A new study published Jan. 8 in the journal Nature Geoscience reveals that strong El Nino events can cause significant ice loss in some Antarctic ice shelves while the opposite may occur during strong La Nina events.
The East Antarctic Ice Sheet locks away enough water to raise sea level an estimated 53 meters (174 feet), more than any other ice sheet on the planet. It’s also thought to be among the most stable, not gaining or losing mass even as ice sheets in West Antarctica and Greenland shrink.
For the first time scientists have directly observed living bacteria in polar ice and snow — an environment once considered sterile. “As microbial activity and its influence on its local environment has never been taken into account when looking at ice-core gas samples it could provide a moderate source of error in climate history interpretations.”
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.
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.
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.”
La géologie, une science plus que passionnante … et diverse