Archives par mot-clé : Greenland

Deep Purple — future biological darkening of the Greenland Ice Sheet

by GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre, October 12, 2019  in WUWT


Purple algae are making the western Greenland Ice Sheet melt faster, as the algae darken the ice surface and make it absorb more sunlight.

 

The ERC (European Research Council) has awarded an €11 million Euro Synergy grant called DEEP PURPLE to Liane G. Benning at the German Research Centre for Geosciences (GFZ) Potsdam, Germany, Alexandre Anesio at Aarhus University, Denmark and Martyn Tranter at University of Bristol, UK. Their common goal is to examine over the next six years (2020-2026) the role of glacier algae in progressively darkening the Greenland Ice Sheet surface in a warming climate.

The three researchers have already changed our understanding of why the ice darkens during the melt season by identifying the purple-pigmented ice algal blooms in the ice surface. These glacier algae are pigmented deep purple to shield their vital elements from the intense UV radiation in sunlight. During the melt season there are so many of these deep purple algae that they look as black as the soot from tundra fires. They form a dark band that has been progressively growing down the western side of the Greenland Ice Sheet during the summer melt season for the last 20 years, causing increased melting of the darkening ice.

Just why these glacier algae grow so densely is not really known at the moment, and neither is whether they will grow in the new melt zones on the ice sheet surface, to the north and to the ice sheet interior, as the climate continues to warm.

Project DEEP PURPLE

Questions such as this need answering if future sea level rise is to be predicted accurately, since Greenland melt is a major driver of current sea level rise.

Project DEEP PURPLE aims to answer these questions over the next six years, combining curisoity driven science about how the glacier algae grow and interact with their icy habitat, and societally relevant research into the processes that lead to ice surface darkening that are needed by ice melt modellers.

The scientists will work around many different sites in Greenland, making measurements of surface darkening, glacier algae density, how much soot and dust the algae trap on the surface and the physical properties of the melting ice surface to finally understand, how biological darkening occurs, and to predict where and when it will occur in the future.

New Study: Modern Arctic Sea Ice Cover Is Present MONTHS Longer Than Nearly All Of The Last 8000 Years

by Caron et al., 2019, 30 Sep. 2019 in NoTricksZone


A new reconstruction of Arctic (NW Greenland) sea ice cover (Caron et al., 2019) reveals modern day sea ice is present multiple months longer than almost any time in the last 8000 years…and today’s summer sea surface temperatures s are among the coldest of the Holocene.
Yet another new study (Caron et al., 2019) shows today’s Arctic sea ice cover is still quite extensive when compared to the last several thousand years, when CO2 concentrations ranged between 260 and 270 ppm.

Other new Arctic sea ice reconstructions from the north of Iceland (Harning et al., 2019) and Barents Sea (Berben et al., 2019) regions indicate a) modern sea ice extent has changed very little in the last several hundred years, or since the Little Ice Age, and b) the Early Holocene had millennial-scale periods of sea-ice-free and open water conditions, which is in stark contrast to “modern conditions” – the “highest value” or furthest extent of the sea ice record.

[T]he PBIP25 values [proxy for sea ice presence] reach their highest value (0.87) of the record at ca. 0 cal yr BP. An increase in PBIP25 suggests a further extension in sea ice cover, reflecting Arctic Front conditions (Müller et al., 2011), most similar to modern conditions.” (Berben et al., 2019)

 

What Greenland Heatwave?

by P. Homewood, September 1, 2019 in NotaLotofPeopleKnowThat


Let’s start with Qaanaaq (Thule), which the Mirror reporter visited during w/e 25th August. She wrote:

 

A heatwave is gripping The Arctic, melting away Greenland’s ice sheet on an unprecedented scale and threatening a global rise in sea levels – an urgent reminder of the climate crisis we are now all facing.

Kids splashing each other in the sea and locals wearing t-shirts were unheard of here in August 10 years ago.

But now, alongside teenage girls wearing skirts to school and increasing mosquitoes, it is a common occurrence for the residents of Qaanaaq, in north-west Greenland, one of the world’s most northerly cities situated 700 miles north of the Arctic Circle.

This is the frontline of climate change…..

The country is also experiencing record-breaking temperatures. In mid-June, along the eastern coast it was 9C warmer than the 1981-2010 average.

Just as western Europe has baked in a heatwave with record temperatures at the end of July, the hot air moved as far north as Greenland with the gauge hitting 22C on August 1. The average high is around 7C….

 

According to Weather Underground, however, daily maximum temperatures at Qaanaaq never got above 47F that week. The highest temperature of the month was 63F on the 1st.

KNMI confirm that the record temperature at Qaanaaq is 67F, and that a temperature of 63F was also recorded way back in 1959.

Greenland Meltdown Hoax

by P. Homewood, August 29, 2019 in NotaLotofPeopleKnowThat


You will recall those ridiculous stories about Greenland heatwaves and ice sheet meltdown, which were circulating just a couple of weeks ago :

As I pointed out at the time, they were simply not true. And, now the actual data bears this out.

The Surface Mass Balance (SMB) of the ice sheet, while below average is still well above that of 2012, and also within the historical range.. Most of the shortfall this year is because of dry weather during the winter, hence lack of snow.

[The light grey band shows differences from year to year. For any calendar day, the band shows the range over the 30 years (in the period 1981-2010), however with the lowest and highest values for each day omitted. ]

http://polarportal.dk/en/greenland/surface-conditions/

Analysis: What’s Really Going On In Greenland

by C. Martz, August 12, 2019 in ClimateChangeDispatch


As I’m sure many of my readers are aware, Europe has been having an odd summer as far as temperatures are concerned. The continent has had two major heatwaves this summer; one was in June and the other was in July.

In addition, Greenland has also seen some exceptional “warmth” and lots of ice melt this summer as compared to more recent years.

So, what’s going on? Is climate change to blame? Or, is this a freak of nature?

As with most complicated things in science, the truth is somewhere in between and is not just one way or the other. I hate saying that as a “black and white” person, but it’s an unfortunate fact. One can not make a preconceived notion based on one weather event without looking at a.) the big picture, b.) mechanism, and c.) long-term trends.

The upper air pattern over Europe and Greenland is opposite of what’s been occurring in much of the United States. The U.S. has only had one major heatwave this year, and that in and of itself caused mass hysteria.

Greenland’s ‘Record Temperature’ denied – the data was wrong

by Anthony Watts, August 12, 2019 in WUWT


From the “But, but, wait! Our algorithms can adjust for that!” department comes this tale of alarmist woe. Greenland’s all-time record temperature wasn’t a record at all, and it never got above freezing there.


First, the wailing from news media:

NYT: https://www.nytimes.com/2019/08/02/climate/european-heatwave-climate-change.html

WAPO: https://www.washingtonpost.com/news/capital-weather-gang/wp/2016/06/10/greenland-witnessed-its-highest-june-temperature-ever-recorded-on-thursday/

Climate Progress: https://thinkprogress.org/greenland-hits-record-75-f-sets-melt-record-as-globe-aims-at-hottest-year-e34e534e533e/

Polar Portal: http://polarportal.dk/en/news/news/record-high-temperature-for-june-in-greenland/


Now from the Danish Meteorological Institute (DMI), via the news website The Local, the cooler reality:

For Most Of The Last 10,000 Years, Greenland Ice Sheet and Glacier Volume Was Smaller Than Today

by K. Richard, August 5, 2019 in NoTricksZone


A new paper (Axford et al., 2019) reveals NW Greenland’s “outlet glaciers were smaller than today from ~9.4 to 0.2 ka BP” (9,400 to 200 years before 1950), and that “most of the land-based margin reached its maximum Holocene extent in the last millennium and likely the last few hundred years.”

The authors conclude:

“We infer based upon lake sediment organic and biogenic content that in response to declining temperatures, North Ice Cap reached its present-day size ~1850 AD, having been smaller than present through most of the preceding Holocene.”

Furthermore, the authors assert Greenland was 2.5°C to 3°C warmer than modern on average during the Holocene Thermal Maximum, and peak temperatures were 4°C to 7°C warmer.

 

 

Image Source: Mikkelson et al., 2018

Greenland Ice sheet Meltdown Scare–Except It’s Not True

by P.  Homewood,  August 1, 2019 in NotaLotofPeopleKnowThat


The same heat dome that roasted Europe and broke national temperature records in five countries last week has shifted to Greenland, where it is causing one of the biggest melt events ever observed on the fragile ice sheet.

By some measures, the ice melt is more extreme than during a benchmark record event in July 2012, according to scientists analyzing the latest data. During that event, about 98 percent of the ice sheet experienced some surface melting, speeding up the process of shedding ice into the ocean.

The fate of Greenland’s ice sheet is of critical importance to every coastal resident in the world, since Greenland is already the biggest contributor to modern-day sea level rise. The pace and extent of Greenland ice melt will help determine how high sea levels climb and how quickly….

The Danish Meteorological Institute tweeted that more than half the ice sheet experienced some degree of melting on Tuesday, according to a computer model simulation, which made it the “highest this year by some distance.”

And there is no mention of the fact that the ice sheet grew substantially last year, and also the year before:

The simple fact is that the Greenland ice sheet melts every summer, particularly when the sun shines. That’s what it does. And it grows back again in winter as the snow falls. Indeed, if it did not melt, it would carry on growing year after year.

Inevitably there are some days when the weather is warmer and sunnier than normal, and others when it is colder. To pick an odd day or two is ridiculous and dishonest scaremongering.

See also here and here

Fake “Heatwave for Greenland” Claims

by P. Homewood, July 30, 2019 in NotaLotofPeopleKnowThat


And that Greenland ice? The Surface Mass Balance has been well below normal throughout the winter, because of the dry weather. The rate of summer melt, however, has been pretty much normal, contrary to the fake claims of Ms Nullis.

With only a couple of weeks of melt left, it seems extremely unlikely that, even with the sunshine forecast, that the ice will dip below the 2012 figure (which incidentally is only a “record low” since records began in 1981).

http://polarportal.dk/en/greenland/surface-conditions/

Geoscientists discover mechanisms controlling Greenland ice sheet collapse

by University of South Florida (USF Innovation), July 19, 2019 in ScienceDaily/Nature


 

Greenland’s more than 860,000 square miles are largely covered with ice and glaciers, and its melting fuels as much as one-third of the sea level rise in Florida. That’s why a team of University of South Florida geoscientists’ new discovery of one of the mechanisms that allows Greenland’s glaciers to collapse into the sea has special significance for the Sunshine State.

New radar technology allowed geoscientists to look at Greenland’s dynamic ice-ocean interface that drives sea level rise.

Earlier this spring, NASA scientists reported Jakobshavn Glacier, which has been Greenland’s fastest -thinning glacier for the last 20 years, was slowing in its movement toward the ocean in what appears to be a cyclical pattern of warming and cooling. But because Jakobshavn is still giving up more ice than it accumulates each year, its sheer size makes it an important factor in sea level rise, the NASA scientists maintain.

“Our study helps understand the calving process,” Dixon said. “We are the first to discover that mélange isn’t just some random pile of icebergs in front of the glacier. A mélange wedge can occasionally ‘hold the door’ and keep the glacier from calving.”

Journal Reference:

  1. Surui Xie, Timothy H. Dixon, David M. Holland, Denis Voytenko, Irena Vaňkov�. Rapid iceberg calving following removal of tightly packed pro-glacial mélange. Nature Communications, 2019; 10 (1) DOI: 10.1038/s41467-019-10908-4

Scientist Spots High Geothermal Heat Flux In East Greenland – ‘Dramatic Consequences For Ice Basal Melting’

by K. Richard, July 5, 2019 in NoTricksZone


Geothermal heat flux can foment upper mantle temperature anomalies of 800–1000 °C, and these extreme heat intensities have been found to stretch across 500 km of central-east Greenland. This could result in “a significant contribution of ice melt to the ice-drainage system of Greenland” (Artemieva et al., 2019).

Evidence of more than 100,000 formerly or currently active volcanic vents permeate the Earth’s sea floor (Kelley, 2017).

Active volcanoes spew 380°C sulfuric acid and “metal-laden acidic fluids” into the bottom waters of the world ocean on a daily basis. In other words, literal ocean acidification is a natural phenomenon.

The carbon dioxide concentrations present in these acidic floods reach “astounding” levels, dwarfing the potential for us to even begin to appreciate the impact this explosive geothermal activity has on the Earth’s carbon cycle (Kelley, 2017).

More than 50 newly discovered lakes beneath the Greenland Ice Sheet

by Lancaster University, June 26, 2019 in ScienceDaily


Researchers have discovered 56 previously uncharted subglacial lakes beneath the Greenland Ice Sheet bringing the total known number of lakes to 60. Although these lakes are typically smaller than similar lakes in Antarctica, their discovery demonstrates that lakes beneath the Greenland Ice Sheet are much more common than previously thought.

Dr Stephen J. Livingstone, Senior Lecturer in Physical Geography, University of Sheffield, said:

“The lakes we have identified tend to cluster in eastern Greenland where the bed is rough and can therefore readily trap and store meltwater and in northern Greenland, where we suggest the lakes indicate a patchwork of frozen and thawed bed conditions.

“These lakes could provide important targets for direct exploration to look for evidence of extreme life and to sample the sediments deposited in the lake that preserve a record of environmental change.”

How geologic forces are melting southern Greenland ice sheet

by J.E. Kamis, May 25, 2016 in ClimateChangeDispatch


The most plausible scenario for southern Greenland’s surface ice melt is related to geologically induced heat flow and not atmospheric warming for various, well-established reasons. Based on research by the National Oceanic and Atmospheric Administration (NOAA) (see here), the top surface of southern Greenland’s ice sheet is currently melting at a high rate and therefore greatly reducing surface ice volume. They attribute this geographically localized melting effect to an unusually persistent and man-made atmospheric high pressure system (a so-called Omega Block) that has remained stationary above southern Greenland during the spring of 2016.

This non-moving high-pressure system has trapped a cell of very warm air above southern Greenland resulting in higher-than-normal surface ice melting rates and volumes. NOAA and the mainstream media are portraying this above-average melting as undeniable proof man-made global warming damaging our planet.

This portrayal is vastly misleading.

That’s because southern Greenland’s surface ice melt is more likely caused by natural, geologically induced heat flow from one of Earth’s largest Deep Ocean crustal plate junctures, the 10,000 mile long Mid-Atlantic Ridge (MAR). The Mid-Atlantic Ridge is “an immensely long mountain chain extending for about 10,000 miles (16,000 km) in a curving path from the Arctic Ocean to near the southern tip of Africa. The ridge is equidistant between the continents on either side of it. The mountains forming the ridge reach a width of 1,000 miles.”

Greenland ice loss projections are clouded by clouds

by Brooks Hays, June 24, 2019 in UPI


June 24 (UPI) — Predicting where, how and how quickly Greenland’s ice will melt is difficult. Projections by the best models are cloudy, and new research suggests clouds are doing the clouding.

Currently, models of Greenland’s melting ice sheet put the greatest emphasis on the impacts of greenhouse gas emissions. But new research, published this week in the journal Nature Climate Change, suggests the microphysics of clouds are equally important.

 

Under high emission scenarios, the uncertainties of Greenland ice sheet models are caused almost entirely by the uncertainties of cloud dynamics.

Cloud cover dictates the ice sheet’s longwave radiation exposure. When clouds over Greenland are thicker, they operate like an insulating blanket, encouraging longwave radiation and surface-level melting.

If “Greenland is catastrophically melting”, how do alarmists explain NASA’s growing Greenland glacier?

by A. Watts, June19, 2019 in WUWT


It turned out to be a weather event, unrelated to “climate change”. The next year, there was no “insta-melt“.

In fact. we’d not even know about the melting in Greenland before satellites came on the scene. So how many times in the history of the Earth has Greenland has a quick melt spike? I’m guessing hundreds of thousands of times.

Jakobshavn Glacier in western Greenland is notorious for being the world’s fastest-moving glacier. It is also one of the most active, discharging a tremendous amount of ice from the Greenland Ice Sheet into Ilulissat Icefjord and adjacent Disko Bay—with implications for sea level rise. The image above, acquired on June 6, 2019, by the Operational Land Imager (OLI) on Landsat 8, shows a natural-color view of the glacier.

Jakobshavn has spent decades in retreat—that is, until scientists observed an unexpected advance between 2016 and 2017. In addition to growing toward the ocean, the glacier was found to be slowing and thickening. New data collected in March 2019 confirm that the glacier has grown for the third year in a row, and scientists attribute the change to cool ocean waters.

June 6th, 2019 Jakobshavn Glacier in western Greenland . Image acquired on June 6, 2019, by the Operational Land Imager (OLI) on Landsat 8, shows a natural-color view of the glacier.