Arctic Ice Mid April

 

BOday1042012to2018

Click on image to enlarge.

The most obvious Arctic ice feature this year has been the shrinkage in the Pacific basins, especially Bering Sea (on the right).  The image shows extents on day 104 from the decadal high in 2012 to 2018 (yesterday).  Bering has only 200k km2 mid April 2018 compared to 1100k km2 six years ago.  On the left, Okhotsk has gone through ups and downs, but 2018 is comparable to 2012.  It appears Bering is dominated by Northeast Pacific warming, whose effects are moderated in Okhotsk by Siberian conditions.

This is evident in the current nullschool simulation of wind patterns in the region (link to animation):

https://earth.nullschool.net/#current/wind/surface/level/orthographic=-182.77,53.61,1130/loc=-167.641,51.083

On the European side, Barents continues to show more ice than in recent years. Ice in Barents Sea has retreated lately, but extent there is still above average and slightly larger than 2014,the iciest year.  As the graph shows 2017 came on late in Spring to surpass 2014 for awhile.

The graph below shows how Arctic extent over the last six weeks compared to the 11 year average and to some years of interest.

Note the average max on day 62 and 2018 max on day 74.  In recent weeks 2018 is matching 2017 and slightly higher than 2007. SII (NOAA) continues to show ~200k km2 less extent. The graph below shows that the deficit to average is entirely due to Bering and Okhotsk Seas, since removing those two basins eliminates the shortfall.

The table below confirms that the core Arctic ice remains firmly in place.

Region 2018104 Day 104 
Average
2018-Ave. 2007104 2018-2017
 (0) Northern_Hemisphere 13956065 14373298 -417234 13862996 93068
 (1) Beaufort_Sea 1070445 1068880 1565 1058157 12288
 (2) Chukchi_Sea 962477 965131 -2654 960944 1532
 (3) East_Siberian_Sea 1087137 1085763 1374 1074001 13136
 (4) Laptev_Sea 897845 894331 3514 866524 31321
 (5) Kara_Sea 934919 925323 9596 912398 22521
 (6) Barents_Sea 708699 609715 98984 521344 187355
 (7) Greenland_Sea 575274 663379 -88104 691751 -116477
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1340040 1352819 -12779 1222152 117888
 (9) Canadian_Archipelago 853109 852426 683 846282 6827
 (10) Hudson_Bay 1260022 1245760 14263 1212987 47035
 (11) Central_Arctic 3200334 3238761 -38426 3245148 -44813
 (12) Bering_Sea 189180 780469 -591289 645687 -456507
 (13) Baltic_Sea 68363 44683 23681 20075 48289
 (14) Sea_of_Okhotsk 805400 639794 165606 576913 228487

The overall deficit is~3%, entirely due to Bering Sea.  Okhotsk and Barents are above average, but not enough to offset lack of ice in Bering.

Drift ice in Okhotsk Sea at sunrise.

 

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This Persistent Winter

As many have experienced, Springtime has been slow to arrive in the Northern Hemisphere this year. The data on snow and ice confirm what people are seeing for themselves.  The image above shows how Spring snow cover has been increasing lately on day 98 (April 7-8) 2008 to 2018.

At Rutgers snow lab, such images are digitized into statistics suitable for graphical analysis.  The graph below shows how March snow cover has varied over the decades of satellite observations

The first two decades averaged ~41.5M km2 snow cover in March.  The next two decades averaged about 2M kn2 less, 39.5M.  Since 2008, there was a rise to 2011, a drop to 2016, recovering the last two years.

As for ice extent, the 2018 picture in Barents Sea is exceptional, holding onto ~800k km2 of ice extent, 26% above the 11 year average.

Elsewhere the Arctic ice core is unchanging, the only deficit mostly being in Bering and, somewhat in Okhotsk, the other Pacific basin.

Barents Ice March

Barentsday60to90The month of March saw rapid ice growth in Barents Sea.   It is in a strategic location at the gateway where warm Atlantic water from the gulf stream flows into the Arctic, 90% of all incoming water. In 31 days, the extent went from 513k km2 to 790k km2, a gain of 278k km2, or 54%.  As the graph below shows, Barents ice today is unusual in the last 12 years.

Barents day090

March is the time of the annual Arctic ice maximum, as the graph below shows.  2018 started slow and peaked later than average, and has held on to March end.

NHday090

2018 is running about 200k km2 above both 2017 and 2007.  SII shows ~200k km2 less than MASIE.  The ten year average extent is almost 400k km2 higher, entirely due to 2018 lack of ice in Bering Sea. The table below shows ice extents in the various basins at day 90 or March 31.

Region 2018090 Day 90 
Average
2018-Ave. 2017090 2018-2017
 (0) Northern_Hemisphere 14456459 14842431 -385972 14228992 227467
 (1) Beaufort_Sea 1069836 1070178 -342 1070445 -609
 (2) Chukchi_Sea 964121 966000 -1879 966006 -1885
 (3) East_Siberian_Sea 1087137 1085933 1204 1086168 969
 (4) Laptev_Sea 897845 896562 1283 897845 0
 (5) Kara_Sea 934790 915735 19055 831189 103601
 (6) Barents_Sea 790204 652874 137329 525362 264841
 (7) Greenland_Sea 533694 669996 -136302 705581 -171886
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1380945 1452576 -71631 1467334 -86390
 (9) Canadian_Archipelago 853109 852782 327 853214 -106
 (10) Hudson_Bay 1259857 1252696 7161 1260903 -1047
 (11) Central_Arctic 3202650 3236293 -33643 3247995 -45345
 (12) Bering_Sea 277469 849159 -571690 702504 -425035
 (13) Baltic_Sea 99317 68831 30486 29767 69550
 (14) Sea_of_Okhotsk 1097524 860025 237498 575084 522440

 

 

Barents Ice Machine

Barents Sea on the right adding ice in March 2018.

Arctic ice watchers looking for holes in the ice found one in Bering Sea and raise alarms about it.  Yes, the annual maximum is lower, entirely due to open water in Bering Sea, which melts out every summer anyway.

Elsewhere Arctic ice is ordinary, except for Barents Sea where there seems to be an ice machine that added 238k km2 to the extent there, an increase of 46% since March 1.

To see how unusual is this year in Barents, consider 2018 compared to other years:
To paraphrase George Custer at Little Big Horn:  “Where is all the damn ice coming from?”

To paraphrase David Viner:  “Where is all that damn snow coming from?”

US Submarine breaks through ice in Beaufort Sea March 17.

 

Arctic Ice Stays Put Mar. 22

 

atl064to081After a slow beginning this month, Arctic ice advanced to set a late annual maximum, and is now holding on to its gains the last four days.   The image above shows the last week, setting new 2018 maximums on day 74 for NH overall, as well in Barents Sea.  The graph below shows that as of yesterday, Barents is well above the 11 year average, and matching 2014 the highest year in the decade.

Barents day081

The graph below shows how the Arctic extent has grown compared to the 11 year average and to some years of interest.
NHday081
Note the average max on day 62 and 2018 max on day 74, now matching 2007 and 380k km2 above last year.  SII (NOAA) continues to show ~200k km2 less extent.

Drift ice in Okhotsk Sea at sunrise.

The table below shows ice extents in the regions compared to averages and last year.  11 year averages are from 2007 to 2017 inclusive.

Region 2018081 Day 081 
Average
2018-Ave. 2017081 2018-2017
 (0) Northern_Hemisphere 14568779 14938247 -369468 14187550 381229
 (1) Beaufort_Sea 1070445 1070178 267 1070445 0
 (2) Chukchi_Sea 966006 965867 139 966006 0
 (3) East_Siberian_Sea 1087137 1087046 91 1086168 969
 (4) Laptev_Sea 897845 897791 54 897845 0
 (5) Kara_Sea 934807 915480 19326 847386 87421
 (6) Barents_Sea 713140 625289 87852 512306 200835
 (7) Greenland_Sea 554343 645763 -91419 676556 -122213
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1373947 1552545 -178597 1474155 -100208
 (9) Canadian_Archipelago 853109 852904 205 853214 -106
 (10) Hudson_Bay 1260838 1260527 311 1260903 -66
 (11) Central_Arctic 3156256 3229541 -73284 3246109 -89852
 (12) Bering_Sea 398503 826983 -428479 623357 -224854
 (13) Baltic_Sea 142292 77332 64959 44911 97380
 (14) Sea_of_Okhotsk 1146933 914118 232815 615366 531567

Note the overall NH shortfall is 2.5% and less than the deficit in Bering Sea.  Both Okhotsk and Barents Sea are well above average, more than offsetting less extent in Greenland Sea and Baffin Bay.  The picture is consistent with an ice pack of higher volume than recent years, with the melting showing at the margins.

seaice_20071211

Source: Real Climate Science

Spring Outlook AER

Dr. Judah Cohen has posted his outlook on the spring in Arctic and NH at his AER blog.  Exerpts below with my bolds.

Summary

  • The Arctic Oscillation (AO) is currently slightly negative and is predicted to trend positive but never to stray too far from neutral . The bulk of the atmospheric response to the polar vortex (PV) disruption, which occurred in February seems to have already occurred though some lingering influences continue.
  • The current negative AO is reflective of positive pressure/geopotential height anomalies across the North Atlantic side of the Arctic and negative pressure/geopotential height anomalies across the mid-latitudes of the North Atlantic.
  • The North Atlantic Oscillation (NAO) is currently also negative with positive pressure/geopotential height anomalies across Greenland and negative pressure/geopotential height anomalies across the mid-latitudes of the North Atlantic. The forecasts are for the NAO to also trend positive and then straddle neutral the next two weeks.
  • The PV is predicted to linger across Western Siberia over the next two weeks. This will contribute to persistent troughing/negative geopotential height anomalies across northern Eurasia including Europe. This will allow cold temperatures now stretching from Northern Asia to Europe and the United Kingdom (UK) to mostly remain in place with some fluctuation in intensity over the next two weeks.
  • Currently ridging/positive geopotential height anomalies south of the Aleutians is contributing to troughing/negative geopotential height anomalies in the Gulf of Alaska and the West Coast of North America with additional ridging/positive geopotential height anomalies in central North America and more troughing/negative geopotential height anomalies downstream across the Eastern United States (US). This pattern in general favors normal to above normal temperatures for western North America and normal to below normal temperatures in the Eastern US.
  • However the pattern across North America is predicted to be slowly progressive with time and become much less amplified. This will lead to a general weakening of temperature anomalies for much of the continent, though warm temperature anomalies in the Western US are predicted to remain consistent in magnitude.
  • I continue to believe that the ongoing stratospheric PV displacement in Western Siberia favors overall cold temperatures for Siberia that extend into Europe as well as a cold bias in temperatures in the Northeastern US. These cold temperature anomalies are likely to persist as long as the stratospheric PV lingers across Siberia.

Arctic Methane

AWI sea-ice physicists have erected an ice camp to investigate melt ponds on Arctic sea ice. Credit: Photo : Alfred-Wegener-Institut / Mar Fernandez

Two recent papers enrich our understanding of interactions between oceans, ice and dissolved methane. The latest one is described in a Science Daily article Wandering greenhouse gas Climate models need to take into account the interaction between methane, the Arctic Ocean and ice by E. Damm et al. of Alfred Wegener Institute March 16, 2018. Excerpts with my bolds.

On the seafloor of the shallow coastal regions north of Siberia, microorganisms produce methane when they break down plant remains. If this greenhouse gas finds its way into the water, it can also become trapped in the sea ice that forms in these coastal waters. As a result, the gas can be transported thousands of kilometres across the Arctic Ocean and released in a completely different region months later.

AWI geochemist Dr Ellen Damm tested the waters of the High North for the greenhouse gas methane. In an expedition to the same region four years later, she had the chance to compare the measurements taken at different times, and found significantly less methane in the water samples.

Ellen Damm, together with Dr Dorothea Bauch from the GEOMAR Helmholtz Centre for Ocean Research in Kiel and other colleagues, analysed the samples to determine the regional levels of methane, and the sources. By measuring the oxygen isotopes in the sea ice, the scientists were able to deduce where and when the ice was formed. To do so, they had also taken sea-ice samples. Their findings: the ice transports the methane across the Arctic Ocean. And it appears to do so differently every year.

“As more seawater freezes it can expel the brine contained within, entraining large quantities of the methane locked in the ice,” explains AWI researcher Ellen Damm. As a result, a water-layer is formed beneath the ice that contains large amounts of both salt and methane. Yet the ice on the surface and the dense saltwater below, together with the greenhouse gas it contains, are all pushed on by the wind and currents. According to Thomas Krumpen, “It takes about two and a half years for the ice formed along the coast of the Laptev Sea to be carried across the Arctic Ocean and past the North Pole into the Fram Strait between the east cost of Greenland and Svalbard.” Needless to say, the methane trapped in the ice and the underlying saltwater is along for the ride.

The rising temperatures produced by climate change are increasingly melting this ice. Both the area of water covered by sea ice and the thickness of the ice have been decreasing in recent years, and thinner ice is blown farther and faster by the wind. “In the past few years, we’ve observed that ice is carried across the Arctic Ocean faster and faster,” confirms Thomas Krumpen. And this process naturally means major changes in the Arctic’s methane turnover. Accordingly, quantifying the sources, sinks and transport routes of methane in the Arctic continues to represent a considerable challenge for the scientific community.

Sea ice drift trajectories leading to the 60°E section and δ18O isotopic composition (filled symbols) and salinity (open symbols) in sea ice at this section. Backward drift trajectories from the 60°E section show the sea ice formation areas, i.e. off shore within the Laptev Sea and in the coastal polynya areas. Trajectories were calculated based on a combination of sea ice motion and concentration products from passive microwave satellite data. The colour of the end node indicates the source area of sampled sea ice. Trajectories with red end nodes were formed in polynyas, namely the New Siberian (NS) Polynya, Taymyr (T) Polynya, Northeastern Taymyr (NET) Polynya and East Severnaya Zemlya (ESZ) Polynya. Grey end nodes refer to trajectories that were formed during freeze-up further offshore. The colour coding of the start node characterizes the month of formation (primarily October) of the individual trajectories. The δ18O ice isotopic composition reflects the δ18O composition of the water column from which each segment of the ice core was formed. Light values below about −4‰ indicate formation in coastal polynyas while values above −2‰ indicate freeze-up formation offshore. Salinity of the ice cores is in all cases below 4. The map is generated with IDL (Interactive Data Langue), software for analysis and visualization of data provided by Harris Geospatial Solutions (http://www.harrisgeospatial.com).

The paper itself is The Transpolar Drift conveys methane from the Siberian Shelf to the central Arctic Ocean

Abstract: Methane sources and sinks in the Arctic are poorly quantified. In particular, methane emissions from the Arctic Ocean and the potential sink capacity are still under debate. In this context sea ice impact on and the intense cycling of methane between sea ice and Polar surface water (PSW) becomes pivotal. We report on methane super- and under-saturation in PSW in the Eurasian Basin (EB), strongly linked to sea ice-ocean interactions.

In the southern EB under-saturation in PSW is caused by both inflow of warm Atlantic water and short-time contact with sea ice. By comparison in the northern EB long-time sea ice-PSW contact triggered by freezing and melting events induces a methane excess. We reveal the Transpolar Drift Stream as crucial for methane transport and show that inter-annual shifts in sea ice drift patterns generate inter-annually patchy methane excess in PSW.

Using backward trajectories combined with δ18O signatures of sea ice cores we determine the sea ice source regions to be in the Laptev Sea Polynyas and the off shelf regime in 2011 and 2015, respectively. We denote the Transpolar Drift regime as decisive for the fate of methane released on the Siberian shelves.

From the study conclusions: Our study is focused on sea ice-ocean interaction, while the role of sea ice–air fluxes and oxidation as pathways of methane in the Arctic need further investigation.

Our study confirms that methane release from sea ice is coupled to the ice freeze and melt cycle. Hence the intensity of freeze events in winter and the amount of summer sea ice retreat primarily triggers how much methane is released during transport within the TDS in the central Arctic.

To which extent the interior Arctic Ocean might act as a final or just a temporal sink, i.e. with final efflux to the atmosphere, is another open question. Furthermore, sea ice retreat, thinning, and decreasing multiyear and increasing first-year sea ice will have, yet, unconsidered consequences for the sea ice-air exchange and the source-sink balance of the greenhouse gas methane in the Arctic. In addition to the potential source capacity for efflux from the northern Eurasian Basin, the potential sink capacity of the southern EB for atmospheric methane might be enhanced if the volume of inflowing AW increases and the region becomes seasonally ice free in the future.

How the Ocean Processes Methane

Another study looks at ancient stored methane in the Arctic in relation to ongoing natural fluxes that were the focus of the above research. The paper is described in a Science Daily article Release of ancient methane due to changing climate kept in check by ocean waters by Katy J. Sparrow, John D. Kessler et al. 2018

Trapped in ocean sediments near continents lie ancient reservoirs of methane called methane hydrates. These ice-like water and methane structures encapsulate so much methane that many researchers view them as both a potential energy resource and an agent for environmental change. In response to warming ocean waters, hydrates can degrade, releasing the methane gas. Scientists have warned that release of even part of the giant reservoir could significantly exacerbate ongoing climate change.

However, methane only acts as a greenhouse gas if and when it reaches the atmosphere — a scenario that would occur only if the liberated methane travelled from the point of release at the seafloor to the surface waters and the atmosphere.

A team of scientists conducted fieldwork just offshore of the North Slope of Alaska, near Prudhoe Bay. Sparrow calls the spot “ground zero” for oceanic methane emissions resulting from ocean warming. In some parts of the Arctic Ocean, the shallow regions near continents may be one of the settings where methane hydrates are breaking down now due to warming processes over the past 15,000 years. In addition to methane hydrates, carbon-rich permafrost that is tens of thousands of years old — and found throughout the Arctic on land and in seafloor sediments — can produce methane once this material thaws in response to warming. With the combination of the aggressive warming occurring in the Arctic and the shallow water depths, any released methane has a short journey from emission at the seafloor to release into the atmosphere.

We do observe ancient methane being emitted from the seafloor to the overlying seawater, confirming past suspicions,” Kessler says. “But, we found that this ancient methane signal largely disappears and is replaced by a different methane source the closer you get to the surface waters.” The methane at the surface is instead from recently produced organic matter or from the atmosphere.

“We found that very little ancient methane reaches surface waters even in the relatively shallow depths of 100 feet. Exponentially less methane would be able to reach the atmosphere in waters that are thousands of feet deep at the very edge of the shallow seas near continents, which is the area of the ocean where the bulk of methane hydrates are,” Sparrow says. “Our data suggest that even if increasing amounts of methane are released from degrading hydrates as climate change proceeds, catastrophic emission to the atmosphere is not an inherent outcome.

Full text of study is Limited contribution of ancient methane to surface waters of the U.S. Beaufort Sea shelf

Summary

It seems our knowledge of Arctic methane is incomplete but growing. It is good news to understand how ancient methane released from sediment is neutralized by ocean processes before it can be released. And it is also good that methane captured by shelf sea ice is transported to the North Pole.

Footnote:

The news releases repeat the erroneous claim that methane (CH4) is 25 times more powerful GHG than CO2.  That exaggerated number comes from comparing the two gases on a mass basis. Because CH4 has a lesser atomic weight, a kilogram will have more molecules than the same mass of CO2.  But radiative activity depends on the volume, not the mass.

More background on CH4 as a GHG:  Much Ado About Methane

Arctic Freezing Week

atl066to074.gif

After stalling first week of March, Arctic ice is coming on strong now.  The image above shows the last week, setting new maximums for 2018 for NH overall, as well in Barents Sea.  The graph below shows that as of yesterday, Barents is well above the 11 year average, and even ahead of 2014 the highest year in the decade.

Barents day074

Meanwhile ice extent is increasing on the Pacific side as well.  Bering rapidly grew 200k km2 in a week, setting a new 2018 maximum, while Okhotsk added 110k km2 for a new max ice extent there.

pac066to074

The graph below shows how strongly the Arctic is now freezing over.

NHday074

Note the average max on day 62 and 2018 max yesterday on day 74, now matching 2007 and 120k km2 above last year.  SII (NOAA) continues to show ~200k km2 less extent.

Drift ice in Okhotsk Sea at sunrise.

The graph below shows 2018 NH ice extents since day 1, with and without the Pacific basins Bering and Okhotsk, compared to 11 year averages (2007 to 2017 inclusive).
NHwBandO074
The deficit is almost entirely due to Bering, with the shortfall closing in the last week.

Bering Ice Deficit Gone in Five Days

An update to yesterdays post  Premature Arctic Ice Fears which discussed lop-sided media coverage of  a temporary ice shortfall in Bering Sea.  Now today, the image above shows that in just five days, that deficit has been obliterated.  Since day 66, Bering added 170k km2 to go over 400k km2, close to the previous Bering high in 2018 on day 34.  That was the last Arctic region where some alarm could be raised.  Overall, 2018 is now higher than 2017 at this date, having reached a new maximum of 14.6M km2.

Premature Arctic Ice Fears

Barents60to70

Click on image to enlarge.

The alarms are sounding about lack of ice extent in Bering Sea, studiously ignoring what else is happening in the Arctic.  For instance the above image shows the last 10 days on the European side, with Barents Sea on the right growing steadily to a new maximum. On the left, Gulf of St. Lawrence ice is retreating as usual while Baffin Bay holds steady.

The Barents recovery is interesting and bears watching.  See how 2018 compares with other years in the Graph below.

Barents day070

Note the recent 2018 dramatic rise above average.  Meanwhile on the Pacific side the seesaw between Bering and Okhotsk continues:
BandO60to70

In the last ten days, Bering has gone up, then down, and back up to arrive at the same extent.  In the same period Okhotsk added 70k km2.

Ice extents for February and March appear in the graph below; 11 year average is 2007 to 2017 inclusive.

Note that ice growth slows down in February and March since the Arctic core is frozen and extent can only be added at the margins.  MASIE shows 2018 is now matching 2017, while SII is running about 200k km2 lower.  The 11 year average maxed on day 62 at 15.1M km2 while this year  max was on day 69, ~560k km2 lower . It remains to be seen what max will end up in 2018

It is natural for alarmists to focus on Bering Sea, since that is the only place where a sizable deficit appears (for the moment).  The graph below show NH ice extent from day 1, with and without B and O (Bering and Okhotsk, the Pacific basins that will melt out by September anyway.)

 

Here’s your Valentine’s Day Greeting:

And here’s your PC candy for Valentine’s Day.