Archives par mot-clé : Ice

CO2’s Influence Was 0.006 W/m² Per Decade During The Last Deglaciation. And This Melted Ice Sheets How?

by K. Richard, April 18, 2019 in NoTricksZone


According to the calculations of Dr. James Hansen, the radiative influence derived from the increase in CO2 during the last deglaciation was so negligible that it equated to “a third of energy required to power a honey bee in flight” (Ellis and Palmer, 2016).

 

Image Source: Ellis and Palmer, 2016

We now know how insects and bacteria control ice

by University of Utah, April 14, 2019 in WUWT


Proteins help organisms form or inhibit ice crystals

Contrary to what you may have been taught, water doesn’t always freeze to ice at 32 degrees F (zero degrees C). Knowing, or controlling, at what temperature water will freeze (starting with a process called nucleation) is critically important to answering questions such as whether or not there will be enough snow on the ski slopes or whether or not it will rain tomorrow.

Nature has come up with ways to control the formation of ice, though, and in a paper published today in the Journal of the American Chemical Society University of Utah professor Valeria Molinero and her colleagues show how key proteins produced in bacteria and insects can either promote or inhibit the formation of ice, based on their length and their ability to team up to form large ice-binding surfaces. The results have wide application, particularly in understanding precipitation in clouds.

“We’re now able to predict the temperature at which the bacterium is going to nucleate ice depending on how many ice-nucleating proteins it has,” Molinero says, “and we’re able to predict the temperature at which the antifreeze proteins, which are very small and typically don’t work at very low temperatures, can nucleate ice.”

Less Ice In Arctic Ocean 6000-7000 Years Ago

by Geological Survey of Norway, October 20, 2008 in ScienceDaily


Recent mapping of a number of raised beach ridges on the north coast of Greenland suggests that the ice cover in the Arctic Ocean was greatly reduced some 6000-7000 years ago. The Arctic Ocean may have been periodically ice free.

”The climate in the northern regions has never been milder since the last Ice Age than it was about 6000-7000 years ago. We still don’t know whether the Arctic Ocean was completely ice free, but there was more open water in the area north of Greenland than there is today,” says Astrid Lyså, a geologist and researcher at the Geological Survey of Norway (NGU).

Inconvenient: NASA says a Greenland glacier did an about-face – growing again

by Anthony Watts, March 25, 2019 in WUWT


“…scientists were so shocked to find the change.”

From NASA JPL: Cold Water Currently Slowing Fastest Thinning Greenland Glacier

NASA research shows that Jakobshavn Glacier, which has been Greenland’s fastest-flowing and fastest-thinning glacier for the last 20 years, has made an unexpected about-face. Jakobshavn is now flowing more slowly, thickening, and advancing toward the ocean instead of retreating farther inland. The glacier is still adding to global sea level rise – it continues to lose more ice to the ocean than it gains from snow accumulation – but at a slower rate.

The researchers conclude that the slowdown of this glacier, known in the Greenlandic language as Sermeq Kujalleq, occurred because an ocean current that brings water to the glacier’s ocean face grew much cooler in 2016. Water temperatures in the vicinity of the glacier are now colder than they have been since the mid-1980s.

See also here in NBS

GREENLAND ICE SHEET SIXTH HIGHEST ON RECORD

by GWPF, December 7, 2019


In 2018, Greenland’s total  surface mass budget (SMB) is almost 150bn tonnes above the average for 1981-2010, ranking as sixth highest on record.

 

The Danish Meteorological Institute (DMI) also performs daily simulations of how much ice or water the Ice Sheet loses or accumulates. Based on these simulations, an overall assessment of how the surface mass balance develops across the entire Ice Sheet is obtained (Fig. 4).

At the end of the 2018 season (31 August 2018), the net surface mass balance was 517 Gt, which means that 517 Gt more snow fell than the quantity of snow and ice that melted and ran out into the sea.

Greenland’s Glaciers Expanding Again

by P. Homewood, March 11, 2019 in NotaLotofPeopleKnowThat


As I reported last  September, Greenland’s ice sheet mass balance had grown at close to record levels for the second year running.

To clarify again, the mass balance calculation accounts for:

1) Snowfall

2) Ice melt

3) Ablation

 

In other words, it does not include calving.

http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/#

..

Arctic Sea Ice Extent Same As In 2005

by P. Homewood, March 5, 2019 in NotaLotofPeopleKnowThat


You may wonder why you have not heard much about Arctic sea ice death spirals and Greenland heatwaves this winter.

Hardly surprising, because the Arctic stubbornly refuses to follow the agenda.

Average sea ice extent last month was the highest since 2013, and stands as high as it did in 2005.

http://ocean.dmi.dk/arctic/icecover_30y.uk.php

Strong Arctic sea-ice growth this year

by Andy May / Javier, February 24, 2019 in WUWT


February is not over, and Arctic sea-ice extent is already over half a million square kilometers higher than last year at this day.

The growing season has not ended, and 2019 Arctic sea-ice extent is already higher than the previous four years and six out of the last 14 years.

Figure 1. Arctic sea-ice extent. Note the left edge of the graph is February 1, not January 1.  http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

Arctic sea-ice has stubbornly resisted the very warm years between 2015-2017 caused by the big El Niño. Are we going to see an increase in Arctic sea-ice over the next few years? Only time will tell, but the idea cannot be discarded.

Novel hypothesis goes underground to predict future of Greenland ice sheet

by Penn State, February 2,  2019 in ScienceDaily


Paleoclimatic records indicate that most of Greenland was ice-free within the last 1.1 million years even though temperatures then were not much warmer than conditions today. To explain this, the researchers point to there being more heat beneath the ice sheet in the past than today.

Data show that when the Iceland hot spot — the heat source that feeds volcanoes on Iceland — passed under north-central Greenland 80 to 35 million years ago, it left molten rock deep underground but did not break through the upper mantle and crust to form volcanoes as it had in the west and east. The Earth’s climate then was too warm for Greenland to have an ice sheet, but once it cooled the ice sheet formed, growing and shrinking successive with ice ages.

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 Sea Ice Extent Higher Than 2006 Last Month

by P. Homewood, January 9, 2019 in NotaLotofPeopleKnowThat


Just last March, the Guardian was trying to panic us about record lows in Arctic sea ice during last winter.

Back in the real world, DMI confirm that average Arctic sea ice extent in December was higher last month than in 2006. In reality, there has been very little change at all since 2005.

http://ocean.dmi.dk/arctic/icethickness/txt/IceVol.txt

 

“Terrifying Sea-Level Prediction Now Looks Far Less Likely”… But “marine ice-cliff instability” is “just common sense”

by David Middleton, January 5, 2019 in WUWT


Marine ice cliff instability (MICI) “has not been observed, not at such a scale,” “might simply be a product of running a computer model of ice physics at a too-low resolution,” ignores post glacial rebound, couldn’t occur before ” until 2250 or 2300″… Yet “the idea is cinematic,” “it’s just common sense that Antarctic glaciers will develop problematic ice cliffs” and something we should plan for…

“Our results support growing evidence that calving glaciers are particularly sensitive to climate change.”  Greenland’s climate is always changing… Always has and always will change… And the climate changes observed over the last few decades are not unprecedented. The Greenland ice sheet is no more disappearing this year than it was last year and it is physically impossible for the ice sheet to “collapse” into the ocean.

Figure 6. Jakobshavn Isbrae. (Wikipedia and Google Earth)