Archives par mot-clé : Greenland

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.

New Science Affirms Arctic Region Was 6°C Warmer Than Now 9000 Years Ago, When CO2 Levels Were ‘Safe’

by K. Richard, July 12, 2018 in NoTricksZone


Unearthed new evidence (Mangerud and Svendsen, 2018) reveals that during the Early Holocene, when CO2 concentrations hovered around 260 ppm, “warmth-demanding species” were living in locations 1,000 km farther north of where they exist today in Arctic Svalbard, indicating that summer temperatures must have been about “6°C warmer than at present”.

Proxy evidence from two other new papers suggests Svalbard’s Hinlopen Strait  may have reached about 5 – 9°C warmer than 1955-2012 during the Early Holocene (Bartels et al., 2018), and Greenland may have been “4.0 to 7.0 °C warmer than modern [1952-2014]” between 10,000 and 8,000 years ago according to evidence found in rock formations at the bottom of ancient lakes (McFarlin et al., 2018).

In these 3 new papers, none of the scientists connect the “pronounced” and “exceptional” Early Holocene warmth to CO2 concentrations.

Ancient Greenland was much warmer than previously thought

by Amanda Morris, June 4, 2018 inNorthwesternUniversity


A tiny clue found in ancient sediment has unlocked big secrets about Greenland’s past and future climate.

Just beyond the northwest edge of the vast Greenland Ice Sheet, Northwestern University researchers have discovered lake mud that beat tough odds by surviving the last ice age. The mud, and remains of common flies nestled within it, record two interglacial periods in northwest Greenland. Although researchers have long known these two periods — the early Holocene and Last Interglacial — experienced warming in the Arctic due to changes in the Earth’s orbit, the mix of fly species preserved from these times shows that Greenland was even warmer than previously thought.

Largest High-Arctic Lake Melting From Geothermal Heat, Not Global Warming

by James E. Kamis, April 16, 2018  in ClimateChangeDispatch


Recent changes to Lake Hazen, the world’s largest high-Arctic lake, are from increased heat flow from the area’s known geological features, and not from global warming as per the many alarmist media reports.

Evidence supporting this is abundant and reliable.

Northeast Canada’s Lake Hazen lies adjacent to the world-class Greenland/Iceland mantle plume.

A Geological Perspective of the Greenland Ice Sheet

by D. Middleton, March 22, 2018 in WUWT


How Does the Recent Melting of the Greenland Ice Sheet Compare to the Early Holocene?

Short answer: Same as it ever was.  Vinther et al., 2009 reconstructed the elevations of four ice core sites over the Holocene.  There has been very little change in elevation of the two interior ice core sites (NGRIP and GRIP), while the two outboard sites (Camp Century and DYE3) have lost 546 and 342 m of ice respectively.

High geothermal heat flux in close proximity to the Northeast Greenland Ice Stream

by Rysgaard et al., January 22, 2018 in NatureSci.Reports


The Greenland ice sheet (GIS) is losing mass at an increasing rate due to surface melt and flow acceleration in outlet glaciers. Currently, there is a large disagreement between observed and simulated ice flow, which may arise from inaccurate parameterization of basal motion, subglacial hydrology or geothermal heat sources. Recently it was suggested that there may be a hidden heat source beneath GIS caused by a higher than expected geothermal heat flux (GHF) from the Earth’s interior.

Greenland Is Getting Colder–New Study

by P Homewood, January 29, 2018 in NotaLotofPeopleKnowThat


Using satellite data, a group of scientists has studied the development of temperature over the past 15 years in a large part of Greenland.

More precisely, they looked at surface temperatures (the temperature close to the Earth’s surface) in a part of the country that is not covered by ice—around one fifth of the surface area of Greenland.

Intuitively, you may think that temperature throughout all of Greenland has been increasing, but that is not the case. When you look at the yearly average, the ice-free parts of Greenland show a slight drop in temperature between 2001 and 2015. With swings in temperature from year to year.

However, these results should not be interpreted as “proof” that the Earth is not warming, say the scientists behind the research, which is published in the journal Scientific Reports.

Groundbreaking AGW-Undermining Study: Greenland’s Warming, Ice Loss Due To Geothermal Heat

by K. Richard, January 24, 2018 in NoTricksZone


A few years ago, 10 glaciologists publishing in the journal Nature Geoscience asserted that “large parts of the north-central Greenland ice sheet are melting from below” due to high geothermal heat flux forcing (Rogozhina et al., 2016).

In a new paper published in Scientific Reports, 4 more glaciologists (Rysgaardet al., 2018) report that “hot vents” (or hot springs) of geothermally-heated water underneath the Greenland ice sheet can explain localized rising temperatures and glacial melting.

An Inconvenient Deception: How Al Gore Distorts Climate Science and Energy Policy

by Roy W.  Spencer, Ph. D., August 19, 2017 in GlobalWarming


Al Gore has provided a target-rich environment of deceptions in his new movie.

After viewing Gore’s most recent movie, An Inconvenient Sequel: Truth to Power, and after reading the book version of the movie, I was more than a little astounded. The new movie and book are chock-full of bad science, bad policy, and factual errors.

Three New Papers: Greenland 3-5°C Warmer With 40 Kilometers Less Ice Area 4,000-10,000 Years Ago

by Kenneth Richard, July 11, in ClimateChangeDispatch


It’s official. According to a new paper published in the journal Scientific Reports, Greenland has been cooling slightly since 2005.

This trend development may be a harbinger of what may be in store for the coming years.  Shifts in North Atlantic temperatures typically lead changes in the Arctic by a few years.  And throughout the North Atlantic, rapid cooling has been underway since 2005, plunging below the levels reached in the 1950s

IMPRESSIVE COLD IN GREENLAND AND NEAR RECORD ACCUMULATIONS OF SNOW AND ICE

by Vencore Weather, July 4, 2017


Much of Greenland has been colder-than-normal for the year so far and has had record or near record levels of accumulated snow and ice since the fall of last year. The first week of this month was especially brutal in Greenland resulting in the record low July temperature and it also contributed to an uptick in snow and ice extent – despite the fact that it is now well into their summer season.

Current Surface Mass Budget of the Greenland Ice Sheet

by DMI, July 2017


The model has been updated in 2014 to better account for meltwater refreezing in the snow, and again in 2015 to account for the lower reflectivity of sunlight in bare ice than in snow. Finally, it has been updated again in 2017 with a more advanced representation of percolation and refreezing of meltwater. At the same time, we have extended the reference period to 1981-2010. The update means that the new maps, values and curves will deviate from the previous ones. Everything shown on this site, however, is calculated with this new model, so that all curves and values are comparable.

See also here

Global versus Greenland Holocene Temperatures

by Andy May, June 19, 2017 i


Last week, I posted a global temperature reconstruction based mostly on Marcott, et al. 2013 proxies. The post can be found here. In the comments on the Wattsupwiththat post there was considerable discussion about the difference between my Northern Hemisphere mid-latitude (30°N to 60°N) and the GISP2 Richard Alley central Greenland temperature reconstruction (see here for the reference and data). See the comments by Dr. Don Easterbrook and Joachim Seifert (weltklima) here and here, as well as their earlier comments.

Threshold in North Atlantic-Arctic Ocean circulation controlled by the subsidence of the Greenland-Scotland Ridge

by Michael Stars et al., June 5, 2017 in Nature Communication


High latitude ocean gateway changes are thought to play a key role in Cenozoic climate evolution. However, the underlying ocean dynamics are poorly understood. Here we use a fully coupled atmosphere-ocean model to investigate the effect of ocean gateway formation that is associated with the subsidence of the Greenland–Scotland Ridge. We find a threshold in sill depth (50 m) that is linked to the influence of wind mixing.

Current Surface Mass Budget of the Greenland Ice Sheet

by DMI (Danish Meteorological Institute), May, 2017


Here you can follow the daily surface mass balance on the Greenland Ice Sheet. The snow and ice model from one of DMI’s climate models is driven every six hours with snowfall, sunlight and other parameters from a research weather model for Greenland, Hirlam-Newsnow.

See also, Study: Antarctica’s ice sheet survived warmer times, remains stable today

See also, Antarctic study shows central ice sheet is stable since milder times

Greenland was nearly ice-free for extended periods during the Pleistocene

by JM Schaefer et al., Nature, December8, 2016


Here we show that Greenland was deglaciated for extended periods during the Pleistocene epoch (from 2.6 million years ago to 11,700 years ago), based on new measurements of cosmic-ray-produced beryllium and aluminium isotopes (10Be and 26Al) in a bedrock core from beneath an ice core near the GIS summit.

Current Surface Mass Budget of the Greenland Ice Sheet

Danish Meteorological Institute (DMI), February 2017


Greenland has gained 500 Gt of ice this winter (2016-2017)

Here you can follow the daily surface mass balance on the Greenland Ice Sheet. The snow and ice model from one of DMI’s climate models is driven every six hours with snowfall, sunlight and other parameters from a research weather model for Greenland, Hirlam-Newsnow.