Earlier observations showed that Arctic ice extents were low in the 1940s, grew thereafter up to a peak in 1977, before declining. That decline was gentle until 1994 which started a decade of multi-year ice loss through the Fram Strait. There was also a major earthquake under the north pole in that period. In any case, the effects and the decline ceased in 2007, 30 years after the previous peak. Now we have a plateau in ice extents, which could be the precursor of a growing phase of the quasi-60 year Arctic ice oscillation.
Les prévisions climatiques à très long terme (2100) sont établies à l’aide de modèles qui ne sont rien d’autre des logiciels très complexes, dont le but est de reproduire le comportement du climat terrestre.
Comme on ne peut pas décrire ce qui se passe en tous les points de la terre, celle-ci est découpée en mailles de quelques centaines de kilomètres de côté. Les modèles utilisés par le GIEC pour son cinquième rapport d’évaluation (2013) avaient des résolutions relativement grossières (supérieures à 100 km). La situation évolue toutefois rapidement et les modèles climatiques les plus récents auraient une résolution plus fine (de l’ordre de 20 km).
Rapid expansion of the Arctic sea ice cover is the norm for October as solar input dwindles and the remaining heat in the upper ocean is released upwards, warming the lower atmosphere and escaping to space. Because of late season growth, the seasonal Antarctic maximum we previously reported as occurring on September 15 was exceeded, with a new maximum set on October 11 and 12. This is the second-lowest and second-latest seasonal maximum extent in the satellite record.
by P. Homewood, November 21, 2017 in NotaLotofPeopleKnowThat
A year ago the media was full of fake Arctic heatwave news (…)
And a year later?
Arctic sea ice extent this October was the third highest since 2006, and continues to track recent years. Most of the Arctic basin is full of 2 meter+ thick ice, in stark contrast to 2008.
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
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.
‘Scars’ left by icebergs record West Antarctic ice retreat ten thousand years ago – occurred under climate conditions that were relatively similar to those of today.
by Ron Clutz, October 30, 2017 in ClimateChangeDispatch
Extents expanded rapidly during the last 12 days of October through yesterday, especially on the Eurasian side. At the top center the Laptev Sea fills in completely, and to the left East Siberian Sea is also growing solid ice toward East Asia. Kara sea on the right is growing fast ice from the shore outward, while the Barents Sea fills in from the central Arctic.
A year ago I wrote an article at WUWT analyzing the recent upward trend in summer Arctic sea ice extent. Despite challenges of statistical irrelevancy, the trend has continued another year. Arctic ice experts, that have repeatedly predicted the demise of summer ice, don’t have an explanation for a 10-year trend that contradicts their predictions, beyond statistical variability or unexplained natural variability.
Overall, initial figures suggest that Greenland may have gained a small amount of ice over the 2016-17 year. If confirmed, this would mark a one-year blip in the long-term trend of year-on-year declines over recent decades.
“It is tempting to say that the record low we are seeing this year is global warming finally catching up with Antarctica,” Meier said. “However, this might just be an extreme case of pushing the envelope of year-to-year variability. We’ll need to have several more years of data to be able to say there has been a significant change in the trend.”
(…) Upon our return to the Hotel after visiting the Glacier, we noticed that our brand-new photos appear to show that the Grinnell Glacier has grown slightly from the 2008 images that are displayed on the Hotel walls. There has been no reporting of this in any newspaper or broadcast that we know of. (In fact, all news coverage reports the precise opposite.) The smaller Gem Glacier—which is visible from the valley miles below—also appears to be slightly larger than it is shown in 2008 pictures on display.
The discovery of volcanoes under the Antarctic ice sheet may be old news, but now we have evidence that at least some of them have recently (geologically speaking) erupted…
There are models that predict that the interior of the East Antarctic ice sheet wouldn’t change very much, even if the West Antarctic ice sheet was taken away,” Licht said. According to these models, even if the ice sheet’s perimeter retreats, its core remains stable.
by Ron Clutz, August 25, 2017 in ClimateChangeDispatch
The animated image shown after the jump shows ice extents for day 233 from 2007 to 2017. Particularly interesting is the variation in the CAA (Canadian Arctic Archipelago), crucial for the Northwest Passage
Al Gore has provided a target-rich environment of deceptions in his new movie.
After viewing Gore’s most recent movie, An Inconvenient Sequel: Truth to Power, and after reading the book version of the movie, I was more than a little astounded. The new movie and book are chock-full of bad science, bad policy, and factual errors.
“There are models that predict that the interior of the East Antarctic ice sheet wouldn’t change very much, even if the West Antarctic ice sheet was taken away,” Licht said. According to these models, even if the ice sheet’s perimeter retreats, its core remains stable.
Satellite observations indicate that the average Arctic sea ice extent has generally decreased since the start of the satellite records in October 1978. Is this period long enough to assess whether the current sea level trend is unusual, and to what extent the decline is caused by humans?
This change in Arctic climate is often promoted as evidence that humans are causing drastic climate change. For instance, an April 29th 2017 article in the Economist (“Skating on thin ice”, pg 16) implied that the Arctic is melting unusually, dramatically and worryingly (…)
Scientists announced today that a core drilled in Antarctica has yielded 2.7-million-year-old ice, an astonishing find 1.7 million years older than the previous record-holder
(…)
If the new result holds up, says Yige Zhang, a paleoclimatologist at Texas A&M University in College Station, the proxies will need to be recalibrated. “We have some work to do.”
by Kenneth Richard, August 7, 2017 in NoTricksZone reposted Paul Homewood
In recent months, two new papers published in The Cryosphere have provided a condensed summary of the ice-melt and sea-level-rise consequences of global warming for the Arctic region.
1. Between 1900 and 2010, the Greenland Ice Sheet (GIS) has melted so extensively and so rapidly that the GIS ice-melt contribution to global sea level rise has amounted to 1.5 centimeters for the entire 110-year period. One-and-a-half centimeters. That’s 0.59 of an inch!
2. It gets worse. Between 1993 and 2010, the contribution to global sea level rise has been a disturbing 0.39 of a centimeter. Almost 4/10ths of a centimeter. That’s 0.15 of an inch!
In sharp contrast with previous decades, the past 10 years have seen no change in Northern Hemisphere average sea ice extent, according to MASIE (may-zee, Multi-sensor Analyzed Sea Ice Extent) database from the National Sea & Ice Data Center (NSIDC; see figure 1).
Weathering of Earth by glaciers may have warmed the planet over eons by aiding the release of carbon dioxide into the atmosphere. A new study shows the cumulative effect may have created negative feedback that prevented runaway glaciation.
