Archives par mot-clé : Antarctic

The Antarctic Centennial Oscillation: A Natural Paleoclimate Cycle in the Southern Hemisphere That Influences Global Temperature

by W.J. Davis et al., January 8, 2018 in Climate

We report a previously-unexplored natural temperature cycle recorded in ice cores from Antarctica—the Antarctic Centennial Oscillation (ACO)—that has oscillated for at least the last 226 millennia. Here we document the properties of the ACO and provide an initial assessment of its role in global climate.

See also here

New Study Identifies Thermometer for the Past Global Ocean

by UC San Diego, January 4, 2018

There is a new way to measure the average temperature of the ocean thanks to researchers at Scripps Institution of Oceanography at the University of California San Diego. In an article published in the Jan. 4, 2018, issue of the journal Nature, geoscientist Jeff Severinghaus and colleagues at Scripps Oceanography and institutions in Switzerland and Japan detailed their ground-breaking approach.

Dueling science: One study says melting Antarctic ice sheet will flood US east coast, others say ‘uncertain’

by Anthony Watts, December 13, 2017 in WUWT

(…) All of these press releases appeared within a couple of hours of each other on EurekAlert, which is a Science PR clearing house. They will all inevitably get turned into stories by the media. Who could blame the public for being confused when we have such certainty/uncertainty battles like this going on in climate science?

It seems Yogi Berra was right.

It’s tough to make predictions, especially about the future.

New Antarctic heat map reveals sub-ice hotspots

by  A. Dinar, November 13, 2017 in GeoSpace-AGU

An international team of scientists, led by British Antarctic Survey (BAS), has produced a new map showing how much heat from the Earth’s interior is reaching the base of the Antarctic Ice Sheet. The map is part of a new paper accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

The team has produced the most up to date, accurate and high-resolution map of the so called ‘geothermal heat flux’ at the base of the Antarctic Ice Sheet. Of the basic information that shapes and controls ice flow, the most poorly known about is this heat

New Antarctic Temperature Reconstruction

by Steve McIntyre, November 20, 2017 in ClimateAudit

Stenni et al (2017), Antarctic climate variability on regional and continental scales over the last 2000 years, was published pdf this week by Climate of the Past.  It includes (multiple variations) of a new Antarctic temperature reconstruction, in which 112 d18O and dD isotope series are combined into regional and continental reconstructions.

New map of Antarctic geothermal heat suggests Steig & Mann 2009 weren’t measuring ‘global warming’

by Anthony Watts, November 15, 2017 in WUWT

This is quite interesting. Remember the claim in on the front cover of Nature in 2009 by Steig and Mann that Antarctica was warming, thanks to that “special Mannian PCA math sauce” that was applied to air temperature data to smear surface temperature trends over the entire continent? It was dashed by climate skeptics who wrote a paper. It was accepted for publication and disproved (in my opinion) by a team of credible skeptics that wrote a counter-paper. But, there’s an interesting twist thanks to new and surprising data; Steig and Mann may have captured surface air temperature trends in the exact same areas that have been identified as geothermal hot spots.

NASA – Supervolcano may be melting Antarctic ice sheet from below

by Robert, November 10, 2017 in NASA

Confirms what I’ve been saying all along!
NASA scientists admit that a massive heat source almost as hot as the Yellowstone supervolcano may be melting the Antarctic ice sheet from below. 

It seems like a no-brainer to me. I mean, how can lakes and rivers be flowing beneath the ice unless there’s a heat source down there? And if sub-glacial volcanoes can be melting the ice, why couldn’t underwater volcanoes be heating the sea

Hot News from the Antarctic Underground

by Alan Buis, November, 7, 2017, in JPL, NASA

Study Bolsters Theory of Heat Source Under West Antarctica

A new NASA study adds evidence that a geothermal heat source called a mantle plume lies deep below Antarctica’s Marie Byrd Land, explaining some of the melting that creates lakes and rivers under the ice sheet. Although the heat source isn’t a new or increasing threat to the West Antarctic ice sheet, it may help explain why the ice sheet collapsed rapidly in an earlier era of rapid climate change, and why it is so unstable today.

Estimating the extent of Antarctic summer sea ice during the Heroic Age of Antarctic Exploration

by T. Edimburgh and J. Day, November 21, 2017, in TheCryopshere

In stark contrast to the sharp decline in Arctic sea ice, there has been a steady increase in ice extent around Antarctica during the last three decades, especially in the Weddell and Ross seas. In general, climate models do not to capture this trend and a lack of information about sea ice coverage in the pre-satellite period limits our ability to quantify the sensitivity of sea ice to climate change and robustly validate climate models

Surprise: Defying Models, Antarctic Sea Ice Extent 100 Years Ago Similar To Today

by P. Gosselin, October 17, 2017 in NoTricksZone

from Dr. L. Lüning and Prof. F. Vahrenbolt

Satellite measurements of Antarctic sea ice do not go back even 40 years. That’s not very much, especially when we consider that many natural climate cycles have periods of 60 years and more.

Luckily we have the field of climate reconstruction. Using historical documents and sediment cores, the development of ice cover can be estimated. In November, 2016, Tom Edinburg and Jonathan Day examined shipping log books from the time of Antarctic explorers and published on ice extent in The Cryosphere (…)

Antarctique: des milliers de bébés manchots meurent de faim en terre Adélie

by l’express, 13 october 2017

La découverte a été effectuée par des scientifiques français du CNRS, dans ce groupe qui vivait sur l’île de Petrels, en terre Adélie. Hormis les deux bébés manchots survivants, ils n’ont retrouvé que des corps d’animaux affamés et des oeufs non-éclos. Ces chercheurs, soutenus par le Fonds mondial pour la nature (WWF), observaient depuis 2010 cette colonie. Selon eux, l’étendue inhabituelle de la banquise a contraint les parents à aller plus loin chercher leur nourriture. Leur progéniture ont succombé à la faim.