Climate Science News

Temporary unavailability of the Bulletin Service on July 06, 2017

AVISO Climate Change News - Thu, 2017-07-06 05:15
For maintenance reason, the Bulletin Service (http://bulletin.aviso.altimetry.fr/) is unavailable...
Categories: Climate Science News

Water JPI 2017 Joint Call opening soon!

AVISO Climate Change News - Thu, 2017-07-06 00:27
The Water JPI will launch on 30 August 2017 its new Joint Call on the topic “Water resource management in support of the United Nations Sustainable Development Goals”. For more information, please visit the 2017 Joint Call webpage here!
Categories: Climate Science News

25 Years of Progress in Radar Altimetry Symposium - 24-29 September 2018, Azores

AVISO Climate Change News - Thu, 2017-07-06 00:14

Following on from the "15 Years of Progress in Radar Altimetry"  Symposium in 2006 and the "20 Years of Progress in Radar Altimetry"  Symposium in 2012, in Venice-Lido, Italy, both deemed very successful landmarks by the participants and the readership of the Proceedings, we are now at the twenty-five year anniversary of the launch of ERS-1 and TOPEX/POSEIDON. To mark this occasion the  European Space Agency, in collaboration with the French Space Agency,  CNES, is organising an exceptional Symposium on "25 Years of Progress in Radar Altimetry". This event will also be sponsored by other partner agencies and organisations supporting the development of altimetry. Along with this symposium, several related events will take place on the same week, including the annual meeting of the Ocean Surface Topography Science Team (OSTST) and the International Doris Service (IDS) workshop, as well as other thematic workshops still to be organised; potential topics are Sea Level for Climate, Coastal Zone, Space for Hydrology, Argo, etc. These events will be held over 6 days, from 24 to 29 of September 2018, in Ponta Delgada, São Miguel Island, Azores Archipelago (Portugal). 

Please consider your participation at this exceptional event and reserve the week from 24 to 29 September 2018 in your agenda. For the symposium, a call for papers with detailed information and deadlines will be sent subsequently, along with the details of a dedicated web site to submit your contributions to be reviewed by the Scientific Committee. For OSTST and IDS meetings, additional information and call for contributions will be sent out and linked to the same website.
    

Looking forward to another great "slow-time" event like the 15 and 20 Years of Progress in Radar Altimetry held in Venice in 2006 and 2012, an exceptional scientific Symposium on "25  Years  of  Progress  in  Radar  Altimetry"!

Looking forward to your participation!


Jérôme Benveniste and Pascal Bonnefond
on behalf of the 25 Years of Progress in Radar Altimetry Symposium Organising Committee

Pro Memoria:

The web site for 15YPRA is accessible at http://earth.esa.int/venice06
The web site for 20YPRA is accessible at http://esaconferencebureau.com/2012-events/12c01

Proceedings of 15YPRA on CD-Rom and athttp://www.esa.int/esapub/conference/toc/tocSP614.pdf
Proceedings of 20YPRA on CD-Rom and at http://www.spacebooks-online.com/product_info.php?cPath=104&products_id=17546


SUMMARY AND RECOMMENDATIONS FROM THE “20 YEARS OF PROGRESS IN RADAR ALTIMETRY” SYMPOSIUM, by Jérôme Benveniste, Rosemary Morrow, Jean-Louis Fellous and Albert Fischer is available at  http://esamultimedia.esa.int/multimedia/publications/SP-710/session_summaries.pdf

Categories: Climate Science News

25 June - 2 July, 2017 week

AVISO Climate Change News - Wed, 2017-07-05 23:44
Changement climatique, les atolls résistent bien à l'élévation du niveau de la mer (Tahiti infos, 2017/06/30)
Record June Temperatures in Western Europe (WWA, 2017/06/29)
Comment le phytoplancton domine les océans ? Des chercheurs grenoblois ont la réponse (Placegrenet, 2017/06/27)
C’est donc prouvé, le niveau de la mer monte plus vite à cause de la fonte des glaces (Mashable, 2017/06/27)
Le Groenland, responsable de la hausse du niveau des océans (Le Figaro, 2017/06/26)
Climat. À lui seul, le Groenland peut faire monter les océans de 7 mètres (Ouest France, 2017/06/26)
Climat: les océans se réchauffent plus rapidement que prévu (BFM TV, 2017/06/27)
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

Arctic ice extent near levels recorded in 2012

NSIDC Artic Sea Ice News - Wed, 2017-07-05 13:00

Contrasting with the fairly slow start to the melt season in May, June saw the ice retreat at a faster than average rate. On July 2, Arctic sea ice extent was at the same level recorded in 2012 and 2016. In 2012, September sea ice extent reached the lowest in the satellite record. As a new feature to Arctic Sea Ice News and Analysis, NSIDC now provides a daily updated map of ice concentration in addition to the daily map of ice extent.

Overview of conditions Figure 1. Arctic sea ice extent for June 2017 averaged 11.06 million square kilometers (4.27 million square miles).

Figure 1. Arctic sea ice extent for June 2017 averaged 11.06 million square kilometers (4.27 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

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

Arctic sea ice extent for June 2017 averaged 11.06 million square kilometers (4.27 million square miles), the sixth lowest in the 1979 to 2017 satellite record. The average June 2017 extent was 900,000 square kilometers (348,000 square miles) below the 1981 to 2010 long-term average, and 460,000 square kilometers (178,000 square miles) above the previous record low set in 2016.

Continuing the pattern seen in May, sea ice extent at the end of the month remained below average in the Chukchi Sea and in the Barents Sea. Ice extent was at average levels in the Greenland Sea. Areas of low concentration ice have developed along the ice edge and coastal seas.

Based on imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the NASA Terra and Aqua satellites, summer melt ponds atop the ice cover were somewhat slow to develop. However, there is now widespread melt pond coverage in the Canadian Archipelago and the Laptev and East Siberian Seas. Data from the Advanced Microwave Scanning Radiometer 2 (AMSR-2) instrument analyzed by the University of Bremen, as well as MODIS imagery, indicate that melt ponds have also developed over the Central Arctic Ocean. Researchers in Dease Strait in Northern Canada have observed melt ponds forming about two weeks earlier than average. Melt ponds are important as they decrease the albedo or reflectivity of the ice surface, which hastens further melt.

Conditions in context Figure 2. The graph above shows Arctic sea ice extent as of July 4, 2017, along with daily ice extent data for five previous years. 2017 is shown in blue, 2016 in green, 2015 in orange, 2014 in brown, 2013 in purple, and 2012 in dashed red. 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 July 4, 2017, along with daily ice extent data for five previous years. 2017 is shown in blue, 2016 in green, 2015 in orange, 2014 in brown, 2013 in purple, and 2012 in dashed red. 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

The rate of decline in ice extent was fairly steady through the month, and the average rate of decline of 81,800 square kilometers (31,600 square miles) per day was slightly faster than the 1981 to 2010 long-term average of 56,300 square kilometers (21,700 square miles) per day. On July 2, extent was the same as that recorded in 2012 and 2016. The year 2012 ended up with the lowest September extent in the satellite record.

June air temperatures were modestly above average (1 to 3 degrees Celsius or 2 to 5 degrees Fahrenheit) in a band spanning the Arctic Ocean roughly centered along the date line and the prime meridian. This contrasts with below-average temperatures over the eastern Beaufort Sea and Canadian Arctic Archipelago and the Barents and Laptev Seas (1 to 3 degrees Celsius, 2 to 5 degrees Fahrenheit). Atmospheric pressures at sea level were below-average over the Kara Sea and extending north of the Laptev Sea.

June 2017 compared to previous years Figure 3. Monthly June ice extent for 1979 to 2017 shows a decline of 3.7 percent per decade.

Figure 3. Monthly June ice extent for 1979 to 2017 shows a decline of 3.7 percent per decade.

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

The linear rate of decline for June is 44,300 square kilometers (17,100 square miles) per year, or 3.7 percent per decade.

Ice thickness  University of Washington Pan-Arctic Ice Ocean Modeling and Assimilation System

Figure 4. This figure shows that sea ice thicknesses for May 2017 were below the 2000 to 2015 average over most of the Arctic Ocean (areas in blue) except for the region north and west of the Svalbard archipelago (areas in red).

Credit: University of Washington Pan-Arctic Ice Ocean Modeling and Assimilation System
High-resolution image

The University of Washington Seattle Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) regularly produces maps of ice thickness anomalies (departures from the long-term average). PIOMAS is based on a coupled ice-ocean model that is driven by data from an atmospheric reanalysis, and also assimilates data on observed ocean conditions and ice thickness (e.g., from NASA IceBridge). The PIOMAS analysis suggests that, relative to the average over the period 2000 to 2015, ice thickness for May 2017 (when the melt season was just beginning) was below average over most of the Arctic Ocean, especially in the Chukchi Sea and north of the Canadian Arctic Archipelago. A small region with above-average ice thickness is depicted over the Atlantic side of the Arctic north and west of the Svalbard Archipelago, and in the Greenland Sea. Starting the melt season with below-average ice thickness raises the likelihood of having especially low September ice extent.

Freezing degree days and ice thickness Figure 5. The figure shows departures from average in cumulate freezing degree days, extending from July 1 for a given year through July 1 of the next year, along with the range, 15th through 85th percentile and 30th to 70th percentile values over the base period 1981 through 2010.

Figure 5. The figure shows departures from average in cumulate freezing degree days, extending from July 1 for a given year through July 1 of the next year, along with the range, 15th through 85th percentile and 30th to 70th percentile values over the base period 1981 through 2010.

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

Cumulative Freezing Degree Days (FDD) is a simple measure of how cold it has been and for how long. Cumulative FDD is the sum of daily mean temperatures below zero from some start date. Here we start on July 1. Cumulative FDD is related to ice thickness because, on average, years with longer periods of temperatures below freezing will have more ice growth. A simple empirical model that has been used by scientists relates ice thickness to the square root of cumulative FDD.

Anomalies (departures from the average) in cumulative FDD illustrate the coldness of a given period relative to the long-term average (1981 to 2010). Figure 5 shows that most of the period from July 2016 to July 2017 was extremely mild and was milder (less cold) than both 2006 to 2007 and 2011 to 2012. September of both 2007 and 2012 ended up with very low September sea ice extent. This is consistent with below-average ice thickness seen in the PIOMAS data. Although conditions cooled in May and June, this likely had little impact on ice thickness. This is because ice in the Arctic reaches its maximum thickness earlier in the season during March or April. As noted earlier, ice retreated at a fast rate throughout June. This is likely linked to a thinner than average ice cover as seen in the PIOMAS analysis.

Sudden Antarctic sea ice decline in late 2016

A slight decrease in the rate of sea ice growth at the end of June brought Antarctic sea ice extent back to daily record lows. Sea ice extent in the Bellingshausen, eastern Amundsen, and western Ross Seas was below average.

Our post on December 2016 ice conditions highlighted a precipitous drop in Antarctic sea ice extent in the Weddell and Ross Sea sectors during September, October, and November of 2016. A recent study by John Turner and colleagues links this pattern of sea ice decline to a series of strong storms, marked by long periods of warm winds from the north. These changing weather conditions are associated with large shifts in the Southern Annual Mode index (SAM index).

Further reading

Turner, J., T. Phillips, G. J. Marshall, J. S. Hosking, J. O. Pope, T. J. Bracegirdle, and P. Deb. 2017. Unprecedented springtime retreat of Antarctic sea ice in 2016, Geophysical Research Letters, 44, doi:10.1002/2017GL073656.

Categories: Climate Science News

New product: Mesoscale Eddy Trajectory Atlas

AVISO Climate Change News - Mon, 2017-07-03 05:00
We are proud to announce the release of a new AVISO+ dataset, the "Mesoscale Eddy Trajectory Atlas"...
Categories: Climate Science News

June 2017: Eddies everywhere

AVISO Climate Change News - Mon, 2017-07-03 00:24
Eddies are ubiquitous in the ocean. They can be tracked and followed day by day for nearly 25 years.
Categories: Climate Science News

June 2017: Eddies everywhere

AVISO Climate Change News - Mon, 2017-07-03 00:24
Eddies are ubiquitous in the ocean. They can be tracked and followed day by day for nearly 25 years.
Categories: Climate Science News

19-25 June 2017 week

AVISO Climate Change News - Thu, 2017-06-29 06:48
Satellite image showcases centuries of desertification in India (Space Daily, 2017/06/21)
How phytoplankton rule the oceans (Phys.Org, 2017/06/21)
L’agence spatiale française s’attaque au réchauffement climatique (Le Monde, 2017/06/21)
Réchauffement climatique : les coraux de la mer Rouge font de la résistance (Le Quotidien, 2017/06/21)
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

Temporary unavailability of the CNES ftp server on June 29, 2017

AVISO Climate Change News - Tue, 2017-06-27 04:53
For maintenance reason, the Cnes ftp server (ftp://avisoftp.cnes.fr) will be unavailable on June...
Categories: Climate Science News

[L2P Sentinel-3A] Operational release of Sentinel-3A Value Added products

AVISO Climate Change News - Thu, 2017-06-22 06:30
All information on the front-page news.
Categories: Climate Science News

[Sentinel-3A] Operational release of Sentinel-3A Value Added products

AVISO Climate Change News - Thu, 2017-06-22 05:30
The products processed by the Sentinel-3 Level 2P/L3 Marine Altimetry Service (CNES/CLS consortium under an EUMETSAT Contract, funded by the European Union) have been delivered as a pre-operational service on the AVISO+ dissemination since December 15th, 2016 for L2P NRT, January 17th, 2017 for L2P STC (see AVISO+ web page product) and on the CMEMS Catalogue since April 19th, 2017 for L3 NRT/STC products. The Products These products are derived from the SRAL (dual-frequency Synthetic Aperture Radar Altimeter) instrument onboard Sentinel-3. The L2P products are mono-mission global products containing 1 Hz along-track corrected sea surface heights with respect to a mean sea surface, corrections and geophysical parameters. The last versions of altimetric standards are used and there is a homogenised format for all satellites. They are generated in Near-Real Time (NRT), Short-Time Critical (STC) and Non-Time-Critical (NTC) timeliness. They are distributed in the user friendly NetCDF format. The added value compared to level 2 products is:
  • The update of geophysical standards to calculate sea level anomalies, such as
    • FES2014 ocean tide
    • CNES/CLS 2015 mean sea surface referenced to a 20 year reference period
    • Filtered ionospheric correction
    • Dynamical atmospheric correction for L2P NRT products (instead of only inverted barometer height correction in the case of L2 NRT products).
  • A validity flag to remove spurious measurements
  • The distribution of L2P SLA near real time products splitted in passes (instead of 10 minute granules for L2 near real time products).
The L3 Sentinel-3A products are global along-track products that contain time, sea level anomaly and absolute dynamic topography only for valid marine surfaces. The L3 products have under-gone a multi-mission cross-calibration process versus a reference mission (Jason-3).  The dissemination Considering the success of the pre-operational service delivery, EUMETSAT decided to begin the operational phase. Beginning on June 27th, the operational phase will imply the product’s warranty in terms of accuracy, fitness for use or purpose.  Note also the dissemination of Non-Time-Critical (NTC) Sentinel-3A products
  • will begin on June 27th for L2P on AVISO+ dissemination (delivery of cycle 12 on 27th and cycles 13 to 17 during the following week)
  • will be soon disseminated for L3 by CMEMS (delivery of days 2016/12/24 to 2017/01/07)
The L2P STC/NRT products are also available through EUMETSAT dissemination via EumetCast.              
Categories: Climate Science News

12-18 June, 2017 week

AVISO Climate Change News - Thu, 2017-06-22 05:28
Coopération spatiale entre la France et les Etats-Unis Le CNES signe avec la NASA une déclaration sur Mars et l’océanographie (CNES, 2017/06/19)
Animaux & satellites : main dans la main pour observer l'océan austral (CNES, 2017/06/19)
Les insectes, la nouvelle menace en Antarctique ? (Le Point, 2017/06/18)
Impact d’une fonte accélérée de la calotte groenlandaise sur les mouvements migratoires au Sahel (INSU, 2017/06/09)
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Categories: Climate Science News

Campaign in the Lower Seine valley with GPS carpet/ Drone / Lidar

AVISO Climate Change News - Thu, 2017-06-22 03:03
The SWOT (Surface Water and Ocean Topography) mission, result of a Franco-American cooperation (CNES / NASA, with the participation of CSA and UKSA), will measure rivers, lakes and coastal and estuarine area water heights (and their spatial and temporal variations), using a new technical concept: interferometric altimetry. In 2021, after the launch, the performance of SWOT will have to be calibrated and validated thanks to the contribution of other space missions, to available in-situ data, but also by dedicated means deployed on site during the overflight of the satellite in order to have co-temporal measurements. These means must be able to be deployed in remote sites in order to have ground truths on non-instrumented sites, so they must be light.

The GPS carpet in tow of the boat, and the Lidar



Among the various means envisaged to validate the SWOT measurements, the water height information derived from the GPS measurements on a specific buoy and / or the airborne Lidar and / or drone data are the most promising. In this context, CNES has asked its partners (IRD, INSU, CNRS, CLS, etc.) to develop resources that would be implemented during the Cal / Val phase in orbit in 2021. These resources have been developed and a test on the Seine estuary will take place on 22 and 23 June 2017 in order to validate the behavior of the different vectors.

The estuary of the Seine has been retained as a test zone because of the knowledge of this area and the availability of technical means by the “Continental and Coastal Morphodynamics” UMR CNRS 6143 team (M2C). Moreover, the monitoring of the water levels along the estuary by the tide gauges of the Grand Maritime Port of Rouen will provide an independent ground truth.

The CalNaGeo GPS data carpet produced by the Technical Division of the National Institute for the Sciences of the Universe (DT-INSU) in 2016 follows similar developments in the past for the validation of oceanographic measurements for the Jason-2 and 3 missions. The new design of the GPS carpet has been adapted to the problems of continental hydrology. It will be towed by a boat, the "MONOD-ROUEN" of the M2C laboratory.

A light weight altimeter was developed by engineers of the Collecte Localisation Satellites (CLS) company early 2017 to be embarked on a drone. It uses a lidar technology. The drone should follow the boat in order to compare the altimeter performance with those of the GPS carpet. It should fly in the wake of the boat, just in front of the GPS (about 30 m behind the boat, depending on the wake). The drone flies at 30 m altitude and two people (a telepilot and an operator) are planned on the boat to ensure its control. The drone has an automatic pilot with detection and avoidance of possible obstacles (bridges, electrical wires), the pilot being present on boat to take control in case of an incident.

At the same time lidar surveys will be carried out. The LIDAR instrument of the M2C laboratory will be onboard an aircraft that will fly over the lower Seine valley during the two-day campaign. These surveys will be carried out within the framework of the COTEST project coordinated by the M2C laboratory and supported by the CNES TOSCA program.

Categories: Climate Science News

Special Issue of Remote Sensing, "Satellite Altimetry for Earth Sciences" in preparation

AVISO Climate Change News - Wed, 2017-06-21 07:41
Satellite altimetry was initially designed for measuring the ocean’s topography, with reference to an ellipsoid, and for the determination of the marine geoid. Satellite altimetry has provided extremely valuable information on ocean science (e.g., circulation surface geostrophic currents, eddy structures, wave heights, and the propagation of oceanic Kelvin and Rossby waves). With more than 25 years of observations, it is also becoming vital to climate research, providing accurate measurements of sea level variations from regional to global scales. Altimetry has also demonstrated a strong potential for geophysical, cryospheric and hydrological research, and is now commonly used for the monitoring of Arctic and Antarctic ice shet topography, and of terrestrial surface water levels.

A Special Issue of Remote Sensing, "Satellite Altimetry for Earth Sciences" is in preparation. It aims to present reviews and recent advances of general interest in the use of radar altimetry in Earth sciences. Manuscripts can be related to any aspect of radar altimetry technique or geophysical applications. Manuscript resulting from application of new altimetric technology (SAR, SARin and Ka band) and improvements expected from missions to launched in the close future (i.e., SWOT) are also encouraged.
Contributions can be either a review paper on some specific topics, or an original research in this area. For more information about the Special Issue, please see:
  • http://www.mdpi.com/journal/remotesensing/special_issues/SA
Categories: Climate Science News

[L2P Sentinel-3A] : maintenance of the L2P software on June 19th

AVISO Climate Change News - Thu, 2017-06-15 01:46
Due to a software maintenance, the delay delivery of L2P STC and NRT will be disrupted on June 19th...
Categories: Climate Science News

5-11 June, 2017 week

AVISO Climate Change News - Thu, 2017-06-15 00:48
Impact d’une fonte accélérée de la calotte groenlandaise sur les mouvements migratoires au Sahel (INSU, 2017/06/09)
Les océans, un gage pour l’avenir de la planète (Libération, 2017/06/08)
L’océan mondial, pollué par les déchets plastiques! (Natura Sciences, 2017/06/08)
Finding new homes won't help emperor penguins cope with climate change (Science Daily, 2016/06/07)
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

29 May - 5 June, 2017 week

AVISO Climate Change News - Wed, 2017-06-07 23:58
Journée mondiale de l'océan le 8 juin : "Tortue où vas-tu ?" (CNES, 2017/06/06)
Sale temps pour la planète saison 9 épisode 1 - La Bretagne, contre vents et marées (France TV, 2017/06/06
Le chef de l'ONU appelle à sauver les océans (Presse Ocean, 2017/06/05)
Face au changement climatique, l’ONU veut inciter à la création d’aires marines protégées (Le Monde, 2017/06/05)
Retour sur Terre de Thomas Pesquet le 2/06/2017 (CNES, 2017/06/02)
Le réchauffement climatique pourrait favoriser les émissions de gaz hilarant en Arctique (France TV info, 2017/06/01)
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Categories: Climate Science News

Sluggish ice retreat, except in the Chukchi Sea

NSIDC Artic Sea Ice News - Wed, 2017-06-07 11:30

After setting satellite-era record lows during winter, Arctic sea ice extent declined at a steady but somewhat sluggish pace during May. However, ice has retreated at a record rate in the Chukchi Sea, and open water extended to Barrow, Alaska. In the Southern Hemisphere, ice extent continues its seasonal expansion, but extent remains well below the long-term average for this time of year.

Overview of conditions n_extn_hires

Figure 1. Arctic sea ice extent for May 2017 was 12.74 million square kilometers (4.92 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

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

Arctic sea ice extent for May 2017 averaged 12.74 million square kilometers (4.92 million square miles), the fourth lowest in the 1979 to 2017 satellite record. This contrasts strongly with the past several months, when extent tracked at satellite-era record lows. May 2017 extent was 710,000 square kilometers (274,000 square miles) below the 1981 to 2010 long-term average, and 660,000 square kilometers (255,000 square miles) above the previous record low set in 2016. Sea ice extent remained below average in the Pacific sector of the Arctic and in the Barents Sea, but was slightly above average in Baffin Bay and Davis Strait towards the Labrador Sea. Ice extent was at average levels in the Greenland Sea. In the Chukchi Sea, extent was at record low levels for May.

Conditions in context time series graph

Figure 2a. The graph above shows Arctic sea ice extent as of June 6, 2017, along with daily ice extent data for five previous years. 2017 is shown in blue, 2016 in green, 2015 in orange, 2014 in brown, 2013 in purple, and 2012, the record low year, as a dashed line. 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

temperature difference plot

Figure 2b. The plot shows differences from average for Arctic air temperatures from May 1 to 27, 2017 at the 925 hPa level (about 2,500 feet above sea level) in degrees Celsius. Yellows and reds indicate higher than average temperatures; blues and purples indicate lower than average temperatures.

Credit: NSIDC courtesy NOAA ESRL Physical Sciences Division
High-resolution image

For the Arctic as a whole, the rate of decline in Arctic sea ice extent through May was relatively slow. The May 2017 rate of decline was 42,800 square kilometers (16,500 square miles) per day, compared to the 1981 to 2010 average of 46,990 square kilometers (18,143 square miles) per day.

Sea ice was especially slow to retreat in the Atlantic sector of the Arctic, with little change in the ice edge in Baffin Bay and Davis Strait. The ice edge expanded in the Barents and Greenland Seas until the end of May, when the ice finally started to retreat. Most of the ice retreat in May occurred within the Pacific sector, particularly within the Sea of Okhotsk, and the Bering and Chukchi Seas.

Overall, air temperatures at the 925 hPa level were 2 to 4 degrees Celsius (4 to 7 degrees Fahrenheit) below average over Eurasia and extending over the Barents, Kara and Laptev Seas, and 1 to 4 degrees Celsius (2 to 7 degrees Fahrenheit) above average over the East Siberian, Chukchi, and Beaufort Seas (Figure 2b).

May 2017 compared to previous years monthly_ice_05_NH_v2.1

Figure 3. Monthly May ice extent for 1979 to 2017 shows a decline of 2.5 percent per decade.

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

The linear rate of decline for May is 33,900 square kilometers (13,100 square miles) per year, or 2.5 percent per decade.

Low ice in the Chukchi Sea

Fig. 4a. This map shows sea ice concentration in percent coverage for the Alaska area on May 22, 2017.

Credit: NOAA National Weather Service Alaska Sea Ice Program
High-resolution image

Figure 2d.

Figure 4b. The plot shows daily May sea ice extent, in square kilometers, in the Chukchi Sea region for 2012 to 2017.

Credit: J. Stroeve/ NSIDC
High-resolution image

Figure 4c. The graph shows cumulative temperature departures from average for each year, in degrees Fahrenheit, for Barrow, Alaska from 1921 to May 2017.

Credit: Blake Moore, Alaska Climate Research Center
High-resolution image

Notably, sea ice within the Chukchi Sea retreated earlier than seen at any other time in the satellite data record. By the third week in May, open water extended all the way to Barrow, Alaska (Figure 4a). Figure 4b shows daily ice extent for May from 2012 onward in the Chuckchi Sea. The rapid retreat in 2017 stands out. A recent report by the National Oceanographic Atmospheric Administration (NOAA) indicates that the amount of open water north of 68o N at this time of year is unprecedented.

Part of the explanation for earlier open water formation in the Chukchi Sea is the unusually high air temperatures in that region during the previous winter. It is instructive to look at the cumulative temperature departure from average for Barrow, Alaska (Figure 4c). From 1921 until about 1989, conditions at Barrow actually got progressively cooler. However, since that time, temperatures have markedly increased.

Consistent with warm conditions, extensive open water in the Chukchi Sea region persisted into December; the delayed ice growth potentially led to thinner ice than usual in spring. In addition, strong winds from the north occurred for a few days at the end of March and early April, pushing ice southward in the Bering Sea, breaking up the ice in the Chukchi Sea, and even flushing some ice out through the Bering Strait. At the same time further east near Barrow, winds helped to push ice away from the coast. Based on recent work by NSIDC and the University of Washington, the pattern of spring sea ice retreat also suggests a role of strong oceanic heat inflow to the Chukchi Sea via Bering Strait.

Impacts of low Chukchi Sea on Alaskan communities

The ARCUS Sea Ice for Walrus Outlook (SIWO) provides weekly reports from April to June on sea ice conditions in the northern Bering Sea and southern Chukchi Sea regions of Alaska to support subsistence hunters and coastal communities. While the reports are not intended for operational planning or navigation, they provide detailed ice and weather observations for the region, some made by local community members, others from operational forecast centers. The most recent update on June 2nd discusses the continued rapid deterioration of sea ice between Wales and Shishmaref, Alaska. Nearly ice-free conditions around Nome, Alaska reflect warmer waters from the Bering Sea moving into the region. Some sea ice remains attached to the shore along the northeast coast of St. Lawrence Island, but the Bering Sea is essentially ice free. Prime walrus hunting for these communities is typically in May. However, when the ice retreats early, the walrus go with it, reducing the number of walrus the local communities can hunt.

Sea ice data and analysis tools

NSIDC has released a new set of tools for sea ice analysis and visualization. In addition to Charctic, our interactive sea ice extent graph, the new Sea Ice Data and Analysis Tools page provides access to Arctic and Antarctic sea ice data organized in seven different data workbooks, updated daily or monthly. Animations of September Arctic and Antarctic month average sea ice and concentrations may also be accessed from this page.

Further Reading

Serreze, M.C., Crawford, A., Stroeve, J. C., Barrett, A.P. and Woodgate, R.A. 2016.  Variability, trends and predictability of seasonal sea ice retreat and advance in the Chukchi Sea.  Journal of Geophysical Research, 121, doi:10.1002/2016JC011977.

 

 

Categories: Climate Science News

22-28 May, 2017 week

AVISO Climate Change News - Thu, 2017-06-01 06:02
La réserve mondiale de graines est menacée par le réchauffement climatique (Les Echos, 2017/05/30)
Ocean CleanUp, le projet fou de nettoyer les océans débutera en 2018 (UP Mag, 2017/05/29)
NASA Discovers a New Mode of Ice Loss in Greenland (Space daily, 2017/05/26)
À cause du réchauffement climatique, la végétation s'empare de l'Antarctique (Konbini, 2017/05/25)
Scientists say the pace of sea level rise has nearly tripled since 1990 (The Washington Post, 2017/05/22)
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
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