Archives par mot-clé : Greenland

climate-debate

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.

climate and geology, to keep an eye on...

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.

climate and geology, climate-debate

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.

climate-debate

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.

climate-debate

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.

climate and geology, climate-debate

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.

climate-debate

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.

climate and geology, climate-debate

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

climate-debate

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.

climate-debate

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

climate and geology, climate-debate

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.

climate and geology

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.

climate-debate

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

climate and geology, climate-debate

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.

climate-debate

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)

Current Surface Mass Budget of the Greenland Ice Sheet

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.

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