Arctic sea ice: possible record-low maximum extent occurring

Dear Readers,

We have a situation here.

In the past, I looked little at the Arctic sea ice extent numbers because I considered the sea ice volume to be a far more important measure of what was going on in the Arctic.  However, consider this -- say 5-10 years ago, the ice in general was much thicker.  There were even land-fast ice shelves attached to the Canadian archipelago that were more than 100 feet thick (those are all gone), and multi-year ice could easily be well over 5-6 meters thick, and there was a lot more of it.

These days, in general, all of the ice is fairly thin, thus making the extent graph much more significant.

Have a look (CLICK ON THE IMAGE TO SEE IT IN FULL):

http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png

During the summer melt seasons, it was often (but not always) the case that when the Arctic Oscillation Index was strongly positive, the rate of melt was much higher, primarily due to warm air masses entering the Arctic via the North Atlantic.

Have a look at the current AO Index -- 2 is a fairly normal number, but above 5 is quite extraordinary:

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index.html



Then have a look at the satellite photos of water vapor moving into the Arctic via the North Atlantic and the Bering Strait:

Animation of the satellite images here:

http://synoptic.envsci.rutgers.edu/site/sat/sat.php?sat=nhem&url=../imgs/wv_nhem_anim.gif


And here we can see warm air being pushed into the Arctic at 79 km/h (CLICK ON IMAGE TO ENLARGE):

http://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=317.12,75.45,1382


And what does the University of Maine's ever useful Climate Reanalyzer website tell us?

http://cci-reanalyzer.org/DailySummary/





Oh, wait! Is that a red beanie baby toad on top of the North Pole?

RUSSIAN RIVER WATER UNEXPECTED CULPRIT BEHIND ARCTIC FRESHENING

by Sandra Hines, UW Today, January 4, 2012

A hemisphere-wide phenomenon – and not just regional forces – has caused record-breaking amounts of freshwater to accumulate in the Arctic's Beaufort Sea.



Frigid freshwater flowing into the Arctic Ocean from three of Russia's mighty rivers was diverted hundreds of miles to a completely different part of the ocean in response to a decades-long shift in atmospheric pressure associated with the phenomenon called the Arctic Oscillation, according to findings published in the January 5, 2012, issue of Nature.

The new findings show that a low pressure pattern created by the Arctic Oscillation from 2005 to 2008 drew Russian river water away from the Eurasian Basin, between Russia and Greenland, and into the Beaufort Sea, a part of the Canada Basin bordered by the United States and Canada. It was like adding 10 feet (3 meters) of freshwater over the central part of the Beaufort Sea.

“Knowing the pathways of freshwater in the upper ocean is important to understanding global climate because of freshwater's role in protecting sea ice – it can help create a barrier between the ice and warmer ocean water below – and its role in global ocean circulation. Too much freshwater exiting the Arctic would inhibit the interplay of cold water from the poles and warm water from the tropics,” said Jamie Morison, an oceanographer with the University of Washington's Applied Physics Laboratory and lead author of the Nature paper.

Red arrows show the new path of Russian river water into the Canada Basin. The previous freshwater pathway – across the Eurasian Basin toward Greenland and the Atlantic – was altered by atmospheric conditions created by the Arctic Oscillation. Credit: University of Washington

Morison and his six co-authors from the UW and NASA's Jet Propulsion Laboratory are the first to detect this freshwater pathway and its connection to the Arctic Oscillation. The work is based on water samples gathered in the field combined with satellite oceanography possible for the first time with data from NASA satellites known as ICESat and GRACE.

“Changes in the volume and extent of Arctic sea ice in recent years have focused attention on the impacts of melting ice,” said co-author Ron Kwok, senior research scientist with the Jet Propulsion Laboratory in Pasadena, Calif. “The combined GRACE and ICESat data allow us to now examine the impacts of widespread changes in ocean circulation.”

Red arrows show the new path of Russian river water into the Canada Basin. The previous freshwater pathway – across the Eurasian Basin toward Greenland and the Atlantic – was altered by atmospheric conditions created by the Arctic Oscillation. Credit: University of Washington

Taken as a whole, the salinity of the Arctic Ocean is similar to the past, but the change in the freshwater pathway means the Eurasian Basin has gotten more saline while the Canada Basin has gotten fresher.

“The freshening on the Canadian side of the Arctic over the last few years represents a redistribution of freshwater, there does not seem to be a net freshening of the ocean,” Kwok said.

In the Eurasian Basin, the change means less freshwater enters the layer known as the cold halocline and could be contributing to declines in ice in that part of the Arctic, Morison said. The cold halocline normally sits like a barrier between ice and warm water that comes into the Arctic from the Atlantic Ocean. Without salt the icy cold freshwater is lighter, which is why it is able to float over the warm water.

In the Beaufort Sea, the water is the freshest its been in 50 years of record keeping, he said. The new findings show that only a tiny fraction is from melting ice and the vast majority is Eurasian river water.

The Beaufort Sea stores a significant amount of freshwater from a number of sources, especially when an atmospheric condition known as the Beaufort High causes winds to spin the water in a clockwise gyre. When the winds are weaker or spin in the opposite direction, freshwater is released back into the rest of the Arctic Ocean, and from there to the worlds oceans. Some scientists have said a strengthening of the Beaufort High is the primary cause of freshening, but the paper says salinity began to decline in the early 1990s, a time when the Beaufort High relaxed and the Arctic Oscillation increased.

“We discovered a pathway that allows freshwater to feed the Beaufort gyre,” Kwok said. “The Beaufort High is important but so are the broader-scale effects of the Arctic Oscillation.”

“A number of people have come up with ways of looking at regional forces at work in the Arctic,” Morison said, “To better understand changes in sea ice and the Arctic overall we need to look more broadly at the hemisphere-wide Arctic Oscillation, its effects on circulation of the Arctic Ocean and how global warming might enhance those effects.”

In coming years if the Arctic Oscillation stops perpetuating that low pressure, the freshwater pathway should switch back.

Morison and the co-authors argue that, compared to prior years, the Arctic Oscillation has been in its current state for the last 20 years. For example, the changes detected in response to the Arctic Oscillation between 2005 and 2008 are very similar to freshening seen in the early 1990s, Morison said.

Discerning the track of freshwater from Eurasian rivers would have been impossible without the ICESat and GRACE satellites, Kwok and Morison agree. With satellite measurements of ocean height and bottom pressures, the researchers could separate the changes in mass from changes in density – or freshwater content – of the water column.

“To me its pretty spectacular that you have these satellites zipping around hundreds of kilometers above the Earth and they give us a number about salinity that's very close to what we get from lowering little sampling bottles into the ocean,” Morison said.

Other co-authors are Cecilia Peralta-Ferriz with the UWs School of Oceanography and Matt Alkire, Ignatius Rigor, Roger Andersen and Mike Steele, all with the UWs Applied Physics Laboratory. The work was funded by the National Science Foundation and NASA. For more information: Morison, 206-543-1394 (office), 206-310-5307 (cell), morison@apl.washington.edu and Kwok, contact via Alan Buis, 818-354-0474, alan.d.buis@jpl.nasa.gov

Top Image: Julian Olden and graduate student Thomas Pool weigh invasive carp from an Arizona stream. Credit: Olden Lab

http://depts.washington.edu/coenv/freshwater/2012/01/russian-river-water-unexpected-culprit-behind-arctic-freshening-with-video/

California Drought/Polar Vortex Jet Stream Pattern Linked to Global Warming

by Jeff Masters, Weather Underground, April 16, 2014

From November 2013 through January 2014, a remarkably extreme jet stream pattern set up over North America, bringing the infamous "Polar Vortex" of cold air to the Midwest and Eastern U.S., and a "Ridiculously Resilient Ridge" of high pressure over California, which brought the worst winter drought conditions ever recorded to that state. A new study published this week in Geophysical Research Letters, led by Utah State scientist S.-Y. Simon Wang, found that this jet stream pattern was the most extreme on record, and likely could not have grown so extreme without the influence of human-caused global warming. The study concluded, “there is a traceable anthropogenic warming footprint in the enormous intensity of the anomalous ridge during winter 2013–14, the associated drought and its intensity."


Figure 1. An extreme jet stream pattern observed at 00 UTC on January 16, 2014. Color-coded wind speeds at a pressure of 300 mb (roughly 9,000 meters or 30,000 feet) show the axis of the jet stream over North America, with a large upside-down "U"-shaped ridge of high pressure over the West Coast. California is outlined in orange. The strongest winds of the jet stream (orange colors, 160 mph) were observed over the Northeast United States, where a strong "U"-shaped trough of low pressure was anchored. Image generated from the 00 UTC January 16, 2014, run of the GFS model, and plotted using our wundermap.

Using observations and a climate model to diagnose the human contribution to the jet stream pattern
The researchers studied the historical pressure patterns for November–January over North America during the period 1960–2014, and found that a strong "dipole" pattern of high pressure over Western North America and low pressure over Eastern North America, such as occurred during the winter of 2013–2014, tended to occur naturally during the winter immediately preceding an El Niño event. Since NOAA is giving a greater than 50% of an El Niño event occurring later in 2014, this past winter's dipole pattern may have been a natural expression of the evolving progression towards El Niño. The study also found that the dipole pattern could be intensified by two other natural resonances in the climate system: the Arctic Oscillation, and a variation of ocean temperatures and winds in the Western North Pacific called the Western North Pacific (WNP) pattern. But the dipole of high pressure over California combined with the "Polar Vortex" low pressure trough over Eastern North America during November 2013–January 2014 was of unprecedented intensity, and extremes in this dipole pattern – both in the positive and negative sense – have been increasing since 2000 (the peak negative value occurred during the winter of 2009–2010). The researchers used a climate model to look at whether human-caused climate change might be interfering with the natural pattern to cause this unusual behavior. They ran their climate model both with and without the human-caused change to the base state of the climate included, and found that they could not reproduce the increase in amplitude of the dipole pattern unless human-caused global warming was included. They concluded, "It is important to note that the dipole is projected to intensify, which implies that the periodic and inevitable droughts California will experience will exhibit more severity. The inference from this study is that the abnormal intensity of the winter ridge is traceable to human-induced warming but, more importantly, its development is potentially predicable." In an email to me, the lead author of the study, Simon Wang, emphasized that the opposite sign of the dipole – an extreme trough of low pressure over Western North American, combined with an extreme ridge of high pressure over Eastern North America – is also expected to be more intense when it occurs, leading to an increase in extremely wet winters in California. 

Dr. Joe Romm's post on the study, "Bombshell: Study Ties Epic California Drought, ‘Frigid East’ To Manmade Climate Change," has this quote by climate scientist Michael Mann on the new research:

We know that human-caused climate change has played a hand in the increases in many types of extreme weather impacting the U.S., including the more pronounced heat waves and droughts of recent summers, more devastating hurricanes and superstorms, and more widespread and intense wildfires.

This latest paper adds to the weight of evidence that climate change may be impacting weather in the U.S. in a more subtle way, altering the configuration of the jet stream in a way that disrupts patterns of rainfall and drought, in this case creating an unusually strong atmospheric “ridge” that pushed the jet stream to the north this winter along the west coast, yielding record drought in California, flooding in Washington State, and abnormal warmth in Alaska. The recent IPCC assessment downplays these sorts of connections, making it very conservative in its assessment of risk, and reminding us that uncertainty in the science seems to be cutting against us, not for us. It is a reason for action rather than inaction.


Figure 2. One of the key water supply reservoirs for Central California, Lake Oroville, as seen on January 20, 2014. Thanks to an unusually intense ridge of high pressure over Western North America, California endured its driest November–January period on record this past winter, resulting in the worst winter drought on record. Image credit: California Department of Water Resources.

Other research connecting extreme circulation patterns to human causes
This week's paper by Dr. Wang is the second he has authored which has found a human fingerprint on extreme atmospheric circulation patterns. His 2013 paper, "Identification of extreme precipitation threat across mid-latitude regions based on short-wave circulations," discussed how there's been a trend during the period 1979–2010 towards a pronounced circulation shift involving the low-level jet stream (LLJ), which is capable of bringing more extreme precipitation events (and droughts) to the mid-latitudes. Using four different climate models, the study found that the circulation shift only occurs when one runs climate models with the effects of human-caused emissions of greenhouse gases like carbon dioxide included; "control" runs of these models using only natural changes to the climate could not reproduce the observed increase in this more extreme circulation pattern. The paper concluded that several recent extreme precipitation events, including those leading to the 2008 Midwest flood in U.S., the 2011 tornado outbreaks in southeastern U.S., the 2010 Queensland flood in northeastern Australia, and to the opposite sense, the 2012 central U.S. drought, could have been influenced by human-caused changes to the atmospheric circulation. The fact that his research helps us understand how human-caused climate change is contributing to higher amplitude jet stream patterns should make them more predictable, potentially saving lives and money.

References

Wang, S, Davies, R.E., and R.R. Gillies, 2013, "Identification of extreme precipitation threat across midlatitude regions based on short-wave circulations," J. Geophys. Res. Atmos., 118, 11,059–11,074, doi:10.1002/jgrd.50841.

Wang, S., Hipps, L., Gillies, R.R., and J.-H. Yoon, 2014, "Probable causes of the abnormal ridge accompanying the 2013–14 California drought: ENSO precursor and anthropogenic warming footprint," Geophysical Research Letters, DOI: 10.1002/2014GL059748. News Release.

Related information

There is an growing body of research exploring connections between human-caused climate change and the increase in unusual jet stream patterns we've seen in recent years. Most of this research focuses on potential linkages between Arctic warming and atmospheric circulation patterns. Below are links to wunderground blog posts on the subject, and to the original research studies and associated press releases.

"The Changing Face of Mother Nature", wunderground guest post by Dr. Jennifer Francis of Rutgers, April 22, 2013.

Extreme jet stream causing record warmth in the east, record cold in the west (January 2013)

Arctic sea ice loss tied to unusual jet stream patterns (April 2012)

Our extreme weather: Arctic changes to blame? (December 2011)

Florida shivers; Hot Arctic-Cold Continents pattern is back (December 2010)

Jet stream moved northwards 270 miles in 22 years; climate change to blame? (June 2008)

Dr. Ricky Rood has done a whole series of posts on climate change and the Arctic Oscillation, including:

Cold Weather in Denver: Climate Change and Arctic Oscillation (8)

Are the changes in the Arctic messing with our weather? The Future of Blocking

Papers linking Arctic warming to an increase in negative AO/NAO conditions

Deser, C., R. Tomas, M. Alexander, and D. Lawrence, 2010, "The seasonal atmospheric response to projected Arctic sea ice loss in the late 21st century," J. Clim., 23, 333–351, doi:10.1175/2009JCLI3053.1.

Francis, J. A., and S. J. Vavrus (2012), "Evidence linking Arctic amplification to extreme weather in mid-latitudes," Geophysical Research Letters, 21 February, 2012. Accompanying article at the Yale Forum on Climate Change, Linking Weird Weather to Rapid Warming of the Arctic.

Francis, J. A., W. Chan, D. J. Leathers, J. R. Miller, and D. E. Veron, 2009, "Winter northern hemisphere weather patterns remember summer Arctic sea-ice extent," Geophys. Res. Lett., 36, L07503, doi:10.1029/2009GL037274.

Honda, M., J. Inoue, and S. Yamane, 2009, "Influence of low Arctic sea-ice minima on anomalously cold Eurasian winters," Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079.

Jaiser, R., K. Dethloff, D. Handorf, A. Rinke, J. Cohen (2012), "Impact of sea ice cover changes on the Northern Hemisphere atmospheric winter circulation," Tellus A, 64, 11595, DOI: 10.3402/tellusa.v64i0.11595

Liu et al. (2012), "Impact of declining Arctic sea ice on winter snowfall," Proc. Natl. Academy of Sciences, Published online before print February 27, 2012, doi: 10.1073/pnas.1114910109. Accompanying press release. My blog post. 

Overland, J. E., and M. Wang, 2010, "Large-scale atmospheric circulation changes associated with the recent loss of Arctic sea ice," Tellus, 62A, 1.9.

Petoukhov, V., and V. Semenov, 2010, "A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents," J. Geophys. Res.-Atmos., ISSN 0148–0227.

Seager, R., Y. Kushnir, J. Nakamura, M. Ting, and N. Naik (2010), "Northern Hemisphere winter snow anomalies: ENSO, NAO and the winter of 2009/10," Geophys. Res. Lett., 37, L14703, doi:10.1029/2010GL043830.

Seierstad, I. A., and J. Bader (2009), "Impact of a projected future Arctic Sea Ice reduction on extratropical storminess and the NAO," Clim. Dyn., 33, 937-943, doi:10.1007/s00382-008-0463-x.

Tang et al., "Cold winter extremes in northern continents linked to Arctic sea ice loss," Environ. Res. Lett., 8 014036, doi:10.1088/1748-9326/8/1/014036. My April 2013 blog post.

Papers linking Arctic warming to Western U.S. drought

Sewall, Jacob O., 2005, Precipitation Shifts over Western North America as a Result of Declining Arctic Sea Ice Cover: The Coupled System Response, Earth Interact., 9, 1–23. doi: http://dx.doi.org/10.1175/EI171.1

Sewall, J. O., and L. C. Sloan, 2004, Disappearing Arctic sea ice reduces available water in the American west, Geophys. Res. Lett., 31, L06209, doi:10.1029/2003GL019133. Accompanying news release.

Papers linking Arctic sea ice loss to changes in summer rainfall

Li Y, LR Leung, Z Xiao, M Wei, and Q Li. 2013, Interdecadal Connection between Arctic Temperature and Summer Precipitation over the Yangtze River Valley in the CMIP5 Historical Simulations, Journal of Climate, 26(19):7464-7488. DOI: 10.1175/JCLI-D-12-00776.1.  Accompanying press release.

Li, Y, and L.R. Leung, 2013, "Potential Impacts of the Arctic on Interannual and Interdecadal Summer Precipitation in China," Journal of Climate, 26(3):899–917. DOI: 101175/JCLI-D-12-00075.1

Screen, J.A., 2013, "Influence of Arctic sea ice on European summer precipitation," Environ. Res. Lett., 8, 044015 doi:10.1088/1748-9326/8/4/044015. Accompanying press release.

Wu, B., Zhang R., D’Arrigo, R., and J. Su, 2013, "On the relationship between winter sea ice and summer atmospheric circulation over Eurasia," J. Clim., 26 5523–36

Papers exploring the link between Arctic warming to changes in large-scale atmospheric circulation

Cassano, E. N., Cassano, J. J., Higgins, M. E., and M. C. Serreze, 2013, "Atmospheric impacts of an Arctic sea ice minimum as seen in the Community Atmosphere Model," Int. J. Climatol., in press. (doi:10.1002/joc.3723)

Overland, J. E., Francis, J. A., Hanna, E., and M. Wang, 2012, "The recent shift in early summer Arctic atmospheric circulation," Geophys. Res. Lett., 39 L19804, DOI: 10.1029/2012GL053268

Petoukhov, V., Rahmstorf, S., Petri, S., Schellnhuber, H. J. (2013), "Quasi-resonant amplification of planetary waves and recent Northern Hemisphere weather extremes" Proceedings of the National Academy of Sciences, (Early Edition) [doi:10.1073/pnas.1222000110]. Easy-to-read description of the paper by the authors, published at http://theconversation.edu.au. Accompanying press release. My March 2013 blog post.

Screen, J. A., and I. Simmonds, 2013, "Exploring links between Arctic amplification and mid-latitude weather," Geophys. Res. Lett., 40, 959–64.

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2665

NOAA Arctic Sea Ice Report of April 2, 2014

Arctic sea ice at fifth lowest annual maximum

Arctic sea ice reached its annual maximum extent on March 21, after a brief surge in extent mid-month. Overall the 2014 Arctic maximum was the fifth lowest in the 1978 to 2014 record. Antarctic sea ice reached its annual minimum on February 23, and was the fourth highest Antarctic minimum in the satellite record. While this continues a strong pattern of greater-than-average sea ice extent in Antarctica for the past two years, Antarctic sea ice remains more variable year-to-year than the Arctic.

Overview of conditions

Figure 1. Arctic sea ice extent for March 2014 was 14.80 million square kilometers (5.70 million square miles). The magenta line shows the 1981 to 2010 median extent for that month. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data.
Credit: National Snow and Ice Data Center
High-resolution image

Arctic sea ice extent for March 2014 averaged 14.80 million square kilometers (5.70 million square miles). This is 730,000 square kilometers (282,000 square miles) below the 1981 to 2010 average extent, and 330,000 square kilometers (127,000 square miles) above the record March monthly low, which happened in 2006. Extent remains slightly below average in the Barents Sea and the Sea of Okhotsk, but is at near-average levels elsewhere. Extent hovered around two standard deviations below the long-term average through February and early March. The middle of March by contrast saw a period of fairly rapid expansion, temporarily bringing extent to within about one standard deviation of the long-term average.

Conditions in context

Figure 2. The graph above shows Arctic sea ice extent as of April 1, 2014, along with daily ice extent data for four previous years. 2013 to 2014 is shown in blue, 2012 to 2013 in green, 2011 to 2012 in orange, 2010 to 2011 in brown, and 2009 to 2010 in purple. The 1981 to 2010 average is in dark gray. Sea Ice Index data.
Credit: National Snow and Ice Data Center
High-resolution image

In the Arctic, the maximum extent for the year is reached on average around March 9. However, the timing varies considerably from year to year. This winter the ice cover continued to expand until March 21, reaching 14.91 million square kilometers (5.76 million square miles), making it both the fifth lowest maximum and the fifth latest timing of the maximum since 1979. The latest timing of the maximum extent was on March 31, 2010 and the lowest maximum extent occurred in 2011 (14.63 million square kilometers or 5.65 million square miles).

The late-season surge in extent came as the Arctic Oscillation turned strongly positive the second week of March. This was associated with unusually low sea level pressure in the eastern Arctic and the northern North Atlantic. The pattern of surface winds helped to spread out the ice pack in the Barents Sea where the ice cover had been anomalously low all winter. Northeasterly winds also helped push the ice pack southwards in the Bering Sea, another site of persistently low extent earlier in the 2013 to 2014 Arctic winter. Air temperatures however remained unusually high throughout the Arctic during the second half of March, at 2 to 6 degrees Celsius (4 to 11 degrees Fahrenheit) above the 1981 to 2010 average.

March 2014 compared to previous years

Figure 3. Monthly March ice extent for 1979 to 2014 shows a decline of 2.6% per decade relative to the 1981 to 2010 average. Credit: National Snow and Ice Data Center. High-resolution image

Average ice extent for March 2014 was the fifth lowest for the month in the satellite record. Through 2014, the linear rate of decline for March ice extent is 2.6% per decade relative to the 1981 to 2010 average.

An increase in multiyear ice

Figure 4. Imagery from the European Advanced Scatterometer (ASCAT) show the distribution of multiyear ice compared to first year ice for March 28, 2013 (yellow line) and March 2, 2014 (blue line).
Credit: Advanced Scatterometer imagery courtesy NOAA NESDIS, analysis courtesy T. Wohlleben, Canadian Ice Service
High-resolution image

The extent of multiyear ice within the Arctic Ocean is distinctly greater than it was at the beginning of last winter. During the summer of 2013, a larger fraction of first-year ice survived compared to recent years. This ice has now become second-year ice. Additionally, the predominant recirculation of the multiyear ice pack within the Beaufort Gyre this winter and a reduced transport of multiyear ice through Fram Strait maintained the multiyear ice extent throughout the winter.

In Figure 4, Advanced Scatterometer (ASCAT) imagery reveals the distribution of multiyear ice compared to first year ice for March 28, 2013 (yellow line) and March 2, 2014 (blue line). The ASCAT sensor measures the radar–frequency reflection brightness of the sea ice at a few kilometers resolution. Sea ice radar reflectivity is sensitive to the roughness of the ice and the presence of saltwater droplets within newer ice (and, later in the season, the presence of surface melt). Thus older and more deformed multiyear ice appears white or light grey (more reflection), whereas younger, first-year ice looks dark grey and/or black.

Ice age tracking confirms large increase in multiyear ice

Figure 5. The map at top shows the ages of ice in the Arctic at the end of March 2014; the bottom graph shows how the percentage of ice in each age group has changed from 1983 to 2014.
Credit: NSIDC, Courtesy M. Tschudi, University of Colorado. High-resolution image

Satellite data on ice age reveal that multiyear ice within the Arctic basin increased from 2.25 to 3.17 million square kilometers (869,000 to 1,220,000 square miles) between the end of February in 2013 and 2014. This winter the multiyear ice makes up 43% of the icepack compared to only 30% in 2013. While this is a large increase, and may portend a more extensive September ice cover this year compared to last year, the fraction of the Arctic Ocean consisting of multiyear ice remains less than that at the beginning of the 2007 melt season (46%) when a large amount of the multiyear ice melted. The percentage of the Arctic Ocean consisting of ice at least five years or older remains at only 7%, half of what it was in February 2007. Moreover, a large area of the multiyear ice has drifted to the southern Beaufort Sea and East Siberian Sea (north of Alaska and the Lena River delta), where warm conditions are likely to exist later in the year.

Satellite Observations of Arctic Change

NSIDC now offers a new Web site, Satellite Observations of Arctic Change (SOAC)  with interactive maps of the Arctic based on NASA satellite and related data. The site allows you to explore how conditions in the Arctic have changed over time. Data sets include air temperature, water vapor, sea ice, snow cover, NDVI, soil freezing, and exposed snow and ice. Time periods vary by data set, but range from 1979 to 2013. You can animate a time series, zoom in or out, and view a bar graph of anomalies over time. Links to the source data and documentation are also included. Additional pages provide brief scientific discussion, and overviews of the scientific importance of these data. SOAC was developed with support from NASA Earth Sciences.

Reference

Stroeve, J., L. Hamilton, C. M. Bitz, and E. Blanchard-Wrigglesworth. 2014. Predicting September Sea Ice: Ensemble Skill of the SEARCH Sea Ice Outlook 2008–2013. Geophysical Research Letters, Accepted, doi: 10.1002/2014GL059388.

https://nsidc.org/arcticseaicenews/

Polar vortex: Glaciologist Jason Box in Svalbard interviewed by Peter Sinclair via skype

Probably you could just skip the first part and focus on the discussion beginning at minute 5:30 at this link:

http://www.youtube.com/watch?v=oV5LGAXWZm8#t=330

NSIDC, Arctic Sea Ice News, December 2013: Slow growth on the Atlantic side of the Arctic, Antarctic ice extent remains high

NSIDC, December 4, 2013

Ice extent in the Arctic was below average during November. There was substantially less ice than average in the northern Barents Sea, likely due to an influx of warm ocean waters and the persistence of a strong positive Arctic Oscillation (AO). In contrast, sea ice extent in Antarctica remained unusually high.

Overview of conditions

Figure 1. Arctic sea ice extent for November 2013 was 10.24 million square kilometers (3.95 million square miles). The magenta line shows the 1981–2010 median extent for that month. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data. Credit: National Snow and Ice Data Center. High-resolution image

Arctic sea ice continued to expand during November, gaining 2.24 million square kilometers (865,000 million square miles) of ice since the beginning of the month. Sea ice extent for November averaged 10.24 million square kilometers (3.95 million square miles). This is 750,000 square kilometers (290,000 square miles) below the 1981–2010 average extent and is the 6th lowest November extent in the 35-year satellite data record. As was the case for October 2013, sea ice extent for November 2013 remained within two standard deviations of the long-term 1981–2010 average.

Conditions in context

Figure 2. The graph above shows Arctic sea ice extent as of December 2, 2013, along with daily ice extent data for the previous five years. 2013 is shown in blue, 2012 in green, 2011 in orange, 2010 in pink, 2009 in navy, and 2008 in purple. The 1981-2010 average is in dark gray. Sea Ice Index data. Credit: National Snow and Ice Data Center. High-resolution image

For the month as a whole, ice grew at near average rates throughout November at 74,800 square kilometers (28,900 square miles) per day compared to the 1981–2010 average of 70,500 square kilometers (27,200 square miles) per day. This was despite a period of slow ice growth during the first part of the month. At the end of the month, extent was 580,000 square kilometers (224,000 square miles) lower than average and 420,000 million square kilometers (162,000 square miles) above the same time last year.

The below average ice extent in the Arctic was largely due to a lack of ice in the Barents Sea, which has shown a pattern of low autumn and winter ice extent over the recent years. This November, the overall extent in the Barents Sea was the second lowest in the satellite record, with the lowest occurring in 2012.

The low ice in the Barents Sea is due to several possible factors. First, it could reflect the influx of warm ocean currents that inhibited ice growth. The atmosphere also played some role. Sea level pressure over the Arctic Ocean was lower than normal by as much as 9–12 hPa. This is consistent with the persistent strongly positive phase of the AO seen through the month; a positive AO generally leads to higher than average air temperatures over Eurasia and adjacent sea ice areas. November air temperatures in the Barents Sea were on the order of 2–4 C (4–7 F) above average. The higher than average temperatures may also simply reflect the lack of sea ice in the Barents Sea. This is because under open water conditions, the ocean readily releases heat to the overlying atmosphere.

November 2013 compared to previous years

Figure 3. Monthly November ice extent for 1978–2013 shows a decline of –4.9% per decade relative to the 1981–2010 average. Credit: National Snow and Ice Data Center. High-resolution image

Including 2013, the linear trend in November ice extent is –4.9% per decade relative to the 1981–2010 mean, or –53,500 square kilometers per year (–20,700 square miles per year).

 Extensive ice in Antarctica

Figure 4a. Antarctic sea ice extent for November 2013 was 17.2 million square kilometers (6.63 million square miles). The magenta line shows the 1981–2010 median extent for that month. The black cross indicates the geographic South Pole. Sea Ice Index data. About the data. Credit: National Snow and Ice Data Center. High-resolution image

While it is early winter in the Arctic, it is early summer in the Antarctic. Continuing patterns seen in recent years, Antarctic sea ice extent remains unusually high, near or above previous daily maximum values for each day in November. Sea ice is anomalously extensive across the Peninsula, the Amundsen Sea, and the Wilkes Land sectors. However, it has retreated in the northern Ross Sea  region—where it had been far to the north of the mean ice edge—to more typical extent locations. Sea ice extent averaged 17.16 million square kilometers (6.63 million square miles) for November. The long-term 1981–2010 average extent for this month is 16.30 million square kilometers (6.29 million square miles).

Figure 4b. The graph above shows Antarctic sea ice extent as of December 2, 2013, along with daily ice extent data for the previous year. 2013 is shown in blue and 2012 in green. The 1981–2010 average is in dark gray. Sea Ice Index data. Credit: National Snow and Ice Data Center. High-resolution image

Beginning in October, wind conditions in the Ross Sea shifted from a direction favoring a northward growth of sea ice to a more westerly direction. This and the coming of sunshine and warmth with spring led to a retreat from record ice extents there. However, November brought cool conditions (1 to 3 C, or 2–5 F, below the 1981–2010 average) around the Peninsula and much of the western hemisphere of the Southern Ocean. Winds have also favored a northward drift along the western Peninsula. Overall, cool conditions and extensive ice around the Peninsula strongly contrast with the past few decades’ shift to a more ice free Peninsula and extensive surface melting there. Palmer Station, the U.S. Antarctic research base, was once again briefly surrounded by sea ice this winter, as it was in 2012.

Overall, the extreme sea ice extent may be linked to strong variations in the westerly wind flow, the main circulation around Antarctica. Strong westerly flow favors ice growth in autumn and early winter, and this was the case; however, as sea ice approached a maximum, the westerly wind pattern abated, allowing ice to drift even further north than usual, in some places urged on by southerly winds.

At the same time, part of the interior has seen record warm winter events, with several daily temperature records set at the South Pole . These warm events are also linked to the reduction in westerly wind strength in August to October. Weaker westerly winds allow more north-south flow into Antarctica, occasionally bringing relatively warm air masses into the interior. Between September 11 and September 15, usually a time of unimaginable cold, four daily maximum temperature records were set, in one case by more than 8.5 C (15.3 F). On September 13, the temperature reached –27.7 C (–17.9 F), a temperature more typical of early summer conditions.

Big berg backs out of bay

Figure 5. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured a true-color image of the iceberg in Pine Island Bay on November 16. The iceberg has been named B-31 by the U.S. National Ice Center and is about 35 kilometers by 20 kilometers, roughly the size of Singapore.
Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC High-resolution image

In Pine Island Bay, a medium-sized iceberg that had been pinned on a shoal near the front of Pine Island Glacier began to drift into the Southern Ocean. The iceberg has received significant attention because it has broken away from Antarctica’s largest glacier (as measured by amount of ice moved per year). Pine Island Glacier has accelerated significantly in recent years as increasingly warm ocean water at depth have melted and thinned the ice at the point where the glacier goes afloat. NASA scientists and other groups like the British Antarctic Survey have installed instruments and are making further measurements to determine if the glacier will accelerate further in the aftermath of the loss of the iceberg.

Increased methane emission from the Siberian sea floor

A recent paper by colleagues at the University of Alaska Fairbanks suggests that ocean bottom water temperatures are increasing as Arctic sea ice cover has decreased, leading to a recent increase in methane flux from the seabed to the atmosphere. Ship-based observations show that methane concentrations in the air above the East Siberian Sea Shelf are nearly twice as high as the global average.

The Siberian continental shelf is a vast region of shallow-water covered continental crust, comprising about 20% of the global area of the continental shelf. During the last glacial maximum, much of the shelf was exposed to the cold atmosphere and froze to a depth of about 1.5 kilometers (about 1 mile). Layers of sediment below the permafrost slowly emit methane gas, and this gas has been trapped for millennia beneath the permafrost. As sea levels rose at the end of the ice age, the shelf was once again covered by relatively warm ocean water, thawing the permafrost and releasing the trapped methane. Methane is a potent greenhouse gas but is relatively short-lived in the atmosphere (about 12 years), leading to reduced global warming potential over time. In the short-term however, methane has a global warming potential 86 times that of carbon dioxide.

Reference

Shakhova, N., I. Semiletov, I. Leifer, V. Sergienko, A. Salyuk, D. Kosmach, D. Chernykh, C. Stubbs, D. Nicolsky, V. Tumskoy, and Ö. Gustafsson. 2013. Ebullition and storm-induced methane release from the East Siberian Arctic Shelf. Nature Geoscience, http://dx.doi.org/10.1038/ngeo2007 .

http://nsidc.org/arcticseaicenews/