Showing posts with label concentration. Show all posts
Showing posts with label concentration. Show all posts

Tuesday, June 30, 2015

Dramatic Sea Ice Decline In Beaufort Sea in June 2015

The image below illustrates the dramatic fall in sea ice thickness (in m) in the Beaufort Sea over the past month. The left panel shows sea ice thickness on May 29, 2015, and the panel on the right shows sea ice thickness on June 29, 2015.


The 30-day animation below further illustrates this dramatic fall in sea ice thickness (from June 8-29, with forecast up to July 7, 2015).




Another perspective is sea ice concentration. The image below shows the high concentration back on May 1, 2015.



The 30-day animation below shows the dramatic fall in sea ice concentration (from June 8-29, with forecast up to July 7, 2015).



Below an interview by Judy Sole with Professor Peter Wadhams, held May 15, 2015, and entitled 'Our time is running out - The Arctic sea ice is going!'


Meanwhile, very high temperatures keep showing up within the Arctic Circle. On July 1, 2015, a temperature of 36°C (96.8°F) was reached near the Kolyma River that ends in the East Siberian Sea, as illustrated by the images below (green circle).


The image below also shows the location where this high temperature was reached (red marker), as well as the depth of the seabed and the Gakkel Ridge that runs in between the northern tip of Greenland and the Laptev Sea.



Related

- High Methane Levels over Laptev Sea
http://arctic-news.blogspot.com/2013/10/high-methane-levels-over-laptev-sea.html

- Accelerated Warming in the Arctic
http://arctic-news.blogspot.com/2015/06/accelerated-warming-in-the-arctic.html

- Gulf Stream brings ever warmer water into Arctic Ocean
http://arctic-news.blogspot.com/2015/06/gulf-stream-brings-ever-warmer-water-into-arctic-ocean.html

- High Temperatures in the Arctic
http://arctic-news.blogspot.com/2015/06/high-temperatures-in-the-arctic.html

- Heat Wave Forecast For Russia Early June 2015 
http://arctic-news.blogspot.com/2015/06/heat-wave-forecast-for-russia-early-june-2015.html

Dramatic Sea Ice Decline In Beaufort Sea in June 2015 http://arctic-news.blogspot.com/2015/06/dramatic-sea-ice-decline-in-beaufort-sea-in-june-2015.html
Posted by Sam Carana on Tuesday, June 30, 2015

Monday, June 9, 2014

Arctic Sea Ice Steep Decline Continues


Steep decline of the Arctic sea ice continues. The yellow line on the image below follows 2014 sea ice area up to June 5 and shows that sea ice area now is close to a record low for the time of the year.

[ click on image to enlarge ]
The Naval Research Laboratory image below compares sea ice concentration on May 14, 2014 (left) with the sea ice concentration forecast for June 15, 2014 (run on June 7, 2014, on the right).



Above image shows falling sea ice concentration, with low sea ice concentration extending to the center of the Arctic Ocean.

Low sea ice concentration at the center of the Arctic Ocean is an ominous sign; at last year's minimum, very little sea ice was left close to the North Pole, as discussed in an earlier post.

On the right is an image of the University of Bremen showing sea ice concentration on June 8, 2014 (click on the images to enlarge them).

Arctic sea ice already is very thin, as discussed in recent posts. The image below shows that the sea ice volume trend down to zero was confirmed for the months April and May 2014.

[ image by Andy Lee Robinson based on PIOMAS data, click on image to enlarge ]
The lowest sea ice volume for 2014 is expected to be reached in September, and - given the shape the ice is in now - will likely be one of the lowest minima on record. In fact, there is a chance that there will be no ice left whatsoever later this year. As illustrated by the image by Wipneus below, an exponential curve based on annual minima from 1979 points at zero ice volume end 2016, with the lower limit of the 95% confidence interval pointing at zero ice end of 2014.
As the sea ice disappears, a lot more heat will be absorbed by the Arctic Ocean. Sea ice reflects 50% to 70% of the incoming energy, describes NSIDC.org, but thick sea ice covered with snow reflects as much as 90% of the incoming solar radiation. Melting of snow creates melt ponds on the ice and because shallow melt ponds have an albedo of approximately 0.2 to 0.4, the surface albedo drops to about 0.75. As melt ponds grow and deepen, the surface albedo can drop to 0.15. The ocean reflects only 6% of the incoming solar radiation and absorbs the rest. Snow and ice decline comes with a further feedback in that all the energy that during the melt went into transforming ice into water will - in the absence of ice - now be absorbed by the ocean as well.

Accelerated Warming in the Arctic

[ from the post Near-Term Human Extinction ]
Such feedbacks are causing warming to accelerate in the Arctic Ocean, as depicted in above image and described in the earlier post Feedbacks in the Arctic. Much of the Arctic Ocean is very shallow and the seafloor is thus vulnerable to warming. The Gulf Stream can be expected to keep carrying warmer water into the Arctic Ocean, so the situation is dire, while extreme weather events such as heatwaves and cyclones can make the situation even worse.

The NOAA image below shows huge sea surface temperature anomalies all over the Northern Hemisphere on June 8, 2014.

[ click on image to enlarge ]
Large areas with sea surface temperature anomalies up to 8°C and higher show up in and around the Arctic Ocean, as further illustrated by the image below.

[ click on image to enlarge ]
The image below shows high sea surface temperature anomalies from February 21, 2014, up to June 9, 2014, on the Northern Hemisphere (red bars), next to global average anomalies (orange/shaded bars).


The global sea surface temperature anomaly is worrying (a 1.25°C anomaly was reached on May 22, 2014). See the NOAA website to compare this with earlier months. Note that on specific spots the anomaly is much higher, as illustrated by the images further above.

Warm surface waters in the Arctic sea ice spell bad news, given that the sea ice is already at or close to record lows, in terms of area and volume.

And as ocean heat threatens to melt the sea ice from beneath, the sun is now strongly warming up the ice from above. Insolation in the Arctic is at its highest at this time of year, 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 discussed at this earlier post.

The diminishing temperature difference between the equator and the North Pole reduces the speed at which the Jet Stream circumnavigates Earth and it makes the Jet Stream become wavier, increasing opportunities for cold air to escape from the Arctic and for warm air to move in. More extreme weather increases the chance of intense and prolonged heatwaves and fierce cyclones, storms and winds to hit the Arctic Ocean.

Making things even worsen, there is the prospect of an El Niño event, projected to occur later this year. According to NOAA (June 5, 2014), the chance of El Niño is 70% during the Northern Hemisphere summer and reaches 80% during the fall and winter. El Niño odds are even higher than this, according to this post at the Wunderground blog.


Methane

Temperature rises of the water close to the seafloor of the Arctic Ocean are very dangerous, as heat can penetrate sediments and cause hydrate destabilization. Huge amounts of methane are held in sediments at the seafloor, in the form of free gas and hydrates. In shallow waters, methane released from the seafloor can more easily enter the atmosphere without getting broken down by microbes in the water.

Methane levels are already very high. On June 6, 2014, mean global methane reached levels as high as 1809 ppb, with peaks as high as 2516 ppb.

Methane release from the seafloor of the Arctic Ocean will warm up the Arctic even further, triggering even more methane releases, heatwaves, wildfires and further feedbacks, in a spiral of runaway warming, threatening to cause starvation, destruction and extintion at massive scale across the globe.


Earthquakes

Earthquakes are a further worry. A huge amount of melting takes place in Greenland, as described in the post Ten Cubic Kilometers of Ice Lost From Jakobshavn Glacier in Less than One Month. As the ice disappears, a large weight is lefted from Greenland, causing the Earth's crust there to be lifted in a phenomenon referred to as isostatic rebound. This can cause earthquakes to occur on the seafloor of the waters around Greenland, as illustrated by the image below.

[ click on image to enlarge ]

As the image below shows, the faultline alongside Greenland crosses the Arctic Ocean and extends into the Laptev Sea and Siberia, an area recently hit by two large earthquakes.

[ click on image to enlarge ]
Earthquakes in this region are very worrying. Earthquakes can trigger further earthquakes, especially at locations closeby on the same faultline. Earthquakes and subsequent shockwaves and landslides can further contribute to destabilization of methane hydrates contained in sediments under the seafloor of the Arctic Ocean.

In conclusion, the situation is dire and calls for comprehensive and effective action, as discussed at the climate plan blog.


Related

- M4.4 Earthquake hits Arctic Ocean north of Greenland
http://arctic-news.blogspot.com/2014/04/m45-earthquake-hits-arctic-ocean.html

- M4.5 Earthquake hits Arctic Ocean
http://arctic-news.blogspot.com/2014/04/m45-earthquake-hits-arctic-ocean.html

- Earthquakes in the Arctic Ocean
http://arctic-news.blogspot.com/2014/04/earthquakes-in-the-arctic-ocean.html

- Methane, Faults and Sea Ice
http://arctic-news.blogspot.com/2013/11/methane-faults-and-sea-ice.html

- Norwegian Sea hit by 4.6M Earthquake
http://arctic-news.blogspot.com/2013/11/norwegian-sea-hit-by-46m-earthquake.html

- Greenland Sea hit by M5.3 Earthquake
http://arctic-news.blogspot.com/2013/10/greenland-sea-hit-by-m53-earthquake.html

- Earthquake hits waters off Japan
http://arctic-news.blogspot.com/2013/10/earthquake-hits-waters-off-japan.html

- Earthquake hits Laptev Sea
http://arctic-news.blogspot.com/2013/09/earthquake-hits-laptev-sea.html

- Methane Release caused by Earthquakes
http://arctic-news.blogspot.com/2013/09/methane-release-caused-by-earthquakes.html

- Earthquake M6.7 hits Sea of Okhotsk
http://methane-hydrates.blogspot.com/2013/10/earthquake-m67-hits-sea-of-okhotsk.html

- Sea of Okhotsk
http://methane-hydrates.blogspot.com/2013/06/sea-of-okhotsk.html

- Seismic activity
http://arctic-news.blogspot.com/p/seismic-activity.html

- Climate Plan
http://climateplan.blogspot.com

Tuesday, June 3, 2014

Arctic sea ice in steep decline

Arctic sea ice area is in steep decline. The yellow line on the image below shows the sea ice area for 2014 up to June 1st, showing an almost vertical fall over the past few days.

[ click on image to enlarge ]
The Naval Research Laboratory image below compares the May 14, 2014, sea ice concentration (left) with the sea ice concentration forecast for June 10, 2014 (run on June 2, 2014, on the right).

[ click on image to enlarge ]
The NOAA image below shows sea surface temperature anomalies on June 3rd, 2014.


The NOAA image shows the huge sea surface temperature anomalies all over the Northern Hemisphere on June 3rd, 2014. Large areas with sea surface temperature anomalies up to 8 degrees Celsius and higher show up in and around the Arctic Ocean

[ click on image to enlarge ]
The image below shows sea surface temperature anomalies up to 1.5 degrees Celsius over the May-June 2014 period, with global average anomalies that hover just above 1 degree Celsius.



Above sea surface anomalies are very high, much higher than historic annual temperature anomalies over land and oceans, as shown on the image below for comparison.


In conclusion, the situation spells bad news for the sea ice, also given the prospect of an El Niño event projected to occur later this year. As discussed in earlier posts, the sea ice is already very thin, and as this image shows, ocean heat is melting the sea ice from beneath, while the sun is warming up the ice from above. At this time of year, insolation in the Arctic is at its highest, 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 discussed at this earlier post.

Feedbacks further accelerate warming in the Arctic, as described in the earlier post Feedbacks in the Arctic. Temperature rises of the water close to the seafloor of the Arctic Ocean is very dangerous, as heat penetrating sediments there could cause hydrate destabilization, resulting in huge amounts of methane entering the atmosphere over the Arctic Ocean.

Friday, October 18, 2013

Unfolding Methane Catastrophe


The above image shows that, over a period of less than two days, huge amounts of methane show up over the depth of the Arctic Ocean, especially along the fault line that crosses the Arctic Ocean and extends into Siberia and further into the Sea of Okhotsk. On October 17, 2013, readings of up to 2351 ppb were recorded.



The above image shows that such high readings have occurred before over the past few months. This time, however, this high reading can be more clearly attributed to methane escaping from the depth of the Arctic Ocean, as also indicated by the image below that shows that at 469 mb (i.e. the altitude at which this high reading was recorded on the afternoon of October 17) methane was predominantly present at higher northern latitudes.

The methane that appears over the depth of the Arctic Ocean is likely have traveled a long path through the vertical water column before entering the atmosphere. Clearly, some of the methane must have oxidized in the ocean. Therefore, methane must be escaping from the seabed in amounts far higher than what is visible in the air.

Below follows some history regarding this unfolding methane catastrophe. Note that methane concentrations in the water are measured in nM, while methane concentrations in the atmosphere are typically measured in parts per billion (ppb).

There are vast amounts of methane in sediments underneath the Arctic Ocean.  Natalia Shakhova et al. (2010) estimate the accumulated potential for the East Siberian Arctic Shelf (ESAS) region alone (image on the right) as follows:
  • organic carbon in permafrost of about 500 Gt
  • about 1000 Gt in hydrate deposits
  • about 700 Gt in free gas beneath the gas hydrate stability zone.8
Natalia Shakhova et al. (2008) consider release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time. By comparison, the total amount of methane currently in the atmosphere is about 5 Gt.3

The danger that volcanic and earthquake activity along the Gakkel Ridge could lead to destabilization and abrupt methane release into the atmosphere was highlighted by Light and Sorana back in 2002.1

Measurements taken in September 2003 and September 2004 show that the surface layer of shelf water in the East-Siberian Sea and Laptev Sea was supersaturated up to 2500% relative to the present average atmospheric methane content of 1.85 ppm. Anomalously high concentrations (up to 154 nM or 4400% supersaturation) of dissolved methane in the bottom layer of shelf water suggest that the bottom layer is somehow affected by near-bottom sources. Considering the possible formation mechanisms of such plumes, we favor thermo-abrasion and the effects of shallow gas or gas hydrates release, conclude the authors of this study, published in 2005.2

In September 2005, extremely high concentrations of methane (up to 8 ppm) were measured in the atmospheric layer above the sea surface of the East Siberian Shelf, along with anomalously high concentrations of dissolved methane in the water column (up to 560 nM, or 12000% of super saturation).3

The authors conclude: "Since the area of geological disjunctives (fault zones, tectonically and seismically active areas) within the Siberian Arctic shelf composes not less than 1-2% of the total area and area of open taliks (area of melt through permafrost), acting as a pathway for methane escape within the Siberian Arctic shelf reaches up to 5-10% of the total area, we consider release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time. That may cause ∼12-times increase of modern atmospheric methane burden with consequent catastrophic greenhouse warming".3

In 2007, concentrations of dissolved methane in the water column reached a level of over 5141 nM at a location in the Laptev Sea.4

A study published in 2008 found volcanoes up to 2,000 m in diameter and a few hundred metres high at the bottom of the Arctic Ocean, at Gakkel Ridge.5



End September 2011, a cluster of methane plumes, over one km in diameter, appeared in the Laptev Sea, as shown on the image below, from a paper on the unfolding "Methane Catastrophe".6

In early October 2013, high atmospheric levels of methane started to appear over the depth of the Arctic Ocean.9  See image at top for most recent readings.


References

1. Arctic Methane Hydrates: A Potential Greenhouse Gas Hazard. - Light, M.P.R. and Solana, C. (2002)
http://adsabs.harvard.edu/abs/2002EGSGA..27.4077L
For more details, see also
http://arctic-news.blogspot.com/p/seismic-activity.html

2. The distribution of methane on the Siberian Arctic shelves: Implications for the marine methane cycle. - Natalia Shakhova, Igor Semiletov and Gleb Panteleev (2005)
http://onlinelibrary.wiley.com/doi/10.1029/2005GL022751/abstract

3. Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates? - N. Shakhova, I. Semiletov, A. Salyuk and D. Kosmach (2008)
http://meetings.copernicus.org/www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf

4. Siberian Sea Shelf Study, International Arctic Research Center, University of Alaska Fairbanks
http://research.iarc.uaf.edu/SSSS/data2010.php

5. Explosive volcanism on the ultraslow-spreading Gakkel ridge, Arctic Ocean. - Sohn RA et al. (2008)
http://www.ncbi.nlm.nih.gov/pubmed/18580949

6. The Degradation of Submarine Permafrost and the Destruction of Hydrates on the Shelf of East Arctic Seas as a Potential Cause of the “Methane Catastrophe”: Some Results of Integrated Studies in 2011. - V. I. Sergienko et al., in Oceanology (Sept. 2012)
http://link.springer.com/article/10.1134/S102833

7. On carbon transport and fate in the East Siberian Arctic land–shelf–atmosphere system. - Semiletov et al. (2012)
http://iopscience.iop.org/1748-9326/7/1/015201

8. Methane release from the East Siberian Arctic Shelf and the Potential for Abrupt Climate Change. - Natalia Shakhova and Igor Semiletov (2010), Presentation at Symposium, November 30, 2010
http://symposium2010.serdp-estcp.org/content/download/8914/107496/version/3/file/1A_Shakhova_Final.pdf

9. High Methane Readings continue over Depth of Arctic Ocean
http://arctic-news.blogspot.com/2013/10/high-methane-readings-continue-over-depth-of-arctic-ocean.html


Sunday, October 6, 2013

Algae Bloom or Clathrates

There has been some discussion lately as to whether the high levels of methane observed over the Arctic Ocean originated from algae bloom or from clathrates (i.e methane hydrates).

The image below, from Arctic.io, does indeed indicate extensive algae bloom.

[ click on image to enlarge ]
The green color indicates extensive algae bloom, especially in areas where the sea water has been very warm recently, as discussed in earlier posts such as 'Is the North Pole now ice-free?' The image below shows sea surface temperature anomalies as at September 30, 2013.

[ click on image to enlarge ]
Indeed, no surprise to see extensive algae bloom, especially close to Svalbard, where the highest anomalies were recorded. The question is, however, where the methane came from that has showed up so prominently over the Arctic Ocean recently. The animation below shows methane readings over the past week, against a recent sea ice concentration map.

Monday, September 2, 2013

North Hole

Sea Surface Temperature Anomalies

A dust storm approaches Stratford, Texas, in 1935. From: Wikipedia: Dust Bowl
During the 1930s, North America experienced a devastating drought affecting almost two-thirds of the United States as well as parts of Mexico and Canada. The period is referred to as the Dust Bowl, for its numerous dust storms.

Rapid creation of farms and use of gasoline tractors had caused erosion at massive scale.

Extensive deep plowing of the virgin topsoil of the Great Plains in the preceding decade had removed the natural deep-rooted vegetation that previously kept the soil in place and trapped moisture even during periods of drought and high winds.

So, when the drought came, the dust storms emerged. But what caused the drought?

A 2004 study concludes that the drought was caused by anomalous sea surface temperatures (SST) during that decade and that interactions between the atmosphere and the land surface increased its severity (see image above right with SST anomalies).

Sea Surface Temperature Anomalies in the Arctic

As the above chart shows, SST anomalies in the days of the Dust Bowl were not greater than one degree Celsius. It is in this context that the current situation in the Arctic must be seen. This year, SST anomalies of 5 degrees Celsius or more are showing up in virtually all areas in the Arctic Ocean where the sea ice has disappeared; some areas are exposed to sea surface temperature anomalies higher than 8°C (14.4°F), as discussed in the post Arctic Ocean is turning red.

High SST anomalies can change weather patterns in many places, as discussed in an earlier post on changes to the Polar Jet Stream. The world is now stumbling from one extreme weather event into another, and things look set to get worse every year.

Feedbacks in many ways make things even worse in the Arctic, as described in the post Diagram of Doom. A recent paper by Feng et al. notes that river runoff has significantly increased across the Eurasian Arctic in recent decades, resulting in increased export of young surface carbon. In addition, the paper says, climate change-induced mobilization of old permafrost carbon is well underway in the Arctic. An earlier paper already warned about coastal erosion due to the permafrost melt. In conclusion, the Arctic is hit by climate change like no other place on Earth.

North Hole

As the ice thickness map below shows, holes have appeared in the sea ice in places that once were covered by thick multi-year sea ice.


One such hole, for its proximity to the North Pole, has been aptly named the "North Hole". On the sea ice concentration map below, this hole shows up as a blue spot (i.e. zero ice).


The "Methane Catastrophe"

Why do we care? For starters, methane appears to be rising up from these holes in the sea ice, forming a cloud of high methane concentrations over the Arctic Ocean.



Perhaps this is a good occasion to again look at the methane plume over one km in diameter that appeared in the Laptev Sea end September 2011. The image is part of a paper on the unfolding "Methane Catastrophe".


Back in 2008, Shakhova et al., in the study Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates? considered release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time.

For more on the methane threat, please read the post methane hydrates or view the FAQ page.

Action

The threat of the "Methane Catastrophe" requires action to be taken urgently, such as discussed at the Climate Plan.


Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• On the Cause of the 1930s Dust Bowl - by Siegfried Schubert
https://science.sciencemag.org/content/303/5665/1855

• Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates? - by Natalia Shakhova et al.
http://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf

• The degradation of submarine permafrost and the destruction of hydrates on the shelf of east arctic seas as a potential cause of the “Methane Catastrophe”: some results of integrated studies in 2011 - by V. I. Sergienko et al.
https://link.springer.com/article/10.1134/S1028334X12080144

• Methane hydrates
https://methane-hydrates.blogspot.com/2013/04/methane-hydrates.html

• Frequently Asked Questions (FAQ)
https://arcticmethane.blogspot.com/p/faq.html



Thursday, August 15, 2013

Arctic Sea Ice in Free Fall

Arctic Sea Ice has declined dramatically recently. The recent image below, by the Danish Meteorological Institute, shows the decline in extent over the past few days, with extent calculated by including all areas with ice concentration higher than 30%.


As the above image shows, sea ice extent (30%+ concentration) is now lower than any other year, except 2007 and 2012. Moreover, the sharp decline looks set to continue.

Ice volume and concentration have dropped dramatically, partly as a result of the cyclone that hit the Arctic Ocean a few days ago. The eye of the cyclone is still visible almost exactly above the North Pole on the Naval Research Laboratory image below on the right, where sea ice concentration appears to form a circle.

The sea ice looks set for an all-time record low; all this thin ice looks set to disappear over the next few weeks.

The graph below, also by the Danish Meteorological Institute, calculates sea ice extent by including all areas with 15% or more ice concentration.
The above graph also shows a steep recent descent, although not as pronounced as in the graph at the top that includes spots with 30% or more ice concentration. The graph at the top better illustrates recent drops in ice concentration from, say, 40% to 20%, which can occur quite abruptly due to the impact of a cyclone. 

The Danish Meteorological Institute has meanwhile produced a more recent version of the graph based on spots with 30% or more ice concentration (added below).


The above graph shows an August 15 extent that appears to be back in line with the earlier trend. At first glance, it may appear as if the sea ice has largely recovered from the impact of three cyclones that have hit the Arctic Ocean over the past two months. 

However, these cyclones are likely to have contributed to the appearance and persistence of thin spots in the ice close to the North Pole. This phenomenon was earlier described in posts such as Thin Spots developing in Arctic Sea Ice

The conclusion remains the same as the one drawn then in that post, i.e. that for years, observation-based projections have been warning about Arctic sea ice collapse within years, with dire consequences for the Arctic and for the world at large.

Cyclones can speed up this collapse. On this point, it's good to remember what Prof. Peter Wadhams said in 2012:
". . apart from melting, strong winds can also influence sea ice extent, as happened in 2007 when much ice was driven across the Arctic Ocean by southerly winds (not northerly, as she stated). The fact that this occurred can only lead us to conclude that this could happen again. Natural variability offers no reason to rule out such a collapse, since natural variability works both ways, it could bring about such a collapse either earlier or later than models indicate.

In fact, the thinner the sea ice gets, the more likely an early collapse is to occur. It is accepted science that global warming will increase the intensity of extreme weather events, so more heavy winds and more intense storms can be expected to increasingly break up the remaining ice, both mechanically and by enhancing ocean heat transfer to the under-ice surface."
Hopefully, more people will realize the urgency of the situation and realize the need for a comprehensive and effective plan of action as described here.

Monday, August 12, 2013

Cyclone raging on Thin Ice

Another cyclone is raging over the Arctic Ocean. The Naval Research Laboratory image below shows the speed and drift of the sea ice.

[ click on image to enlarge ]
Last time a cyclone hit the Arctic, this resulted in a temporary increase in area covered by sea ice, as shown on the Cryosphere Today image below. The cyclone pushed down on the sea ice, flattening it and pushing it sideways. 


Note that area as measured by the Cryosphere Today includes all spots that have a 15% or higher concentration of ice. This way of measuring area ignores the fact that the cyclone reduced the sea ice concentration in many spots, from a high sea ice concentration (around 90%) to a lower concentration (less than 80%), as shown on the Naval Research Laboratory image below. 


Furthermore, sea ice has since dropped in thickness, as illustrated by the Naval Research Laboratory image below. 

Much of the ice is now less than one meter thick, while some areas close to the North Pole have ice that is only between zero and half a meter thick.

The cyclone is raging most fiercely in those areas and much of the ice is drifting out into the Atlantic Ocean.

Neven mentioned at the Arctic Sea Ice Blog that average thickness (crudely calculated by dividing PIOMAS (PI) volume numbers with Cryosphere Today (CT) sea ice area numbers, see image below) had a very steep drop in July, similar to the drop in 2010. This year's trend line is now lowest, probably signifying that the ice pack is spread out and thin at the edges (read: melting potential).

[ click on image to enlarge ]
The image below, from the University of Bremen, Germany, shows sea ice concentration on August 11, 2013.



Friday, July 19, 2013

Arctic Ocean Events - Videos by Paul Beckwith

by Paul Beckwith


Massive Arctic cyclone effect on sea ice in August 2012
Part 1: August 1st to 16th, 2012
http://www.youtube.com/watch?v=nli47-9dT5o

Arctic sea ice motion (speed and direction) is compared to sea ice thickness from August 1st to August 16th, 2012. Sea ice motion is then compared to meteorology (500 mb pressure heights and 200 mb vector winds).




Massive Arctic cyclone effect on sea ice in August 2012
Part 2: August 1st to 16th, 2012
http://www.youtube.com/watch?v=WqwIVEpSg3w

Northern hemisphere meteorology (500mb pressure heights) and Arctic sea ice concentration compared to SST (sea surface temperatures) are examined from August 1st to August 16th, 2012 encompassing the mass persistent cyclone.




Massive Arctic cyclone effect on sea ice in August 2012
Part 3: August 1st to 16th, 2012
http://www.youtube.com/watch?v=HjYxRV0fzz4

Arctic basin SSS (sea surface salinity) is compared to SSH (sea surface height) during the period August 1st to August 16th, 2012 which encompassed a massive persistent cyclone. Detailed meteorology is also examined (tropopause temperature + pressure, surface precipitable water + pressure). Also examined is ocean profile salinity and temperature from an ice tethered buoy.




Massive Arctic cyclone effect on sea ice in August 2012
Part 4:  August 1st to 16th, 2012
http://www.youtube.com/watch?v=aAJRIV8YITY

The jet streams in the Arctic ocean basin are shown (200mb vector winds) from NOAA/ESRL daily data, as well as from 4 times daily data from SFSU. The data is given from August 1st to August 16th, 2012 which encompasses the massive Arctic cyclone.




2013

Arctic sea ice thickness + motion
May 14th to June 10th, 2013
http://www.youtube.com/watch?v=5ljHI0VITgk

Arctic sea ice data from May 14 to June 10, 2013
Left pane shows Arctic sea ice thickness; right pane shows sea ice motion (direction and speed).




Arctic sea ice thickness + motion
July 1st to 17th 2013
http://www.youtube.com/watch?v=cUZr51_yW5s

Arctic sea ice data from July 1st to July 17th, 2013. Left pane shows the Arctic sea ice thickness; right pane shows sea ice motion (direction and speed).




Sea ice concentration, temperature, salinity, and height;
July 1st to 18th, 2013
http://www.youtube.com/watch?v=icUtGqpkFx8

Arctic ocean data from US Navy for
1) sea ice concentration,
2) sea surface temperature (SST),
3) sea surface salinity (SSS), and
4) sea surface height (SSH)




Jet streams
July 1st to July 17th 2013
http://www.youtube.com/watch?v=IFbJCFVSiPI

Northern hemisphere (NH) jet streams are shown from two sources:
1) NOAA/ESRL data collected daily, and
2) SFSU data collect every 6 hours. Data is given for the time period from July 1st to July 17th, 2013.




Meteorology
July 1st to 18th 2013
http://www.youtube.com/watch?v=LONJT8JbM7I

The following meteorology plots are shown for time period July 1st to July 18th, 2013 over the Arctic Ocean between 60 degrees N and 90 degrees N:
1) 500mb pressure levels,
2) 200mb vector winds (jet streams),
3) precipitable water, and
4) tropopause temperatures.

Wednesday, May 22, 2013

Is the permafrost's integrity breaking down?


The chart below shows very high methane levels over Antarctica in April and May 2013. High levels of methane over Antarctica were recorded before in 2013, as described in an earlier post at the methane-hydrates blog.

Meanwhile, a methane reading of 2475 ppb was recorded on April 26, 2013, appearing to originate from the Himalayan Plateau, as illustrated by the image below.


Recurring high readings could indicate that methane is bubbling up through the permafrost, both in Antarctica and on the Himalayan Plateau.

Loss of the integrity of the permafrost is particularly threatening in the Arctic, where the sea ice looks set to disappear within years, resulting in huge albedo changes in summer. Decrease of surface reflectivity results in increases in absorption of energy from sunlight and decreases in shortwave radiation in the atmosphere. The latter results in lower photo-dissociation rates of tropospheric gases. Photo-dissociation of the ozone molecule is the major process that leads to the production of OH (hydroxyl radical), the main oxidizing (i.e., cleansing) gas species in the troposphere. A 2009 NASA study projects this to lead to a decrease in OH concentrations and a weakening of the oxidizing capacity of the Arctic troposphere, further increasing the vulnerability of the Arctic to warming in case of additional methane releases.

Levels of greenhouse gases such as carbon dioxide and methane are already very high in the Arctic atmosphere, while large quantities of black carbon get deposited on snow and ice, further contributing to the albedo changes. This threatens to result in rapid summer warming of many parts of the Arctic Ocean with very shallow waters. Additionally, rivers can bring increasingly warm water into those shallow seas in summer, adding to the threat that heat will penetrate the seabed that contains huge quantities of methane.



Above image, earlier included in an animation at the Arctic-news blog, shows methane concentrations on January 23, 2013, when a reading of 2241 ppb was recorded in the Arctic.

Analysis of sediment cores collected in 2009 from under ice-covered Lake El'gygytgyn in the northeast Russian Arctic suggest that, last time the level of carbon dioxide in the atmosphere was about as high as it is today (roughly 3.5 to 2 million years ago), regional precipitation was three times higher and summer temperatures were about 15 to 16 degrees Celsius (59 to 61 degrees Fahrenheit), or about 8 degrees Celsius (14.4 degrees Fahrenheit) warmer than today.

As temperatures rose back in history, it is likely that a lot of methane will have vented from hydrates in the Arctic, yet without causing runaway warming. Why not? The rise in temperature then is likely to have taken place slowly over many years. While on occasion this may have caused large abrupt releases of methane, the additional methane from such releases could each time be broken down within decades, also because global methane levels in the atmosphere were much lower than today.

In conclusion, the situation today is much more threatening, particularly in the East Siberian Arctic Shelf (ESAS), as further described in the earlier post methane hydrates.

Above post is an extract of the full post at the methane-hydrates blog