Climate Science News

Smoke on the frozen water

NSIDC Artic Sea Ice News - Tue, 2018-07-17 11:00

Sea ice declined at a near average rate through the first half of July as low sea level pressure dominated the Arctic Ocean. Wind patterns caused smoke from Siberian forest fires to sweep over the ice.

Overview of conditions Figure 1. Arctic sea ice extent for July 15, 2018 was 3.3 million square kilometers (3.8 million square miles). The orange line shows the 1981 to 2010 average extent for that day.

Figure 1. Arctic sea ice extent for July 15, 2018 was 8.5 million square kilometers (3.3 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 15, Arctic sea ice extent was 8.5 million square kilometers (3.3 million square miles). This is 1.24 million square kilometers (479,000 square miles) below the 1981 to 2010 average, but 670,000 square kilometers (259,000 square miles) above the record low for this day in 2011. While total Arctic sea ice extent was tracking at record low levels during winter, the rate of summer ice loss has been unremarkable thus far. Thus far in July, ice retreat has been most pronounced in the Kara Sea, whereas in the Beaufort Sea, the ice edge expanded slightly southwards. The ice edge has changed little within the Barents and East Greenland Seas on the Atlantic side, and retreat has been sluggish in the Chukchi Sea on the Pacific side of the Arctic Ocean.

Conditions in context Figure 2. The graph above shows Arctic sea ice extent as of July 15 , 2018, along with daily ice extent data for four previous years and the record low year. 2018 is shown in blue, 2017 in green, 2016 in orange, 2015 in brown, 2015 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 2a. The graph above shows Arctic sea ice extent as of July 15, 2018, along with daily ice extent data for four previous years and the record low year. 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

Figure 2b. This plot shows average sea level pressure in the Arctic, in millibars, for July 1 to 15, 2018. Yellows and reds indicate higher than average sea level pressure; blues and purples indicate lower than average sea level pressure.

Figure 2b. This plot shows average sea level pressure in the Arctic, in millibars, for July 1 to 15, 2018. Yellows and reds indicate higher than average sea level pressure; blues and purples indicate lower than average sea level pressure.

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

Through the first two weeks of July, ice extent declined at a rate of 134,000 square kilometers (52,000 square miles) per day, which is near the 1981 to 2010 average. The spatial pattern of ice loss has not changed much since the end of June, with minimal ice loss around the entire ice edge. The Beaufort Sea saw some increase in extent due to the transport of ice from the north. Low sea level pressure dominated the central Arctic Ocean and Greenland. Typically, this pattern, associated with counterclockwise (cyclonic) winds is associated with cool conditions and also causes ice divergence, helping to spread the ice cover over a larger area. However, air temperatures over the pole and the East Siberian and Chukchi Seas at the 925 hPa level (approximately 2,500 feet above the surface) ranged 1 to 2 degrees Celsius (2 to 4 degrees Fahrenheit) above average for the first part of July. Regions with below average air temperatures were found in the Kara, Laptev, and Beaufort Seas (-1 to -3 degrees Celsius or -2 to -5 degrees Fahrenheit below average).

The passive microwave data show a decrease in ice concentration in several areas of the Arctic Ocean, particularly in northern areas of the Beaufort and Chukchi Seas. This is not necessarily a real decrease—it manifests as surface melt and the development of melt ponds on the ice surface. Microwave emission is sensitive to the freeze-thaw state of water. Liquid water atop the ice surface changes the returned signal, mimicking a reduced sea ice concentration. Because the calculation of ice extent does not consider concentration (except for the 15 percent concentration threshold), extent values are much less sensitive to this melt effect. During the melt season, ice extent provides a more consistent and reliable measure of total ice cover.

Siberian smoke over the Arctic Ocean  NASA| High-resolution image

Figure 3. These images from the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) sensor show the Arctic Ocean and surrounding land from July 3 to 6, 2018. Blue arrows indicate smoke that had drifted from fires in Siberia.

Credit: NASA
High-resolution image

Fires in the western United States have been much in the news lately. Less noted are significant fires in Siberia. Over several days at the beginning of July, smoke from these fires was brought into the Arctic Ocean by winds associated with the pattern of low pressure in the region. The smoke streamed over the East Siberian, Chukchi, and Beaufort Seas and eventually across Alaska into northern Canada.

The smoke has two potential effects on sea ice. First, as it drifts over the ice, the smoke particles scatter solar radiation and reduce how much is received at the surface. This has a cooling effect that will tend to reduce the rate of ice loss. However, smoke particles that settle onto the ice will darken the surface, thus decreasing the reflectivity of the surface, or albedo. This increases the amount of solar energy absorbed by the ice and enhances melt. The atmospheric scattering effect of the smoke is short term and dissipates after the smoke drifts away. The surface albedo effect has a longer-term impact and could serve to enhance melt rates through the summer. The magnitude of the effect will depend on how many smoke particles are deposited on the surface, the albedo of the surface that the particles fall on, and the amount of cloud cover which reduces the incoming sunlight. The biggest effect would be on bright, snow-covered ice. It would be smaller on darker melting ice and melt ponds, and there would be no effect in open water areas.

 

 

 

Categories: Climate Science News

2 - 8 July week

AVISO Climate Change News - Thu, 2018-07-12 08:02
Baltic Sea oxygen levels at '1,500-year low due to human activity' (The Guardian, 05/07/2018) Red-hot planet: All-time heat records have been set all over the world during the past week (The Washington Post, 05/07/2018) Démarrage officiel de l’Observatoire spatial du climat (Air&Cosmos, 05/07/2018) Great Barrier Reef Imperiled as Heat Worsens Die-Offs, Experts Say (The New York Times, 04/07/2018) Les cyclones tropicaux sont plus lents, et donc potentiellement plus destructeurs (Pour la Science, 04/07/2018) Rising sea levels could cost the world $14 trillion a year by 2100 (Science Daily, 03/07/2018) Gulf stream eddies as a source of iron (Science Daily, 03/07/2018) Le dérèglement du Jet Stream multiplie les canicules dans le monde (Up' magazine, 02/07/2018) 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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July 2018: Adopting a Swot crossover for biophysical studies

AVISO Climate Change News - Fri, 2018-07-06 03:13
Swot will be a major asset to study the socean fine scales, especially relevant for marine biology....
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A sluggish June

NSIDC Artic Sea Ice News - Wed, 2018-07-04 11:44

Arctic sea ice extent declined at a slightly slower-than average pace in June. Despite the slow loss, warm conditions and winds from the south developed a large area of open water in the Laptev Sea.

Overview of conditions  National Snow and Ice Data Center High-resolution image

Figure 1. Arctic sea ice extent for June 2018 was 10.7 million square kilometers (4.1 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 2018 averaged 10.7 million square kilometers (4.1 million square miles). This was 1.05 million square kilometers (405,000 square miles) below the 1981 to 2010 average and 360,000 square kilometers (139,000 square miles) above the record low June extent set in 2016. This was the fourth lowest June average extent in the satellite record.

Extent at the end of June remained below average in the Chukchi Sea, but because of slow retreat through June in the region, extent in the Chukchi is now closer to average than was the case at the end of May. The Barents Sea and East Siberian Sea also have extents well below average at the end of June. Most of the ice in the Sea of Okhotsk has melted. Ice has been retreating in the west side of Hudson Bay where extent is below average. However, this is countered by above average extent in the eastern side of the bay. Notably, a large area of open water has developed in the Laptev Sea, leading to record low extents in that region during the first half of June.

Conditions in context

Figure 2. The graph above shows Arctic sea ice extent as of July, 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. Sea Ice Index data.

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

Figure 3

Figure 3a. This plot shows the average sea level pressure in the Arctic at the 925 hPa level, in millibars, for June 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

Figure 3b

Figure 3b. This plot shows departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for June 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

The salient features of the atmospheric pattern for June include a region of low sea level pressure centered over the northern Barents Sea, and a high pressure cell centered over the Laptev Sea. A ridge of high pressure also extends eastward into northern Canada (Figure 3a). Winds from the south between the low pressure area in the Barents Sea and the high pressure area in the Laptev Sea gave rise to a pronounced region of above-average temperatures centered over Central Siberia and extending over the Laptev and East Siberian Seas (Figure 3b). However, elsewhere over the Arctic Ocean, temperatures were near average or slightly below average.

The temperature pattern is consistent with the early development of open water in the Laptev Sea. Extents in this area oscillated between slightly above and below the record low extent set in June 2014. Parts of the Laptev Sea opened as early as mid-April, likely due to winds transporting ice away from the fast ice zone (ice that is locked to the shoreline). While new ice formed in these open water areas, this ice was thin and prone to melting out once the summer melt season started.

Also of note was the passage of a strong cyclone in early June. This system moved into the Kara Sea on June 6, and reached a minimum central pressure of less than 970 hPa on June 7. By June 10, it had migrated into the Beaufort Sea. It dissipated on June 13.

June 2018 compared to previous years  National Snow and Ice Data Center| High-resolution image

Figure 4. Monthly June ice extent for 1979 to 2018 shows a decline of 4.1 percent per decade.

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

The linear rate of decline for June sea ice extent is 48,000 square kilometers (18,500 square miles) per year, or 4.1 percent per decade relative to the 1981 to 2010 average. Ice loss during the month was 1.6 million square kilometers (618,000 square miles), somewhat slower than the 1981 to 2010 average loss of 1.7 million square kilometers (656,000 square miles) for the month. Clearly the early ice losses in the Laptev Sea, associated with warm conditions over the region, could not make up for slower retreats elsewhere.

New insights into warming in the northern Barents Sea

An interesting feature of recent years is a region of unusually high winter air temperatures, or a winter hotspot, over the northern Barents Sea. Previous studies have provided evidence linking the hotspot to a halocline retreat, which is a retreat or weakening of the cold, fresh waters at the ocean surface that prevent ocean heat imported from the Atlantic from mixing upwards. A new paper by Lind et al. (2018) argues that the hotspot is driven by the lack of sea ice transport. Sea ice is mostly fresh water (low salinity) and less is being transported into that region. Hence the ocean surface becomes less fresh over the northern Barents Sea, allowing the warm Atlantic water to mix upwards.

Antarctica in June Figure 5

Figure 5. This plot shows departure from average air temperature in Antarctica at the 925 hPa level, in degrees Celsius, for June 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

Sea ice expanded at a faster-than-average pace in June in the Southern Hemisphere, bringing Antarctic sea ice extent closer to typical ice extents for this time of year. This follows on the heels of a period of below-average ice extent since austral winter in 2016. Sea ice extent is near average in all sectors except the northeastern Weddell Sea, and a small area in the northern Davis Sea. Higher-than-average air temperatures prevailed in these regions, and cool conditions prevailed over the northern Ross Sea.

Antarctica’s sea ice and ice shelf disintegration

A new study in the Journal Nature found that reduced sea ice in the northwestern Weddell Sea and southern Bellingshausen Sea likely contributed to the weakening of major ice shelves prior to their disintegration in the 1990s and early 2000s. Loss of the sea ice buffer near Antarctica’s coast allows long-period ocean swell to flex ice shelves. Under ordinary conditions, this flexing has little effect. However, if the ice shelves have been pre-conditioned by seasonal melt-water flooding, the flexing by wave action in late summer can have a devastating effect. Minor flexure of the ice shelf plate allows water to infiltrate existing cracks and initiate fracturing of the ice.

Four major ice shelf break-up events in 1995 (Larsen A), 2002 (Larsen B), and 2008 and 2009 (Wilkins) all occurred after multiple weeks where no sea ice was present near the ice shelf fronts to dampen ocean swell. In the case of the Larsen A and B events, the loss of the ice shelves initiated a significant acceleration of the tributary glaciers. The study demonstrates that sea ice—a component of the cryosphere that is very sensitive to changing climate and ocean—has an important protective effect on the Antarctic ice sheet.

Further Reading

Lind, S., R. B. Ingvaldsen, and T. Furevik. 2018. Arctic warming hotspot in the Northern Barents Sea linked to declining sea-ice import. Nature Climate Changedoi:10.1038/s41558-018-0205-y.

Massom, R., T. A. Scambos, L. G. Benetts, P. Reid, V. A. Squire, and S. Stammerjohn. 2018. Antarctic ice shelf disintegration triggered by sea ice loss and ocean swell. Nature, 558, 383-389, doi:10.1038/s41586-018-0212-1.

Categories: Climate Science News

25 June - 1 July 2018 week

AVISO Climate Change News - Tue, 2018-07-03 01:41
Comment les satellites Jason ont révolutionné notre connaissance du climat (Futura Sciences, 30/06/2018) Politique américaine des océans : exit le climat (Science Presse, 29/06/2018) The Sounds of Satellites (Earth Observatory, 28/06/2018) Global surface area of rivers and streams is 45 percent higher than previously thought (Science Daily, 28/06/2018) Un œil sur l’océan (Télématin Sciences, 27/06/2018) Images satellitaires et drones, de nouveaux alliés contre le réchauffement climatique (Le Monde, 26/06/2018) L’Europe met à disposition toutes ses données climatiques. On ne pourra pas dire qu’on ne savait pas… (Up' magazine, 26/06/2018) 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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New SSALTO/DUACS Experimental products delivery

AVISO Climate Change News - Fri, 2018-06-29 06:02
We are proud to announce the release of the new AVISO+ SSALTO/DUACS experimental products. For 20...
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11 June -24 June 2018 weeks

AVISO Climate Change News - Mon, 2018-06-25 03:27
Losing Ice in Svalbard (Earth Observatory, 25/06/2018) Goélette scientifique Tara, journal de bord n° 2 : les défis d’une navigation scientifique « propre » (Le Monde, 24/06/2018) Marine plastic: Hundreds of fragments in dead seabirds (BBC news, 23/06/2018) 10 raisons pour lesquelles le changement climatique nous passe au-dessus de la tête (Slate, 22/06/2018) Plastic Odyssey, ce bateau avance grâce aux déchets plastiques (Science Post, 22/06/2018) Une nouvelle étude révèle que les îles Britanniques étaient recouvertes d’une calotte glaciaire il y a 2,5 millions d’années (Science Post, 22/06/2018) Here are 4 ways we can adapt to the growing danger of climate change (World Economic Forum, 21/06/2018) Antarctic ice sheet is melting, but rising bedrock below could slow it down (Science Daily, 21/06/2018) OMG, the Water's Warm! NASA Study Solves Glacier Puzzle (Nasa, 21/06/2018) What will Antarctica look like in 2070? (World Economic Forum, 19/06/2018) Sentinel-3 flies tandem (ESA, 19/06/2018) Ocean's heat cycle shows that atmospheric carbon may be headed elsewhere (Science Daily, 19/06/2018) New model for gauging ice sheet movement may improve sea-level-rise predictions (Science Daily, 19/06/2018) We now know how much ice Antarctica has lost in the last 25 years - three trillion tonnes (World Economic Forum, 14/06/2018) Climate change is moving fish around faster than laws can handle, study says (The Washington Post, 14/06/2018) Fonte des glaces : comment a-t-on pesé l’Antarctique? (Science Presse, 14/06/2018) Fonte accélérée des glaces de l'Antarctique (Le Figaro, 14/06/2018) Ocean waves following sea ice loss trigger Antarctic ice shelf collapse (Science Daily, 14/06/2018) Quand les sources hydrothermales fertilisent l’océan de surface dans le Pacifique Sud-Ouest (CNRS, 13/06/2018) Underwater Robots Give Unique Insight into Arctic Climate Change (Ocean News & Technology, 11/06/2018) On line availability of articles depends on the Newspaper/magazine. We can't thus certify that above articles will be freely and permanently available.
Categories: Climate Science News

DMSP F18 to undergo testing late June, early July

NSIDC Artic Sea Ice News - Fri, 2018-06-22 13:09

The Defense Meteorological Satellite Program (DMSP) F18 satellite will be undergoing testing from June 25 to 29 and from July 9 to 12. During this time, data from the Special Sensor Microwave Imager/Sounder (SSMIS) sensor on F18 may have degraded quality or may not be collected. DMSP F18 is the primary sensor that provides NSIDC with near-real-time data for sea ice monitoring (nsidc-0081, the Sea Ice Index, and the Arctic Sea Ice News and Analysis web page). If the data quality does not meet operational standards, NSIDC will remove the resulting sea ice fields or NSIDC may not distribute data from the F18 SSMIS during the test periods.

Categories: Climate Science News

Happy Birthday Jason-2!

AVISO Climate Change News - Thu, 2018-06-21 01:37

On June 20th, the OSTM/Jason-2 mission (Ocean Surface Topography Mission) marks its 10th year in orbit. Jason-2 has now completed 47,000 orbital revolutions of our planet, acquiring measurements of unequalled precision from more than 300 million radar pulses.

Jason-2 has enabled numerous scientists all over the world to gain new insights into the ocean phenomena playing a key role in our planet’s changing climate. Extending the long series of measurements started in 1992 with TOPEX/Poseidon and then continued by Jason-1, it has quantified and provided evidence for the mean rise in sea level of three millimetres a year, which today is undisputable and a crucial indicator for assessing and planning for the impacts of climate change that are proving dramatic for certain coastal regions and islands.

Let’s wish a long life to Jason 2 on LRO !

Categories: Climate Science News

21 may - 10 june 2018 weeks

AVISO Climate Change News - Thu, 2018-06-14 06:13
Widespread ocean anoxia was cause for past mass extinction (Science Daily, 21/05/2018) Des changements majeurs dans la répartition des réserves mondiales d’eau douce sont en cours (SciencePost, 21/05/2018) Researchers Hunting Microplastic with Jellyfish (Ocean News & Technology, 21/05/2018) Hawaï. Fumées acides avec la lave du Kilauea qui atteint l’océan (Le Télégramme, 22/05/2018) Le changement climatique peut-il augmenter le risque de gelées tardives ? (CNRS, 23/05/2018) The catastrophe that killed the dinosaurs created a global hothouse for 100,000 years, study says (Washington post, 24/05/2018) Un forage en Antarctique pourrait remonter plus d’1 million d’années dans le passé et résoudre un mystère paléo-climatique (SciencePost, 27/05/2018) Un océan de plastique (CNRS, 28/05/2018) Rise and fall of the Great Barrier Reef (Science Daily, 28/05/2018) Surexploitation et changement climatique : au Sénégal, la pêche est en danger (Reporterre, 29/05/2018) NOAA’s Next Generation Polar Satellite System Now Operational (Ocean News & Technology, 31/05/2018) Réchauffement climatique : avions et ballons traquent les gaz à effet de serre (La Dépêche, 01/06/2018) Our plastic problem is out of control. Here’s how we can fight it (The World Economic Forum, 05/06/2018) Nutrient pollution makes ocean acidification worse for coral reefs (Science Daily, 06/06/2018) Le réchauffement climatique accentue la force destructrice des ouragans (Métro, 08/06/2018) Here are 5 of the biggest threats to our oceans, and how we can solve them (The World Economic Forum, 08/06/2018) Journée mondiale de l’océan : Agir pour des « Océans propres » (Minute News, 08/06/2018) Aeolus: Wind satellite weathers technical storm (BBC News, 09/06/2018) On line availability of articles depends on the Newspaper/magazine. We can't thus certify that above articles will be freely and permanently available.
Categories: Climate Science News

Springtime for the Arctic

NSIDC Artic Sea Ice News - Wed, 2018-06-06 13:00

Arctic sea ice extent for May 2018 was the second lowest in the satellite record. Above average temperatures and high sea level pressure prevailed over most of the Arctic Ocean, while some surrounding continental regions were colder than usual.

Overview of conditions Figure 1. Arctic sea ice extent for May 2018 was 12.2 million square kilometers (4.7 million square miles). The magenta line shows the 1981 to 2010 average extent for that month.

Figure 1. Arctic sea ice extent for May 2018 was 12.2 million square kilometers (4.7 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 2018 was 12.2 million square kilometers (4.7 million square miles). This was the second lowest May extent in the 39-year satellite record, and is 310,000 square kilometers (120,000 square miles) above May 2016, the record low for the month. Compared to May 2016, the ice cover remained slightly more extensive in the Barents and Kara Seas, within Baffin Bay, Davis Strait, and the southern Beaufort Sea, but less extensive in the Chukchi and East Greenland Seas.

In Svalbard, the average temperature for May 2018 was 6 degrees Celsius (11 degrees Fahrenheit) above average. By the end of the month, the north and west coasts of Svalbard were largely ice-free and a tongue of open water east of the islands extended northeast to Franz Joseph Land. According to NSIDC data, open water stretched as far north as ~82 degrees N at the end of May.

In the Chukchi Sea, open water developed to the west of Point Barrow, Alaska throughout the month. This may be in part a result of the inflow of warm waters from the Pacific, where sea surface temperatures were higher than average. It may also be due to the general lack of sea ice in the region that allows the ocean to readily absorb the sun’s energy. Ice retreat was also substantial within the Sea of Okhotsk, and little ice remains in the region. Hudson Bay began to open up, with a significant area of open water in the northwest sector of the bay.

Conditions in context Figure 2a. The graph above shows Arctic sea ice extent as of June 3, 2018, along with daily ice extent data for four previous years and the record low year. 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 2a. The graph above shows Arctic sea ice extent as of June 3, 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

 NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Division

Figure 2b. This plot shows departure from average sea level pressure in the Arctic, in millibars, for May 2018. Yellows and reds indicate higher than average sea level pressure; blues and purples indicate lower than average sea level pressure.

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

 A. P. Barrett, NSIDC

Figure 2c. This plot shows air temperatures at the 925 mb level averaged over the Arctic Ocean region. This region covers only ocean areas in the Arctic, bounded by the Bering Strait on the Pacific side, and Fram Strait and roughly the 20 degree E meridian between Svalbard and Norway.

Credit: A. P. Barrett, NSIDC
High-resolution image

The atmospheric pattern (Figure 2b) for May was characterized by a region of above average sea level pressure centered over the Fenno-Scandinavian Peninsula and below average pressure centered over Greenland. This pattern helped to funnel warm winds from the south into the Barents Sea sector favoring retreat of ice. Air temperatures at the 925 hPa level (about 2,500 feet above sea level) in the Barents Sea were up to 5 degrees Celsius (9 degrees Fahrenheit) above average (not shown). On the Pacific side, departures from average sea level pressure were small and a fairly typical Beaufort Sea High and Aleutian Low pattern reigned for much of the month. Overall it was warm across the Arctic Ocean with temperatures at the 925 hPa level ranging between 2 to 5 degrees Celsius (4 to 9 degrees Fahrenheit) above average for the month. By contrast, conditions over land regions surrounding the Arctic were relatively cool. Parts of Central Siberia and Nunavut in northern Quebec saw temperatures more than 5 degrees Celsius (9 degrees Fahrenheit) below average. However, Europe, eastern Asia and western North America were warmer than usual.

Air temperatures at the 925 mb level (about 2,500 feet above sea level) over the Arctic Ocean have been above average through most this year (Figure 2c). Temperatures were extremely high compared to typical conditions from January through early March. After a brief cold period in March, temperatures returned to near average and increased at typical rates through most of May.

While it is still relatively early in the melt season, images from the Moderate Resolution Imaging Spectroradiometer (MODIS) show considerable fracturing of multiyear ice floes in the Beaufort Sea. The early development of open water around these large ice floes can help accelerate melt through absorption of solar energy. Some of these ice floes appear already partially covered by melt ponds.

May 2018 compared to previous years Figure 3. Monthly May ice extent for 1979 to 2018 shows a decline of 2.6 percent per decade.

Figure 3. Monthly May 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 May sea ice extent is 36,000 square kilometers (14,000 square miles) per year, or 2.6 percent per decade relative to the 1981 to 2010 average. Ice loss during the month was 1.7 million square kilometers (656,000 square miles), which was faster than the 1981 to 2010 average loss of 1.5 million square kilometers (579,000 square miles) for the month.

Another season for the Sea Ice Outlook

The Sea Ice Prediction Network is once again soliciting contributions to the Sea Ice Outlook predicting the September 2018 sea ice extent. This effort is coordinated by the Arctic Research Consortium of the United States (ARCUS). This is the second phase of the Sea Ice Prediction Network, and is currently funded by the National Science Foundation, the Office of Naval Research, and the United Kingdom’s National Environment Research Council. While all prediction methods are welcome, a new focus of the project is to assess the economic value of seasonal ice forecasts. To make the forecasts more useful to stakeholders, there is an increased emphasis on predicting the spatial pattern of the ice cover for September, not just the total extent. The Sea Ice Outlook will summarize contributions and assess the seasonal evolution of conditions each month through summer and in post-season reports at https://www.arcus.org/sipn.

Autumn in Antarctica Figure 4a. Arctic sea ice extent for June 1, 2018 was 11.0 million square kilometers (4.2 million square miles). The orange line shows the 1981 to 2010 average extent for that day.

Figure 4a. Arctic sea ice extent for June 1, 2018 was 11.0 million square kilometers (4.2 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

Sea ice extent in the Southern Ocean grew steadily in May at the rate of 123,000 square kilometers (47,000 square miles) per day, somewhat faster than the 1981 to 2010 average growth rate of 108,000 square kilometers (42,000 square miles) per day. This pushed Antarctic ice extent from third lowest at the start of the month to sixth lowest by June 1. Ice extent was near average for all regions except for a broad section of the far eastern Weddell Sea, where ice extent was less than the 1981 to 2010 average. The eastern Ross, Amundsen, and Bellingshausen Seas began the month with less ice cover than average, but rapid growth in these regions brought ice extent to near average by the end of the month.

Reference

Nilsen, T. “Warmest May ever on Arctic Islands,” The Barents Observer, June 3, 2018, 11:00 a.m., MST, https://thebarentsobserver.com/en/ecology/2018/06/warmest-may-ever-arctic-islands.

Categories: Climate Science News

Temporary unavailibility of AVISO+ Sea views

AVISO Climate Change News - Tue, 2018-06-05 00:54
Due to a maintenance operation AVISO+ Sea views : http://bulletin.aviso.altimetry.fr will be unavailable today June 5th between 7h and 12h UTC.
Categories: Climate Science News

June 2018: As the flood flows

AVISO Climate Change News - Thu, 2018-05-31 23:34
Satellite observations of floods may be used in early flood warning systems. SWOT is not planned as...
Categories: Climate Science News

14 - 20 May 2018 week

AVISO Climate Change News - Fri, 2018-05-25 01:46
Deux satellites pour observer l'eau sur Terre (Sciences et Avenir, 18/05/2018) The Baltic Sea as a Time Machine (Ocean News & Technology, 14/05/2018) La NASA révèle l’impact du changement climatique sur les réserves mondiales d’eau douce (LCI, 18/05/2018) How large can a tsunami be in the Caribbean? (Science Daily, 16/05/2018) Pourquoi les éruptions du Kilauea à Hawaï ne refroidissent-elles pas le climat ? (Sud Ouest, 18/05/2018) Sur Europe, la lune glacée de Jupiter, il y a un océan subglacière.. et aussi des geysers ! (France Culture, 18/05/2018) Hope for Corals : growing species resilience in Coral Nurseries (NOAA, 14/05/2018) On line availability of articles depends on the Newspaper/magazine. We can't thus certify that above articles will be freely and permanently available.
Categories: Climate Science News

Jason2 IGDR during last AMR anomaly have been disseminated on 2018/05/22

AVISO Climate Change News - Tue, 2018-05-22 07:55
2018/04/17 Jason2 IGDR during AMR anomaly (cycle 528 passes 121 to 128) have been disseminated on 2018/05/22. Note that they contain no valid radiometer data during the incident on 2018/04/17  from 01:41:24 to 07:46:08.
Categories: Climate Science News

23 April - 13 May 2018 weeks

AVISO Climate Change News - Fri, 2018-05-18 06:40
On est allé dans la ville la plus au nord du monde et les effets du réchauffement climatique font froid dans le dos (France Info, 22/04/2018) Plastiques dans les océans : l'Ocean Cleanup va être lancé cet été (Le Vif, 23/04/2018) Comment les crevettes influencent le climat en brassant les océans (Le Monde, 24/04/2018) Taux record de microplastique dans l’océan Arctique (Le Monde, 25/04/2018) Les coraux face au réchauffement climatique (Futura Planète, 26/04/2018) Internal control helps corals resist acidification (Science Daily, 02/05/2018) GRACE-FO: Cracking a Cold Case (Nasa, 02/05/2018) Les baleines à bosse de l’Antarctique se rétablissent peu à peu de leur quasi-extinction (06/05/2018) Réchauffement climatique : un archipel norvégien menacé (LCI, 07/05/2018) Avec le réchauffement climatique, la frontière entre la Suisse et l’Italie se déplace (Vivre Demain, 08/05/2018) How to save the high seas (Nature, 09/05/2018) Growing ‘Dead Zone” in Gulf of Oman Confirmed by Underwater Robots (Ocean News, 10/05/2018) Le méthane des lacs, la bombe climatique que nous avions totalement sous-estimé (Atlantico, 13/05/2018) On line availability of articles depends on the Newspaper/magazine. We can't thus certify that above articles will be freely and permanently available.
Categories: Climate Science News

[Sentinel-3B] Already starting Calval activities on all instruments

AVISO Climate Change News - Thu, 2018-05-17 00:56
The second Copernicus Sentinel-3 satellite, Sentinel-3B, lifted off on a Rockot from the Plesetsk Cosmodrome in northern Russia at 17:57 GMT (19:57 CEST) on 25 April 2018. It will join its twin Sentinel-3A, in orbit since 2016, for a tandem phase of four months which will start at the beginning of June. Both Sentinels will fly just 223 km apart, which means that Sentinel-3B will be a mere 30 seconds behind Sentinel-3A. After this, Sentinel-3B will be moved apart on the same orbit to a wider separation (140°). Both ESA-developed Copernicus satellites carry four Earth-observing instruments to measure oceans, land, ice and atmosphere:
  • Ocean and Land Colour Instrument (OLCI),
  • Sea and Land Surface Temperature Radiometer (SLSTR), 
  • SAR Radar Altimeter (SRAL), 
  • MicroWave Radiometer (MWR), 
and instruments fo Precise Orbit Determination (POD) including:
  • DORIS receiver (Doppler Orbitography and Radiopositioning Integrated by Satellite)
  • GNSS receiver (Global Navigation Satellite System)
  • LRR (Laser Retro Reflector)
All instruments have been progressively switched on, in particular :
DORIS on May 1st at 10:30:00 UTC
MWR (radiometer) on May 7th at  09:48:00 UTC
SRAL (altimeter) on May 8th at 06:02:05 UTC CalVal activites are already ongoing with a strong implication of CNES, CLS and Noveltis team.
Categories: Climate Science News

Temporary interruption of the Aviso+ website on May 15th

AVISO Climate Change News - Mon, 2018-05-14 07:43
Temporary interruption of the Aviso+ website on May 15th  For maintenance reasons, the AVISO+ website will be unavailable on Tuesday 15th May for some hours from 10:00 CET.  We apologize for the inconvenience.
Categories: Climate Science News

May 2018: Eddies' birth and decay around Antarctica

AVISO Climate Change News - Tue, 2018-05-08 01:38
25 year long time series of eddy detection is now available and enable to better understand the...
Categories: 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
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