Archives par mot-clé : Greenland

Greenland Temperature Data For 2018

by P. Homewood, April 24, 2019 in NotaLotOfPeopleKnowThat


The DMI has just published its Greenland Climate Data Collection for last year, and it is worth looking at the temperature data:

There are six stations with long records, Upernavik, Nuuk, Ilulissat, Qaqortoq, Narsarsuaq and Tasilaq.

Throughout Greenland we find that temperatures in the last two decades are little different to the 1920s to 60s.

The only exceptions were 2010 on the west coast sites, which was an unusually warm year, and 2016 on the east coast at Tasilaq, another warm year there.

Noticeably, last year was actually colder than the 1981-2010 average at all of the west and south coast stations.

 

Inconvenient: NASA says a Greenland glacier did an about-face – growing again

by Anthony Watts, March 25, 2019 in WUWT


“…scientists were so shocked to find the change.”

From NASA JPL: Cold Water Currently Slowing Fastest Thinning Greenland Glacier

NASA research shows that Jakobshavn Glacier, which has been Greenland’s fastest-flowing and fastest-thinning glacier for the last 20 years, has made an unexpected about-face. Jakobshavn is now flowing more slowly, thickening, and advancing toward the ocean instead of retreating farther inland. The glacier is still adding to global sea level rise – it continues to lose more ice to the ocean than it gains from snow accumulation – but at a slower rate.

The researchers conclude that the slowdown of this glacier, known in the Greenlandic language as Sermeq Kujalleq, occurred because an ocean current that brings water to the glacier’s ocean face grew much cooler in 2016. Water temperatures in the vicinity of the glacier are now colder than they have been since the mid-1980s.

See also here in NBS

GREENLAND ICE SHEET SIXTH HIGHEST ON RECORD

by GWPF, December 7, 2019


In 2018, Greenland’s total  surface mass budget (SMB) is almost 150bn tonnes above the average for 1981-2010, ranking as sixth highest on record.

 

The Danish Meteorological Institute (DMI) also performs daily simulations of how much ice or water the Ice Sheet loses or accumulates. Based on these simulations, an overall assessment of how the surface mass balance develops across the entire Ice Sheet is obtained (Fig. 4).

At the end of the 2018 season (31 August 2018), the net surface mass balance was 517 Gt, which means that 517 Gt more snow fell than the quantity of snow and ice that melted and ran out into the sea.

Greenland’s Glaciers Expanding Again

by P. Homewood, March 11, 2019 in NotaLotofPeopleKnowThat


As I reported last  September, Greenland’s ice sheet mass balance had grown at close to record levels for the second year running.

To clarify again, the mass balance calculation accounts for:

1) Snowfall

2) Ice melt

3) Ablation

 

In other words, it does not include calving.

http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/#

..

Polar bear habitat update: abundant sea ice across the Arctic, even in the Barents Sea

by Polar Bear Science, March 12, 2019


Abundant ice in Svalbard, East Greenland and the Labrador Sea is excellent news for the spring feeding season ahead because this is when bears truly need the presence of ice for hunting and mating. As far as I can tell, sea ice has not reached Bear Island, Norway at this time of year since 2010 but this year ice moved down to the island on 3 March and has been there ever since. This may mean we’ll be getting reports of polar bear sightings from the meteorological station there, so stay tuned.


Novel hypothesis goes underground to predict future of Greenland ice sheet

by Penn State, February 2,  2019 in ScienceDaily


Paleoclimatic records indicate that most of Greenland was ice-free within the last 1.1 million years even though temperatures then were not much warmer than conditions today. To explain this, the researchers point to there being more heat beneath the ice sheet in the past than today.

Data show that when the Iceland hot spot — the heat source that feeds volcanoes on Iceland — passed under north-central Greenland 80 to 35 million years ago, it left molten rock deep underground but did not break through the upper mantle and crust to form volcanoes as it had in the west and east. The Earth’s climate then was too warm for Greenland to have an ice sheet, but once it cooled the ice sheet formed, growing and shrinking successive with ice ages.

Greenland Is Way Cool

by Willis Eschenbach, January 8, 2019


As a result of a tweet by Steve McIntyre, I was made aware of an interesting dataset. This is a look by Vinther et al. at the last ~12,000 years of temperatures on the Greenland ice cap. The dataset is available here.

Figure 1 shows the full length of the data, along with the change in summer insolation at 75°N, the general location of the ice cores used to create the temperature dataset.

Figure 1. Temperature anomalies of the Greenland ice sheet (left scale, yellow/black line), and the summer insolation in watts per square metre at 75°N (right scale, blue/black line). The red horizontal dashed line shows the average ice sheet temperature 1960-1980.

I’ll only say a few things about each of the graphs in this post. Regarding Figure 1, the insolation swing shown above is about fifty watts per square metre. Over the period in question, the temperature dropped about two and a half degrees from the peak in about 5800 BCE. That would mean the change is on the order of 0.05°C for each watt per square metre change in insolation …

Algae thrive under Greenland sea ice

by Bigelow Laboratory for Ocean Sciences, January 8, 2019 in ScicneDaily


Microscopic marine plants flourish beneath the ice that covers the Greenland Sea, according to a new study. These phytoplankton create the energy that fuels ocean ecosystems, and the study found that half of this energy is produced under the sea ice in late winter and early spring, and the other half at the edge of the ice in spring.

“Terrifying Sea-Level Prediction Now Looks Far Less Likely”… But “marine ice-cliff instability” is “just common sense”

by David Middleton, January 5, 2019 in WUWT


Marine ice cliff instability (MICI) “has not been observed, not at such a scale,” “might simply be a product of running a computer model of ice physics at a too-low resolution,” ignores post glacial rebound, couldn’t occur before ” until 2250 or 2300″… Yet “the idea is cinematic,” “it’s just common sense that Antarctic glaciers will develop problematic ice cliffs” and something we should plan for…

“Our results support growing evidence that calving glaciers are particularly sensitive to climate change.”  Greenland’s climate is always changing… Always has and always will change… And the climate changes observed over the last few decades are not unprecedented. The Greenland ice sheet is no more disappearing this year than it was last year and it is physically impossible for the ice sheet to “collapse” into the ocean.

Figure 6. Jakobshavn Isbrae. (Wikipedia and Google Earth)

GREENLAND ICE SHEET SIXTH HIGHEST ON RECORD

by GWPF, December 7, 2018


The Danish Meteorological Institute (DMI) also performs daily simulations of how much ice or water the Ice Sheet loses or accumulates. Based on these simulations, an overall assessment of how the surface mass balance develops across the entire Ice Sheet is obtained (Fig. 4).

At the end of the 2018 season (31 August 2018), the net surface mass balance was 517 Gt, which means that 517 Gt more snow fell than the quantity of snow and ice that melted and ran out into the sea. This number only contains the balance at the surface, and thus not the total balance, which also includes melting of glaciers and calving of icebergs.

Although the total SMB  (Surface Mass Budget) for the 2016-2017 and 2017-2018 seasons are similar, development during the two seasons has been very different. Last year, the season began by gaining a lot of mass during the winter, whilst the development in SMB from the summer onwards reflected the long-term average. During the 2017-2018 season, SMB remained in line with the average from 1981-2010 until the summer, after which the development in SMB was higher than average.

How the Greenland ice sheet fared in 2018

by R. Mottram et al.  (DMI), October 27, 2018 in ScienceNordic


The end of August traditionally marks the end of the melt season for the Greenland ice sheet as it shifts from mostly melting to mostly gaining snow.

As usual, this is the time when the scientists at DMI and our partners in the Polar Portal assess the state of the ice sheet after a year of snowfall and ice melt. Using daily output from a weather forecasting model combined with a model that calculates melt of snow and ice, we calculate the “surface mass budget” (SMB) of the ice sheet.

This budget takes into account the balance between snow that is added to the ice sheet and melting snow and glacier ice that runs off into the ocean. The ice sheet also loses ice by the breaking off, or “calving”, of icebergs from its edge, but that is not included in this type of budget. As a result, the SMB will always be positive – that is, the ice sheet gains more snow than the ice it loses.

For this year, we calculated a total SMB of 517bn tonnes, which is almost 150bn tonnes above the average for 1981-2010, ranking just behind the 2016-17 season as sixth highest on record.

By contrast, the lowest SMB in the record was 2011-2012 with just 38bn tonnes, which shows how variable SMB can be from one year to another.

Maps show the difference between the annual SMB in 2017 (left) and 2018 (right) compared with the 1981-2010 period (in mm of ice melt). Blue shows more ice gain than average and red shows more ice loss than average. (Credit: DMI Polar Portal)

Greenland Temperatures In 2017

by P. Homewood, July 1, 2018 in NotaLotofPeopleKnowThat


As we all know, Greenland is warming up rapidly, causing the ice sheet to melt faster and faster.

Well, according to the BBC and New York Times, at least.

Only one slight problem – the temperature record shows quite a different story.

There is certainly no evidence of rising temperature trends, and every likelihood that temperatures will plummet again when the AMO turns cold again.

Glacier depth affects plankton blooms off Greenland

by Helmholtz Centre for Ocean Research Kiel (GEOMAR), Auhsut 14, 2018 in ScienceDaily


The unusual timing of highly-productive summer plankton blooms off Greenland indicates a connection between increasing amounts of meltwater and nutrients in these coastal waters. Researchers now show that this connection exists, but is much more complex than widely supposed. Whether increasing meltwater has a positive or negative effect on summertime phytoplankton depends on the depth at which a glacier sits in the ocean.

“So, the study shows that further melting of Greenland’s glaciers only leads to stronger summer plankton blooms under very specific conditions, an effect that will ultimately end with very extensive further melting,” Hopwood summarizes the results of the study.