Climate Science News

Arctic winter warms up to a low summer ice season

NSIDC Artic Sea Ice News - Thu, 2018-05-03 01:00

Sea ice extent in the Bering Sea remains at record low levels for this time of year. Total ice extent over the Arctic Ocean also remains low.

Overview of conditions Figure 1. Arctic sea ice extent for March 2018 was 14.30 million square kilometers (5.52 million square miles). The magenta line shows the 1981 to 2010 average extent for the month.

Figure 1. Arctic sea ice extent for April 2018 was 13.71 million square kilometers (5.29 million square miles). The magenta line shows the 1981 to 2010 average extent for the month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Arctic sea ice extent for April 2018 averaged 13.71 million square kilometers (5.29 million square miles). This was 980,000 square kilometers (378,400 square miles) below the 1981 to 2010 average and only 20,000 square kilometers (7,700 square miles) above the record low April extent set in 2016. Given the uncertainty in measurements, NSIDC considers 2016 and 2018 as tying for lowest April sea ice extent on record. As seen throughout the 2017 to 2018 winter, extent remained below average in the Bering Sea and Barents Sea. While retreat was especially pronounced in the Sea of Okhotsk during the month of April, the ice edge was only slightly further north than is typical at this time of year. Sea ice extent in the Bering Sea remains the lowest recorded since at least 1979. The lack of sea ice within this region created many coastal hazards this past winter.

Conditions in context Figure 2a. The graph above shows Arctic sea ice extent as of April 4, 2018, along with daily ice extent data for four previous years and 2012, the year with record low minimum extent. 2018 is shown in blue, 2017 in green, 2016 in orange, 2015 in brown, 2014 in purple, and 2012 in dotted brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data.

Figure 2. The graph above shows Arctic sea ice extent as of April 30, 2018, along with daily ice extent data for four previous years and 2012, the year with record low minimum extent. 2018 is shown in blue, 2017 in green, 2016 in orange, 2015 in brown, 2014 in purple, and 2012 in dotted brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

Overall, sea ice extent for April 2018 declined by 920,000 square kilometers (355,000 square miles). The amount of ice lost for the month was less than the 1981 to 2010 average of 1.1 million square kilometers (424,700 square miles). The ice edge retreated everywhere except in Hudson Bay and Baffin Bay/Davis Strait. The sea ice expanded slightly within Davis Strait during the month. Sea ice in the Hudson Bay usually does not begin to retreat until the end of May.

Air temperatures at 925 hPa (about 2,500 feet above sea level) for April were up to 10 degrees Celsius (18 degrees Fahrenheit) higher than average in the East Siberian Sea and stretching towards the pole. Air temperatures were also up to 5 degrees Celsius (9 degrees Fahrenheit) above average within the East Greenland Sea and 3 degrees Celsius (5 degrees Fahrenheit) above average over Baffin Bay. By contrast, air temperatures were near average within the Barents and Kara seas and lower than average over Canada and the Hudson Bay. The pattern of temperature departures from average resulted from higher than average sea level pressure over the Beaufort Sea as well as the North Atlantic, combined with below average sea level pressure over Eurasia and western Greenland through eastern Canada. On the Pacific side of the Arctic, this pressure pattern drove warm air from the south over the East Siberian and Chukchi Seas, while bringing cold air into northern Canada. The pattern of above average sea level pressure over the North Atlantic was combined with lower than average sea level pressure over western Greenland and the Canadian Archipelago, bringing in warm air in from the south over Greenland and Baffin Bay.

April 2018 compared to previous years Figure 3. Monthly March ice extent for 1979 to 2018 shows a decline of 2.7 percent per decade.

Figure 3. Monthly April ice extent for 1979 to 2018 shows a decline of 2.6 percent per decade.

Credit: National Snow and Ice Data Center
High-resolution image

The linear rate of decline for April sea ice extent is 37,500 square kilometers (14,500 square miles) per year, or 2.6 percent per decade relative to the 1981 to 2010 average.

Continued loss of the oldest sea ice, five-years or older  Preliminary analysis courtesy M. Tschudi, University of Colorado Boulder. Images by M. Tschudi, S. Stewart, University of Colorado, Boulder, and W. Meier, J. Stroeve, NSIDC|

Figure 4a-d. These maps show the ice age distribution during week nine in 1984 (a) and 2018 (b). The time-series (c) shows total sea ice extent for different age classes as is outlined in the Arctic Ocean Domain (d).

Credit: Preliminary analysis courtesy M. Tschudi, University of Colorado Boulder. Images by M. Tschudi, S. Stewart, University of Colorado, Boulder, and W. Meier, J. Stroeve, NSIDC
High-resolution image

An updated assessment of ice age changes in the Arctic through week nine (early March) in 2018 shows a substantial amount of first-year ice within the Beaufort, Chukchi, East Siberian, Laptev, Kara and Barents Seas (Figure 4b). Multiyear ice near the Alaskan and Siberian coast is limited to scattered regions off shore in the Beaufort and Chukchi Seas. A tongue of second- and third-year ice extends from near the pole toward the New Siberian Islands, and a region of second-year ice extends toward Severnaya Zemlya. As averaged over the Arctic Ocean domain (Figure 4d), the multiyear ice cover has declined from 61 percent in 1984 to 34 percent in 2018. In addition, only 2 percent of the ice age cover is categorized as five-plus years, the least amount recorded during the winter period. While the proportion of first-year versus multiyear ice will largely depend on how much ice melted during summer, how much ice is exported out of Fram Strait each winter also plays a role. First-year ice grows to about 1.5 to 2 meters (5 to 6.5 feet) thick over a winter season, while older ice is often 3 to 4 meters (9.8 to 13.1 feet) thick.

Note: The ice age fields originally posted on Thursday, May 3, were incorrect. The ice age field has its “birthday” each September after the minimum, when all of the age values are incremented by one after the end of the summer melt season. For example, first-year ice becomes second-year ice after the minimum, second-year ice becomes third-year ice, and so on. However, in the original post, the near-real-time age fields were not incremented after the 2017 minimum. The ice age fields are now corrected (as of Monday, May 7). However, as these are near-real-time data, minor adjustments may occur during final processing. Final numbers will be available in the next few months.

Is winter warming resulting in less winter ice growth? Figure 5a. These maps show the cumulative number of freezing degree day anomalies from the Climate Forecast System version 2 (CFSv2). Courtesy of A. Barrett, National Snow and Ice Data Center|

Figure 5a. These maps show the cumulative number of freezing degree day anomalies from the Climate Forecast System version 2 (CFSv2).

Credit: A. Barrett, National Snow and Ice Data Center
High-resolution image

Figure xx. This time-series from 1985 to 2017 shows the mean winter ice growth (mid-November to mid-April) simulated by the Los Alamos sea ice model (CICE) forced by NCEP-2 atmospheric reanalysis (a). Also shown are the mean 2 meters NCEP-2 air temperature averaged over the Arctic Ocean (b), cumulative freezing degree days (FDDs) (c) and CICE-simulated November ice thickness (d). See Stroeve et al. (2018) for more details.

Figure 5b. This time-series (a) from 1985 to 2017 shows the mean winter ice growth (mid-November to mid-April) simulated by the Los Alamos sea ice model (CICE) forced by the National Center for Environmental Prediction (NCEP-2) atmospheric reanalysis. Also shown are the mean 2 meters NCEP-2 air temperature averaged over the Arctic Ocean (b), cumulative freezing degree days (FDDs) (c), and CICE-simulated November ice thickness (d).

See Stroeve et al. (2018) for more details.
High-resolution image

The last three winters have seen air temperatures at the North Pole surge above 0 degrees Celsius (32 degrees Fahrenheit). While heat transport associated with individual storms can result in high air temperatures persisting over several days, a more important metric in regard to how winter warming impacts the sea ice cover is the cumulative number of freezing degree days. This is defined as the number of days below freezing multiplied by the magnitude of the temperatures below the freezing point. Widespread reductions in the total number of freezing degree days (as compared to average) are apparent for the last three winters, being most pronounced this past winter (Figure 5a).

Previous studies evaluated how the low number of cumulative freezing degree days in the 2015 to 2016 winter over the Barents and Kara Seas impacted the ice thickness and sea ice extent in that region. A newer study looks at the effects of warm winters for a larger area. NSIDC scientist Julienne Stroeve found that in response to the warm winter of 2016 to 2017, ice growth over the Arctic Ocean was likely reduced by 13 centimeters (5 inches). Generally, one does not expect variations in winter air temperature to have a significant impact on winter ice growth—temperatures still generally remain well below freezing and the rate at which ice grows (thickens) is greater for thin ice than thick ice. Thus, despite an overall increase in winter air temperatures, thermodynamic ice growth over winter has generally increased in tandem with thinning at the end of summer (Figure 5b). However, since 2012, this relationship appears to be changing. Overall winter ice growth in the 2016 to 2017 winter was similar to that in 2003, despite having a mean November ice thickness well below that seen in 2003. A similar analysis is not yet available for the 2017 to 2018 winter, but given the very warm conditions, it is likely that thermodynamic ice growth was reduced compared to average.

Unusual polynya opening north of Greenland Figure6_adj

Figure 6a. This sequence of high-resolution images from the NASA Advanced Microwave Scanning Radiometer 2 (AMSR2) show the formation of a large polynya north of Greenland.

Credit: J. Stroeve, National Snow and Ice Data Center
High-resolution image

Figure 6b. This graph shows average daily temperatures at Cape Morris Jesup, Greenland’s northernmost station.

Credit: J. Stroeve, National Snow and Ice Data Center
High-resolution image

During the middle of February, a large polynya opened north of Greenland and persisted through the first week of March (Figure 6a). Development of the polynya was driven in part by strong winds from the south and unusually high air temperatures. On February 24, during the peak of the polynya opening, air temperatures at Cape Morris Jesup, Greenland’s northernmost station, surged well above freezing, reaching 6.1 degrees Celsius (43 degrees Fahrenheit), while the daily average temperature hovered just above freezing (Figure 6b). Such periods of extremely warm winter temperatures have been unusual since the beginning of the Cape Morris Jesup record in 1981. During the month of February, only a few years exhibited hourly air temperatures rising above 0 degrees Celsius (32 degrees Fahrenheit): once in 1997, five times in 2011, seven in 2017 and 59 times in 2018.

References

Beitsch, A., L. Kaleschke, and S. Kern. 2014. Investigating high-resolution AMSR2 sea ice concentrations during the February 2013 fracture event in the Beaufort Sea. Remote Sensing 6, 3841-3856, doi.org/10.3390/rs6053841.

Boisvert, L.N., A.A. Petty, and J. Stroeve. 2016. The impact of the extreme winter 2015/16 Arctic cyclone on the Barents–Kara Seas, Bulletin of the American Meteorological Society, doi:10.1175/MWR-D-16-0234.1.

Ricker, R., S. Hendricks, F. Girard-Ardhuin, L. Kaleschke, C. Lique, X. Tian-Kunze, M. Nicolaus, and T. Krumpen. 2017a. Satellite observed drop of Arctic sea ice growth in winter 2015-2015, Geophysical Research Letters, doi:10.1002/2016GL072244.

Stroeve, J., D. Schroeder, M. Tsamados, and D. Feltham. 2018. Warm winter, thin ice? The Cryosphere, doi:10.5194/tc-2017-287, accepted.

Further reading

Thompson, A. “Shock and thaw—Alaskan sea ice just took a steep, unprecedented dive.” Scientific American. https://www.scientificamerican.com/article/shock-and-thaw-alaskan-sea-ice-just-took-a-steep-unprecedented-dive.

Hansen, K. “Historic low sea ice in the Bering Sea.” NASA Earth Observatory. https://earthobservatory.nasa.gov/IOTD/view.php?id=92084.

Categories: Climate Science News

16 - 22 April 2018 week

AVISO Climate Change News - Fri, 2018-04-27 07:20
More than 12,000 marine creatures uncovered during West Java deep-sea exploration (Science Daily, 17/04/18) "Le glacier n'est plus qu'une carapace vide" : au Pérou, sur "la route du changement climatique" (France Info, 22/04/18) La Nasa lance avec succès un télescope en quête de vie dans l'espace (Presse Océan, 19/04/18) Meteorite diamonds 'came from lost planet' (BBC, 18/04/18) How gravitational waves might help fundamental cosmology (Nature International journal of Science, 11/04/18) Les océans étaient probablement très chauds il y a 760 millions d’années (Futura Planète, 19/04/18) On line availability of articles depends on the Newspaper/magazine. We can't thus certify that above articles will be freely and permanently available.
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September 2018 : CALL FOR ABSTRACTS for annual meeting of the Ocean Surface Topography Science Team (OSTST)

AVISO Climate Change News - Fri, 2018-04-20 02:50
The annual meeting of the Ocean Surface Topography Science Team (OSTST), will be held in the second part of the "25 Years of Progress in Radar Altimetry" Symposium and will address specific issues on the TOPEX/Poseidon-Jason series of missions, including algorithm and model improvement, Cal/Val activities, merging with other altimetric satellites (CryoSat-2, SARAL/AltiKa, HY-2, Sentinel-3), and preparation for the Sentinel-6/Jason-CS and SWOT missions.   Because of the obvious relationship with the Symposium, it is proposed that the purely science presentations of the OSTST PIs and Co-Is be given in the Symposium. This will leave more time during OSTST for specific splinters, technical presentations, including a poster session. The International Doris Service (IDS) workshop (1.5 days) will take place in parallel to the "25 Years of Progress in Radar Altimetry" Symposium and start after the Monday morning plenary session. Abstracts submission for the OSTST and IDS meetings is open through this interface  and will end on May 14 (midnight UTC).   For OSTST, splinters descriptions to choose where to submit your abstract can be found here.
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[Sentinel-3B] The second Sentinel-3 satellite is set for launch on 25 April

AVISO Climate Change News - Fri, 2018-04-20 02:08
The second Sentinel-3 satellite, Sentinel-3B, is set for launch on 25 April. Discover this multitalented mission and follow preparations for the liftoff of Europe’s next Copernicus satellite.   Meet Sentinel-3
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April 2018: Sea ice leads by two sentinels

AVISO Climate Change News - Thu, 2018-04-19 07:03
The fractures in sea ice (or "leads") are important for the estimate of ice thickness from remote...
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9 - 15 April 2018 week

AVISO Climate Change News - Thu, 2018-04-19 02:50
Pourquoi étudier l’ADN de l’océan?? (Sud Ouest, 10/04/18) Atlantic Ocean Circulation at weakest point in 1,600 years (Science Daily, 11/04/18)  Cette boue japonaise trouvée au fond de l'océan pourrait sauver les nouvelles technologies (et notre civilisation) (Huffpost, 11/04/18) L’océan martien gagne en crédibilité et ses dates se précisent (Le Blog de Pierre Brisson, 10/04/18) Changement climatique : doucement mais sûrement, le plus vaste désert du monde s'étend (Sciences et Avenir, 12/04/18) Bound for Mars: Countdown to First Interplanetary Launch from California (Nasa, 06/04/18) On line availability of articles depends on the Newspaper/magazine. We can't thus certify that above articles will be freely and permanently available.
Categories: Climate Science News

2 - 8 April 2018 week

AVISO Climate Change News - Thu, 2018-04-12 01:38
Scientists Surprised by Relentless Cosmic Cold Front (NASA, 03/04/18) Plastic partout ! Histoires de déchets (Arte, 04/04/18) Antarctica loses grip(ESA, 03/04/18) Même un réchauffement de 2°C aura une incidence importante (Capital, 02/04/18) China's first space station was decimated in a fireball over the South Pacific — here's how it went from launch to crashing back to Earth (Business Insider, 02/04/18) Réchauffement climatique : le pouvoir des tourbières du Congo (France Info, 05/04/18) On line availability of articles depends on the Newspaper/magazine. We can't thus certify that above articles will be freely and permanently available.
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Jason-2 MOE/IGDR production may be delayed

AVISO Climate Change News - Fri, 2018-04-06 08:35
Some excess fuel depletion maneuvers for Jason-2 are planned from 2018/04/06 to 2018/04/17. During this period, Jason-2 MOE/IGDR production may be delayed. Sorry for the inconvenience
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19 March - 1 April 2018 weeks

AVISO Climate Change News - Thu, 2018-04-05 06:47
Réchauffement climatique : la menace d’une montée des eaux se confirme dans l’Antarctique (Sud Ouest, 20/03/2018)
Geoengineering polar glaciers to slow sea-level rise (Science Daily, 19/03/2018)
Cyclone Tropical MARCUS dans l'océan indien sud-est (Cyclone Ocean Indien, 20/03/2018)
Il faut s'attendre à davantage de catastrophes liées au climat (L’Obs, 21/03/2018)
Découverte d’une « zone crépusculaire » cachée dans l’océan et remplie de poissons inconnus (Science Post, 22/03/18)
These Climate Pollutants Don't Last Long, But They’re Wreaking Havoc on the Arctic (Inside Climate News, 19/03/2018)
Visualisez la taille de l’énorme « décharge flottante » de plastique dans l’océan Pacifique (Le Monde, 23/03/18)
Earth Hour : quand les lumières s’éteignent pour la planète (Sud Ouest, 25/03/2018)
Ce robot-poisson passe totalement inaperçu dans l’océan (Science Post, 27/03/2018)
Weather phenomena such as El Niño affect up to two-thirds of the world's harvests (Science Daily, 28/03/2018)
Drones, animaux et avion pour observer les cyclones de l'océan indien sud-ouest (Cyclone Ocean Indien, 28/03/2018) On line availability of articles depends on the Newspaper/magazine. We can't thus certify that above articles will be freely and permanently available.
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2018 winter Arctic sea ice: Bering down

NSIDC Artic Sea Ice News - Wed, 2018-04-04 14:00

The 2018 winter sea ice maximum has passed, and the melt season has begun. The most notable aspect of the 2017 to 2018 winter ice extent was the persistently low ice extent in the Bering Sea. While December, January, and February were characterized by very warm conditions over the Arctic, March temperatures were mixed, with cool conditions over the Eurasian side and moderately warm conditions over the North American side.

Overview of conditions Figure 1. Arctic sea ice extent for March 2018 was 14.3 million square kilometers (5.52 million square miles). The magenta line shows the 1981 to 2010 average extent for that month.

Figure 1. Arctic sea ice extent for March 2018 was 14.30 million square kilometers (5.52 million square miles). The magenta line shows the 1981 to 2010 average extent for the month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Arctic sea ice extent for March 2018 averaged 14.30 million square kilometers (5.52 million square miles), the second lowest in the 1979 to 2018 satellite record. This was 1.13 million square kilometers (436,300 square miles) below the 1981 to 2010 average and 30,000 square kilometers (11,600 square miles) above the record low March extent in 2017. Extent at the end of the month was far below average in the Bering Sea, as it has been for the past several months, and slightly below average in the far northern Atlantic Ocean and Barents Sea. Ice extent was slightly above average in the Sea of Okhotsk.

Conditions in context Figure 2a. The graph above shows Arctic sea ice extent as of April 4, 2018, along with daily ice extent data for four previous years, and the record low year. 2017 to 2018 is shown in blue, 2016 to 2017 in green, 2015 to 2016 in orange, 2014 to 2015 in brown, 2013 to 2014 in purple, and 2011 to 2012 in dotted brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data.

Figure 2a. The graph above shows Arctic sea ice extent as of April 4, 2018, along with daily ice extent data for four previous years, and the record low year. 2017 to 2018 is shown in blue, 2016 to 2017 in green, 2015 to 2016 in orange, 2014 to 2015 in brown, 2013 to 2014 in purple, and 2011 to 2012 in dotted brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

Figure 2b. This plot shows the departure from average air temperatures at the 925 hPa level in degrees Celsius in the Arctic for March 2018. Yellows and reds indicate higher than average temperatures; blues and purples indicate lower than average temperatures.

Figure 2b. This plot shows departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for March 2018. Yellows and reds indicate higher than average temperature; blues and purples indicate lower than average temperature.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Division
High-resolution image

Figure 2c. This plot shows the average sea level pressures in the Arctic (in millibars) at the 925 hPa level for March 2018. Yellows and reds indicate higher than average air pressures; blues and purples indicate lower than average air pressures.

Figure 2c. This plot shows the average sea level pressure in the Arctic at the 925 hPa level, in millibars, for March 2018. Yellows and reds indicate higher than average air pressure; blues and purples indicate lower than average air pressure.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Division
High-resolution image

Overall, ice extent for March 2018 changed little. Extent reached the annual maximum on March 17 and declined by March 31 to nearly the same level as at the beginning of the month. Ice loss following the seasonal maximum has been almost entirely restricted to the Bering Sea and the Sea of Okhotsk, with slight increases in extent in the Barents Sea and near Svalbard.

Air temperatures at the 925 hPa level (about 2,500 feet above sea level) were 2 to 4 degrees Celsius (4 to 7 degrees Fahrenheit) higher than average in regions near Greenland and Alaska. Cooler conditions prevailed over Scandinavia, the Kara Sea, and far eastern Siberia, where temperatures were generally 4 to 7 degrees Celsius (7 to 13 degrees Fahrenheit) below average.

Higher than average sea level pressure was present over the western Arctic, including Canada, the Beaufort Sea, and Greenland, while lower than average sea level pressure prevailed over most of Europe and Siberia. This pattern was associated with winds from the south in the Bering Sea and Alaska, helping to push ice toward the pole. Conversely, over Scandinavia and the Barents Sea this pressure pattern resulted in winds from the northeast that pushed Arctic air onto the northern Eurasian landmass leading to colder air temperatures.

The Arctic Oscillation (AO), an indicator for general wind, precipitation, and temperature patterns in the Arctic, was strongly negative in early March, reflecting the higher than average sea level pressure in the western Arctic. This negative phase is characterized by a weakening of the circumpolar wind pattern, a pattern that favors cold air outbreaks over much of the United States as well as parts of Europe and Asia.

March 2018 compared to previous years  National Snow and Ice Data Center

Figure 3. Monthly March ice extent for 1979 to 2018 shows a decline of 2.7 percent per decade.

Credit: National Snow and Ice Data Center
High-resolution image

The linear rate of decline for March ice extent is 42,200 square kilometers (16,400 square miles) per year, or 2.7 percent per decade relative to the 1981 to 2010 average.

Review of winter season 2017 to 2018  NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Division| High-resolution image

Figure 4. This plot shows the departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for December 2017 and January and February in 2018. Yellows and reds indicate higher than average temperature; blues and purples indicate lower than average temperature.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Division
High-resolution image

Unusually warm conditions and some prominent warm air intrusions characterized the 2017 to 2018 winter over the Arctic Ocean. Mean air temperature for the months of December, January, and February combined (the climatological winter season) was as much as 7 degrees Celsius (13 degrees Fahrenheit) higher than average, and nearly the entire Arctic Ocean was 4 degrees Celsius (7 degrees Fahrenheit) higher than average. This is the fourth year in a row that unusual jet stream patterns have led to warm air intrusions over the Arctic Ocean. However, some Arctic and subarctic land areas experienced unusually cold periods during the winter. Recent studies show that the frequency and intensity of warm air intrusions has increased in the last few years, particularly in the Atlantic sector, helping to reduce ice growth in the Barents Sea. The winter of 2017 to 2018 marks the second year in a row of pronounced warming events in the Pacific sector.

Deep snow in Russia and Europe Figure 5. These images show the Northern Hemisphere water equivalent of snow cover in millimeters (top) and the Northern Hemisphere Total snow mass from October 2017 to March 31, 2018, in gigatons.

Figure 5. These images show Northern Hemisphere water equivalent of snow cover in millimeters (top) and Northern Hemisphere total snow mass in gigatons (bottom) from October 2017 to March 31, 2018.

Credit: GlobSnow Project and the Finnish Meteorological Institute
High-resolution image

Snow cover extent on the land masses surrounding the Arctic Ocean was average this past winter. However, an analysis of the snow cover thickness and density showed that the total snow mass this past winter was high. Estimates of total snow mass as of March 31 showed that the Northern Hemisphere had nearly 700 billion tons more snow this winter than the 1982 to 2012 average. Many areas of Russia and northern Europe had more than 150 millimeters (6 inches) of water-equivalent on the ground, present as deep snow cover. Snow extent had been above average the entire autumn-winter season but grew to exceptional levels beginning in February. Although the total snow mass has begun to decrease, it is still far above average. The analysis is based on many sources of snow and snow depth data, including passive microwave data produced by NSIDC (EASE-Grid Snow Water Equivalent and Daily Snow Cover), and data derived from several other groups from the European Space Agency and the National Oceanographic and Atmospheric Administration.

Sea ice drift in the Arctic Ocean  NSIDC courtesy Ocean and Sea Ice Satellite Application Facility (OSI-SAF)

Figure 6. This plot shows monthly average sea ice motion in the Arctic, in centimeters per second, for the months of January, February, and March in 2018.

Credit: Alek Petty/NASA Goddard Space Flight Center (GSFC) and the Ocean and Sea Ice Satellite Application Facility (OSI-SAF)
High-resolution image

Plots of monthly average sea ice motion for January, February, and March 2018 reveal pronounced changes in drift direction, since sea ice movement is largely controlled by winds, and therefore storms and pressure patterns. The maps include averages of sea surface temperature outside of the ice-covered area, and indicate that the surface of both the northern Pacific and northern Atlantic were substantially warmer relative to a 1982 to 2015 reference period. Strong Beaufort Gyre and Transpolar Drift patterns were present for January and March of 2018. Ice motion and sea surface temperature data are based on a multi-sensor estimate created by the Ocean and Sea Ice Satellite Application Facility (OSI-SAF), a European meteorological consortium.

Seasonal increase in Antarctic sea ice

After reaching a minimum extent for the year on February 20 and 21, Antarctic sea ice grew rapidly in March 2018. Sea ice extent averaged 3.53 million square kilometers (1.36 million square miles) for the month, not far below the 1981 to 2010 average of 4.03 million square kilometers (1.56 million square miles). Growth was especially rapid in the Amundsen and Ross Seas, nearly erasing the area of below-average sea ice extent that had been in the eastern Ross Sea and western Amundsen in early March.

Rapid sea ice growth in the Amundsen and eastern Ross Seas was reflected in temperatures at the 925 hPa level that were 1 to 3 degrees Celsius (2 to 5 degrees Fahrenheit) below average across the Pine Island Bay region. This is likely related to cool winds from the south coming up against the west side of a low-pressure area over the Bellingshausen Sea. By comparison, temperatures 2.5 to 4.5 degrees Celsius (4 to 8 degrees Fahrenheit) higher than average were the rule over much of the continental interior from Dronning Maud Land to northern Victoria Land along the Transantarctic Mountains. The index of the strength of the circumpolar vortex (or Southern Annular Mode) was near-neutral for March.

References

Boisvert, L. N., A. A. Petty, and J. Stroeve. 2016. The Impact of the Extreme Winter 2015/16 Arctic Cyclone on the Barents–Kara Seas, Bulletin of the American Meteorological Society, doi:10.1175/MWR-D-16-0234.1.

Graham, R. M., L. Cohen, A. A. Petty, L. N. Boisvert, A. Rinke, S. R. Hudson, M. Nicolaus, and M. A. Granskog. 2017. Increasing frequency and duration of Arctic winter warming events, Geophysical Research Letters, 44, 6974–6983, doi:10.1002/2017GL073395.

Ricker, R., S. Hendricks, F. Girard-Ardhuin, L. Kaleschke, C. Lique, X. Tian-Kunze, M. Nicolaus, and T. Krumpen. 2017. Satellite observed drop of Arctic sea ice growth in winter 2015-2015, Geophysical Research Letters, doi:10.1002/2016GL072244.

Rinke, A., M. Maturilli, R. M. Graham, H. Matthes, D. Handorf, L. Cohen, S. R. Hudson, and J. C. Moore. 2017. Extreme cyclone events in the Arctic: Wintertime variability and trends , Environmental Research Letters, 12 (9), 094006, doi:10.1088/1748-9326/aa7def.

Correction

On April 20, we revised a sentence under the section Seasonal increase in Antarctic sea ice. The sentence originally read “Growth was especially rapid in the Amundsen and eastern Ross Sea, where sea ice was nearly absent at the time of the minimum extent, and along the East Antarctic coast, where many areas now exceed the daily median extent for the end of March.” We revised it to “Growth was especially rapid in the Amundsen and Ross Seas, nearly erasing the area of below-average sea ice extent that had been in the eastern Ross Sea and western Amundsen in early March.”

 

Categories: Climate Science News

Feeling the heat

NASA Climate News - Fri, 2012-09-14 00:09
A former intern tells why she?s returned to JPL
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Grace mission offers a novel view of Earth?s water supplies

NASA Climate News - Thu, 2012-09-13 02:09
The Grace mission offers a novel and much needed view of Earth?s water supplies.
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'Earth Now' available for Android

NASA Climate News - Mon, 2012-09-10 02:09
Follow the vital signs of our planet
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NASA's Global Hawk mission begins with flight to Hurricane Leslie

NASA Climate News - Fri, 2012-09-07 01:09
NASA has begun its latest hurricane science field campaign.
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NASA voyage set to explore link between sea saltiness and climate

NASA Climate News - Tue, 2012-09-04 22:09
A NASA-sponsored expedition is set to sail to the North Atlantic's saltiest spot.
Categories: Climate Science News

No surprise

NASA Climate News - Wed, 2012-08-29 05:08
JPL ice expert reflects on record Arctic low
Categories: Climate Science News

New Arctic minimum

NASA Climate News - Mon, 2012-08-27 22:08
Sea ice breaks lowest extent on record
Categories: Climate Science News

Tracking shuttle exhaust reveals more information about atmospheric winds

NASA Climate News - Mon, 2012-08-27 22:08
On July 8, 2011 the Space Shuttle Atlantis launched for the very last time. As the shuttle reached a height of about 70 miles over the east coast of the U.S., it released ? as it always did shortly after launch ? 350 tons of water vapor exhaust.
Categories: Climate Science News

Tropical storm Isaac brings heavy rains to eastern Caribbean

NASA Climate News - Wed, 2012-08-22 23:08
NASA's Tropical Rainfall Measuring Mission satellite captured rainfall data from Tropical Storm Isaac as it continues moving through the Caribbean Sea.
Categories: Climate Science News

NASA expands network for measurement of tiny airborne particles

NASA Climate News - Thu, 2012-08-16 01:08
Scientists at NASA have added yet another instrument to an expanding climate research hub at NASA's Langley Research Center, putting Hampton, Va., on the map in a worldwide network of atmospheric measurements.
Categories: Climate Science News
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