Click on image to enlarge.

With 2017 ice extent estimates complete we can look at the year in perspective.  Above is a graph showing the annual average extents since 2007, comparing MASIE and SII (v3.0).  Obviously, the trend in MASIE could not be flatter, while SII shows a decline.  The first five years the two indices were nearly the same, and since then SII shows less ice, about 260k km2 each year.  Note also how small is the variance year over year: Standard deviation is +/- 260k km2, or about 2.5% of the average annual extent.  This holds for both indices.  Note also a pattern of three higher years followed by two lower years.

A previous post Sea Ice Index Updates to v.3.0 reported on the newest SII version, and we can see how it compares with MASIE over this last year.

Click on image to enlarge.

The first four months show more diversity, both in the 10 year averages and in 2017 results. From May on MASIE 2017 tracks closely to its average, while SII shows 2017 below its average every month. For those who want to see the numbers a table is provided below.

Some are proclaiming dire warnings about melting ice and imagining various dangerous impacts. Some fluctuations do appear but not very large and somewhat cyclical. Since 2007 it resembles a plateau more than anything else.

Background on MASIE Data Sources

MASIE reports are generated by National Ice Center from the Interactive Multisensor Snow and Ice Mapping System (IMS). From the documentation, the multiple sources feeding IMS are:

Platform(s) AQUA, DMSP, DMSP 5D-3/F17, GOES-10, GOES-11, GOES-13, GOES-9, METEOSAT, MSG, MTSAT-1R, MTSAT-2, NOAA-14, NOAA-15, NOAA-16, NOAA-17, NOAA-18, NOAA-N, RADARSAT-2, SUOMI-NPP, TERRA

Sensor(s): AMSU-A, ATMS, AVHRR, GOES I-M IMAGER, MODIS, MTSAT 1R Imager, MTSAT 2 Imager, MVIRI, SAR, SEVIRI, SSM/I, SSMIS, VIIRS

Summary: IMS Daily Northern Hemisphere Snow and Ice Analysis

The National Oceanic and Atmospheric Administration / National Environmental Satellite, Data, and Information Service (NOAA/NESDIS) has an extensive history of monitoring snow and ice coverage.Accurate monitoring of global snow/ice cover is a key component in the study of climate and global change as well as daily weather forecasting.

The Polar and Geostationary Operational Environmental Satellite programs (POES/GOES) operated by NESDIS provide invaluable visible and infrared spectral data in support of these efforts. Clear-sky imagery from both the POES and the GOES sensors show snow/ice boundaries very well; however, the visible and infrared techniques may suffer from persistent cloud cover near the snowline, making observations difficult (Ramsay, 1995). The microwave products (DMSP and AMSR-E) are unobstructed by clouds and thus can be used as another observational platform in most regions. Synthetic Aperture Radar (SAR) imagery also provides all-weather, near daily capacities to discriminate sea and lake ice. With several other derived snow/ice products of varying accuracy, such as those from NCEP and the NWS NOHRSC, it is highly desirable for analysts to be able to interactively compare and contrast the products so that a more accurate composite map can be produced.

The Satellite Analysis Branch (SAB) of NESDIS first began generating Northern Hemisphere Weekly Snow and Ice Cover analysis charts derived from the visible satellite imagery in November, 1966. The spatial and temporal resolutions of the analysis (190 km and 7 days, respectively) remained unchanged for the product’s 33-year lifespan.

As a result of increasing customer needs and expectations, it was decided that an efficient, interactive workstation application should be constructed which would enable SAB to produce snow/ice analyses at a higher resolution and on a daily basis (~25 km / 1024 x 1024 grid and once per day) using a consolidated array of new as well as existing satellite and surface imagery products. The Daily Northern Hemisphere Snow and Ice Cover chart has been produced since February, 1997 by SAB meteorologists on the IMS.

Another large resolution improvement began in early 2004, when improved technology allowed the SAB to begin creation of a daily ~4 km (6144×6144) grid. At this time, both the ~4 km and ~24 km products are available from NSIDC with a slight delay. Near real-time gridded data is available in ASCII format by request.

In March 2008, the product was migrated from SAB to the National Ice Center (NIC) of NESDIS. The production system and methodology was preserved during the migration. Improved access to DMSP, SAR, and modeled data sources is expected as a short-term from the migration, with longer term plans of twice daily production, GRIB2 output format, a Southern Hemisphere analysis, and an expanded suite of integrated snow and ice variable on horizon.

http://www.natice.noaa.gov/ims/ims_1.html

Footnote

Some people unhappy with the higher amounts of ice extent shown by MASIE continue to claim that Sea Ice Index is the only dataset that can be used. This is false in fact and in logic. Why should anyone accept that the highest quality picture of ice day to day has no shelf life, that one year’s charts can not be compared with another year? Researchers do this, including Walt Meier in charge of Sea Ice Index. That said, I understand his interest in directing people to use his product rather than one he does not control. As I have said before:

MASIE is rigorous, reliable, serves as calibration for satellite products, and continues the long and honorable tradition of naval ice charting using modern technologies. More on this at my post Support MASIE Arctic Ice Dataset

Arctic ice extent grows slowly this time of year since many regions are already covered completely.  In recent days 2017 reached 84% of the maximum last March, but dropped below the 10 year average.  As we can see, most of the action was a dramatic seesaw in Okhotsk Sea, a Siberian basin in the North Pacific.

Mid-December Okhotsk Sea on the left began growing ice steadily to reach half of 2017 March max, then inexplicably lost over 300k km2 of ice in just four days.  Meanwhile, Chukchi (upper right) froze completely, then retreated somewhat.  Bering Sea on the right has been advancing steadily but more slowly than average.

The overall effect in December is shown in the graph below:
Note that 2007 matches the 10 year average, while 2012 is well above.  Lagging behind are 2016, 2017 and SII 2017.  This year’s deficit to average appears in the last 11 days, mostly due to Bering and the Okhotsk year end surprise.
Most of the month combined Bering and Okhotsk (B&O) extents were average, until the inexplicable drop starting day 361. Except for those two seas, the month was unremarkable.
At year end, 2017 NH ice, excluding B&O, is down about 200k km2, or 2% of average.  Below is the analysis of regions on day 365.

Most of 2017 deficit is in Bering and Barents, less so in Okhotsk with yesterday’s recovery.  Perhaps the Polar Vortex sent frigid air into the US and Canada and replaced it with warmer southern air, and ice receded as a result.  I have reported on Arctic incursions in a post Arctic Inversions and Intrusions but the speed of the effect on ice (if that is the phenomenon) is still surprising.  We shall see if it persists or not.

Background:  Winter Forecast by Dr. Judah Cohen, Dec. 25

On Christmas Day Dr. Judah Cohen published his updated Arctic Oscillation and Polar Vortex Analysis and Forecast  Excerpts below

As I have been discussing the past two blog posts I continue to believe that this is the most critical period of the winter and will ultimately determine the character of the winter. In my opinion, we have approached a fork in the road and the atmosphere can take two possible paths one is a path where the rest of the winter is relatively mild across the mid-latitudes of the NH and the second is a colder path or solution. The tropospheric polar vortex has been relatively weak for much of the month of December as illustrated by the relatively warm polar cap geopotential heights (PCHs) for the first half of December that then boomeranged off the mid-stratosphere and after a short respite with colder tropospheric PCHs, warmer PCHs in the troposphere are predicted through the end of the month and into early January.

Based on the easterly phase of the Quasi-Biennial Oscillation (QBO) I have been favoring a significant PV disruption most likely in January for much of the fall.  A significant stratospheric PV disruption would then be followed by an extended period of severe winter weather across the mid-latitudes of the NH.  However, I have to admit as of yet there are no signs of this scenario.  There is still time but not much.  However, there is another scenario that could still yield a relatively cold winter and that is one analogous to what happened in the winter of 2013/14 where no significant disruptions of the stratospheric occurred but rather repeated minor disruptions that yielded a cold winter for central and eastern North America. Though at first, I acknowledged this possibility I was hesitant to favor this scenario.  However, the longer the delay in a major disruption of the stratospheric PV the more I favor this scenario.

The Arctic Oscillation (AO) is currently slightly positive and is predicted to trend slowly negative through the end of the week towards neutral. The forecast is for the AO to remain close to neutral next week, likely a sign of uncertainty.

Figure 7. Forecasted snowfall anomalies (mm/day; shading) from 31 December 2017 – 4 January 2018. The forecasts are from the 00Z 18 December 2017 GFS ensemble. Note the new projection to provide finer resolution.

The current positive AO is reflective of mixed pressure/geopotential height anomalies across the Arctic and mostly positive pressure/geopotential height anomalies across the mid-latitudes. The North Atlantic Oscillation (NAO) is also currently slightly positive with weak pressure/geopotential height anomalies across Greenland and Iceland and positive pressure/geopotential height anomalies across the mid-latitudes of the North Atlantic.

A return to Ural ridging/blocking at the turn of the calendar year favors active energy transfer from the troposphere to the stratosphere. Another pulse is predicted to commence this week and peak the first few days of January. The pulse itself is likely related to relaxation of the pattern and mild temperatures across North America. However, the predicted resultant perturbation to the stratospheric polar vortex (PV) especially the building of heights over northwestern North America in my opinion could once again favor the return of cold temperatures across eastern North America later in January.

Figure 9. Forecasted snowfall anomalies (mm/day; shading) from 5 – 9 January 2018. The forecasts are from the 00Z 25 December 2017 GFS ensemble. Troughing and/or cold temperatures will support the potential of additional snowfall across Eastern Europe, Siberia, West and East Asia, Alaska, Canada and the Northwestern US. Despite below normal temperatures, temperatures warm sufficiently to support snowmelt across the Eastern US (Figure 9).

Ice did not grow this past week on the North Pacific side of the Arctic basin, still I expect the negative ice anomalies in the region to shrink.  Sea ice is below normal in the Barents-Kara Seas as well and with time the greatest negative sea ice anomalies will likely reside in this region.  As I have been writing for much of the fall I do believe that the record low sea ice anomalies in the Chukchi and Bering Seas has focused ridging/blocking in this region.  Though model forecasts do not predict a return of the blocking in the foreseeable future.

Recent research has shown that regional anomalies are important and the sea ice region most highly correlated with the winter AO is the Barents-Kara Seas region where low Arctic sea ice favors a negative winter AO and a cold Eurasia.  Below normal sea ice in this region may be contributing to more active Wave Activity Flux/poleward heat transport predicted in the models that eventually could result in a negative AO.

As we have seen, the Polar Vortex did indeed return to North America, freezing Niagara Falls in the process.

Whichever fork the ice takes, the Polar Bears had a Merry Christmas

On Christmas Day Dr. Judah Cohen published his updated Arctic Oscillation and Polar Vortex Analysis and Forecast  Excerpts below

As I have been discussing the past two blog posts I continue to believe that this is the most critical period of the winter and will ultimately determine the character of the winter. In my opinion, we have approached a fork in the road and the atmosphere can take two possible paths one is a path where the rest of the winter is relatively mild across the mid-latitudes of the NH and the second is a colder path or solution. The tropospheric polar vortex has been relatively weak for much of the month of December as illustrated by the relatively warm polar cap geopotential heights (PCHs) for the first half of December that then boomeranged off the mid-stratosphere and after a short respite with colder tropospheric PCHs, warmer PCHs in the troposphere are predicted through the end of the month and into early January.

Based on the easterly phase of the Quasi-Biennial Oscillation (QBO) I have been favoring a significant PV disruption most likely in January for much of the fall.  A significant stratospheric PV disruption would then be followed by an extended period of severe winter weather across the mid-latitudes of the NH.  However, I have to admit as of yet there are no signs of this scenario.  There is still time but not much.  However, there is another scenario that could still yield a relatively cold winter and that is one analogous to what happened in the winter of 2013/14 where no significant disruptions of the stratospheric occurred but rather repeated minor disruptions that yielded a cold winter for central and eastern North America. Though at first, I acknowledged this possibility I was hesitant to favor this scenario.  However, the longer the delay in a major disruption of the stratospheric PV the more I favor this scenario.

The Arctic Oscillation (AO) is currently slightly positive and is predicted to trend slowly negative through the end of the week towards neutral. The forecast is for the AO to remain close to neutral next week, likely a sign of uncertainty.

Figure 7. Forecasted snowfall anomalies (mm/day; shading) from 31 December 2017 – 4 January 2018. The forecasts are from the 00Z 18 December 2017 GFS ensemble. Note the new projection to provide finer resolution.

The current positive AO is reflective of mixed pressure/geopotential height anomalies across the Arctic and mostly positive pressure/geopotential height anomalies across the mid-latitudes. The North Atlantic Oscillation (NAO) is also currently slightly positive with weak pressure/geopotential height anomalies across Greenland and Iceland and positive pressure/geopotential height anomalies across the mid-latitudes of the North Atlantic.

A return to Ural ridging/blocking at the turn of the calendar year favors active energy transfer from the troposphere to the stratosphere. Another pulse is predicted to commence this week and peak the first few days of January. The pulse itself is likely related to relaxation of the pattern and mild temperatures across North America. However, the predicted resultant perturbation to the stratospheric polar vortex (PV) especially the building of heights over northwestern North America in my opinion could once again favor the return of cold temperatures across eastern North America later in January.

Figure 9. Forecasted snowfall anomalies (mm/day; shading) from 5 – 9 January 2018. The forecasts are from the 00Z 25 December 2017 GFS ensemble. Troughing and/or cold temperatures will support the potential of additional snowfall across Eastern Europe, Siberia, West and East Asia, Alaska, Canada and the Northwestern US. Despite below normal temperatures, temperatures warm sufficiently to support snowmelt across the Eastern US (Figure 9).

Ice did not grow this past week on the North Pacific side of the Arctic basin, still I expect the negative ice anomalies in the region to shrink.  Sea ice is below normal in the Barents-Kara Seas as well and with time the greatest negative sea ice anomalies will likely reside in this region.  As I have been writing for much of the fall I do believe that the record low sea ice anomalies in the Chukchi and Bering Seas has focused ridging/blocking in this region.  Though model forecasts do not predict a return of the blocking in the foreseeable future.

Recent research has shown that regional anomalies are important and the sea ice region most highly correlated with the winter AO is the Barents-Kara Seas region where low Arctic sea ice favors a negative winter AO and a cold Eurasia.  Below normal sea ice in this region may be contributing to more active Wave Activity Flux/poleward heat transport predicted in the models that eventually could result in a negative AO.

Okhotsk Doubles in 12 Days

While the refreezing rate slowed in recent days, we again see contrast in the Pacific Basins.

Mid month, Chukchi (top right) refroze almost completely, then reversed in the last week.  Meanwhile, Okhotsk (Left) grew ice fairly steadily doubling in 12 days to cover nearly half of the annual maximum.  At the moment the Arctic is slightly below the 10 year average, due to the slowdown.

Whichever fork the ice takes, the Polar Bears had a Merry Christmas

Click on image to enlarge.

In the first two weeks of December we can see Chukchi at the left filling in with only 8% open water remaining, and Bering starting to freeze. On the right,  Hudson bay is almost fully iced, while Baffin is freezing toward Greenland.  Maximum ice is showing in CAA (Canadian Archipelago), Beaufort, East Siberian, Central Arctic, Laptev and Kara.

Arctic Ice Extents have reached 12M km2, up from 4.6M km2 at Sept. minimum.  This means 50% of the annual maximum has been gained, with 20% of ice cover to be added in the three months before mid March.

The graph compares extents over the first 14 days of December.

2017 has reached 12M km2, close to the 10 year average, while 2012 has recovered with a surplus.  2016 is about 260k km2 behind and 2007 lags by 520k km2.  At this point MASIE and SII are both tracking the 10-year average, with SII about 200k km2 lower.

The Table below shows where ice is located on day 348 in regions of the Arctic ocean. 10 year average comes from 2007 through 2016 inclusive.

The deficits to average are primarily in Barents and Bering Seas. Surpluses are large in Hudson Bay, Okhotsk and Kara Seas.  Compared to 2007, most seas are in surplus, with only Hudson Bay slightly late.

Footnote

Some people unhappy with the higher amounts of ice extent shown by MASIE continue to claim that Sea Ice Index is the only dataset that can be used. This is false in fact and in logic. Why should anyone accept that the highest quality picture of ice day to day has no shelf life, that one year’s charts can not be compared with another year? Researchers do this analysis, including Walt Meier in charge of Sea Ice Index. That said, I understand his interest in directing people to use his product rather than one he does not control. As I have said before:

MASIE is rigorous, reliable, serves as calibration for satellite products, and uses modern technologies to continue the long and honorable tradition of naval ice charting.  More on this at my post Support MASIE Arctic Ice Dataset

Click on image to enlarge.

This year Hudson Bay added 728k km2 from day 318 to 344 (yesterday).  Nov. 14  showed 280k km2 rising to 1008k on Dec. 10, 2017. About 20% of the basin is yet to freeze.

Click on image to enlarge.

Arctic Ice Extents have more than doubled since the Sept. minimum and are now up to 10.4M km2.  The last 30% of maximum will take until March, principally because several basins are frozen over and cannot add coverage.  To date, Beaufort and CAA (Canadian Archipelago) are full, as are Laptev and East Siberian on the Russian side.  Kara is 88% covered and the Central Arctic will add only 2% from here.

In the last nine days of November we can see Chukchi at the top adding ice up to 50% of maximum with Beaufort  and East Siberian already frozen.  On the left, Baffin and especially Hudson bay are now growing more strongly.  On the right is Kara filling in with Barents freezing more slowly.

The graph compares extents over the first 25 days of November.

2017 has reached 10.4M km2, 2007 and 2012 nearly the same, and all are close to the 10 year average of 10.6M km2.  2016 is about 1M km2 behind.  At this point MASIE and SII are both tracking the 10-year average, with SII about 200k km2 lower.

The Table below shows where ice is located on day 329 in regions of the Arctic ocean. 10 year average comes from 2007 through 2016 inclusive.

The deficits to average are primarily in Chukchi and Greenland Seas. Surpluses are large in Hudson and Baffin Bays, along with Kara Sea.  Compared to last year, Kara, Barents and Hudson Bay all have much greater ice extents.

Footnote

Some people unhappy with the higher amounts of ice extent shown by MASIE continue to claim that Sea Ice Index is the only dataset that can be used. This is false in fact and in logic. Why should anyone accept that the highest quality picture of ice day to day has no shelf life, that one year’s charts can not be compared with another year? Researchers do this analysis, including Walt Meier in charge of Sea Ice Index. That said, I understand his interest in directing people to use his product rather than one he does not control. As I have said before:

MASIE is rigorous, reliable, serves as calibration for satellite products, and uses modern technologies to continue the long and honorable tradition of naval ice charting.  More on this at my post Support MASIE Arctic Ice Dataset

Movember Foundation encourages growing mustaches in support of men’s health and fitness.

Click on image to enlarge

Arctic Ice Extents have roughly doubled since the Sept. minimum and are now up to 10M km2.  The last 1/3 of maximum will take until March, principally because several basins are frozen over and cannot add coverage.  To date, Beaufort and CAA (Canadian Archipelago) are full, as are Laptev and East Siberian on the Russian side.  Kara is 3/4 covered and the Central Arctic wil add only 3% from here.

During the first half of November we can see at the bottom Beaufort  and East Siberian filling in, leaving only Chukchi with open water.  On the right, Both Baffin and Hudson bays are now growing more strongly.   At the top Kara ice extent has reached 75% of its March maximum.

The graph compares extents over the first 17 days of November.

2017 has reached 9.9M km2, 2007 nearly the same, and both are close to the 10 year average of 10M km2.  2012 lags 300k km2 lower than 2017, while 2016 is 877k km2 behind.  At this point MASIE and SII are tracking the 10-year average, with SII about 200k km2 lower.

The Table below shows where ice is located on day 321 in regions of the Arctic ocean. 10 year average comes from 2007 through 2016 inclusive.

The deficits to average are primarily in Chukchi, also Barents and Greenland Seas. Surpluses are large in Hudson and Baffin Bays, along with Kara Sea.

Footnote

Some people unhappy with the higher amounts of ice extent shown by MASIE continue to claim that Sea Ice Index is the only dataset that can be used. This is false in fact and in logic. Why should anyone accept that the highest quality picture of ice day to day has no shelf life, that one year’s charts can not be compared with another year? Researchers do this analysis, including Walt Meier in charge of Sea Ice Index. That said, I understand his interest in directing people to use his product rather than one he does not control. As I have said before:

MASIE is rigorous, reliable, serves as calibration for satellite products, and uses modern technologies to continue the long and honorable tradition of naval ice charting.  More on this at my post Support MASIE Arctic Ice Dataset

Movember Foundation encourages growing mustaches in support of men’s health and fitness.

An imposing panorama of an ice-fjord floating along the bone-chilling water in Svalbard. From Daily Mail

Arctic ice extent went over 9M km2 yesterday, or about 60% of annual maximum.  Several seas are already maxed out:  Laptev, East Siberian, Canadian Archipelago.  The image below shows the refreezing this month.

Click on image to enlarge.

At the bottom watch Beaufort Sea filling in.  On the middle right Baffin Bay steadily adds ice, while Hudson bay starts from its top, but also gets fast ice way down the western coastline into James Bay.  At the top center is Svalbard with Greenland Sea growing on its right, and Kara and Barents filling in on its left.

Dr. Judah Cohen from Atmospheric and Environmental Research (AER) saw this coming.  From his blog November 6 2017:

The forecast for November (Figure 13a) shows cold temperatures in Canada that extend into the Eastern US. The cold temperatures in Canada seem likely but the cold temperatures in the Eastern US will likely depend on the strength of Greenland blocking. The forecast for Eurasia is relatively mild and I think that the forecast is likely to be wrong. In my opinion the predicted blocking across northern Eurasia favors more widespread cold than predicted by the CFS especially across Siberia and East Asia.

My thoughts on the weather pattern over the next several weeks  By Brett Anderson, AccuWeather senior meteorologist  11/08/2017, 4:30:48 PM

Interesting weather pattern setting up across North America as we progress through November and get into early December.

–A series of potent, Pacific storms will likely impact southern BC and the U.S. Pacific Northwest between Nov. 13 and 23. Expect several rounds of heavier rain and gusty winds for Vancouver Island and the mainland coast. Heavy snowfall for the Coastal Range and Rockies should help set the ski season off on a good start.

–A strong Arctic, cold front will press southward through Ontario and Quebec on Thursday. Behind the front, rain showers will quickly change to snow showers and a brief, heavier snow squall. There is the potential for brief whiteout conditions with any squall from southern and eastern Ontario through southern Quebec late Thursday afternoon and into the night. These squalls can quickly drop visibility making travel dangerous for motorists, especially on highways. Roads will generally be wet Thursday afternoon, but untreated roads may briefly get snow covered and icy Thursday evening and night as temperatures rapidly fall below the freezing mark.

In addition to the cold, northwesterly winds will be quite strong Thursday night into early Friday with gusts in the 60- to 80-km/h range from eastern Ontario through Quebec and into western New Brunswick.

Dr. Cohen’s view of the winter Arctic climate system is posted in Snowing and Freezing in the Arctic