Climate Science News

11-17 September 2017 week

AVISO Climate Change News - Thu, 2017-09-21 07:03
Vers le début d'une période La Niña (Meteo Paris, 2017/09/16) Recul des glaciers des Alpes face au réchauffement climatique (Meteo Paris, 2017/09/15) Ouragans géants et réchauffement climatique : a-t-on encore besoin de preuves ? (Sud Ouest, 2017/09/12) Climat: un réchauffement d'un degré peut bouleverser l'écosystème antarctique (Tahiti infos, 2017/08/31 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 sea ice at minimum extent

NSIDC Artic Sea Ice News - Tue, 2017-09-19 12:00

On September 13, Arctic sea ice appears to have reached its seasonal minimum extent of 4.64 million square kilometers (1.79 million square miles), the eighth lowest in the 38-year satellite record. The overall rate of ice loss this summer was slowed by a persistent pattern of low sea level pressure focused over the central Arctic Ocean.

Please note that this is a preliminary announcement. Changing winds or late-season melt could still reduce the Arctic ice extent, as happened in 2005 and 2010. NSIDC scientists will release a full analysis of the Arctic melt season, and discuss the Antarctic winter sea ice growth, in early October.

Overview of conditions Figure 1. Arctic sea ice extent for September 13, 2017 was 4.64 million square kilometers (1.79 million square miles), the eighth lowest in the satellite record. The orange line shows the 1981 to 2010 average extent for that day.

Figure 1. Arctic sea ice extent for September 13, 2017 was 4.64 million square kilometers (1.79 million square miles), the eighth lowest in the satellite record. The orange line shows the 1981 to 2010 average extent for that day. Sea Ice Index data. About the data

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

On September 13, 2017, sea ice extent reached an annual minimum of 4.64 million square kilometers (1.79 million square miles). This was 1.58 million square kilometers (610,000 square miles) below the 1981 to 2010 median extent for the same day, and 1.25 million square kilometers (483,000 square miles) and 500,000 square kilometers (193,000 square miles) above the 2012 and 2016 extents for the same day, respectively.

During the first two weeks of September, the ice edge continued to retreat in the Chukchi, East Siberian, and Kara Seas, whereas it slightly expanded in the Beaufort and Laptev Seas. The ice edge remains far to the north of its average position in the Chukchi Sea. The Northern Sea Route is largely open; Amundsen’s Northwest Passage (the southern route) has up to 50 percent ice cover in some places, though as noted in our last post, ships have successfully navigated through the southern route with icebreaker assistance. The northern Northwest Passage route, entered from the west via McClure Strait, remains choked by consolidated, thick, multi-year ice.

Conditions in context  National Snow and Ice Data Center|High-resolution image

Figure 2a. The graph above shows Arctic sea ice extent as of September 17, 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 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 image shows average sea level pressure over the Arctic Ocean for the period of September 1 to 16, 2017.

Figure 2b. This image shows average sea level pressure over the Arctic Ocean for the period of September 1 to 16, 2017.

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

The date of the minimum ice extent for 2017 was two days earlier than the average minimum date of September 15. The earliest annual sea ice minimum in the satellite record occurred on September 5 in the years 1980 and 1987, and the latest on September 23, 1997.

As is typical of this time of year when the solar radiation received at the surface is quickly waning, the rate of ice loss slowed during the first half of September. Ice retreat from the beginning of September until the minimum averaged 25,300 square kilometers (9,770 square miles) per day, slightly faster than the 1981 to 2010 average for the same period of 22,800 square kilometers (8,800 square miles) per day.

The pattern of low sea level pressure over the central Arctic Ocean that persisted through this summer and inhibited summer ice loss has broken down. For the first half of September, the pattern has instead been one of above-average sea level pressure centered over the Barents Sea and extending across part of the Arctic Ocean (Figure 2b). Corresponding air temperatures at the 925 hPa level (about 2,500 feet above sea level) were above average over most of the Arctic Ocean. Above average temperatures over some parts of the Arctic Ocean likely reflect heat transfer to the atmosphere from areas of open water, hence cooling the ocean.

Ten lowest minimum Arctic sea ice extents (satellite record, 1979 to present) Table 1.  Ten lowest minimum Arctic sea ice extents (satellite record, 1979 to present)  RANK  YEAR MINIMUM ICE EXTENT DATE IN MILLIONS OF SQUARE KILOMETERS IN MILLIONS OF SQUARE MILES 1 2012 3.39 1.31 Sept. 17 2 2016
2007 4.14
4.15 1.60
1.60 Sept. 10
Sept. 18 4 2011 4.34 1.67 Sept. 11 5 2015 4.43 1.71 Sept. 9 6 2008 4.59 1.77 Sept. 19 7 2010 4.62 1.78 Sept. 21 8 2017 4.64 1.79 Sept. 13 9 2014 5.03 1.94 Sept. 17 10 2013 5.05 1.94 Sept. 13 Effects of seasonal ice retreat in the Beaufort and Chukchi Seas  Courtesy R. Thoman/National Weather Service Alaska Region Environmental and Scientific Services Division| High-resolution image

Figure 3. This chart shows combined sea ice extent in the Chukchi and Beaufort Seas from August 15 to October 7 for the years 2006 to 2016, including the extent so far for 2017. The colored dots show the day the minimum occurred in the region during a specific year. Data are from the Multisensor Analyzed Sea Ice Extent (MASIE) product.

Credit: Courtesy R. Thoman/National Weather Service Alaska Region Environmental and Scientific Services Division
High-resolution image

According to a report by the Alaska Dispatch News, the lack of sea ice forced walruses to the shore of Alaska’s Chukchi Sea earlier than any time on record. The lack of ice also forced biologists monitoring Alaska polar bears to cut short their spring field season. In turn, the NOAA National Weather Service Climate Prediction Center states that because of the extensive open water, air temperatures over the Beaufort and Chukchi Seas and along the North Slope of Alaska will likely be far above average through this autumn.

Rick Thoman of the National Weather Service in Fairbanks, Alaska compiled an analysis of the combined Chukchi and Beaufort Seas ice extent from the Multisensor Analyzed Sea Ice Extent (MASIE) product. MASIE is based on operational ice analyses at the U.S. National Ice Center and is archived and distributed by NSIDC. It shows that 2017 tracked near record lows for the region through much of the summer, but after mid-August the pace of ice loss slowed relative to recent years. While it appears unlikely that extent in the Beaufort and Chukchi Seas will reach a record low (set in 2012), it will still be among the four or five lowest in the MASIE record (Figure 3). Note that the range in dates for the minimum extent in the region differs from those for the Arctic as a whole and tend to be later, ranging from September 10 in 2015 to September 25 in 2007 and 2008. In other words, the Chukchi and Beaufort Seas may continue to lose ice even after the overall Arctic minimum extent is reached. From the passive microwave data (not shown), the Chukchi/Beaufort minimum has occurred as early as August 14 in 1980 to as late as October 2 in 1991.

Antarctic sea ice approaching winter maximum Figure 4a. The graph above shows Antarctic sea ice extent as of September 17, 2017, along with daily ice extent data for four previous years.

Figure 4a. The graph above shows Antarctic sea ice extent as of September 17, 2017, along with daily ice extent data for four previous years. 2017 is shown in blue, 2016 in green, 2015 in orange, 2014 in dashed brown, 2013 in purple. 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

 This map shows Antarctic sea ice concentration on September 16, 2017. Note the Maud Rise polynya at the top of the image. Data are from the Advanced Microwave Scannig Radiometer 2 (AMSR2).

Figure 4b: This map shows Antarctic sea ice concentration on September 16, 2017. Note the Maud Rise polynya at the top of the image. Data are from the Advanced Microwave Scannig Radiometer 2 (AMSR2).

Credit: G. Heygster, C. Melsheimer, J. Notholt/Institute of Environmental Physics, University of Bremen
High-resolution image

Following the record low summer minimum extent in March, Antarctic sea ice extent is now nearing its winter maximum. This will likely be among the five lowest winter extents in the satellite era. As of mid-September, Antarctic ice extent was just under 18 million square kilometers (7 million square miles), which is approximately half a million square kilometers below the 1981 to 2010 median ice extent. Sea ice is below the typical extent in the Indian Ocean sector, the northern Ross Sea, and the northern Weddell Sea, and slightly above average extent in the northern Amundsen Sea region.

Between September 9 and September 17 of 2016, Antarctic sea ice lost nearly 100,000 square kilometers (38,600 square miles) of sea ice per day, and sea ice extent moved from near-average to a near-record-daily low by September 17. For the next 12 months Antarctic sea ice remained extremely low. Record low ice extents were set every day from November 5, 2016 to April 10, 2017. Extents averaged for November and December of 2016 were five standard deviations below average. No other 12-month period (September 2016 to August 2017) has had such persistently low sea ice extent. The year 1986 had near-record low extent for the winter period (June to December), but there were periods of near-average and even above-average ice extent earlier in the calendar year.

Beginning around September 2, an opening in the Antarctic sea ice pack formed north of Dronning Maud Land in the easternmost Weddell Sea (near 64°S, 5°E). By mid-September, this opening, or polynya, had grown to about 12,000 square kilometers (4,600 square miles). This feature has been observed intermittently in the Antarctic pack ice since the first satellite data became available in the 1970s. In 1974, 1975, and 1976, the polynya was much larger, averaging 250,000 square kilometers (96,500 square miles). It was absent for many years in the 1980s and 1990s. In recent years the feature has been observed sporadically and has been much smaller.

The polynya is formed when ocean currents uplift deep warm ocean water to the surface where it melts the sea ice. An oceanic plateau called the Maud Rise is responsible for forcing the vertical movement of the water. The persistence of certain atmospheric patterns, such as the southern annular mode, or SAM, is thought to play a role in driving the deep water layer against the Maud Rise.

2017 Arctic sea ice minimum animation

See the NASA animation of Arctic sea ice extent from the beginning of the melt season on March 8, 2017 to the day of the annual minimum on September 13, 2017 here.

Further reading

Gordon, A.L., Visbeck, M. and Comiso, J.C. 2007. A possible link between the Weddell Polynya and the Southern Annular Mode. Journal of Climate20(11), 2558-2571. doi:10.1175/JCLI4046.1

Holland, D.M. 2001. Explaining the Weddell Polynya–a large ocean eddy shed at Maud Rise. Science, 292(5522), 1697-1700. doi:10.1126/science.1059322.

Erratum

In Table 1, years 2014 and 2013 were both ranked ninth lowest. They should have been ninth and tenth respectively. This has been corrected.

 

 

Categories: Climate Science News

[Jason-2] : Satellite in Safe Hold Mode since 14 September 2017 07:13:04 UTC

AVISO Climate Change News - Thu, 2017-09-14 17:00
After 2 months of smooth operation on the Long Repeat Orbit (LRO) the Jason-2 spacecraft entered safe hold mode yesterday (Thursday, September 14th) at 07:13:04 UTC, immediately interrupting its measurements. The OPS team at NOAA and CNES applied immediately necessary procedures and the satellite is currently in a safe and stable Sun-pointing configuration. First investigations show that Gyrometer 1 was blocked, triggering the reconfiguration to SHM. The gyros temperature increase during period where Beta angle is high remains a concern.  All other equipments were OK at the time of the reconfiguration.
The 4 partners operational teams are working closely to support current and future operations. The mission will resume as soon as technically possible. T. Guinle & C. Marechal, CNES
Categories: Climate Science News

Hurricane Irma seen by remote sensing satellites

AVISO Climate Change News - Thu, 2017-09-14 06:32
Hurricane Irma seen by remote sensing satellites : wind speed from Sentinel-1, wave heights from...
Categories: Climate Science News

4-11 September, 2017 week

AVISO Climate Change News - Thu, 2017-09-14 05:18
Au Cnes on étudie l'évolution de l'océan et la prédiction des cyclones (La Dépêche, 2017/09/08)
Les coraux de l'océan Pacifique subissent un blanchissement massif (RTL, 2017/09/07)
Evidence of sea level 'fingerprints'  (NASA, 2017/09/07)
Réchauffement climatique : l'expédition Tara alerte sur le blanchissement massif des coraux (France Info, 2017/09/06)
Les grizzlys sont-ils en train de devenir « végétariens » sous l’effet du réchauffement climatique ? (Science Post, 2017/09/04)
Climat : "On aura des étés de plus en plus chauds, surtout si rien n'est fait contre le réchauffement" (France TV info, 2017/09/01)
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

September 2017: 25 years, and many more to come

AVISO Climate Change News - Mon, 2017-09-11 01:10
Topex/Poseidon was launched 25 years ago: the starting point of a success story, still ongoing.
Categories: Climate Science News

August 20 - Septembre 3, 2017 weeks

AVISO Climate Change News - Thu, 2017-09-07 06:42
Des ouragans plus puissants à cause du réchauffement climatique ? (Science Post, 2017/01/09)
Le réchauffement climatique pourrait réduire la taille du poisson (Le marin, 2018/08/29)
Ouragans : la faute du réchauffement climatique ? (Sciences Avenir, 2018/08/28)
Le réchauffement climatique rend l’est des Etats-Unis extrêmement vulnérable (le Monde, 2018/08/28)
Changement climatique : des cyclones plus intenses, mais pas plus fréquents (Sud Ouest, 2017/08/27)
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

The end of summer nears

NSIDC Artic Sea Ice News - Wed, 2017-09-06 14:00

Average sea ice extent for August 2017 ended up third lowest in the satellite record. Ice loss rates through August were variable, but slower overall than in recent years. Extensive areas of low concentration ice cover (40 to 70 percent) are still present across much of the Eurasian side of the Arctic Ocean.

Overview of conditions Figure 1. Arctic sea ice extent for August 2017 was 5.51 million square kilometers (2.13 million square miles). The magenta line shows the 1981 to 2010 average extent for that month.

Figure 1. Arctic sea ice extent for August 2017 was 5.51 million square kilometers (2.13 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 August 2017 averaged 5.51 million square kilometers (2.13 million square miles), the third lowest August in the 1979 to 2017 satellite record. This was 1.77 million square kilometers (683,000 square miles) below the 1981 to 2010 average, and 800,000 square kilometers (309,000 square miles) above the record low August set in 2012.

Ice retreat was most pronounced in the western Beaufort Sea. A large region in the Beaufort Sea and East Siberian Sea has low concentration sea ice (40 to 70 percent). Patches of low concentration sea ice and some open water northeast of the Taymyr Peninsula are also present.

While a record low minimum extent in the Arctic is unlikely this year, the ice edge in the Beaufort Sea is extremely far north. In parts of this region, the ice edge is farther north than at any time since the satellite record began in 1979. This highlights the pronounced regional variability in ice conditions from year to year. A couple of the models that contribute to the Sea Ice Prediction Network Sea Ice Outlooks forecasted significantly less ice in the Beaufort Sea in July this year compared to average conditions.

Conditions in context  National Snow and Ice Data Center|High-resolution image

Figure 2a. The graph above shows Arctic sea ice extent as of September 5, 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 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 image shows average sea level pressure over the Arctic for the month of August 2017.

Figure 2b. This image shows average sea level pressure in millibars over the Arctic for the month of August 2017.

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

Over the month, low atmospheric pressure prevailed over much of the Arctic Ocean, centered over the northern Beaufort Sea (Figure 2b). This helped to push the ice edge in that region northward. Summers dominated by low pressure, as has been the case for 2017, are generally not conducive to ice loss. Low pressure brings generally cool conditions and the cyclonic (counterclockwise) winds help spread the ice over a larger area. However, it appears that strong individual storms, such as the intense summer cyclone of 2012, may break up the ice and mix warm ocean waters into the sea ice, contributing to ice loss.

August 2017 compared to previous years Figure 3. Monthly August ice extent for 1979 to 2017 shows a decline of 10.48 percent per decade.

Figure 3. Monthly August ice extent for 1979 to 2017 shows a decline of 10.5 percent per decade.

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

The linear rate of decline for August 2017 is 76,300 square kilometers (29,000 square miles) per year, or 10.5 percent per decade. The daily ice loss rate was variable over the month, slowing considerably during the middle and end of the month. Overall, the loss rate during August 2017 was slower than recent years, particularly 2012, when extent decreased rapidly during the first half of the month after a the passage of a strong storm.

A report on the Northwest Passage Figure 4a. This shows the route of the Crystal Serenity (yellow line) overlaid on a map of ice cover in the Northwest Passage region.

Figure 4a. This shows the route of the Crystal Serenity (yellow line) overlaid on a map of ice cover in the Northwest Passage region for September 5, 2017.

Credit: Canadian Ice Service Daily and Regional Ice Charts
High-resolution image

 Environment and Climate Change Canada|

Figure 4b. This chart shows sea ice area in the Parry Channel region of the Canadian Archipelago from April 30 to November 26 for the years 2010 (magenta), 2011 (dashed green), 2014 (blue green), 2016 (purple), and 2017 (red). The black line shows the 1981 to 2010 long-term average.

Credit: Environment and Climate Change Canada
High-resolution image

 C. Haas|High-resolution image

Figure 4c. This photo shows sea ice conditions along the route of the Crystal Serenity.

Credit: C. Haas, York University
High-resolution image

Of particular interest each year are the ice conditions in the Northwest Passage. Our colleagues, Stephen Howell and Michael Brady of the Climate Research Division at Environment and Climate Change Canada, provided a status update based on sea ice charts produced by the Canadian Ice Service.

As of August 28, the northern route of the Northwest Passage was blocked by high concentration ice at the western (Parry Channel) entrance (Figure 4a), but overall extent in the passage is still tracking below the 1981 to 2010 average (Figure 4b). The record low seasonal extent in the northern route was in 2011. Low ice years in the northern route are typically the result of early breakup associated with above-average sea level pressure over the Beaufort Sea and Canadian Basin; this pattern tends to displace ice away from the western entrance. Conversely, low sea level pressure over the Beaufort Sea, such as seen this summer, packs ice up against the western entrance. It is unlikely the northern route will open in this year. Ice concentrations are much milder in the southern route (Amundsen’s Passage) but some ice still blocks the eastern part of that passage. This is primarily first year ice that may melt out in the coming weeks. During low ice summers, thick multi-year ice originating from the Arctic Ocean is typically advected into the channels of both the northern and southern routes, representing a significant hazard to transiting ships.

The Crystal Serenity luxury cruise ship, accompanied by an icebreaker, is attempting a repeat of last year’s cruise through the passage. Professor Christian Haas of York University in Toronto, who is providing sea ice expertise on board the ship, sent us a first-hand account of conditions:

“On August 29 and 30, we encountered some high concentration ice, up to 90 percent, just before entering Bellot Strait. The ice was mostly first-year ice, with about 30 percent multi-year ice having thicknesses greater than 2 meters (6.5 feet). Due to the relatively severe ice conditions, we were supported by the Canadian Coast Guard icebreaker Des Groseilliers, which helped clear some ice on our route into Franklin Strait. Overall, ice conditions have been much more severe than during the first transit of the Northwest Passage of the Crystal Serenity in 2016, when no ice was encountered at all.”

Figure 4c shows conditions along the route. The ship’s latest position is available at the cruise’s blog.

Also of note, the Finnish icebreaker MSV Nordica, set a new record for the earliest transit through the passage on July 29, traveling 10,000 kilometers (6,000 miles) in 24 days.

On the other side of the Arctic, the Northeast Passage (or Northern Sea Route) along the coast of Siberia appears largely open as shown by NSIDC data, though operational analysis by the U.S. National Ice Center shows some remaining ice along the coast of the Taymyr Peninsula.

A radar view of the Arctic Figure 5. Composite image from Sentinel-1 SAR imagery for August 29, 2017 overlaid with passive microwave sea ice concentration from the JAXA AMSR2 sensor. Red/pink shades indicate regions of high (>90 percent) concentration, while green/brown shades indicate lower (~30-70 percent) concentration. Open water is in black to blue/gray shades. Open water is evident between floes of ice in the low concentration regions.

Figure 5. This figure shows a composite image from Sentinel-1 SAR imagery for August 29, 2017 overlaid with passive microwave sea ice concentration from the Japan Aerospace Exploration Agency (JAXA) Advanced Microwave Scanning Radiometer 2 (AMSR2) sensor. Red/pink shades indicate regions of high (more than 90 percent) concentration, while green/brown shades indicate lower (~30-70 percent) concentration. Open water is in black to blue/gray shades. Open water is evident between floes of ice in the low concentration regions.

Credit: Image from Danish Technical University, courtesy Leif Pedersen and Roberto Saldo
High-resolution image

The passive microwave satellite imagery that NSIDC uses is ideal for showing long-term changes in sea ice because it provides a continuous record extending back to 1979. Its drawback is low spatial resolution. Satellite radar images, though more limited in spatial and temporal coverage, provide a more detailed picture of the ice cover. A daily composite of images from the European Space Agency’s Sentinel-1 satellite, with a synthetic aperture radar (SAR) instrument, shows substantial open water well within the ice pack, north of 80° N latitude.

Categories: Climate Science News

August 2017: Currents & waves

AVISO Climate Change News - Wed, 2017-09-06 02:20
Currents can influence waves. With the coming of SWOT high-resolution data, it is important to...
Categories: Climate Science News

[JASON-3] Expected telemetry outage during next JA3 DEM upload

AVISO Climate Change News - Wed, 2017-08-30 00:53
A DEM (Digital Earth Model) update operation is currently ongoing on Jason 3. This DEM update will enable, once finished, measurements on 4400 new river targets and ~450 new lakes. Today, Wednesday 30th of August, the most complex part of that upload will take place between 14:00UTC and 14:20UTC. During that timeframe, a telemetry outage of less than 10 minutes should be expected. After that operation, Jason-3 telemetry will already benefit the updates of the DEM.  A last operation will take place tomorrow, Thursday 31st of August, around 14:30UTC, with an expected telemetry outage of approximately 3 minutes.
Categories: Climate Science News

Cooler conditions, slower melt

NSIDC Artic Sea Ice News - Mon, 2017-08-21 12:57

A cooler than average first half of the month kept ice loss at a sluggish pace with little change in the ice edge within the eastern Arctic. Retreat was mostly confined to the western Beaufort and northern Chukchi seas. Ice extent remains above that seen in 2012 and 2007.

Overview of conditions

Figure 1. Arctic sea ice extent for August 21, 2017 was 5.27 million square kilometers (2.03 million square miles). The orange line shows the 1981 to 2010 average extent for that day. Sea Ice Index data. About the data

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

On August 21, 2017, ice extent stood at 5.27 million square kilometers (2.03 million square miles). This was 1.82 million square kilometers (703,000 square miles) below the 1981 to 2010 median extent for the same day, and 804,000 square kilometers (310,000 square miles) and 221,000 square kilometers (85,000 square miles) above the 2012 and 2007 extents for the same day, respectively. The ice edge remained nearly constant through the first half of the month in the Barents and Kara Seas, and retreated only slightly within the East Greenland Sea. The ice edge also remained stable in the Laptev and East Siberian Seas through the first half of the month. Ice retreat occurred primarily within the Chukchi and western Beaufort Seas as well as near the New Siberian Islands. Some ice continues to block the Northern Sea Route near Severnaya Zemlya. Both McClure Strait and the Amundsen Gulf routes within the Northwest Passage remain blocked by ice. On August 17, the Russian nuclear powered icebreaker 50 let pobedy reached the North Pole in just 79 hours, the fastest time yet.

Conditions in context

Figure 2. The graph above shows Arctic sea ice extent as of August 21, 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 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

Ice retreat from August 1 to August 21 averaged 73,000 square kilometers (28,000 square miles) per day. This was faster than the 1981 to 2010 average rates of ice loss of 57,300 square kilometers (22,000 square miles) per day, but slower than in 2012, which exhibited the fastest rate of ice loss compared to any other August in the passive microwave satellite data record. Normally the rate of ice retreat slows in August as the sun starts to dip lower in the sky. The rate of ice loss was more rapid at the beginning of August, slowing down considerably starting on August 17.

Air temperatures the first two weeks of August were 1 to 3 degrees Celsius (2 to 5 degrees Fahrenheit) cooler than the 1981 to 2010 average throughout the Arctic Ocean and over Greenland and the North Atlantic. The lowest air temperatures relative to the long-term average were found in coastal regions of the Kara and Barents Seas, continuing the pattern seen throughout much of this summer. Cooler than average conditions within the Central Arctic were a result of persistent cold-core cyclones. These cyclones have not been as large or as strong as the Great Arctic Cyclones of 2012 and 2016, despite the central pressure of one of these systems dropping down to 974 hPa on August 10. In addition, these cyclones are located closer towards the pole within the consolidated ice pack, where they are less likely to cause significant ice loss, as did the 2012 Great Arctic Cyclone in the Chukchi Sea.

While air temperatures start to drop in August, ice melt continues through the month as heat gained in the ocean mixed layer during summer continues to melt the ice from below and from the sides. Sea surface temperatures have been up to 5 degrees Celsius (9 degrees Fahrenheit) above average near the coastal regions, but generally near average or slightly below average along the ice edge in the Beaufort and Chukchi Seas.

NASA Operation IceBridge conducts summer flights

Figure 3. This photograph, taken during NASA Operation IceBridge on July 25, 2017, shows melt ponds on the surface of Arctic sea ice.

Credit: Eric Fraim/NASA
High-resolution image

NASA’s Operation IceBridge (OIB) airborne campaign flew several missions over the Greenland ice sheet this summer to study changes in Greenland outlet glaciers, as well as to observe sea ice. A recent mission collected laser altimeter data to investigate sea ice thickness changes resulting from the piling up of sea ice (or convergence) as ice motion pushes the ice up against the coast. Flights were completed on July 17 and July 25. High-resolution visible imagery collected on the flights also provides close-up looks of melt pond development.

Influence of warm Pacific water

Figure 4. This plot shows measurements of sea surface temperature from drifting buoys, along with satellite-derived sea surface temperature from NOAA and ice concentration from NSIDC for August 6, 2017. Buoy positions as of August 6 are indicated with circles. A gray dot indicates that the buoy is reporting a temperature value outside the range of -2 to 10 degrees Celsius. Red, orange, and yellow indicate higher temperatures, while blues and purples indicate lower temperatures. Whites indicate higher sea ice concentration, and grays indicate lower concentration.

Credit: University of Washington Polar Science Center
High-resolution image

This May, sea ice in the Chukchi Sea was at a record low for the satellite data record. The early retreat of ice in this region may partially be a result of unusually warm ocean temperatures in the region. As reported by Rebecca Woodgate of the University of Washington, Seattle, the Research Vessel Norseman II spent eight days in the Bering Strait and southern Chukchi Sea region to recover oceanographic moorings and whale acoustic instruments, in addition to deploying new instruments. The mooring data indicated early arrival of warm water in the strait, about a month earlier than the average, resulting in June ocean temperatures that were 3 degrees Celsius (5 degrees Fahrenheit) above average. Early intrusion of warm water in the Bering Strait back in May helped to melt sea ice from below, and may have been one of the factors for early development of open water in the region.

Arctic air temperatures and the Paris Climate Accord target

Figure 5. The bar graph, top, shows the Berkeley Earth evaluation of the ten warmest years since 1979 in the Arctic north of 80°N; the plot, middle, shows Arctic average temperatures for the period 1900 to 2016, relative to a 1951 to 1980 reference period; bottom, a map of Arctic temperature differences, in degrees Celsius, for the 2012 to 2016 period (5 years) relative to a 1981 to 2010 reference period.

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

Our past reports, and many other sources, have noted that the Arctic region is warming faster than the rest of the globe. This warming has accelerated in recent years, particularly since 2005. The ten warmest years on record for the Arctic are within the past twelve years, and 2016 was by far the warmest in the record since 1900. These observations are supported by both NOAA National Centers for Environmental Prediction (NCEP) reanalysis climate data, and by our colleagues at Berkeley Earth. Berkeley Earth is an independent climate fact- and analysis-checking group dedicated to an objective evaluation of the main claims and data sets used to support climate trends and forecasts.

One of the major statements of the recent Paris Climate Accord, dealing with heat-trapping ga reductions, is a target to hold the increase in the global average temperature to well below 2 degrees Celsius (3.6 degrees Fahrenheit) above the pre-industrial average. While this reference for the increase (pre-industrial average) is somewhat ambiguous, using reference average temperatures of either 1951 to 1980 or 1980 to 2010 for the Arctic shows that much of the area north of 80°N is already above this guideline over the past five years (2012 to 2016). As the Arctic will likely continue to warm above 2 degrees Celsius, other areas will need to warm less than that if the threshold is not to be exceeded. In general, land warms about 30 percent faster than oceans in the models, so in a global-average 2 degree Celsius warmer world, much of the global land area would have warmed more than 2 degrees Celsius.

The annual average air temperature for 2016 for the Arctic north of 80°N was more than 3.5 degrees Celsius (6.3 degrees Fahrenheit) above the 1951 to 1980 reference period, the warmest year yet, and most years during the past decade had annual average temperatures between 2 to  2.5 degrees Celsius (3.6 to 4.5 degrees Fahrenheit) above the reference period. Geographically, the NOAA NCEP reanalysis shows that recent warming is primarily located over the Arctic Ocean, and smaller warming trends are seen in the circum-Arctic land areas.

Further reading

Hawkins, E., Ortega, P., Suckling, E., Schurer, A., Hegerl, G., Jones, P., Joshi, M., Osborn, T.J., Masson-Delmotte, V., Mignot, J. and Thorne, P. 2017. Estimating changes in global temperature since the pre-industrial period. Bulletin of the American Meteorological Society, doi:10.1175/BAMS-D-16-0007.1.

Categories: Climate Science News

Which August will we get?

NSIDC Artic Sea Ice News - Thu, 2017-08-03 12:30

Average sea ice extent for July 2017 ended up fifth lowest in the satellite record. This reflects weather conditions that were not favorable for ice loss. It will be important to monitor August 2017, as weather conditions and storm events during this month have been closely related to the seasonal minimum sea ice extent in the recent years.

Overview of conditions Figure 1. Arctic sea ice extent for July 2017 was 8.2 million square kilometers (3.2 million square miles). The magenta line shows the 1981 to 2010 average extent for that month.

Figure 1. Arctic sea ice extent for July 2017 was 8.21 million square kilometers (3.17 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 July 2017 averaged 8.21 million square kilometers (3.17 million square miles), the fifth lowest July in the 1979 to 2017 satellite record. The average July extent was 1.58 million square kilometers (610,000 square miles) below the 1981 to 2010 long-term average, and 270,000 square kilometers (104,000 square miles) above the previous record low July set in 2011. July 2017 tracked 250,000 square kilometers (97,000 square miles) above the July 2012 extent and 20,000 square kilometers (7,700 square miles) above the July 2007 extent.

Ice extent was lower than average over most of the Arctic, particularly on the Pacific side where the ice retreated throughout July in the Beaufort, Chukchi, and East Siberian Seas. In the eastern Beaufort Sea on the other hand, extent slightly expanded during July. This may relate to the cyclonic (counterclockwise) pattern of winds favoring the drift of sea ice into the region.

Conditions in context Figure 2a. The graph above shows Arctic sea ice extent as of August 1, 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 dotted 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 2a. The graph above shows Arctic sea ice extent as of August 1, 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 dotted 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

Figure 2b. The plot shows differences from average for Arctic air temperatures 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.

Figure 2b. The plot shows Arctic air temperature differences relative to the 1981 to 2010 long-term average 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 Earth System Research Laboratory Physical Sciences Division
High-resolution image

The air temperature pattern over the Arctic was rather complex in July. Temperatures were above average over Alaska, extending into the Beaufort Sea (1 to 2 degrees Celsius or 2 to 4 degrees Fahrenheit) and the Kara and Barents Seas (2 to 4 degrees Celsius or 4 to 7 degrees Fahrenheit). By contrast, temperatures were 2 to 4 degrees Celsius (4 to 7 degrees Fahrenheit) lower than average over Greenland, East Central Siberia, and the Laptev Sea. The air pressure pattern at sea level was dominated by a broad area of low pressure covering most of the Arctic Ocean, with the lowest pressures centered just south of the Pole and west of the date line. Another locus of low pressure was centered over the southern Canadian Arctic Archipelago.

A cyclonic circulation over the central Arctic Ocean is generally viewed as unfavorable for rapid summer ice loss. Ice loss rates tend to be higher when the central Arctic Ocean is dominated by high pressure during summer.

July 2017 compared to previous years Figure 3. Monthly July ice extent for 1979 to 2017 shows a decline of 7.4 percent per decade.

Figure 3. Monthly July ice extent for 1979 to 2017 shows a decline of 7.4 percent per decade.

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

The linear rate of decline for July 2017 was 72,500 square kilometers (28,000 square miles) per year, or 7.4 percent per decade.

Onset of surface melt Figure 4. The plot on the left shows melt onset dates in day of the year (left). Warm colors indicate early melt onset and cooler colors indicate a later melt onset. The plot on the right shows departures from the average melt onset dates in number of days. Warmer colors indicate later than average melt onset and cooler colors indicate later than average melt onset.

Figure 4. The plot on the left shows the average melt onset dates in day of the year. Warm colors indicate early melt onset and cooler colors indicate a later melt onset. The plot on the right shows departures from the average melt onset dates in number of days. Warmer colors indicate later than average melt onset and cooler colors indicate earlier than average melt onset.

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

One important influence on the pace of summer sea ice retreat is the timing of the onset of surface melt. Surface melt drops the albedo, allowing more solar radiation to be absorbed at the surface. The onset of surface melt in 2017 was quite early in the Chukchi and Eastern Beaufort Seas—as much as 35 days earlier than the 1981 to 2010 average. Early melt was also seen in the Kara Sea, Baffin Bay, and Canadian Arctic Archipelago (10 to 20 days earlier than average). However, over a large portion of the Arctic Ocean’s central ice pack, melt onset was a few days later than average. Melt onset was up to ten days later than average in the polar areas at the northern extents of the Beaufort and East Siberian Seas. The spatial pattern in the timing of melt onset reflects the combination of the warm winter and early spring conditions along the edge of the pack on the Pacific side, very warm winter conditions in the Barents and Kara Sea areas, and relatively cool late spring to early summer conditions over the central Arctic Ocean.

Sea ice predictions for the 2017 minimum Figure 5. This chart summarizes the 2017 summer September minimum forecasts from 36 different models and approaches to predicting the evolution of the Arctic pack.

Figure 5. This chart summarizes the 2017 summer September minimum forecasts from 36 different models and approaches to predicting the evolution of the Arctic pack.

Credit: SIPN/ARCUS
High-resolution image

A report released by the Sea Ice Prediction Network (SIPN), an activity of the Arctic Research Council of the United States (ARCUS), compiled 36 forecasts of September average sea ice extent that were submitted during July. Additionally, SIPN produces estimates for sea ice extent in the Alaska region and, new this year, for the Antarctic sea ice maximum (not shown). The September Arctic extent forecasts range from a new record low of 3.1 million square kilometers (1.2 million square miles) to an eleventh lowest extent of 5.5 million square kilometers (2.1 million square miles). The median of the estimates is slightly below the September 2016 value, currently the fifth lowest. A variety of methods are used to make these forecasts, ranging from coupled ice-ocean-atmospheric models to statistical approaches and heuristic guesses. NSIDC scientists Julienne Stroeve, Walt Meier, Andrew Barrett, Mark Serreze, and the late Drew Slater have regularly contributed to several separate estimations for the SIPN.

Sea ice retreat may be changing the AMOC

In the far northern Atlantic, warm water flowing northward from the tropics is cooled by the atmosphere, becomes denser, and eventually sinks to great depths. The descending water is key in driving a sub-surface and surface ocean circulation system called the Atlantic Meridional Overturning Circulation (AMOC), which is part of the global ocean conveyor belt of heat and salinity. Where the Atlantic water sinks has a very important effect on the climate of Northern Europe; the heat that the ocean loses to the atmosphere is what keeps Northern Europe quite warm relative to its latitude. For example, Amsterdam is at the same latitude as Winnipeg, Canada, but experiences much warmer winters.

Based on a recent modeling study, Florian Sévellec and colleagues propose that the ongoing loss of Arctic sea ice may disrupt the AMOC. The sea ice loss leads to a freshening of the northern North Atlantic and stronger heat absorption at the surface. This means that waters in the northern North Atlantic are less dense than they used to be, which has the effect of providing a cap, or lid, that may inhibit the northward flow of warm waters at the surface and the eventual sinking of these waters. The authors suggest that the Arctic sea ice decline may help to explain observations suggesting that the AMOC may be slowing down, and why there is a regional minimum in warming (sometimes called the Warming Hole) over the subpolar North Atlantic.

Further reading

Sea Ice Prediction Network. “2017: July Report.” Arctic Research Council of the United States. https://www.arcus.org/sipn/sea-ice-outlook/2017/july.

Sévellec, F., A. V. Fedorov, and W. Liu. 2017. Arctic sea-ice decline weakens the Atlantic Meridional Overturning Circulation. Nature Climate Change, doi:10.1038/nclimate3353.

Categories: Climate Science News

23 July - 3 August, 2017 weeks

AVISO Climate Change News - Thu, 2017-08-03 07:20
Un continent de déchets plastiques a été découvert dans l'océan Pacifique Sud, et il ferait plus d'1,5 fois la taille du Texas (Demotivateur, 2017/08/01)
Seulement 5 % de chances de limiter le réchauffement climatique à 2 °C (Le Monde, 2017/08/01)
Un satellite franco-israélien pour lutter contre le réchauffement climatique (Le Monde, 2017/07/08)
Maldives Plongée dans l'océan pour soigner les coraux (VSD, 2017/07/27)
Sécheresses et incendies, des phénomènes appelés à s’intensifier (Libération, 2017/07/26)
À l'assaut des déchets plastiques dans l'océan (L’Express, 2017/07/23)
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Categories: Climate Science News

July 2017: Higher resolution knowledge of flooded areas over the whole Earth

AVISO Climate Change News - Mon, 2017-07-31 00:48
Waiting for Swot, knowledge of wetlands and flooded areas can be computed from the wealth of...
Categories: Climate Science News

CNES SEF-NG disturbences

AVISO Climate Change News - Fri, 2017-07-28 06:12
Since July 20, recurring disturbances are observed on the CNES SEF-NG file exchange service. Everything is currently being implemented to restore service. We apologize for the inconvinience.
Categories: Climate Science News

[Jason-2] : Data production resumed - first products available

AVISO Climate Change News - Thu, 2017-07-27 02:30
On 20 June 2017, the 4-Partner Joint Steering Group directed the Jason-2 Project to undertake a series of maneuvers to reduce the orbit semi-major axis by 27 km.  This has placed Jason-2 into a new long-repeat orbit (LRO) at roughly 1309.5 km altitude.  Final orbit transfer activities were completed on 10 July 2017. At 09:16 UTC on Tuesday, 11 July, CNES control centre successfully commanded the restart of the core Jason-2 payload instruments.     Before authorizing data dissemination, we have performed a lot of controls, calval analysis and cross-calibrations in order to guarantee the quality of the products. Meanwhile, this period has been useful to prepare a detailed technical note about the characteristics of the new orbit and impacts on new products. Please find attached the note prepared by MSE’s. As was the case with Jason-1, science cycle numbering for the new LRO mission phase on Jason-2 will begin at Cycle 500. Today, we recover the OSTM/Jason-2 mission from the extended safe hold it has been in since 17 May 2017 and we are pleased to announce that Jason-2 OGDR and IGDR are available for dissemination. First OGDR is for pass 031 of cycle 500. First IGDR is for pass 033 of cycle 500. They are available through the usual facilities. We hope to keep Jason-2 operational for a long time, Best regards,   T. Guinle on behalf the whole Jason-2 Project Team PS : The move of Jason-2 from the altimetry reference orbit was a difficult decision to take, but it also signals the start of an exciting new chapter in the extraordinary mission of Jason-2, as it begins its 10th year of operation.  
Categories: Climate Science News

16-22 July 2017 week

AVISO Climate Change News - Thu, 2017-07-27 02:04
Feux de forêts: «Les incendies vont se multiplier avec le réchauffement climatique» (20 minutes, 2017/07/20)
Climat: l’appel désespéré des climatologues (Journal de l’environnement, 2017/07/19)
Une expédition pour évaluer l'acidification de l'océan Arctique (Centre d’information internet de Chine, 2017/07/19)
Globe had 2nd warmest year to date and 3rd warmest June on record (Noaa, 2017/07/18)
Stronger winds heat up West Antarctic ice melt (Science Daily, 201/07/17)
Drifting Antarctic iceberg A-68 opens up clear water (BBC, 2017/07/17)
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Categories: Climate Science News

10-16 July 2017 week

AVISO Climate Change News - Thu, 2017-07-20 01:00
Antarctic Ice Shelf Sheds Massive Iceberg (Earthobservatory, 2017/07/12)
Antarctique : l’un des plus gros icebergs de l’histoire vient de se détacher ! (SciencePost, 2017/07/12)
Warm winter events in Arctic becoming more frequent, lasting longer (Science Daily, 2017/07/11)
Dans l’Océan, les coraux produisent leur propre lumière pour survivre (SciencePost, 2017/07/11)
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

A recent slowdown

NSIDC Artic Sea Ice News - Tue, 2017-07-18 10:14

Arctic extent nearly matched 2012 values through the first week of July, but the rate of decline slowed during the second week. Weather patterns were unremarkable during the first half of July.

Overview of conditions

Figure 1. Arctic sea ice extent for July 17, 2017 was 7.88 million square kilometers (3.04 million square miles). The orange line shows the 1981 to 2010 average extent for that day. Sea Ice Index data. About the data

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

As of July 17, Arctic sea ice extent stood at 7.88 million square kilometers (3.04 million square miles). This is 1.69 million square kilometers (653,000 square miles) below the 1981 to 2010 average, and 714,000 square kilometers (276,000 million square miles) below the interdecile range. Extent was lower than average over most of the Arctic, except for the East Greenland Sea (Figure 1). Hudson Bay was nearly ice free by mid July, much earlier than is typical, but in line with what has been observed in recent years.

Conditions in context

Figure 2a. The graph above shows Arctic sea ice extent as of July 17, 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 as a dotted brown 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

Figure 2b. This map compares sea ice extent for July 11 in 2017 and in 2012. White shows where ice occurred only in 2012, medium blue is where ice occurred only in 2017, and light blue is where ice occurred in both years.

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

Through the first week of July, extent closely tracked 2012 levels. The rate of decline then slowed, so that as of July 17, extent was 169,000 square kilometers (65,300 square miles) above 2012 for the same date (Figure 2a). The spatial pattern of ice extent differs from 2012, with less ice in the Chukchi and East Siberian Seas in 2017, but more in the Beaufort, Kara, and Barents Seas and in Baffin Bay (Figure 2b).

Visible imagery provides up close details  RESEARCHER'S NAME/ORGANIZATION *or * National Snow and Ice Data Center| High-resolution image

Figure 3a. This image from the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) shows sea ice in the Canadian Archipelago on July 3, 2017. The blue hues indicate areas of widespread melt ponds on the surface of the ice.

Credit: Land Atmosphere Near-Real Time Capability for EOS (LANCE) System, NASA/GSFC
High-resolution image

sea ice floes

Figure 3b. The Sentinel-2 satellite captured this image of large sea ice floes in Nares Strait on July 8, 2017.

Credit: European Space Agency
High-resolution image

MODIS image of arctic

Figure 3c. This false-color composite image of the Arctic is based on NASA MODIS imagery from July 4 to 10. Most clouds are eliminated by using several images over a week, but some clouds remain, particularly over the ocean areas.

Credit: NASA/Canadian Ice Service
High-resolution image

NSIDC primarily relies on passive microwave data because it provides complete coverage—night and day, and through clouds—and because it is consistent over its long data record. However, other types of satellite data, for example visible imagery from the NASA MODIS instrument on the Aqua and Terra satellites or from the European Space Agency Sentinel 2 satellite, can sometimes provide more detail. When skies clear, details of the ice cover can be seen, including leads, individual ice floes and melt ponds. For example, on July 3 in the Canadian Archipelago, 1-kilometer resolution MODIS imagery shows that the ice surface has a distinctive blueish hue due to the presence of melt ponds on the surface (Figure 3a). Higher resolution Sentinel-2 imagery (10 meters, Figure 3b) on the other hand provides up close detail on individual melt ponds on the ice floes.

The Arctic is a cloudy place, and generally, it is difficult to obtain a clear-sky image of the entire region. However, if images are compiled, or composited, over several days, most of the region may have at least some clear sky. This approach can yield a composite image that is mostly cloud-free. The Canadian Ice Service uses this approach to create a weekly nearly cloud-free composite image of the Arctic (Figure 3c). However, because the ice cover moves (typically several kilometers per day) and melts (during the summer), over the week-long composite period, fine details that can be seen in the daily imagery are not as evident because they have been “smeared” out over the week.

An ice-diminished Arctic

In response to diminishing ice extent, the US Navy has been holding a semi-annual symposium to bring together scientists, policy makers, and others to discuss the sea ice changes and their impacts. The seventh Symposium is taking place this week in Washington, DC, and will be attended by NSIDC scientists Mark Serreze, Walt Meier, Florence Fetterer, and Ted Scambos.

Tendency for warmer winters is increasing

A new study published this week in Geophysical Research Letters by Robert Graham at the Norwegian Polar Institute shows that warm winters in the Arctic are becoming more frequent and lasting for longer periods of time than they used to. Warm events were defined by when the air temperatures rose above -10 degrees Celsius (14 degrees  Fahrenheit). While this is still well below the freezing point, it is 20 degrees Celsius (36 degrees Fahrenheit) higher than average. The last two winters have seen temperatures near the North Pole rising to 0 degrees Celsius. While an earlier study showed that winter 2015/2016 was the warmest recorded at that time, the winter of 2016/2017 was even warmer.

Reference

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, Geophys. Res. Lett., 44, doi:10.1002/2017GL073395.

Categories: Climate Science News

3-9 July, 2017 week

AVISO Climate Change News - Wed, 2017-07-12 23:51
Réchauffement climatique: et cet iceberg géant qui finit de se détacher en Antarctique... (Sud Ouest, 2017/07/08)
Pour étudier les effets du changement climatique dans les océans : le navire Dr Fridtjof Nansen explore les eaux sénégalaises (Le Quotidien, 2017/07/07)
Le réchauffement climatique pourra entraîner des pluies diluviennes sur le Sahel (Sciences Avenir, 2017/07/06)
Veteran Ocean Satellite to Assume Added Role (Spacedaily, 2017/07/03)
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Categories: Climate Science News
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