This week was a true roller coaster ride with Arctic Sea Ice. It is best summed up by looking at the JAXA graph for extent, shown below:
Below, see the area of interest magnified.
I’ve added the 5 million square kilometer line for reference.
The roller coaster ride actually looked for a day like it might cross the 2009 line, but soon turned down again, ending this week at 5,142,813. Here’s the recent JAXA data
08,28,2010,5342656 08,29,2010,5352500 08,30,2010,5348281 08,31,2010,5329375 09,01,2010,5332344 09,02,2010,5304219 09,03,2010,5245625 09,04,2010,5192188 09,05,2010,5142813
Source: http://www.ijis.iarc.uaf.edu/seaice/extent/plot.csv
JAXA sea ice area has dropped to 2008 levels:
JAXA AMSR-E Sea Ice Area – click to enlarge
Sea ice concentration from JAXA:
While JAXA shows extent now lower than 2009, DMI and NANSEN plots show it to be about even. The differences in observing sensor/platform AMSRE -vs-SSMI and methodologies at agencies are in play.
Above: Danish Meteorological Institute Arctic Sea Ice Extent – 30% or greater. Note that while this graph shows 30% concentration at the cutoff point, it is valuable to compare.
Above: NANSEN Artic ROOS- Sea ice extent 15% or greater – click for larger image
The differences appear to be in the low end of concentration, the 15% to 30% range. It suggests that the brief gains we saw may be wind related, blowing floating ice around, compacting it when winds are strong versus allowing expansion when winds are weak.
Temperature, after holding near freezing, now appears headed sharply downward.
Above: Danish Meteorological Institute – Mean Temperature above 80°N
Some light refreezing may take place before the end of September, which could minimize the ability of wind to sharply change extent like we saw recently.
With all these variables in play, choosing a winner will be as much a game of luck as of skill. Based on what we’ve seen, it seems probable that it will come from the middle of the pack between 2008 and 2009.
From SEARCH:
The estimates from the scientific community range from 4.0 to 5.6 million square kilometers, with 8 of the contributors suggesting a September minimum below 5.0 million square kilometers, 3 contributors suggesting a minimum of 5.0 million square kilometers, and 5 contributors suggesting a September minimum above 5.0 million square kilometers. Two contributors forecast a September minimum below that of 2007 at 4.0 million square kilometers and 3 contributors suggest a return to the long term downward linear trend for September sea ice loss (5.5 to 5.6 million square kilometers). None of the contributors indicate a return to the climatological sea ice extent of 6.7 million square kilometers.
Including all 18 contributions gives a September ice extent minimum of 4.8 +/- 0.77 million square kilometers, with a range of 2.5 to 5.6 million square kilometers.
Individual responses were based on a range of methods: statistical, numerical models, comparison with previous observations and rates of ice loss, or composites of several approaches.
On my special AMSR-E sea-ice extent anomaly plot (with a 31-year average NSIDC melt-freeze shape subtracted) it looks like the worm has turned and is now back in negative anomaly territory again (below average for AMSR-E data.) Based on recent years, this declining anomaly trend may last until the first of October.
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In the news of 9/10 we find that the Finnish sailing yacht Sarema (length 14.3m) with a “mom and pop” crew of Pekka and Riitta Kauppila has succesfully sailed the NW passage west-to-east. Let’s all give them a big hand!
http://www.sarema.fi/images/stories/sy_sarema.jpg
Bilingual (Finn. & Eng.) blog at
http://sarema.fi/
Confirmed JAXA 15% extent for Sept 10th: 4952813. In case anyone is still following this nonsense, updated charts …
15-day: http://img196.imageshack.us/img196/2103/15day20100910.png
7-day: http://img203.imageshack.us/img203/290/7day20100910.png
Take a look at: http://ocean.dmi.dk/arctic/icedrift_anim/index.uk.php
Select Ice Concentration and pan forward and back a few days. Look at the coasts and inlets. Is the variance pinch around 6th to 8th due largely to coastal geography and zenith angle? Will there be a second late bite of the main cherry or not? Lumps of it still look vulnerable but temps seem to be falling.
Only time will tell. Chocolate pipe wrenches do not good micrometers make. Seems to me extent numbers tell us very little about the thermal dynamics of what has taken place. A pretty pointless exercise really, good press fodder on both sides of the argument at particular points in the season but that’s about it.
AJB says:
September 11, 2010 at 8:18 am
Cryosphere today has the area increasing by ~29000 km^2 with the extent being essentially equal to yesterday. This year’s area is still above 2008’s minimum by ~100000 km^2, so pretty doubtful we’ll see it go under, but it’s definitely possible.
Extent is now closer to 2008’s minimum than 2009’s, which was a fairly important, though arbitrary, mark to me. 2009 showed a lot of improvement over 2008, so we’ll have to see a lot of improvement between 2010/2011 to see 2011 go above 2009, which will be nearly required for the sceptics to make claim of recovery. Another drop like 2009/2010 and we’ll see 2011 below 2008, which would be a big blow to the sceptics.
-Scott
JAXA Extent Changes versus the recent years:
… A bit longer than my normal chart, to show how the RATE of Loss/day is falling.
… Also, some Weather forecasted for the next week.
… Pips Drift for tomorrow, weakens for the first time in weeks.
… Most Area measures dropped faster than Extent, but abruptly stopped today.
Daily: ___________2007___ to___ 2010__&__(2009__2008
Spt_6-to-7______ – 10,312_____ -66,093___(-16,250__-68,437
Spt_7-to-8______ – 23,281_____ -37,813___(-_1,563__-24,375
Spt_8-to-9______ – 13,907_____ -16,719___(-14,531__-_7,656
Spt_9to10______ – 32,343_____ -25,994___(-20,625__XX=Min
Spt_10-11______ – 25,650_____ – ?__? ___(-19,219__-_
Spt_11-12______ – 15,569_____ – ?__? ___(-_9,531_-_
Spt_12-13______ -_4,219 ___(Anti-Dipole)_(XX=Minimum_
Spt_13-14______ – 32,500_____ – weird __
Spt_14-15______ – 23,437_____ – ?__? _(2007=Bottom +469)
Spt_15-16______ -__157 _____ – High over Pole (clear?)
2007 then rose 42,567 in 4 days, then lost that AND 312 more.
On the other hand, both the Lowest & Highest Concentration maps imply the 1/2 million km2 “arm” to the New Siberian Islands is breaking in the assault of 50 degree (F) water (!) from the Bering Strait (but the passing Gale will slow, even reverse, this for 2-3 days):
Low: http://www.osdpd.noaa.gov/ml/mspps/seaiceprd.html (does not show ice under 25%)
High: http://polar.ncep.noaa.gov/seaice/Analyses.html (mid-page)
PS Love to see Steve lay into these 2. Not because I’d believe 1 is a “conspiracy”, but because we might find out why they are different. Perhaps Anthony can ?
AJB:
DMI drift is for May (201005). Note the Ice, South of the Bering Strait ?
Doomsdayers need to “Drift” over to this site..http://www.science20.com/chatter_box/arctic_ice_september_2010_update_1
Long range F-casts for Arctic Temps back on the 24th of Aug which made me “Hope” that the melt would slow down to a trickle after the 6th & halt by the 12th have been about 80% correct…
I will have to adjust some figures for next year, paying more attention to SST though, since the slow down started on the 9th but with air temps at the outer Ice edge at -1.5 to -3.5 c I’m still thinking that the melt will halt in the next couple of days…
I know that none of you Brainiologists pay a hoot to what I post but My game plan is to find a user friendly way to f-cast ice melt than the uncomprehenable methods presented by most of you’all…. This year is my 1st practice,..next year i will be better but maybe I can find someone to follow & I won’t have to think so much..ruins my beer buzzzz!
Actually I made the Predict on the 23rd..Like I said,.I know no one is paying me no mind ..This is just Practice for Me!…The 12th is tomorrow!!
Looks like the giant iceburg that broke off that shelf in Greenland has now broken in two. The larger portion is still lodged at the mouth and the broken off piece looks to have drifted west and north about 50 miles.
Here’s August 18th (I hope): http://exploreourpla.net/explorer/?map=Arc&sat=ter&lvl=8&lat=81.479352&lon=-61.250332&yir=2010&dag=230
Use the calendar on the page to check Sep 5th and Sep 11th to see the before and after.
Rod
Preliminary JAXA number for Sept 11 is up…shows a 10000 km^2 gain. There’s a fair chance that Sept 10 was the minimum, but it would be a pretty abrupt minimum like in 2008. Last time we saw some gains, a few days later gave some brutal losses. The gain in yesterday’s area according to Cryosphere Today hints that the minimum might be here though. Still, late minima like 2005 or 2007 are still easily possible, even if we have several days of gain in a row.
Current extent predicts a minimum extent of 4.89e6 km^2. My preferred method gives 4.88e6 km^2 with a std dev of 120000 km^2. At this point, these methods don’t mean much because current extent is within the uncertainty of the minimum extent.
-Scott
With JAXA 2010 ice extend minimum standing at 4813594 sq.km, if that holds it is remarkably close to the average (4.8 million sq.km) that our scientists predicted.
Also interesting that Watt’s/Goddards prediction of ice “recovery” is back to fairy tale land. Not just did 2010 not “recover” to the average over the past 30 years, it did not even “recover” w.r.t. last year. In fact, it is painfully close to being the second smallest ice extent since satellite recordings started. On the positive side, 2011 now has a higher chance of seeing some “recovery” in Arctic Ice extend. Or maybe not. Will Anthony issue a new prediction for 2011 ? [he already has . . mod]
With all due respect for opinions, but maybe we should listen to what our scientists tell us rather than what bloggers (even wattsupwiththat) reports.