These spiky little bunches of ice form on thin and new ice in the Arctic Ocean. But these badboys can only form under very special conditions:
1) Calm winds. We can’t have these beauties blown away can we?
2) Cold, cold air. It has to be about 20C less than the water and since seawater freezes around -2C, that means the air must be about -22C or -7.6F. BRRR.
Frost flowers form when newly formed ice sublimates, that is ice changes directly from a solid to a gas totally bypassing the liquid stage. Initially, the water vapor formed by sublimation is the same temperature as the sea ice, but gets quickly cooled by the cold air. The air is then becomes supersaturated with water vapor, which means the air has too water much in it. Air really doesn’t want to hold all that excess water vapor, so when the supersaturated air touches another ice crystal the water vapor quickly turns back into ice. (Click the image to enlarge)
via The icy plumage of the Arctic | Deep Sea News. Continue reading “Arctic Ocean Flowers”
No this video isn’t of this arctic event, but shows the force unleashed just by a large chunk. One piece flew off and broke womans leg – you can see a piece of ice whistle by the cameraman.
An ice chunk four times the size of Manhattan has broken off of Greenland’s Petermann glacier—possibly the biggest glacier collapse in recorded history, scientists announced Friday.(Greenland map).
via Ice Island Breaks off Greenland; Bigger Than Manhattan.
Danish researchers analyzed ancient pieces of driftwood in north Greenland which they say is an accurate way to measure the extent of ancient ice loss. Writing in the journal Science, the team found evidence that ice levels were about 50% lower 5,000 years ago. They say changes to wind systems can slow down the rate of melting. They argue, therefore, that a tipping point under current scenarios is unlikely.
A Danish team believes it has found an indirect method that gives a clear picture of the ice loss dating back 11,000 years.Dr Svend Funder from the Natural History Museum of Denmark led several expeditions to inhospitable regions of Northern Greenland. On these frozen shores the Danish team noticed several pieces of ancient driftwood. They concluded that it could be an important method of unlocking the secrets of the ancient ice.
“Driftwood cannot float across the water, it has to be ferried across the ocean on ice, and this voyage takes several years, which means that driftwood is actually a signal of multi-year sea ice in the ocean and it is this ice that is at risk at the moment” said Dr Funder.
Carbon dating was used to determine the age of the wood. And figuring out its origins also yielded important information.
“It’s so lovely that drift wood from Siberia is mainly larch and from North America is mainly spruce. So if we see there was more larch or spruce we can see that the wind system had changed and in some periods there was little spruce and in other periods there was lots,” he said.
via BBC News – Arctic ‘tipping point’ may not be reached.