Archives par mot-clé : Ice

Arctic Sea Ice Extent

by DMI (Danish Meterological Institute), July 2017

The graphic shows the mean September sea ice extent on the northern hemisphere. The plotted values correspond approximately to the sea ice area that ‘survived’ the summer melt in the respective years

The graph illustrates a decreasing trend in sea ice extent since 1978, with annual variations of occationally more than 1 million square kilometres. The 2012 sea ice minimum extented set a new minimum record.

See also here

Abrupt summer sea ice decline has not affected polar bear numbers as predicted

by  Dr. Susan J. Crockford, July 14, 2017 in ClimateChangeDispatch

Yes, Arctic sea ice has declined since satellite records began in 1979 but polar bears have adjusted well to this change, especially to the abrupt decline to low summer sea ice levels that have been the norm since 2007. Some polar bear subpopulations have indeed spent more time on land in summer than in previous decades but this had little negative impact on health or survival and while polar bear attacks on humans appear to have increased in recent years (Wilder et al. 2017), the reasons for this are not clear: reduced summer sea ice is almost certainly not the causal factor (see previous post here).

Media gets high on Antarctic Crack

by Anthony Watts, July 13, 2017 in WUWT

I thought I’d take a moment from my R&R to write about all the hullabaloo surrounding the calving of the large iceberg off the Larsen C ice shelf in Antarctica. First, a few of the headlines:

LA Times: After Antarctica sheds a trillion-ton block of ice, the world asks: Now what?

The Grauniad: Iceberg twice size of Luxembourg breaks off Antarctic ice shelf

NYT: Warnings from Antarctica


by Maja Sojtaric, June 27, 2017

The Eurasian ice sheet was an enormous conveyor of ice that covered most of northern Europe some 23,000 years ago. Its extent was such that one could have skied 4,500 km continuously across it – from the far southwestern isles in Britain to Franz Josef Land in the Siberian Arctic. Suffice to say its existence had a massive and extremely hostile impact on Europe at the time.

This ice sheet alone lowered global sea-level by over 20 meters. As it melted and collapsed, it caused severe flooding across the continent, led to dramatic sea-level rise, and diverted mega-rivers that raged on the continent. A new model, investigating the retreat of this ice sheet and its many impacts has just been published in Quaternary Science Reviews.

Lowest Solar Activity In 200 Years Accompanied By High Northern Hemispheric Snow And Ice

by P. Gosselin from F. Bosse and F. Vahrenholt, June 18, 2017

In May the sun was very quiet as sunspot number was a mere 18.8, which is only 36% of what is typical for the month this far into the cycle. Seven days saw no sunspot activity at all.

The following chart shows the current cycle, Solar Cycle 24 (red), compared to the mean of the previous cycles (blue) and the similarly behaving SC 5 (black).

It’s clear that the current cycle is significantly weaker than the mean and far weaker than the cycles we saw throughout most of the warming 20th century.

NASA Study: Mass Gains of Antarctic Ice Sheet Greater than Losses

by NASA, October 30, 2015

A new NASA study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers.

The research challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change’s (IPCC) 2013 report, which says that Antarctica is overall losing land ice.

According to the new analysis of satellite data, the Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed   to 82 billion tons of ice per year between 2003 and 2008.

They are diseases hidden in ice, and they are waking up

by Jasmin Fox-Skelly, BBC, May 4, 2017

Throughout history, humans have existed side-by-side with bacteria and viruses. From the bubonic plague to smallpox, we have evolved to resist them, and in response they have developed new ways of infecting us.

However, what would happen if we were suddenly exposed to deadly bacteria and viruses that have been absent for thousands of years, or that we have never met before?