Many of you watch sea ice as closely as some people follow the NFL, soccer, or NASCAR. So when something of interest happens, I’m not without an inbox full of notices.
Today it is encouraging to see the NANSEN is reporting that both Arctic Sea Ice area and extent are above the normal line. Usually we don’t see both in this mode. Here’s area:
And here is extent:
Source: http://arctic-roos.org/observations/satellite-data/sea-ice/ice-area-and-extent-in-arctic
By itself, this is just a small thing, but it is just one more indication that there’s some improvement in the Arctic Ice situation again, and the indications are that we’ll have another summer extent that is higher than the previous year, for the third year in a row.
Of course our friends will argue that extent and area don’t matter now, that only volume and ice quality (the rotten ice meme) matters.
Interestingly, if you go back to the press releases on the record minimum extent in 2007 at NSIDC here:
http://nsidc.org/arcticseaicenews/2007.html
And search the entire set of release for the word “volume”, you won’t find it used anywhere that year. The volume worry is a more recent talking point that first appeared in October 2008 when it became apparent that extent wasn’t continuing to decline. They couldn’t tout another record low extent, so volume became the next big thing:
http://nsidc.org/arcticseaicenews/2008/
Arctic sea ice minimum press release
Please see the NSIDC press release, “Arctic Sea Ice Down to Second-Lowest Extent; Likely Record-Low Volume” for a detailed analysis of this year’s Arctic sea ice minimum and a synopsis of the 2008 melt season.
With nature still not cooperating with “death spiral predictions”, what will be the press release ice meme this year? Color? Texture? Cracks per square kilometer? It will be interesting to watch.
David Corcoran says:
April 30, 2010 at 8:36 am
I notice the chart doesn’t actually show the ICESat data since 2007. Why?
Because that chart was based on this paper (as noted on the chart):
http://rkwok.jpl.nasa.gov/publications/Kwok.2009.JGR.pdf
That paper used the data from 10 ICESat campaigns, from September 2003 to March 2008. Doing the analysis and writing the paper takes time, and the paper was submitted Feb 2009.
Why didn’t the satellite run continuously ?
I too would like to see that chart with the 2008 data, and whatever they observed in 2009 before the satellite died in October. I’ve read that the volume recovered a bit in 2008, but the larger extent in 2009 was offset by continuing loss of thicker ice.
I’d like to see how closely the ICESat data matches those PIOMAS data points for 2008 and 2009.
So for how many years does the sea ice need to expand before it isn’t decreasing anymore?
kadaka (KD Knoebel) says:
April 30, 2010 at 9:12 am
… the second city founded by Nimrod in Shinar.
According to the Book of Genesis, Nimrod is a great-grandson of Noah and the king of Shinar. Hardly impeccable archaeology. The whole Noah story was copied from the Epic of Gilgamesh…
The Wikipedia “Cradle of civilization” article is interesting reading. By a certain definition Sumer is the first known civilization, but there are other places that also have a good claim to it, with “civilization” existing long before then.
Civilization is by definition humans living in cities. The definition of “city” varies among archaeologists, with hamlets blending into villages blending into towns blending into cities.
I think some of the thresholds for “city” are too low – a settlement like Eridu is very old, but at it’s height in 2900 BC was only 20 or 25 acres in size and it had a few thousand people, while Uruk was 250 acres and the first city in history to surpass 50,000 inhabitants.
Uruk might not be the “first” by some definitions of “city”, but:
In addition to being one of the first cities, Uruk was the main force of urbanization during the Uruk Period (4000–3200 BC). This period of 800 years saw a shift from small, agricultural villages to a larger urban center with a full-time bureaucracy, military, and stratified society. Although other settlements coexisted with Uruk they were generally about 10 hectares while Uruk was significantly larger and more complex. The Uruk period culture exported by Sumerian traders and colonists had an effect on all surrounding peoples, who gradually evolved their own comparable, competing economies and cultures. Ultimately, Uruk could not maintain long-distance control over colonies such as Tell Brak by military force.
Geographic factors underpin Uruk’s unprecedented growth. The city was located in the alluvial plain area of southern Mesopotamia, on the Euphrates rivers. Through the gradual and eventual domestication of native grains from the Zagros foothills and extensive irrigation techniques, the area supported a vast variety of edible vegetation. This domestication of grain and its proximity to rivers enabled Uruk’s growth into the largest Sumerian settlement, in both population and area, with relative ease.
Uruk’s agricultural surplus and large population base facilitated processes such as trade, specialization of crafts and the evolution of writing. Evidence from excavations such as extensive pottery and the earliest known tablets of writing support these events.
http://en.wikipedia.org/wiki/Uruk#Prominence
Just for inventing writing, Uruk should be remembered and honored.
Plus, the Epic of Gilgamesh (a king of Uruk) is the oldest literature in the world.
BTW Enlil was the Sumerian god of the sky. He was also the god of the weather. Despite weather not being climate, I can not find mention of a Sumerian god of the climate. Guess their civilization really wasn’t that advanced since they apparently never noticed the difference.
There were lots of gods in the Sumerian pantheon – Enki, god of water, Enlil, god of wind, Ninurta, god of thunderstorms, etc.
I figured I’d go with Anu, Enlil’s father. Enlil is the father of the god of thunderstorms – Anu is father of all the climate-related gods, the Zeus/Jupiter of Mesopotamia.
Anu says:
April 30, 2010 at 7:02 am
++++
You guys are hilarious. Care to explain how you get to a 30 year recovery without going thru years 3, 4, 5, etc?
At this rate you’ll still be insisting in 2030 that those darn skeptics are being way too hasty in claiming a recovery is underway.
Yet oddly, when computer modellers predict doom and gloom 75 years from now, *that* has credibility we’re all supposed to be taking very seriously indeed.
Smokey says:
April 30, 2010 at 6:03 am
The photos I’ve seen, and I think there’s only one village, at least one getting this amount of attention, show several other prefab buildings, the sort that would cost more to move than replace.
You’re welcome. I didn’t become active in the AGW discussion, deliberately, until the end of the warm PDO. As such, I never saw a live post from him, a great pity. One of the first things I searched for in the Climategate Emails after seeing Jone’s comment were other John Daly references. Included were a couple Emails from Daly himself and served to drive home what a loss his death represents.
He seems like the ideal skeptic – always respectful, always well prepared and well researched, and persistent when he had something that deserved attention from the scientific community. That’s why his web site is still remarkably useful and informative.
Another Player in the “Why so much Ice loss in 2007” was referenced by “DR” last year:
— a 16% Cloud Reduction analyzed by Graeme L. Stephens, see: http://www.arm.gov/science/highlights/pdf/R00143.pdf
Bonus: Norwegian Researcher Asgeir Sorteberg claims
Ice Extent is Poor indicator of Ice Health & suggests using Volume instead. Thanx to the blogger whose name I frogot to write down:ttp://translate.googleusercontent.com/translate_c?hl=en&ie=UTF-8&sl=no&tl=en&u=http://www.forskning.no/artikler/2010/april/248227&prev=_t&rurl=translate.google.com&usg=ALkJrhhcPyhQaL-e5A0l1OVisZBTdiUB9Q
PS: Beware the The PDO index .
It is really a compilation of EFFECTS thought to be from the PDO, e.g. South American coastal rainfall.
The Real PDO, is simply Pacific temperature.
There appear to be 2 Oscillations: 30 years Up & 30 down ( e.g. 1977-2007 was hot) and a much more variable “short” oscillation which runs for a dozen years or so, PLUS, up to another dozen years. Apparently, whenever it feels like it. (There is likely some underlying link to the Sunspot cycle or whatever). Sorry I’m so vague on the numbers.
The Short Cycle , turned Cool in 2003? or 2007? — La Nina/Ninos are more numerous depending on the Short Cycle but Strength is more dependant on the Long) .
Charles Wilson says:
April 30, 2010 at 6:32 pm
PS: Beware the The PDO index .
It is really a compilation of EFFECTS thought to be from the PDO, e.g. South American coastal rainfall.
The Real PDO, is simply Pacific temperature
The PDO Index is defined as the leading principal component of North Pacific monthly sea surface temperature variability.
geo says:
April 30, 2010 at 3:25 pm
You guys are hilarious. Care to explain how you get to a 30 year recovery without going thru years 3, 4, 5, etc?
Feeling pretty confident with the 2D results of year 1 and 2 , are you ?
At this rate you’ll still be insisting in 2030 that those darn skeptics are being way too hasty in claiming a recovery is underway.
You’re still postulating a 30 year recovery, but talking about 20 years from now ?
Well, that would get people’s attention, sure.
Yet oddly, when computer modellers predict doom and gloom 75 years from now, *that* has credibility we’re all supposed to be taking very seriously indeed.
You mean professional climate scientists ?
Yeah, I believe their work more than random bloggers; even hardworking retirees with no formal training in climate science.
But if this reverses for 20 years:
http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif
and this reverses for 20 years:
http://nsidc.org/images/arcticseaicenews/20091005_Figure3.png
I will start to think modern science is more like this:
http://www.youtube.com/watch%3Fv%3DDQaF4YXCXsc
I’ll keep in mind your hilarity if we go thru years 3, 4, 5, etc…
See you in September, Anu.
For the moment, I don’t see any significant milestones between now and July 1-15. We’re entering a yearly choke-point on extent –we exit the choke-point on July 1.
But the central core is what is important, which is why I focus on the 30 years of comparator images showing how dense that core is. Extent at 15% concentration is way too unuseful at certain times of years, and we’re entering one of them now.
So far as I can tell, I’m a minority of one in the skeptic community on not being fully satisfied by the “wind and tide” explanation for 2007. Yeah, it played a role. . . but in my view, the analysis should not have stopped there. I’m of the opinion that the lesser the concentration of the central core, the greater the role wind and tide can play on “rotten ice” vs the role it will play on large, thick blocks. The comparator images show that in 2007 the concentrations in the central core were anemic. In 2010 they aren’t (so far).
I would have thought a reduction in snowfall would allow evaporation (sublimation)to reduce ice volume even if temp remained low as it appears to have been at least in main antarctic mass.
Anu says:
However, the fact that you hide behind a pseudonym means that you do not have the courage of your convictions. You like running with the herd but don’t want to be punished for it.
If it turns out that these so-called professionals you put your faith in are wrong, you can slink away with your tail between your legs and pretend that all along you never thought they had it right.
No [snip]s!
What flavour do you want?
What flavours have you got?
Pineapple and Cherry.
I’ll go for cherry…
Richard Sharpe says:
May 1, 2010 at 7:30 am
However, the fact that you hide behind a pseudonym means that you do not have the courage of your convictions. You like running with the herd but don’t want to be punished for it.
While you use the name of a character in a TV historical drama!
R. Gates says:
April 29, 2010 at 11:35 am
Your comments have a certain fascination because of your forecasts and odds making about what to expect in Arctic ice later this year based upon most recent year’s data. We can all roll dice, stones, bones or sticks and models too, but for what purpose. Wouldn’t it be better to understand the physical forces behind the natural variation we see over time?
Wouldn’t you want to know why the Northwest passage opened in the early 1900’s and again in the 1940’s? Wouldn’t the Vikings have appreciated some understanding of why their colonization of Greenland was not such a good idea, even though it was warm enough for agricultural production?
The ice comes and goes. Twenty periods of glaciation over the last 2.5 million years. How did the Earth get along without us all those years?
Phil. said on May 1, 2010 at 8:34 am:
While you use the name of a character in a TV historical drama!
Sorry to let reality intrude upon your existence, Phil-dot, but there are real living people named Richard Sharpe. Are you certain you have not just impugned the honor of this fine fellow?
(Interestingly enough, this does show one of the advantages of using a pseudonym, namely that you can duck demands for a duel on the field of honour…)
Phil. says:
May 1, 2010 at 8:34 am
It is true, I was born with a different name, and my mother paid dearly for not being married when I was born. Thank you for reminding me of my part in her death.
The name I use here is the name that is on my birth certificate and on my passport. It is the name I have used in contributing to several open source software projects, the books and other documentation I have been involved with, and the domain that I own.
I’ve been doing mind experiments while trying to stay warm in NE Oregon. It snowed in the Wallowa Valley today and caused several tourist attractions to close due to the cold wet weather. Anyway, back to the experiment.
I have been noticing the very cold waters in the northern Pacific, much colder than usual, and wonder if we have a mini-wind affect from the negative AO pealing away warmer surface water and mixing it with deeper cold water. It is certainly the case that wind blowing from East to West does this around the equator. In the Polar region, I am thinking that wind coming from the Arctic northeast towards the southwest out the Bering Strait might do the same thing and could be the source of the unseasonally cold storms we are experiencing well past what we should be experiencing during an El Nino.
To be sure, we have had El Nino storms in April and May before, wet and warmish. But these are very cold wet storms. The jet stream is certainly also playing loop de loop allowing cold temps to reach us, but the added wet air flow from the Northern Pacific just about froze our “hoo haas” off today. So here we are still in El Nino but it isn’t acting like it up here. You don’t suppose the negative AO not only affects the Arctic and Atlantic seas, but can reach all the way into the Northern Pacific through the Bering Strait?
I hadn’t read the thread before I posted. Feathers have been getting ruffled! And by the way, ….”iceholes”….!!!!!!!! spit sputter cough gag gurgle rotflmao!
I think the temperature of the ice is an important factor.
Troposheric temperatures, calculated from satellite imaging, are rising, which suggests that the ice may be warmer. This suggests also that it is likely to be less salty.
Why does ice spread when it warms? Suppose we start with extremely cold, very salty ice. As this warms and melts, Latent Heat of Fusion may be drawn from the surrounding seawater.
This could lead to a re-freeze of less salty water at a higher temperature, causing an increase in the extent of ice but at a higher temperature.
It could also lead to lowering of the temperature of the surrounding atmosphere with resultant blizzards.
Thus as global average temperatures rise we could see more sea ice in polar regions and could experience more snow storms in temperate and sub-arctic regions.
These storms could in turn distort the average temperature readings because weather stations in the affected areas would of course show a drop in temperature.
geo says:
April 29, 2010 at 10:18 pm
Oh, Phil –my bad. I’m on record for a 6.0-6.2M km/2 minimum for several weeks now. What are you on? Just so we have some male apparatus waving rights when we get there. . . . unless, of course, you’re just of the bray defiance at everyone else without putting your own prediction on the line tribe. . .
As I’ve stated elsewhere I think this year will be a strong melt year probably close to 2008. As far a numbers are concerned probably about 3Mm^2 in area (CT of course, I find Arctic ROOS to be not credible after their satellite issues last year). In extent that would be somewhere in the 4.5-5.0 range depending on the winds. Given the nature of the ice at present I would think that there’s about a 20% shot of a melt below 2007 values.
By the way what happened to the analysis of those images you promised?
Apologies.
I should have googled the Definition of “PDO index” — but I got sloppy.
It’s true that the sea ice extent curves are not great predictors for summer sea ice minimum:
http://nsidc.org/images/arcticseaicenews/20090804_Figure2.png
Here we see 2009 and 2007 overlap in June, yet diverge in August (and September – see below).
However, given the trend downwards as the planet warms:
http://iup.physik.uni-bremen.de:8084/amsr/ice_ext_n.png
all the recent years (2003 to 2010) are below the 36 year average of 1972-2008.
Does anybody here really expect that to change this summer ?
Even betting on the summer minimum being within 2 standard deviations within the 1979-2000 average is a longshot:
http://nsidc.org/images/arcticseaicenews/20091005_Figure2.png
And the word is “average”, not “normal”. Normal is changing, but the average can be defined for any group of years with good data.
The most interesting question about this summer’s minimum: will it be below that of 2009 ? I expect that it will be.
Do you understand the difference between area and volume or mass?
Do you understand the difference between concentration expressed as % surface cover and as cubic meters of ice per square meter?
Thin Arctic se ice melts fast once the Arctic melt season starts.
The past few weeks are the proof of that.
Ships Navigating the Canadian Arctic this past mild winter found most of it covered with rotten ice which broke up easily for ice capable ships to navigate. Nothing like the 20 meter pressure ridges that stopped the Ice Ramming Manhattan in it’s tracks in September of 1968 and 1969.
What a change in 4 decades. Well beyond the scope of natural variation.
REPLY: yeah sure whatever, you’re an expert then on natural variation of the Arctic sea ice 1000 years ago?
I’m amazed that in this day and age there are still people who think that global warming isn’t happening. From what I’ve seen, these are often (but not always) the same people who (a) think that the phrase “climate change” also allows for global cooling (it does not) instead of realizing that it encompasses global warming, and (b) think that the Time/Newsweek story in the ’70s on global cooling represented the opinions of a majority of climatologists (it did not even represent the opinions of a significant minority).
The mocking of ice quality and volume aside, I’m amazed that they still can’t see how ignorant they come across. I fully expect that in ten years, they’ll still be saying it’s completely natural to see such huge fluctuations in arctic sea ice. The few that finally realize they were wrong will probably claim that there’s no way they could know something that most scientifically educated people think is as clear as the Earth not being flat. (And no, Columbus did not prove the Earth was round, either. Scientists of the time, such as they were, already knew that. They also knew approximately how large the world was, which would’ve caused a huge problem for Columbus if he hadn’t accidentally “discovered” America – which he thought was Asia.)