Archives par mot-clé : Greenland

Greenland’s 2021 spring: more snow, less melt

by C. Rotter, July 14, 2021 in WUWTfromNSIDC


Surface melt and total melt-day area for the Greenland Ice Sheet at the end of the 2021 spring season was below the 1981 to 2010 average. Snowfall and rain (minus runoff) added mass to the ice sheet. As of June 20, total mass gain for the ice sheet since September 2020 was slightly above average. The spike from June 25 to June 27 will be discussed in later a post.

Greenland Temperatures & The AMO

by P. Homewood, June 13, 2021 in NotaLotofPeopleKnowThat


It’s not new, but it’s worth going over it again.

We have seen how Greenland temperatures rose sharply in the 1920s, and remained at levels similar to the last decade until the 1960s, when they fell equally sharply. This change in climate is closely interlinked with the Atlantic Multidecadal Oscillation (AMO), which switches from cold to warm phase, and back again, roughly every 50 to 60 years:

The anatomy of past abrupt warmings recorded in Greenland ice

by C. Rotter, Apr 19, 2021 in WUWT/Nature


New paper at Nature Communications

Abstract

Data availability and temporal resolution make it challenging to unravel the anatomy (duration and temporal phasing) of the Last Glacial abrupt climate changes. Here, we address these limitations by investigating the anatomy of abrupt changes using sub-decadal-scale records from Greenland ice cores. We highlight the absence of a systematic pattern in the anatomy of abrupt changes as recorded in different ice parameters. This diversity in the sequence of changes seen in ice-core data is also observed in climate parameters derived from numerical simulations which exhibit self-sustained abrupt variability arising from internal atmosphere-ice-ocean interactions. Our analysis of two ice cores shows that the diversity of abrupt warming transitions represents variability inherent to the climate system and not archive-specific noise. Our results hint that during these abrupt events, it may not be possible to infer statistically-robust leads and lags between the different components of the climate system because of their tight coupling.

Greenland And Iceland Mean Winter Temperatures Continue Cooling Since Start Of The Century

by Kirye & Pierre, March 24, 2021 in NoTricksZone


The February 2021 data for Iceland and Greenland are available from the Japan Meteorological Agency (JMA), which means the latest meteorological DJF winter mean temperature can be computed.

Icelandic winters have cooled since 2001

We plotted the JMA data for three stations (the ones with sufficient data) in Iceland. Result: no warming over the past 18 winters!

Danish Institute Data: Greenland Ice Melt Has Slowed Down Significantly Over Past Decade

by P. Gosselin, March 10, 2021 in NoTricksZone


The media and activists, among them a number of “Climate scientists”, have been declaring that Greenland ice melt has been accelerating.

Today the German Klimaschau climate news video reports, however, that this has not been the case over the recent years. All the recent talk about accelerating Greenland ice loss over the past years is false.

SMB on the rise

First a plot of Greenland’s surface mass balance SMB (blue curve below) shows that snow accumulation has occurred faster than snow and ice have melted over the past 35 years:

Chart: cropped from Klimaschau here

Though the annual SMB values declined from 1985 to 2012, the trend has rebounded since.

Loss through coastal discharge steady over the past 15 years

Southeast Greenland Sea Surface Temperature 1° – 2°C Warmer In 1940 Than Today, New Study Shows

by P. Gosselin, Feb 14, 2021 in NoTricksZone


A team of Danish scientists led by David Wangner published a paper a year ago about the results of a Greenland sediment core from Skjoldungen Fjord, near the Thrym Glacier, which allowed sea surface temperatures to be reconstructed.

The core covers the past 200 years (1796–2013). The scientists find that the SST record compares well with other alkenone‐based reconstructions from SE‐Greenland and thus features regional shelf water variability.

Today some scientists like claiming the present is warmer than at any time in the past 1000 years and suggest the Greenland ice sheets are rapidly melting. But the results of the core reconstruction show that it was warmer in the past, some 80 years ago

Ocean forcing drives glacier retreat in Greenland

by M. Wood et al., Jan 01, 2021 in AAAS OPEN ACCESS


INTRODUCTION

The Greenland Ice Sheet has contributed substantially to sea-level rise over the past few decades. Since 1972, approximately two-thirds of the ice sheet’s contribution to sea-level rise resulted from increased glacier flux with the remaining one-third from anomalous surface melt (1). Before 2000, anomalous ice discharge was the dominant driver of mass loss, but in recent years, increasingly negative surface mass balance anomalies have contributed to a larger proportion of the total mass loss from the ice sheet (1). The acceleration in mass flux has been partially attributed to a warming of subsurface waters around Greenland near the end of the 1990s (2, 3) and increased runoff, resulting in enhanced water mixing and melt at glacier margins, destabilization of terminus regions (4, 5), ice front retreat (6, 7), and, in most cases, accelerated ice flow (8). The increase in flow speed, combined with enhanced surface melt, results in increased glacier thinning, which is conducive to further retreat (9). Other processes may have additionally contributed to the glacier retreat, e.g., increases in basal lubrication, melting of the ice mélange in front of glaciers, or weakening of glacier shear margins, but quantitative evidence about their impact has been limited (1012).

The warming of subsurface waters at the turn of the 21st century was caused by the spreading of ocean heat from the subpolar gyre during a transition in the North Atlantic Oscillation (NAO) from a high positive phase to a low-to-negative phase (3). In this shift, the North Atlantic subpolar gyre expanded, enhancing ocean heat fluxes through the coastal Irminger and West Greenland currents, yielding warmer subsurface waters on the continental shelf of all seven major basins of Greenland (Fig. 1). Since 2010, the NAO has transitioned back to a more positive phase, yielding a relative cooling of the ocean waters, however, not sufficiently to bring back ocean heat fluxes to the levels of the 1990s (13).

Newly discovered Greenland plume drives thermal activities in the Arctic

by Tohoku University, Dec 7, 2020 in ScienceDaily


A team of researchers understands more about the melting of the Greenland ice sheet. They discovered a flow of hot rocks, known as a mantle plume, rising from the core-mantle boundary beneath central Greenland that melts the ice from below.

The results of their two-part study were published in the Journal of Geophysical Research.

“Knowledge about the Greenland plume will bolster our understanding of volcanic activities in these regions and the problematic issue of global sea-level rising caused by the melting of the Greenland ice sheet,” said Dr. Genti Toyokuni, co-author of the studies.

The North Atlantic region is awash with geothermal activity. Iceland and Jan Mayen contain active volcanoes with their own distinct mantle plumes, whilst Svalbard — a Norwegian archipelago in the Arctic Ocean — is a geothermal area. However, the origin of these activities and their interconnectedness has largely been unexplored

 

Possible 1,000-kilometer-long river running deep below Greenland’s ice sheet

by  Hokkaido University, Nov 12, 2020 in EurekaAlert


Computational models suggest that melting water originating in the deep interior of Greenland could flow the entire length of a subglacial valley and exit at Petermann Fjord, along the northern coast of the island. Updating ice sheet models with this open valley could provide additional insight for future climate change predictions.

IMAGE: THE SUGGESTED VALLEY AND POSSIBLE RIVER FLOWING FROM THE DEEP INTERIOR OF GREENLAND TO PETERMANN FJORD DEEP BELOW GREENLAND’S ICE SHEET (500 METERS BELOW SEA LEVEL). (CHRISTOPHER CHAMBERS ET AL,… view more 

CREDIT: CHRISTOPHER CHAMBERS ET AL, THE CRYOSPHERE, NOVEMBER 12, 2020.

Radar surveys have previously mapped Greenland’s bedrock buried beneath two to three thousand meters of ice. Mathematical models were used to fill in the gaps in survey data and infer bedrock depths. The surveys revealed the long valley, but suggested it was segmented, preventing water from flowing freely through it. However, the peaks breaking the valley into segments only show up in areas where the mathematical modelling was used to fill in missing data, so could not be real.

Christopher Chambers and Ralf Greve, scientists at Hokkaido University’s Institute of Low Temperature Science, wanted to explore what might happen if the valley is open and melting increases at an area deep in Greenland’s interior known for melting. Collaborating with researchers at the University of Oslo, they ran numerous simulations to compare water dynamics in northern Greenland with and without valley segmentation.

The results, recently published in The Cryosphere, show a dramatic change in how water melting at the base of the ice sheet would flow, if the valley is indeed open. A distinct subglacial watercourse runs all the way from the melting site to Petermann Fjord, which is located more than 1,000 kilometers away on the northern coast of Greenland. The watercourse only appears when valley segmentation is removed; there are no other major changes to the landscape or water dynamics.

“The results are consistent with a long subglacial river,” Chambers says, “but considerable uncertainty remains. For example, we don’t know how much water, if any, is available to flow along the valley, and if it does indeed exit at Petermann Fjord or is refrozen, or escapes the valley, along the way.”

If water is flowing, the model suggests it could traverse the whole length of the valley because the valley is relatively flat, similar to a riverbed. This suggests no parts of the ice sheet form a physical blockade. The simulations also suggested that there was more water flow towards the fjord with a level valley base set at 500 meters below sea level than when set at 100 meters below. In addition, when melting is increased only in the deep interior at a known region of basal melting, the simulated discharge is increased down the entire length of the valley only when the valley is unblocked. This suggests that a quite finely tuned relationship between the valley form and overlying ice can allow a very long down-valley water pathway to develop.

“Additional radar surveys are needed to confirm the simulations are accurate,” says Greve, who has been developing the model used in the study, called Simulation Code for Polythermal Ice Sheets (SICOPOLIS). “This could introduce a fundamentally different hydrological system for the Greenland ice sheet. The correct simulation of such a long subglacial hydrological system could be important for accurate future ice sheet simulations under a changing climate.”

“Low-Fact Propaganda”: Spiegel’s Alarmism Exposed (Again), Greenland Ice Not “Doomed”

by P. Gosselin, August 16, 2020 in NoTricksZone


German skeptic site Die Kalte Sonne here debunks a recent alarmist article appearing in Spiegel aimed at shocking its readers. The reality, it turns out, is not shocking at all.

Greenland ice doomed?

According to Spiegel, the Greenland ice sheet is already doomed (that is unless we skip the usual democratic process and just act immediately).

Spiegel claims Greenland “glaciers are continuously losing huge masses of ice” and that the system there is “dramatically off balance”. The leftist Hamburg-based weekly reported:

The melting of the glaciers on Greenland has apparently passed the point of no return. Even if the global rise in temperature were to stop immediately, the ice sheet would continue to retreat, report researchers led by Michalea King of Ohio State University report in the journal “Communications Earth and Environment“.

Read more at Spiegel

4°C warmer 11,000 years ago

But Die kalte Sonne wondered if this were really so, and needed only 2 mouse clicks to find a recent temperature reconstruction for Greenland’s past (Lecavalier et al. 2017, pdf here). The paper’s Figure 4a  shows the temperatures, with the temperature of 1950 at the far right which in paleo-climatology is always meant as “present”.

Thus, 11,000 years ago, it was up to 4°C warmer than in 1950 over long periods of thousands of years, and today the warming has been about 1°C since then. Since we can see an ice sheet of 2,850,000 km³ (that is roughly Gt) today, the “point of no return” cannot have been exceeded 10,000 years ago. How does the heading then come about? We take a look at the associated work by King et al. 2020:

 

What Happened To Greenland’s Tipping Point?

by P. Homewood, June 22, 2020 in NotaLotofPeopleKnowThat


Ten years ago, the Guardian warned us that Greenland would have passed a tipping point by now, with the whole ice sheet due to disappear by the end of the century:

How did that work out then?

The article was written in 2010, which was the warmest on record. Since then, however, Greenland’s temperatures have returned to normal, and are no higher than they were in the 1930s.

Far from being the start of a new trend, 2010 was simply an outlier:

 

ASTONISHING, RECORD-BREAKING GAINS CONTINUE ACROSS THE GREENLAND ICE SHEET — MSM SILENT

by Cap Allon, June 11, 2020 in Electroverse


The month of June is breaking records across the Greenland ice sheet, and not records for warmth and melt –as the mainstream media have trained you to expect– but new benchmarks for COLD and GAINS.

The SMB gains occurring right now across Greenland are truly astonishing.

Data-driven FACTS reveal vast regions to the south have been GAINING RECORD/NEAR-RECORD LEVELS of snow & ice all month.

Never before in June has the Greenland ice sheet grown by more than 4 Gigatons in a single day (since 1981 when DMI records began), but now the past week has gone and delivered two such days — June 3, and now yesterday, June 10.

In fact, yesterday’s gains actually neared 5 Gts — you can see from the chart below how anomalous that gain is for the time of year:

 

Blue line (Gt/day): total daily contribution to the SMB from the entire ice sheet. Grey line: mean value from 1981-2010 (DMI).

New Studies Show Cloud Cover Changes Have Driven Greenland Warming And Ice Melt Trends Since The 1990s

by K. Richard, April 20, 2020 in NoTricksZone


Scientists now acknowledge cloud cover changes “control the Earth’s hydrological cycle”, “regulate the Earth’s climate”, and “dominate the melt signal” for the Greenland ice sheet via modulation of absorbed shortwave radiation.  CO2 goes unmentioned as a contributing factor.

 

 

Is Greenland Warming, Melting? Hell No! NASA Data Show No Warming In Nearly 100 Years!

by Kirye & Gosselin, April 3, 2020 in NoTricksZone


But then NASA adjusted the V3 data and called it GHCN V4 “unadjusted”. The chart shown above in my tweet toggles between the prior V3 chart and the “unadjusted” V4. See the difference?

Note how the lack of warming has been removed and now the V4 data show modest warming. The missing heat was found – in the statistics! So in a sense, global warming has been “man-made” – done through statistical fudging and not human activity.

GREENLAND’S SMB GAINED 6 GIGATONS YESTERDAY + NORTHERN HEMISPHERE SNOW MASS SITTING AT 500 GIGAGTONS ABOVE THE NORM

by Cap Allon, March 29, 2020 in Electroverse


Despite decades of doom-and-gloom prophecies, Greenland’s Ice Sheet is currently GAINING monster amounts of “mass”— 6 gigatons yesterday alone (March 28, 2020).

Crucial to the survival of a glacier is its surface mass balance (SMB)–the difference between accumulation and ablation (sublimation and melting). Changes in mass balance control a glacier’s long-term behavior, and are its most sensitive climate indicators (wikipedia.org).

On the back of substantial SMB gains over the past few years, the Greenland ice sheet looks set to continue that trend in 2019-20. On March 28, 2020, the world’s largest island added a monster 6 gigatons to its ice sheet. According to climate alarmists, this simply shouldn’t be happening in a warming world. In fact, it might as well not be happening–developments like this NEVER receive MSM attention, meaning alarmists are NEVER privy to the full and unalarming picture…

polarportal.dk/

In addition, Total Snow Mass for the Northern Hemisphere continues to track WELL-above average with the latest data point (March 27) seeing NH snow at a staggering 500+ gigatons above the norm—another real-world reality we were told should be an impossibility by now: IPCC 2001: “Milder winter temperatures will decrease heavy snowstorms…”

Continuer la lecture de GREENLAND’S SMB GAINED 6 GIGATONS YESTERDAY + NORTHERN HEMISPHERE SNOW MASS SITTING AT 500 GIGAGTONS ABOVE THE NORM

Jan 2020: Coldest ever day in Greenland -65C comes, goes, no one notices

by JoNova, February 2020


The coldest ever day recorded in Greenland stands at -63.3 C  (minus 81 F).  But on January 2nd in 2020, after Greenland suffered a century of global warming, the thermometer at Summit Camp sunk to at least -64.9C. I say, at least, because it may have been even colder. Sharp eyes of Cap Allon at Electroverse saw it hit minus 66C. Ryan Maue also saw it and predicted there would be cold as the Arctic Oscillation broke down.

I sought confirmation at the time (among the Bushfire days in Australia). I looked for any official tweet even, but couldn’t find any. How’s that work — a new all time record for a whole continent for any month of the year, and no one who was paid to care about these things even writes a paragraph?

Good for Paul Homewood, who wrote to the DMI (Danish Met Institute) and has now confirmed that the NOAA GeoSummit  records showed it got down to -64.9 C, an all time record.

The Insignificance of Greenland’s Ice Mass Loss in Five Easy Charts…

by David Middleton, February 5, 2020 in WUWT


This is a sort of a spin-off of Rutgers University Global Snow Lab and “the Snows of Yesteryear” and A Geological Perspective of the Greenland Ice Sheet. And, yes, there are a lot more than five charts in this post… And, none of them were all that easy.

Introduction

There is a general scientific consensus that the Greenland Ice Sheet (GrIS) has been losing ice mass since the Little Ice Age (LIA). This should come as no surprise, since the LIA was quite likely the coldest climatic episode of the Holocene Epoch. Although it does appear that the GrIS may have gained ice mass during the mid-20th century global cooling crisis.

According to Mouginot et al, 2019, the GrIS was gaining an average of +47 ± 21 Gt/y from 1972–1980, then began to lose ice mass after 1980:

  • -51 ± 17 Gt/y from 1980–1990

  • -41 ± 17 Gt/y from 1990–2000

  • -187 ± 17 Gt/y from 2000–2010

  • -286 ± 20 Gt/y from 2010–2018

 

Figure 4. Central Greenland temperature reconstruction (Alley, 2000).

Major Greenland Glacier Is Growing

by NASA (Earth Observatory), June 6, 2019 in NASA.E.Observ.


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.

“The third straight year of thickening of Greenland’s biggest glacier supports our conclusion that the ocean is the culprit,” said Josh Willis, an ocean scientist at NASA’s Jet Propulsion Laboratory and principal investigator of the Oceans Melting Greenland (OMG) mission

Greenland Ice Core CO2 Concentrations Deserve Reconsideration

by Renee Hannon, January 7, 2020, in WUWT


Introduction
Ice cores datasets are important tools when reconstructing Earth’s paleoclimate. Antarctic ice core data are routinely used as proxies for past CO2 concentrations. This is because twenty years ago scientists theorized Greenland ice core CO2 data was unreliable since CO2trapped in air bubbles had potentially been altered by in-situ chemical reactions. As a result, Greenland CO2 datasets are not used in scientific studies to understand Northern and Southern hemispheres interactions and sensitivity of greenhouse gases under various climatic conditions.

This theory was put forward because Greenland CO2 data were more variable and different than Antarctic CO2 measurements located in the opposite polar region about 11,000 miles away. This article re-examines Greenland ice cores to see if they do indeed contain useful CO2 data. The theory of in-situ chemical reactions to explain a surplus and deficit of CO2, relative to Antarctic data, will be shown to be tenuous. The Greenland CO2 data demonstrates a response to the Medieval Warm Period, Little Ice Age, Dansgaard-Oeschger and other past climate change events. This response to past climate changes offers an improved explanation for why Greenland and Antarctic CO2 measurements differ. Further, Greenland CO2 measurements show rapid increases of 100 ppm during warm events in relatively short periods of time.

Atmospheric CO2 is More Variable in Northern Latitudes

Figure 1, from NOAA, shows atmospheric CO2 concentrations measured from the continuous monitoring program at four key baseline stations spanning from the South Pole to Barrow, Alaska. CO2 has risen from about 330 ppm to over 400 ppm since 1975 and is increasing at approximately 1-2+ ppm/year. Many scientists believe that rapidly increasing CO2 is mostly due to fossil fuel emissions.

Figure 1. Atmospheric CO2 concentrations from NOAA

Failed Serial Doomcasting

by Willis Eschenbach, December 27, 2019 in WUWT


People sometimes ask me why I don’t believe the endless climate/energy use predictions of impending doom and gloom for the year 2050 or 2100. The reason is, neither the climate models nor the energy use models are worth a bucket of warm spit for such predictions. Folks concentrate a lot on the obvious problems with the climate models. But the energy models are just as bad, and the climate models totally depend on the energy models for estimating future emissions. However, consider the following US Energy Information Agency (EIA) predictions of energy use from 2010, quoted from here (emphasis mine):

The only thing that seems clear about all of those questions is that the answer is not “CO2”. Here’s another look at Greenland, this time with CO2 overlaid on the temperature:

8000 Years Of Zero Correlation Between CO2 And Temperature, GISP 2 Ice Core Shows – Opposite Is True!

by P. Gosselin, December 20, 2019 in NoTricksZone


A plot of ice core data from Greenland reveals that CO2 does not drive temperatures.

At Facebook, Gregory Wrightstone posted a chart plotting atmospheric CO2 concentration reconstructed from  Dome C Ice Core versus temperature that was reconstructed from the GISP 2 Ice Core.

According to global warming scientists, there’s supposed to be tandem movement between the two magnitudes.

CO2, they say, drives global temperature.

But over the past 8000 years, the data show that temperature in reality has moved in the opposite direction of CO2 and thus of what climate alarmist scientists have told us.

 

If anything can be drawn from the plotted data, it is that there’s an inverse correlation: As CO2 rises, temperature drops. But of course there’s a lot more to it. CO2 is not that huge major climate driver that alarmists like having us believe it is.

THE DANISH METEOROLOGICAL INSTITUTE ADMITS IT WRONGLY REPORTED GREENLAND’S “RECORD WARM TEMPERATURE” THIS SUMMER

by Cap Allon, November 17, 2019 in Electroverse


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.”

Blue Melt River, Petermann Glacier, in remote northwestern Greenland, on Nares Strait. (Photo by: Dave Walsh/VW Pics/Universal Images Group via Getty Images)

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)