contrails

On Jan 11, 4:39*pm, Eric Greenwell wrote:
"Only 19 percent of the ice cover was over 2 years old, the least in the
satellite record and far below the 1981-2000 average of 52 percent."

I don't know about you, but it seems clear to me that if ice was at
the lowest level ever two years ago and has since staged a huge
recovery, then saying that 81% of the the ice cover is less than two
years old doesn't actually add any new information and certainly is
not bad news.

Bruce Hoult wrote:
On Jan 11, 4:39 pm, Eric Greenwell wrote:
"Only 19 percent of the ice cover was over 2 years old, the least in the
satellite record and far below the 1981-2000 average of 52 percent."

I don't know about you, but it seems clear to me that if ice was at
the lowest level ever two years ago and has since staged a huge
recovery, then saying that 81% of the the ice cover is less than two
years old doesn't actually add any new information and certainly is
not bad news.


On the face of it, this looks like the opinion of a person with a 2 year
time horizon, but there's more to it: if 81% of ice in some location
disappeared at least 2 years ago, then we are not seeing catastrophic
results from that.

Or are we? :-)

Brian W

Bruce Hoult wrote:
On Jan 11, 4:39 pm, Eric Greenwell wrote:

"Only 19 percent of the ice cover was over 2 years old, the least in the
satellite record and far below the 1981-2000 average of 52 percent."


I don't know about you, but it seems clear to me that if ice was at
the lowest level ever two years ago and has since staged a huge
recovery, then saying that 81% of the the ice cover is less than two
years old doesn't actually add any new information and certainly is
not bad news.

It has not staged a "huge" recovery. 2009 is the _third lowest year_ in
the 30 year satellite record. And the loss of multi-year ice is crucial:
"The ice cover remained thin, leaving the ice cover vulnerable to melt
in coming summers."

That's from http://nsidc.org/news/press/20091005_minimumpr.html

While you are on that page, take a look at fig. 3 to see the extent of
the recovery.

And finally, the examination of the ice from ships found the ice was
less that the satellites were reporting:

"Recently published research by Barber and colleagues shows that the ice
cover was even more fragile at the end of the melt season than satellite
data indicated, with regions of the Beaufort and Chukchi Seas covered by
small, rotten ice http://nsidc.org/cgi-bin/words/word.pl?rotten%20ice
floes."

There is no good news from the National Snow and Ice Center, regardless
of the The Mail says.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

On Jan 11, 7:34*pm, Eric Greenwell wrote:
Bruce Hoult wrote:
On Jan 11, 4:39 pm, Eric Greenwell wrote:

"Only 19 percent of the ice cover was over 2 years old, the least in the
satellite record and far below the 1981-2000 average of 52 percent."

I don't know about you, but it seems clear to me that if ice was at
the lowest level ever two years ago and has since staged a huge
recovery, then saying that 81% of the the ice cover is less than two
years old doesn't actually add any new information and certainly is
not bad news.

It has not staged a "huge" recovery. 2009 is the _third lowest year_ in
the 30 year satellite record. And the loss of multi-year ice is crucial:
"The ice cover remained thin, leaving the ice cover vulnerable to melt
in coming summers."

That's fromhttp://nsidc.org/news/press/20091005_minimumpr.html

While you are on that page, take a look at fig. 3 to see the extent of
the recovery.

And finally, the examination of the ice from ships found the ice was
less that the satellites were reporting:

"Recently published research by Barber and colleagues shows that the ice
cover was even more fragile at the end of the melt season than satellite
data indicated, with regions of the Beaufort and Chukchi Seas covered by
small, rotten ice http://nsidc.org/cgi-bin/words/word.pl?rotten%20ice
floes."

There is no good news from the National Snow and Ice Center, regardless
of the The Mail says.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

Look at this:

http://climate.nasa.gov/news/index.c...ews&NewsID=242

bildan wrote:

"Recently published research by Barber and colleagues shows that the ice
cover was even more fragile at the end of the melt season than satellite
data indicated, with regions of the Beaufort and Chukchi Seas covered by
small, rotten ice http://nsidc.org/cgi-bin/words/word.pl?rotten%20ice
floes."

There is no good news from the National Snow and Ice Center, regardless
of the The Mail says.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly


Look at this:

http://climate.nasa.gov/news/index.c...ews&NewsID=242

I had no idea the mass loss was accelerating. No good news at the South
Pole, either.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

On 1/13/2010 9:43 PM, Eric Greenwell wrote:
bildan wrote:

"Recently published research by Barber and colleagues shows that the ice
cover was even more fragile at the end of the melt season than satellite
data indicated, with regions of the Beaufort and Chukchi Seas covered by
small, rotten ice http://nsidc.org/cgi-bin/words/word.pl?rotten%20ice
floes."

There is no good news from the National Snow and Ice Center, regardless
of the The Mail says.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

Look at this:

http://climate.nasa.gov/news/index.c...ews&NewsID=242
I had no idea the mass loss was accelerating. No good news at the South
Pole, either.

Hmmm. 24 cubic miles of ice loss per year since 2002 across Antarctica.
Sounds pretty bad. Thats a lot of ice.

But the area of Antarctica is 5.5 million square miles. Average ice
depth across the interior is estimated to be 1.2 km. Thats a couple
million cubic miles of ice. Now that's a lot of ice.

Makes 24 cubic miles seem pretty trivial. But maybe its wildly abnormal
to loose that much. Or maybe it really is trivial normal variation. I
don't know.

But watch out for scale and context. Big numbers can be used to
illustrate, impress, or deceive.

A seven knot thermal may sound pretty impressive. But on a strong day at
Parowan, its not even worth slowing down for

-Dave

Speaking of big numbers, here's a recent article that explains how the
temps at the Vostok research station in Antarctica dropped to a record
-89 C in 1983; http://insciences.org/article.php?article_id=8087

-Scott