Posts Tagged ‘Sea ice’

Antarctic sea ice much thicker than expected

November 25, 2014

The British Antarctic Survey has issued a press release regarding the use of a robot submarine which has been measuring the thickness of Antarctic sea ice. The submarine can operate at upto 30m depth and maps the sea ice from underneath. They found that, on average, the thickness of the ice beneath sea level was much greater than previously thought at 1.4 to 5.5m, with the thickest sea ice measured at 16m. They also encountered a lot of highly deformed ice, where one block had ridden over another, increasing the overall draft.

“We suggest that thick ice in the near-coastal and interior pack may be under-represented in existing in situ assessments of Antarctic sea ice and hence, on average, Antarctic sea ice may be thicker than previously thought.”

No doubt some will contort their theories and themselves to show how increased sea ice thickness and greatly increased ice cover in the Antarctic are perfectly consistent with global warming. I am inclined to the much more parsimonious explanation that increased freezing is always a sign of cooling.

The first detailed, high-resolution 3-D maps of Antarctic sea ice have been developed using an underwater robot. Scientists from the UK, USA and Australia say the new technology provides accurate ice thickness measurements from areas that were previously too difficult to access. …

Now, with the Autonomous Underwater Vehicle (AUV) known as SeaBED, scientists have an invaluable new tool to fill this gap.

While most oceanographic survey instruments look down at the seafloor, SeaBED was fitted with an upward-looking sonar in order to measure and map the underside of sea ice floes. The AUV operated at a depth of 20 to 30 meters and was driven in a lawnmower pattern. These lines of data were merged to form high-resolution 3D bathymetric surveys of the underside of the ice.

Photo

SeaBed vehicle recovery Photo P. Kimball / Woods Hole Oceanographic Institution

 

The yellow SeaBED robot, which is approximately two meters long and weighs nearly 200 kilograms, has a twin-hull design that gives the robot enhanced stability for low-speed photographic surveys. …….. 
The research was carried out by scientists at the Institute of Antarctic and Marine Science (Australia), Antarctic Climate and Ecosystem Cooperative Research Centre (Australia), Woods Hole Oceanographic Institution (USA) and British Antarctic Survey (UK).

Live Science:

Not only is the amount of sea ice increasing each year, but an underwater robot now shows the ice is also much thicker than was previously thought, a new study reports.

The discovery adds to the ongoing mystery of Antarctica’s expanding sea ice. According to climate models, the region’s sea ice should be shrinking each year because of global warming. Instead, satellite observations show the ice is expanding, and the continent’s sea ice has set new records for the past three winters. At the same time, Antarctica’s ice sheet (the glacial ice on land) is melting and retreating. …….

The findings were published today (Nov. 24) in the journal Nature Geoscience. ….. 

The sea ice growth around Antarctica has averaged about 1.2 percent to 1.8 percent per decade between 1979 and 2012, according to the 2013 Intergovernmental Panel on Climate Change’s Fifth Assessment Report. The increases are concentrated primarily in the Ross Sea in western Antarctica. Sea ice in the nearby Bellingshausen and Amundsen seas has significantly decreased. Researchers suspect these regional differences could result from stronger winds or increased meltwater from the Antarctic ice sheet, or a combination of both factors.

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China to industrialise desalination of sea-ice

January 16, 2014

During an ice age as water gets trapped in expanding ice, the entire water cycle stabilises at much lower rates of flux than during an inter-glacial period. Evaporation (due to absorption of solar energy) is the primary force which drives the water cycle. During an ice age, rates of evaporation will decrease sharply, precipitation will reduce and the flow of fresh water through rivers and streams back into the seas will reduce as a consequence. Sea levels would drop by up to 150 m from current levels and while currently submerged land will be exposed, desertification of many regions will also take place.

One of the technologies that will be necessary at such a time will be for the extraction of fresh water from sea ice.

Bohai Bay China

Bohai Bay China

The Bohai Rim is one of the water-scarce regions in China. But every winter, more than 1 billion m3 of sea ice formed in the sea, about 40% of which distributes within 10 km offshore and is expected to be exploited and utilized as source of freshwater.

They may not be expecting a return to full glacial conditions anytime soon, but perhaps the Chinese are already preparing for another Little Ice Age and the fresh water availability reduction that will undoubtedly cause.

Xinhua reports:

China will soon begin production of large amounts of fresh water through the desalination of sea ice, according university research team and a Chinese company on Tuesday. A research team from Beijing Normal University signed a sea ice desalination technology transfer agreement with Beijing Huahaideyuan Technology Co. Ltd on Tuesday.

The company is expected to be able to produce at least 1 billion cubic meters of fresh water annually by 2023, said Yu Jian, executive president of the company. The salinity of sea ice is between 0.4 percent to 0.8 percent, much lower than that of sea water, which stands at about 2.8 percent to 3.1 percent, said Professor Gu Wei, head of the research team.

The research team has mastered the basic principles and technology of sea ice desalination and developed the equipment to be used in the process, including an ice-breaking platform and an ice-gatherer, he said. The salinity of sea ice water after desalination is 0.1 percent, which meets the national standard. The water can be used in agriculture, by industry and for drinking, he said.

The cost of desalination is expected to fall to 4 yuan per tonne, he said.

China’s sea ice desalination program started in 1996 when Shi Peijun, a professor from Beijing Normal University, realized that low saline ice could ease the water shortage around the Pan-Bohai Bay area in north China, after desalination. The program has received a total of 29.72 million yuan (4.88 million U.S. dollars) from various government departments in the past 18 years.

In winter in high-latitude oceans, there is a great amount of sea ice, which is being recognized as a new resource of fresh water by scientists.

Ironies multiply as rescue ice-breaker is also stuck in Antarctic ice

December 28, 2013

I posted earlier about the irony of the Guardian having to report this story about the lack of the expected melting of ice during the Antarctic summer.

The ironies multiply.

The objective of the tourists, the journalists and the ostensibly “scientific” team was to recreate the journey of Douglas Mawson 100 years ago. They got stuck in 3m thick ice and three ice-breakers have gone to their rescue. The first, a Chinese ice-breaker is now also stuck in the ice. The “scientific” team is led by – wait for it – Chris Turney, a “professor of climate change” at the University of New South Wales in Australia!!

Some immediate questions arise:

  1. Who pays for the rescue ships? (I do hope the Guardian and the BBC and the University of NSW pay their fair share).
  2. If the journey of 100 years ago cannot be retraced because there is more ice now – what does that say about global warming theory and melting polar ice?
  3. What does a professor of climate change do – apart from profess his faith in climate change?
  4. When does “climate change” change from being global warming to global cooling?

CNN reports:

Only at the South Pole: Icebreaker also stuck — in ice — heading for stranded ship

South Pole weather has stymied a rescue by a Chinese icebreaker trying to reach an expedition vessel trapped for the past four days in frozen seas, a ship officer told CNN Friday.

The Chinese icebreaker Xue Long, or Snow Dragon, was just six nautical miles away from the rescue, but now it’s stuck in an Antarctica ice floe, too.

The Chinese crew is hoping a French icebreaker 14 nautical miles away will arrive and offer relief, said Zhu Li, chief officer of the Chinese ship.

But it’s likely the French vessel Astrolabe will also be slowed by the polar cap’s extreme frigidity, Zhu said.

Those two icebreakers — plus a third, from Australia — were battling the planet’s coldest environment in trying to reach the stranded Russian ship MV Akademik Shokalskiy, whose 74 researchers, crew and tourists remained in good condition despite being at a frozen standstill since Monday. …..

Antarctic sea ice is currently at record levels and global sea ice extent is greater than it has been for two decades. It should be noted that few proponents of climate change yet have the courage to state what is really happening but which is politically incorrect. That global warming has stopped and global cooling has begun and that carbon dioxide emissions are largely irrelevant to climate.

Summer in the Antarctic and expedition is trapped in thick ice

December 25, 2013

“Global sea ice area is second highest on record for the date after 1988, and closing in the #1 spot. Antarctic ice is melting very slowly this summer, due to record cold Antarctic temperatures”.Real Science, 21st December 2013

Certainly no irony would have been intended but irony there undoubtedly is when even The Guardian is forced to report that:

Antarctic expedition stranded as ship gets stuck in ice

Scientists and explorers on Spirit of Mawson voyage will spend Christmas and Boxing Day awaiting rescue. Explorers are stranded near Antarctica after their ship became wedged in by thick sheets of sea ice.

The Spirit of Mawson voyage, which includes scientists, explorers, tourists and the Guardian journalists Alok Jha and Laurence Topham, is trapped in Antarctic ice floes and awaiting rescue.

But with the nearest ship with ice-breaking abilities at least two days away, the crew will spend Christmas and Boxing Day stuck about 1500 nautical miles south of Hobart.

The Australian Maritime Safety Authority received a distress call on Christmas morning, notifying the rescue co-ordination centre that the ship was trapped and would need help. …

Akademik Shokalskiy surrounded by ice

A view of the ice from the boat. Photograph: Laurence Topham

The voyage is part of a research expedition to commemorate the centenary of Douglas Mawson’s exploration.

The Australasian Antarctic Expedition leader, Chris Turney, wrote on Twitter: “Heavy ice. Beautiful; light wind. Only -1degC. All well. Merry Xmas everyone from AAE.”

Global Warming gone missing: Arctic ice back to “normal” and Antarctic ice at highest ever recorded levels

October 20, 2013

IF THE GLOBE IS WARMING, WHERE’S THE HEAT?

Arctic Ice levels are increasing fast and are within 1 standard deviation of the 1979-2000 mean.

Arctic Ice Extent 20131018 DMI Centre for Ocean and Ice

Arctic Ice Extent 20131018 DMI Centre for Ocean and Ice

In the Anatrctic ice extent should normally have started reducing by 22nd Sepptember but kept increasing till about 1st October. At maximum it reached levels never recorded before. It is currently at a level more than 2 standard deviations higher than the long term 1981 – 2010 average.

Antarctic Ice Extent 20131018 NSIDC Boulder

Antarctic Ice Extent 20131018 NSIDC Boulder

This leads to obvious but simple conclusions:

  1. Over the last 34 years therefore, Arctic ice extent has shown great variability but is currently at values within one standard deviation of the 30 year average.
  2. Global warming – if it is taking place – has not left any significant signature in the extent of Arctic Ice which is larger than “natural variability”.
  3. Over the last 32 years Antarctic ice extent has consistently shown a small but steady increase.
  4. Global warming – if it is taking place – is completely absent in the record of the ice extent.

It could be argued – but it would stretch credulity – that heat is being stored in the deep ocean (having bypassed the surface waters by a hitherto unknown form of “deep sea radiation”)  and that this will all be released in a coming catastrophic event (to be known as the Ehrlich Rapture) in 2047.

Or, it could be argued – again with little credibility – that man-made particulate emissions from China in the Northern Hemisphere and from Indonesian forest fires in the Southern Hemisphere have reflected away the Sun’s radiation and prevented the warming that should have taken place. This argument then fails since it would appear to describe a very successful  application – if inadvertent – of geo-engineering.

Or we could choose the parsimonious explanation. There has been no global warming for the last 2 decades or so.

Any discussion about whether or how much warming is caused by carbon dioxide emissions becomes moot if there is no warming.

WHERE’S THE HEAT?

Arctic sea ice reaches minimum for 2013 – about a week early

September 6, 2013

A late spring and a short summer has led to Arctic ice melting much slower than for many years: IS ARCTIC SEA ICE REBOUNDING? 

It would seem that the minimum ice extent in the Arctic which usually happens around the middle of September has already been reached – about a week early.

From DMI – Centre for Ocean and Ice (coastal zones masked)

Arctic Sea Ice Extent 2013 minimum

Arctic Sea Ice Extent 2013 minimum

A real rebound in the ice extent and almost back to the level of 2005.

And of course the Antarctic which is reaching its maximum ice extent seems to be at a level significantly higher than the average for 1981 -2010. (NSIDC, Boulder).

Antarctic sea ice extent 20130904

Antarctic sea ice extent 20130904

These levels of ice extent correspond to the lack of significant increase in sea levels.

There does not seem to be very much to be alarmed about.

 

Increasing Antarctic sea ice correlates with global cooling

August 18, 2013

A new paper shows that for the last 30 years Antarctic ice is increasing and correlates best with a cooling global temperature.

Qi Shu, Fangli Qiao, Zhenya Song and Chunzai Wang, Sea ice trends in the Antarctic and their relationship to surface air temperature during 1979–2009, Clim Dyn (2012) 38:2355–2363, DOI 10.1007/s00382-011-1143-9

Abstract: Surface air temperature (SAT) from four reanalysis/analysis datasets are analyzed and compared with the observed SAT from 11 stations in the Antarctic. It is found that the SAT variation from Goddard Institute for Space Studies (GISS) is the best to represent the observed SAT. Then we use the sea ice concentration (SIC) data from satellite measurements, the SAT data from the GISS dataset and station observations to examine the trends and variations of sea ice and SAT in the Antarctic during 1979–2009. The Antarctic sea ice extent (SIE) shows an increased trend during 1979–2009, with a trend rate of 1.36 ± 0.43% per decade. Ensemble empirical mode decomposition analysis shows that the rate of the increased trend has been accelerating in the past decade. Antarctic SIE trend depends on the season, with the maximum increase occurring in autumn. If the relationship between SIC and GISS SAT trends is examined regionally, Antarctic SIC trends agree well with the local SAT trends in the most Antarctic regions. That is, Antarctic SIC and SAT show an inverse relationship: a cooling (warming) SAT trend is associated with an upward (downward) SIC trend.

The variations of local  SIC and SAT anomalies in autumn during the past 30 years

The variations of local
SIC and SAT anomalies in
autumn during the past 30 years

Summary: ….

The SAT and SIC trends illustrate an inverse relationship in most of the Antarctic regions, especially in summer and autumn. This indicates that a cooling (warming) SAT trend is associated with an upward (downward) SIC trend in the Antarctic. The station observations also confirm the inverse relationship between SAT and SIC. In most of the Antarctic regions, a cooling trend of SAT in summer and autumn is associated with an increased trend of SIC. …

Our analyses show that the relationship between sea ice and SAT trends should be examined regionally rather than integrally.

Arctic summer relatively short and ice melt-rate slow this year

August 9, 2013

The Arctic ice extent usually reaches a maximum in the 2nd week of March and its minimum during the 2nd week of September.

This year the Arctic summer started later than usual (long winter, late spring all over the Northern hemisphere). Now as Arctic temperatures have already dropped below freezing it could turn out to be a rather short. cool summer. Temperatures rose to above freezing about 3 weeks later than the average and seem to have dropped below zero about 2 weeks ahead of the average. In consequence the ice melt-rates have been much lower than for some time (but not unprecedented by a long way).

Arctic Temperatures North of 80° ( from DMI – Danish Centre for Ocean and Ice)

Daily mean temperatures for the Arctic area north of the 80th northern parallel, plotted with daily climate values calculated from the period 1958-2002.

Calculation of the Arctic Mean Temperature

The daily mean temperature of the Arctic area north of the 80th northern parallel is estimated from the average of the 00z and 12z analysis for all model grid points inside that area. The ERA40 reanalysis data set from ECMWF, has been applied to calculate daily mean temperatures for the period from 1958 to 2002, from 2002 to 2006 data from the global NWP model T511 is used and from 2006 to 2010 T799 data are used and from 2010 to present the T1279 model data are used. 

The ERA40 reanalysis data, has been applied to calculation of daily climate values that are plotted along with the daily analysis values in all plots. The data used to determine climate values is the full ERA40 data set, from 1958 to 2002.
More information can be found here.

Daily mean temperature and climate north of the 80th northern parallel, as a function of the day of year. DMI

Daily mean temperature and climate north of the 80th northern parallel, as a function of the day of year. DMI

Not surprisingly the ice melt-rate this year has been relatively low and the ice extent relatively high.

Total sea ice extent on the northern hemisphere during the past years, including climate mean; plus/minus 1 standard deviation. The ice extent values are calculated from the ice type data from theOcean and Sea Ice, Satellite Application Facility (OSISAF), where areas with ice concentration higher than 15% are classified as ice.

The total area of sea ice is the sum of First Year Ice (FYI), Multi Year Ice (MYI) and the area of ambiguous ice types, from the OSISAF ice type product.

Sea ice extent in recent years for the northern hemisphere.                        The grey shaded area corresponds to the climate mean                       plus/minus 1 standard deviation.

Sea ice extent in recent years for the northern hemisphere.
The grey shaded area corresponds to the climate mean plus/minus 1 standard deviation.

It looks probable that the ice extent minimum for 2013 will be within one standard deviation of the mean 1979-2000 value.

Record ice levels in the Baltic Sea

April 5, 2013

The stubborn high pressure and the late spring have given the highest level of ice coverage for this time of year in the Baltic Sea since records began in the 1960’s.

Svenska Dagbladet reports: The stubborn high pressure has set a new record late date of maximum ice extent. On 29 the March, 176,000 square kilometers of the Baltic Sea surface were covered by ice.

The previous record was on 25th March 2008 when 49,000 square kilometers was present.

Swedish Ice report 

STSN42 ESWI 0310514/3/13

 

BAY OF BOTHNIA IN THE ARCHIPELAGOS UP TO 80 CM FAST ICE. AT SEA OFF THE FAST ICE EDGE IN THE WE STERN AND NORTHERN PARTS, A 15 NAUTICAL MILES WIDE AREA WITH ALTERNATING 10 – 30 CM LEVEL ICE. JUST WEST OF FARSTUGRUNDEN AND IN THE BAY OF SKELLEFTEA THERE ARE LEADS WITH OPEN WATER. EAST OF THERE, NORTH OF THE LATITUDE THROUGH BJUROKLUBB, MOSTLY 30-70 CM VERY CL OSE DRIFT ICE WITH HEAVY RIDES AND CRACKS. RIDGES, DIFFICULT TO PASS OCCUR OFF RAAHE AND FURTHER NORTHWARDS PASSING NAHKIAINEN. SOUTH OF BJUROKLUBB THE DRIFT ICE IS 30-60 CM THICK WITH RIDGES AND CRACKS. OFF THE SWEDISH COAST MOSTLY THIN LEVEL ICE AND SINGLE HEAVY FLOES. ……. 

Polar bears heading out onto rapidly forming Arctic sea ice

November 17, 2012

In spite of all the headlines about the dearth of Arctic ice it seems that polar bears are not too worried. They are heading out onto the rapidly growing ice in a “mass exodus” to hunt for their seals about a week ahead of  schedule. 

Polar Bear Science reports that:

It appears from the ice maps that most of the polar bears throughout the world that have chosen to remain on land during the late summer and fall (about July/August through October/November) can now return to the ice. …

… polar bear watchers in and around Churchill Manitoba (in Western Hudson Bay) are reporting an exodus of polar bears to the sea ice that is rapidly forming offshore. While it appears from the ice map …. that only a narrow strip of sea ice has formed close to shore, this is apparently quite enough for the bears to move off the land and out to sea. Once on the ice, polar bears will start hunting for seals.

The same phenomenon is likely true all over the Arctic – ice forming near shore may not be showing up on the satellite images (e.g. western Russia, Svalbard) but it will be enough to get polar bears off land and back out to sea where they can hunt. ….

…. Kelsey says that the “bay froze about a week earlier than last year” [earlier is good] and reports that polar bears are eagerly moving offshore onto the newly-formed ice.  Sounds like the folks there to promote “Polar Bear Week” won’t find many bears to point cameras at.

Polar Bear Alley also reports:

This whole season has been about a week ahead of last year so it is not a real surprise that the bay froze about a week earlier than last year. Yesterday, we watched the mass exodus of polar bears out onto the sea ice. Most of the day consisted of yellow bear butts wobbling and weaving out towards the floe edge.

Over the past week, there have been daily highs around minus 10-15C and some fairly consistent north winds. This combination is all we need for the ice to freeze along Cape Churchill. From wind and greasy waves last Thursday to a thin band of ice along the shore by Saturday, you could see the end was near.

Most years though a late season south wind ‘saves’ bear season but this wind arrived about a day or two late this year, the ice is now locked in from what I can see. By Monday, ice floes clung to the shore and the smaller bays near Churchill were almost locked in. A north wind that night and the next day then sealed the deal.

Yesterday, there was a constant stream of polar bears crossing Cape Merry, the point between town and the Churchill River. Polar Bear Alert officers hazed some of them to speed their departure but really, once the ice is here, there is not much incentive to stay around. By 3pm, you could see twelve bears out on the ice between Eskimo Point to the west and Miss Piggy beach. ……


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