The Danish Meteorological Institute (DMI) admitted it wrongly reported Greenland’s record summer warmth, in what it called “good news from a climate perspective”…?
The DMI, a key player in monitoring Greenland’s climate, reported a “shocking” early-August temperature of between 2.7C (37F) and 4.7C (40.5F) at the Summit weather station, located some 3,202m above sea level at the center of the Greenland ice sheet.
This news quickly spread to every corner of the left-leaning web, like some nasty EOTW rash. But just a few days later the DMI posted a tweet retracting that record temp, saying that after a “closer look” (whatever that means exactly) it was revealed that the monitoring equipment had been giving “erroneous results”.
“Was there record-level warmth on the inland ice on Friday?” said the institute’s tweet dated Aug 08. “No! A quality check has confirmed out suspicion that the measurement was too high.”
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.
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)
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.
You will recall those ridiculous stories about Greenland heatwavesand 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. ]
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.
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.
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.
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.
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).
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.”
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
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).
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.”
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.”
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.
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.
by P. Homewood, May 22, 2019 in NotaLotofPeopleKnowThat
European satellites have detailed the abrupt change in behaviour of one of Greenland’s most important glaciers.
In the 2000s, Jakobshavn Isbrae was the fastest flowing ice stream on the island, travelling at 17km a year.
As it sped to the ocean, its front end also retreated and thinned, dropping in height by as much as 20m year.
But now it’s all change. Jakobshavn is travelling much more slowly, and its trunk has even begun to thicken and lengthen.
“It’s a complete reversal in behaviour and it wasn’t predicted,” said Dr Anna Hogg from Leeds University and the UK Centre for Polar Observation and Modelling (CPOM).
“The question now is: what’s next for Jakobshavn? Is this just a pause, or is it a switch-off of the dynamic thinning we’ve seen previously?”
The rapid flow, thinning and retreat of Jakobshavn’s front end in the mid to late 2000s were probably driven by warm ocean water from Disko Bay getting into the fjord and attacking the glacier from below.
The phase change, scientists think, may be related to very cold weather in 2013. This would have resulted in less meltwater coming off the glacier, which in turn might have choked the mechanism that pulls warm ocean water towards Jakobshavn.
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.
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.
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.
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.
La géologie, une science plus que passionnante … et diverse