Posted on 08/19/2009 9:18:33 AM PDT by ClimateDepot.com
The issue was handled well by the NRC.What is your interpretation?
What did you take-away from it?
Gotten mean, have you?
The paper explaining the chart is in a PDF link on this page: http://www.frontier.iarc.uaf.edu:8080/~igor/research/ice/index.php and it says:
ice-extent anomalies ( 1000 km 2 )
Yes, both used models, but the Univ of Alaska folks just filled in a few missing years. The Univ of Illinois doesn't have any explanation of measurements before 1953 except the cryptic reference to the Walsh models.
People deserve a reply. Baiting tactics don't necessarily deserve much of one.
The Walsh documentation says it is "infrequent land/sea observations" and then "observationally derived charts". That's why I linked to it.
It also says this:
"1. Danish Meteorlogical Institute
2. Japan Meteorological Agency
3. Naval Oceanographic Office (NAVOCEANO)
4. Kelly ice extent grids (based upon Danish Ice Charts)
5. Walsh and Johnson/Navy-NOAA Joint Ice Center
6. Navy-NOAA Joint Ice Center Climatology
7. Temporal extension of Kelly data (see note below)
8. Nimbus-7 SMMR Arctic Sea Ice Concentrations or DMSP SSM/I Sea Ice Concentrations using the NASA Team Algorithm
Not to belabor the point, but the main thing that's changed in the Arctic that would affect sea ice extent is the length of the melt season. And there are a host of indicators that could be consulted indicating that Northern Hemisphere winters since the 1970s have been decreasing in "intensity". I.e., they've basically been trending shorter and warmer. Thus, the Arctic summer has been trending longer and warmer. (Lest I get brickbats for saying that, there's obviously a lot of variability!) So... if since the end of the LIA, NH summers and winters were basically (within bounds) stable in length and intensity, and then there's been a shift, we'd expect to see sea ice extent be somewhat stable until the 70s and then expect to see a decline.
Which we do.
The reason I said all that is: even though observationally it was difficult to get good sea ice extent numbers in the first half of the century, it's less difficult to assess the meteorologic climatology. Is there anything in that which would indicate any major effects on sea ice extent? (I don't know; I just tend to doubt that there is.)
With that, I must depart for slumberland. Got to watch "300" for the first time tonight, and then I watched "Chronicles of Riddick" AGAIN while posting on commercial breaks. G'night; I'll still respect you in the morning, palmer.
And what about the variability before the 70's?
So... if since the end of the LIA, NH summers and winters were basically (within bounds) stable in length and intensity, and then there's been a shift, we'd expect to see sea ice extent be somewhat stable until the 70s and then expect to see a decline.
Have you looked at other indicators for the early 20th century and determined that they were flat like the hockey stick handle from Walsh and Kelly? The Arctic air temperature chart I posted up thread doesn't say that. It's easy to focus on the post-70's with tons of instrumental measurements but not so easy to dig up accurate depictions of early 20th century climate change. You can just assume that it was stable and leave it at that.
meant to say “can’t just assume”, but either way it’s up to you.
Even “Morono?”
Yeah, definitely a guy the 'tards could love. Fer sure! Just ask John Kerry.
Inaccurate insult. ClimateDepot.com's actually very smart. I should have come up with something more refined. I wonder if he has a mistress... because I'm sure not ever embracing his principles.
You didn't label it Arctic air temperatures. My cursory glance made me think it was global.
What I was trying to emphasize was that the annual temperature cycle doesn't tell us everything. What really matters is the length and intensity of the melt period. What I don't Know is if there is any data pertaining particularly to that for the early part of the 20th century; i.e., is there any reason to think that Arctic summers were widely variable from 1900-1950? I emphasize again that I don't know; I only state that I can't think of anything which would have made it widely variable, such that sea ice extents were markedly affected.
I think it would have varied as much as any other time. I can't think of any reason why it would be flat. To take one climate record (not cherry-picked, just found it now):
There was the period of the late 1800's known in the midwest in particular as the "Little Ice Age" (but it was not The Little Ice Age). Arctic ice would probably have been high then, followed by decreases into the 1940's. There is not the same warmth as the late 20th century (esp in duration) so it should be flatter than the late 20th century. The question is, looking at your hockey stick graph in post 34, would it be completely flat. Especially look at the purple (autumn) graph, is there any reason that it would be completely flat for 50 years? I would think at least some years would have shown icing up above average in autumn headed into a cold winter (e.g. 1917). Here's the page where the graph is from: http://home.att.net/~minn_climo/
I’m not sure now if you’ve got a coaster brake or if you just can’t shift gears.
Look, the true argument here is not over whether one proxy is better than another or whether one measurement is more accurate and meaningful than another but over the essence of argument, rebuttal, debate and reasoned analysis.
It can’t be as much of a crisis as it’s being made out to be except for the fact that agreement among politicians is the most elusive of animals and there is no possibity of the species becoming extinct any time soon.
You once told me you had no dog in this fight and I believed you; of all the people here who comment on this issue, you are the last one that I expected to resort to any sort of name-calling and that’s why I came back at you.
How about we make a bet? By this time next month, Oct 13th, 2009, I estimate that the Arctic ice extent will be within 5,000 sg. mi. of 2005; what say you?
You can go back and review my stuff. I have a dog in this fight: honesty. I have a serious beef with willful, dedicated, consistent, distortionism. Some people want to discuss the issue. Some people have some serious things to say about it that I don't agree with, but I trust that they're serious.
ClimateDepot.com is spoonfeeding distortion and misrepresentation primarily to a gullible listening gallery who don't have the ability to filter his torrent of spew. These a few others with similar modii operandi (pardon my Latin).
By this time next month, Oct 13th, 2009, I estimate that the Arctic ice extent will be within 5,000 sg. mi. of 2005; what say you?
I am unfamiliar with the unit "sg. mi.", and I also prefer SI. (And I'm having a bit of fun with you.) But seriously: it ain't about the number on any given day; it's about the trend. The LONNNNNNNG term trend. As I've said before -- climate is average weather. Daily Arctic sea ice extent -- is weather.
Still thinking.
You dumb ass, :)
We’ve been able to measure the extent only for the past 30 years, what sort of long term am I supposed to stick around for?
Here is one of the posts I stuck in about a month ago:
http://www.freerepublic.com/focus/news/2323553/posts?page=12#12
What’s at stake here anyway, bragging rights?
Our own moon proves that this rock would be unihabitable without its atmosphere; our best understanding of occupied land area and global position has transitioned practically across the current poles; still generations of species live on and prosper.
And what complaint has been registered from our unfeeling host?
Is it that our mortality has now made us vindictive in its current fervor?
With no God left to entreat or curse and cry at his feet are we now reduced to planeticide?
Has arrogance become infinite in its audacity?
It’s in the hands of the politicians now and to the highest bidder belongs the mess.
Fair or unfair - when I hear the New York Times talk about global warming, I hear them saying, "we're the biggest fools on the block"...
I looked at your other post. I don’t think 2009 will beat 1998. Too much cold at the beginning of the year.
I’ll get back to you on the other stuff later. Fingers weren’t working real well for awhile tonight.
Unbelievable. They compare a summer month with twelve month averages THAT INCLUDE THE WINTER MONTHS and find....there is less ice.
Breathtaking.
That's got to be the longest La Nina in history. AGW koolaid drinkers were saying the same thing in 2007 when it was snowing in Baghdad and Buenos Aires; it's the latter part of 2009 and they're still desperately looking for warming to come back, like the little kid in Shane. "Come back, global warming, come back!"
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