Archives par mot-clé : Antarctic

Antarctic sea ice is declining dramatically

by Claire L. Parkinson, July 5, 2019 in WUWT


PNAS first published July 1, 2019 https://doi.org/10.1073/pnas.1906556116

Contributed by Claire L. Parkinson, May 24, 2019 (sent for review April 16, 2019; reviewed by Will Hobbs and Douglas G. Martinson)

Significance

A newly completed 40-y record of satellite observations is used to quantify changes in Antarctic sea ice coverage since the late 1970s. Sea ice spreads over vast areas and has major impacts on the rest of the climate system, reflecting solar radiation and restricting ocean/atmosphere exchanges. The satellite record reveals that a gradual, decades-long overall increase in Antarctic sea ice extents reversed in 2014, with subsequent rates of decrease in 2014–2017 far exceeding the more widely publicized decay rates experienced in the Arctic. The rapid decreases reduced the Antarctic sea ice extents to their lowest values in the 40-y record, both on a yearly average basis (record low in 2017) and on a monthly basis (record low in February 2017).

Abstract

Following over 3 decades of gradual but uneven increases in sea ice coverage, the yearly average Antarctic sea ice extents reached a record high of 12.8 × 106 km2 in 2014, followed by a decline so precipitous that they reached their lowest value in the 40-y 1979–2018 satellite multichannel passive-microwave record, 10.7 × 106 km2, in 2017. In contrast, it took the Arctic sea ice cover a full 3 decades to register a loss that great in yearly average ice extents. Still, when considering the 40-y record as a whole, the Antarctic sea ice continues to have a positive overall trend in yearly average ice extents, although at 11,300 ± 5,300 km2⋅y−1, this trend is only 50% of the trend for 1979–2014, before the precipitous decline. Four of the 5 sectors into which the Antarctic sea ice cover is divided all also have 40-y positive trends that are well reduced from their 2014–2017 values. The one anomalous sector in this regard, the Bellingshausen/Amundsen Seas, has a 40-y negative trend, with the yearly average ice extents decreasing overall in the first 3 decades, reaching a minimum in 2007, and exhibiting an overall upward trend since 2007 (i.e., reflecting a reversal in the opposite direction from the other 4 sectors and the Antarctic sea ice cover as a whole).

Fig. 1. Identification of the 5 sectors used in the regional analyses. These are identical to the sectors used in previous studies (7, 8).

Antarctic Sea Ice Suddenly Declined, But Scientists Warn: Don’t Blame Climate Change

by Adam Vaughan, July 3, 2019 in ClimateChangeDispatch


Decades of expanding sea ice in Antarctica have been wiped out by three years of sudden and dramatic declines, leaving scientist puzzled as to why the region has flipped so abruptly.

A new satellite analysis reveals that between 2014 and 2017 sea ice extent in the southern hemisphere suffered unprecedented annual decreases, leaving the area covered by sea ice at its lowest point in 40 years.

The declines were so big that they outstripped the losses in the fast-melting Arctic over the same period.

“It’s very surprising. We just haven’t seen decreases like that in either hemisphere,” says Claire Parkinson at NASA’s Goddard Space Flight Center, who undertook the analysis.

However, researchers cautioned against pinning the changes on climate change and said it was too early to say if the shrinking is the start of a long-term trend or a blip.

After growing for decades, Antarctic sea ice extent declined at an unprecedented rate between 2014 and 2017.

Antarctic marine life recovery following the dinosaurs’ extinction

by British Antarctic Survey, June 19, 2019 in ScienceDaily


The K-Pg extinction wiped out around 60% of the marine species around Antarctica, and 75% of species around the world. Victims of the extinction included the dinosaurs and the ammonites. It was caused by the impact of a 10 km asteroid on the Yucatán Peninsula, Mexico, and occurred during a time period when the Earth was experiencing environmental instability from a major volcanic episode. Rapid climate change, global darkness, and the collapse of food chains affected life all over the globe.

The K-Pg extinction fundamentally changed the evolutionary history of life on Earth. Most groups of animals that dominate modern ecosystems today, such as mammals, can trace the roots of their current success back to the aftermath of this extinction event.

A team of scientists from British Antarctic Survey, the University of New Mexico and the Geological Survey of Denmark & Greenland show that in Antarctica, for over 320,000 years after the extinction, only burrowing clams and snails dominated the Antarctic sea floor environment. It then took up to one million years for the number of species to recover to pre-extinction levels.

Multiple NASA Studies Confirm Bedrock Heat Flow Behind Melting Polar Ice, Not Global Warming

by James E. Kamis, August 7, 2018 in ClimateChangeDispatch

In what amounts to dissension from National Aeronautics and Space Administration (NASA) climate change policy, a series of just-released studies by working-level scientists prove that geological and not atmospheric forces are responsible for melting of Earth’s polar ice sheets.

 

NASA Greenland Study August 1, 2018

The results of this research study illustrated in Figure 2 confirm the very high geothermal bedrock heat-flow from Greenland’s massive subglacial Mantle Plume, which was originally documented in four previous research studies (see herehere, here, and here).

A geothermal heat-flow cause for the melting of Greenland’s ice sheet has been the focus of numerous Climate Change Dispatch articles (see here, here, here, and here).

 

 

The epic search for oldest ice in Antarctica is starting

by Università Ca’ Foscari Venezia, June 5, 2019 in WUWT


Click here for project video.

On 1st June 2019 the European Beyond EPICA Oldest Ice Core project started with the aim of drilling for and recovering ice from up to 1.5 Million years ago in Antarctica. The previous EPICA project recovered ice from 800,000 years ago. The new project aims to go beyond that. The new core will give us information on the greenhouse gases present during the Middle Pleistocene Transition (MPT), which occurred between 900,000 and 1.2 Million years ago. During this period the climatic periodicity transitioned from 41,000 to 100,000 years between ice ages. Why this change happened is the mystery scientists want to resolve.

To do this, experts from 10 European Countries and 16 different Research Institutions have joined forces under the guidance of Carlo Barbante and his management team at the CNR and Ca’ Foscari University of Venice in Italy, funded by the European Horizon 2020-research programme.

For further information visit https://www.beyondepica.eu/

10 Of 10 Coastal Antarctic Stations Show Zero Warming Over Past Decades. Failed Scientists Need To Resign

by Kirye in P. Gosselin, May 31, 2019 in NoTricksZone


Over the past few years, climate alarmists have increasingly been resorting to weather-ambulance chasing, which has necessitated the trotting of the globe in the search of weather anomalies to behold as proof of man-made climate change.

But one place they have been avoiding like the plague is Antarctica as a number of studies have been showing the opposite of what what predicted earlier has been happening down at the South Pole, except for volcanic activity beneath parts of the Antarctic ice shelf.

Analysis of Antarctic stations show cooling

Climate data shows no recent warming in Antarctica, instead a slight cooling

by Anthony Watts, May 10, 2019 in WUWT


Below is a plot from a resource we have not used before on WUWT, “RIMFROST“. It depicts the average temperatures for all weather stations in Antarctica. Note that there is some recent cooling in contrast to a steady warming since about 1959.


Data and plot provided by
http://rimfrost.no 

Contrast that with claims by Michael Mann, Eric Steig, and others who used statistical tricks to make Antarctica warm up. Fortunately, it wasn’t just falsified by climate skeptics, but rebutted in peer review too.

Flashback 2008 – Climate change study predicts refugees fleeing into Antarctica

by P. Homewood, April 13, 2019 in NotaLotofPeopleKnowThat


Climate change will force refugees to move to Antarctica by 2030, researchers have predicted.

Among future scenarios are the Olympics being held in cyberspace and central Australia being abandoned, according to the think tank report.

Forum for the Future, a research body committed to sustainable development, said they wanted to stir debate about how to avert the worst effects of global warming by presenting a radical set of ‘possible futures’.
There will be a shift towards greater energy efficiency, where desalination plants will run on solar power will turn the Sahara green.

Refugees are expected to move to Antarctica because of the rising temperatures that will see the population of the continent increase to 3.5 million people by 2040.

As the world fails to act on climate change, researchers predict that global trade will collapse as oil prices break through $400 a barrel and electrical appliances will get automatically turned off when households exceed energy quotas.

Geological ‘Hotspot’ Melting Pine Island And Thwaites Glaciers, Not Global Warming

by J.E. Kamis, February 25, 2019 in ClimateChangeDispatch


SUMMARY

Research study after research study has now proven beyond any doubt that the 350,000-square-mile subglacial Marie Byrd Mantle Plume and its associated geological features that are emitting massive amounts of ice melting heat and heated fluid onto the base of the Pine Island Glacier and Thwaites Glaciers.

Failure of the media to include in their numerous articles this telling scientific evidence which substantiates the significant and likely dominant role of this subglacial geologically induced heat flow in melting of West Antarctic glaciers is difficult to reconcile with proper scientific methodology.

A methodology which states that new and relevant data should be used to review old supposedly 100% settled theories.

Most of these research studies have been released one by one during the last three years which has led to minimizing their collective importance.  Numerous previous Climate Change Dispatch articles written by this author beginning in 2014 have inexplicably been ignored by mainstream media outlets.

It’s time for the media to inform the public that by tying all this information together that a clear picture emerges concerning the significant impact of Antarctic subglacial geologically induced heat flow.

Antarctic Losing Tiny Amounts Of Ice (Or Maybe It’s Gaining Ice, NASA Is Not Sure!)

by P. Homewood, January 15, 2019 in NotaLotofPeopleKnowThat


Antarctica is shedding ice at a staggering rate.

Scientists have discovered global warming has caused the melting of the ice on the continent to increase sixfold since 1979.

This phenomenal rate of melting has seen global sea levels rise by more than half an inch – and experts predict it will get worse. 

Scientists have predicted a ‘multi-meter sea level rise from Antarctica in the coming centuries’ as a result of the vast loss of ice.

Researchers discovered that, between 1970 and 1990, the continent was shedding an average of 40 gigatons of ice mass annually.

This jumped to an average of 252 gigatons a year between 2009 and 2017.

https://www.dailymail.co.uk/sciencetech/article-6590841/Antarctica-losing-SIX-TIMES-ice-year-1970s.html#newcomment

 

You may of course recall that it was only three years ago that the same NASA, who are behind this latest scare story, were telling us that the ice cap was actually growing in Antarctica. But more of that in a minute.

There are several aspects to this latest story that need closer examination.

Arctic Ice Volume Shames Climate Experts …Antarctic Stations Show Cooling, Not Warming

by P. Gosselin, December 28, 2018 in NoTricksZone


By Kirye in Tokyo

We constantly hear from the untrustworthy media how polar ice is melting rapidly – due to human-induced global warming.

But when we look at the real data, we understand why audiences worldwide increasing distrust the mainstream media and their constant stream of doomsday reports, which they uncritically produce.

Recently I looked at some island stations near Antarctic, a continent where we are told melting ice will lead to many meters of sea level rise if we continue emitting CO2 into the atmosphere business as usual. These stations I examined are:

Base Arturo P
Bellingshause
Centro Met.An, Marsh
Base Orcadas
Great Wall
Jubany

hese six stations in the South Shetland Islands or the South Orkney Islands (located in the Antarctic Ocean) have even seen a slight cooling trend for decades.

The Increasing Surface Mass Balance of Two Antarctic Glaciers

by Engel, Z.  et al., December 6, 2018 in CO2Sci/J.ofGlaciology


The polar regions of the Earth have long been depicted as canary-in-the-coal-mine sentinels of climate change, given that climate models project that CO2-induced global warming will manifest itself here, first and foremost, compared to other planetary latitudes. Consequently, researchers are frequently examining the Arctic and Antarctic for evidence of recent climate change.

Clearly, as demonstrated here and in other studies (see, for example, The Antarctic Peninsula: No Longer the Canary in the Coal Mine for Climate Alarmists and the references therein) there is a canary in the Antarctic alright, but it is alive and well. And these counter-observations do not bode well for climate models and their projections of CO2-induced global warming.

Figure 1. Surface mass-balance records for glaciers around the northern Antarctic Peninsula. Source: Engel et al. (2018).

Antarctic temperatures recently plunged close to the theoretically coldest achievable on Earth! David Middleton

by David Middleton, November 13, 2018 in WUWT


This story was previously discussed here at WUWT… But, why wasn’t this headline news in the Washington Post, New York Times, etc.?  Yes… That was a rhetorical question.

Comparisons with nearby automated weather stations suggest that air temperatures during these events are near −94 ± 4 °C or about −138 F. Ultracold conditions (below −90 °C) occur more frequently when the Antarctic polar vortex is strong. This temperature appears to be about as low as it is possible to reach, even under clear skies and very dry conditions, because heat radiating from the cold clear air is nearly equal to the heat radiating from the bitterly cold snow surface.

Relics of ‘lost continents’ hidden under Antarctica are revealed by satellite images after scientists track 200 million years of tectonic plate shifts

by H. Pettit, November 9, 2018 in MailOnline


  • Images reveal a timeline of the ancient landmasses buried beneath Antarctica
  • They were taken by the long-dead Gravity field and Ocean Circulation Explorer 
  • The ESA satellite collected data on Earth’s gravitational pull

  • The study revealed that West Antarctica (green) has a thinner crust than East Antarctica (blue), which has a ‘family likeness to Australia and India’

New Science: Arctic AND Antarctic Sea Ice More Extensive Today Than Nearly All Of The Last 10,000 Years

by K. Richard, October 18, 2018 in NoTricksZone


It is often claimed that modern day sea ice changes are “unprecedented”, alarming, and well outside the range of natural variability.  Yet scientists are increasingly finding that biomarker proxies used to reconstruct both Arctic and Antarctic sea ice conditions since the Early Holocene reveal that today’s sea ice changes are not only not unusual, there is more extensive Arctic and Antarctic sea ice during recent decades than there has been for nearly all of the last 10,000 years.

Retracing Antarctica’s glacial past

by Louisiana State University, September 25, 2018 in ScienceDaily


More than 26,000 years ago, sea level was much lower than it is today partly because the ice sheets that jut out from the continent of Antarctica were enormous and covered by grounded ice — ice that was fully attached to the seafloor. As the planet warmed, the ice sheets melted and contracted, and sea level began to rise. Researchers have discovered new information that illuminates how and when this global phenomenon occurred.

More recently in 2002, in the northern part of Antarctica called the Antarctic Peninsula, the Larsen Ice Shelf collapsed. The collapse of this ice shelf quickly led to inland glaciers buttressed by the Larsen Ice Shelf to break up and melt. Scientists have thought that a similar process could have occurred when the Ross Ice Shelf collapsed thousands of years ago in the West Antarctic Ice Sheet.

However, Bart and colleagues from the University of South Florida, Auburn University and the Polish Academy of Sciences found that there was a centuries-long delay from when the Ross Ice Shelf collapsed and the grounded ice began to contract. In the Ross Sea, the delay was between 200 to 1,400 years later. This new information adds a layer of complexity for sea level rise computer simulations and predictions.

A new volcanic province: an inventory of subglacial volcanoes in West Antarctica

by M. Van Wyk De Vries et al., August 16, 2018 in Geol.Soc.London


Abstract: The West Antarctic Ice Sheet overlies the West Antarctic Rift System about which, due to the comprehensive ice cover, we have only limited and sporadic knowledge of volcanic activity and its extent. Improving our understanding of subglacial volcanic activity across the province is important both for helping to constrain how volcanism and rifting may have influenced ice-sheet growth and decay over previous glacial cycles, and in light of concerns over whether enhanced geo- thermal heat fluxes and subglacial melting may contribute to instability of the West Antarctic Ice Sheet. Here, we use ice-sheet bed-elevation data to locate individual conical edifices protruding upwards into the ice across West Antarctica, and we propose that these edifices represent subglacial volcanoes. We used aeromagnetic, aerogravity, satellite imagery and databases of confirmed volca- noes to support this interpretation. The overall result presented here constitutes a first inventory of West Antarctica’s subglacial volcanism. We identified 138 volcanoes, 91 of which have not previously been identified, and which are widely distributed throughout the deep basins of West Antartica, but are especially concentrated and orientated along the >3000 km central axis of the West Antarctic Rift System.

Multiple NASA Studies Confirm Bedrock Heat Flow Behind Melting Polar Ice, Not Global Warming

by James E. Kamis, August 7, 2018 in ClimateChangeDisatch


In what amounts to dissension from National Aeronautics and Space Administration (NASA) climate change policy, a series of just-released studies by working-level scientists prove that geological and not atmospheric forces are responsible for melting of Earth’s polar ice sheets.

Volcanic Heat Found Under Antarctica’s Fastest-Melting Glacier

by M.  Bastach, June 28, 2018 in ClimateChangeDispatch


A group of scientists at the University of Rhode Island stumbled on something unexpected when analyzing data brought back from a 2014 expedition to western Antarctica.

Scientists found an abundance of the noble gas Helium-3, indicating there is a volcanic heat source beneath the Pine Island glacier — the fastest melting glacier in the South Pole. The findings were published in a study in the journal Nature Communications.

“When you find helium-3, it’s like a fingerprint for volcanism. We found that it is relatively abundant in the seawater at the Pine Island shelf,” chemical oceanographer Brice Loose, the study’s lead author, said in a statement.

See also here (National Science Foundation) and here

 

Worse than they thought: Antarctica actually colder than scientists once believed

by Anthony Watts, June 25, 2018 in AGU/WUWT


From the AGU and the “but, but, the continent is melting!” department.

COLDEST PLACE ON EARTH IS COLDER THAN SCIENTISTS THOUGHT

WASHINGTON — Tiny valleys near the top of Antarctica’s ice sheet reach temperatures of nearly minus 100 degrees Celsius (minus 148 degrees Fahrenheit) in the winter, a new study finds. The results could change scientists’ understanding of just how low temperatures can get at Earth’s surface, according to the researchers.

Scientists announced in 2013 they had found the lowest temperatures on Earth’s surface: Sensors on several Earth-observing satellites measured temperatures of minus 93 degrees Celsius (minus 135 degrees Fahrenheit) in several spots on the East Antarctic Plateau, a high snowy plateau in central Antarctica that encompasses the South Pole. But the researchers revised that initial study with new data and found the temperatures actually reach minus 98 degrees Celsius (minus 144 degrees Fahrenheit) during the southern polar night, mostly during July and August.

(…)

Study provides less gloom and doom about Antarctica

by Anthony Watts, June 22, 2018 in WUWT


Antarctic ice sheet is melting, but rising bedrock below could slow it down

An international team, led by DTU Space at the Technical University of Denmark with Colorado State University, has found that the bedrock below the remote West Antarctic Ice Sheet is rising much more rapidly than previously thought, in response to ongoing ice melt.

The study, “Observed rapid bedrock uplift in the Amundsen Sea Embayment promotes ice-sheet stability,” reveals new insights on the geology of the region and its interaction with the ice sheet and is published in the journal Science. The authors noted that the findings have important implications in understanding and predicting the stability of the ice sheet and Earth’s rising sea levels.

NASA glaciologist Jay Zwally puts the hammer down: ‘Antarctica is gaining ice’

by Michael Bastach, June 15, 2018 in A. Watts WUWT


A new paper about to be in press, comes at the end of a flurry of papers and reports published this week that claims Antarctica was losing ice mass. Zwally says ice growth is anywhere from 50 gigatons to 200 gigatons a year. NASA glaciologist Jay Zwally says his new study will show, once again, the eastern Antarctic ice sheet is gaining enough ice to offset losses in the west.

(…)

Antarctic Ice Loss Tripled, from near zero to an extremely tiny number! (Nobody mention those volcanoes)

by JoNova, June 15, 2018


Quick — tax the magma

It’s another round of Antarctic Doom about next to nothing. In April Antarctica’s ice was melting five times faster than usual. Now it’s losing ice three times faster in the last five years than the 15 before that! What you won’t hear is how the Antarctic ice cap has 29 million cubic kilometers of ice and has been there for 30 million, mostly warmer, years. You also won’t hear how Antarctica was warmer in Roman Times, or that the  Antarctic Peninsula has cooled by almost 1 degree.

You also won’t hear a word about any volcanoes

The new paper has zero mentions of the word. But other scientists have published plenty of papers describing how the West Antarctic zone is being warmed from below by 1200 degrees of magma. According to scientist Dustin Schroeder and co,  it is as if the Thwaites Glacier in West Antarctic is sitting on a “stovetop burner”.[1]  His words. Thwaites Glacier,, smack in the middle of the warming is being melted from below by geothermal heat. Then there is the large blob of superheated rock 60 miles below West Antarctica. The researchers use the phrase “like a blow-torch”….  Capping it off, only last year 91 new volcanoes were discovered 2km underneath the West Antarctic Rift. That’s new, as in, we didn’t know they were there.

Follow the reasoning, either a trace gas 10 kilometers up is causing some spots of Antarctica to warm and other parts to cool, or hot magma at 1,200C is. What’s more likely?

NSF study: ‘…current carbon dioxide levels are not enough to destabilize the land-based ice on Antarctica’

by Anthony Watts, June 15, 2018 in WUWT


We covered this yesterday, but today the official press release came out, so worth covering again. Via Eurekalert


Land-based portion of massive East Antarctic ice sheet retreated little during past eight million years

But increases in atmospheric carbon dioxide levels could affect stability and potential for sea level rise

NATIONAL SCIENCE FOUNDATION

Large parts of the massive East Antarctic Ice Sheet did not retreat significantly during a time when atmospheric carbon dioxide concentrations were similar to today’s levels, according to a team of researchers funded by the National Science Foundation (NSF). The finding could have significant implications for global sea level rise.

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