes:
A simplified way to think of extent versus area is to imagine a slice of Swiss cheese. Extent would be a measure of the edges of the slice of cheese and all of the space inside it. Area would be the measure of where there is cheese only, not including the holes. That is why if you compare extent and area in the same time period, extent is always bigger.


Above image shows Sam Carana's projected minimum area of 2 million square km for 2013, based on data by Cryosphere Today and on numerous factors, such as continued warming of the water underneath the ice, stronger cyclones, etc.
Roughly in line with above image, by Wipneus, Sam Carana's projection for Arctic sea ice minimum volume is 2,000 cubic km in September 2013.

Readers are invited to submit comments below with further projections.