August 3, 2011
Arctic sea ice at record low for JulyArctic sea ice extent averaged for July 2011 reached the lowest level for the month in the 1979 to 2011 satellite record, even though the pace of ice loss slowed substantially during the last two weeks of July.
Probably what they meant to say was that the melt rate was at a record low and had essentially flatlined over the last two weeks.
Missing heat melts missing ice!
FYI…numbers from NSIDC
20110730 = 6.7582200
20110731 = 6.7905200
20110801 = 6.6091000
20110802 = 6.6681700
20110803 = 6.5675000
It is true that July 2011 set a new record low for the month of July in the satellite data record despite
the slow-down in ice loss the last 2 weeks of July.
Julienne,
The really interesting information is that melt has slowed to crawl and that cold temperatures are in the forecast. Won’t your readers be expecting a record melt, which clearly is not going to happen?
Why would they expect a record melt? There was a record low for the month of July but that doesn’t imply that this will continue. If the low pressure dominating the Arctic Basin is replaced by high-pressure then perhaps it will since the ice cover in the Beaufort and Chukchi seas remains rather diffuse. We all understand that weather remains an important factor in determining if there is a new record low or not…
Why would they expect a record melt? Maybe because NSIDC said this:
The previous lowest year for July was 2007, which went to break the record for the lowest ice extent at the end of the melt season.
weren’t they recently “tuned” to read melt ponds or scattered ice differently?
huh? what was tuned? There is nothing differently going on with our processing of sea ice data, same sensor, same algorithm.
There are hundreds of news articles out there predicting record melt in 2011 and rightly or wrongly attributing the claim to Mark Serreze. Look at Joe Romm’s site for example.
honestly I haven’t been paying attention to the media on Arctic ice this summer, but I’ll check out Romm’s site.
Julienne
Your post actually talks about average ice extent for July rather than the end of month figures which are way above 2007 and fast catching up other recent years. I have checked the report for June and not surprisingly there is no mention of monthly averages only month end figures.
It is hard to avoid the conclusion that this new way of showing things is designed to accentuate the “warming message” whereas the month end figures clearly point to a better position than 2007 at the very least.
Paul
Paul, basically at the end of each month (or more accurately the beginning of the next month) we provide a summary for the month and how the monthly mean compares to previous years. We also do mid-month posts and sometimes weekly posts depending on what is happening with the ice cover. As you may have noticed during winter we tend to stick to monthly summaries, and then when summer melt begins there is a mix of monthly as well as more frequent postings. It was mentioned in the August 3rd posting that at the end of the month the ice extent was above that in 2007. I’m unclear as to what you mean by the June posting. Are you talking about the July 6th posting that summarizes the month of June or something else?
Yes the July 6th post which summarises June talks about the end of June extent. I cannot find any mention of monthly means.
The truly newsworthy event is that (as Steve has repeatedly and accurately predicted on this site over the past several months) the sea ice melt has slowed to a crawl and that the final figure is likely to be considerably higher than the consensus of what warmist “experts” had earlier predicted.
So Steve can predict the weather? Steve, please share your secret!! 😉
Andy, I’m sure you understand that the slow-down is a result of low pressure replacing the high pressure cell that dominated June and early July in the Beaufort Sea. If the high-pressure had persisted throughout the summer as it did in 2007 it would be a different story.
Julienne,
I avoid making predictions more than about a week out, and base them on NCEP and Navy thickness/wind forecasts.
As Steve repeatedly has pointed out all summer, once the thin ice was gone and multi-year ice was encountered, the melt would slow. That is exactly what seems to be happening.
Hi Paul, I guess I still don’t quite get what you mean.
The entry for July 6th starts with: Arctic sea ice extent for June 2011 was the second lowest in the satellite data record since 1979, continuing the trend of declining summer ice cover. Average ice extent fell below that for June 2007, which had the lowest minimum ice extent at the end of summer. However, ice extent this year was greater than in June 2010.
That discussion is about the monthly mean for June. Then also when you go to June 2011 compared to past years, you see a discussion about the monthly mean.
The temperature map is also a monthly mean and the rate of decline is an average for the month (in conditions in context).
Seems only the last entry in there is about the end of June when a MODIS image is shown…
Julienne,
The really interesting thing though is what has been happening the last three weeks.
I agree it is interesting, and our mid-month post will likely focus more on analysis of the slow-down. Yes we can see that it’s tied to the replacement of the high pressure cell over the Beaufort Sea with low pressure, but would be good to investigate the ice motion fields, how the edge compares with the perennial ice (seems that despite the slow-down, more of the 5+ ice has started to melt out in the Beaufort Sea but in other parts it is likely helping stabilize further retreat), etc.
Julienne,
The fact that there is never a lot of ice much older than five years in the Arctic seems to be a good indication that a lot of 5+ ice gets transported out every year? At steady state, it should be equal to the amount forming.
My apologies- point taken!!
On a positive note where do you think we will be at end of August?
I’m with Steve on this that I wouldn’t make a prediction more than a week out and even that depends on the reliability of the week weather forecast. While it is not possible to make predictions such as whether or not 2011 will end up with more or less ice than 2007, I think you can confidently say that 2011 will continue the pattern of below normal summer sea ice conditions. I do think the September minimum will fall below 5 million sq-km, and that is based on typical rates of decline for the remainder of the summer melt season and the proportion of old versus new ice in the Arctic Basin.
It has got to be a Climatology THINGY!!!! To imagine that some would think when watching ice melt that the mean of the month would actually mean more than the end extent. With a possible error of up to 85% based on Pixel Count and 30 years of historical data the entire exercise is like playing SIM Planet. A virtual world attempting to extrapolate something that resembles the real world, more like a form of modern art than reality. Picasso would probably appreciate it!
Steve, I have to disagree with your statement of ice at least 5 years or older. Back in the 1980s there was more than 2 million sq-km of ice at least 5 years or older and today there is less than 200,000. The GRL paper led by Dr. Maslanik that I sent you a while back shows graphs of changes in the ice age, both for the Arctic as a whole and regionally. The 5+ year old ice is continuing to decline, some of it out of Fram Strait, but now more of it is being lost within the Beaufort/Chukchi seas.
Julienne,
NSIDC animations show that most of the 1980s 5+ ice transported out of Arctic between 1988 and 1996. Over time the average amount of new 5+ ice minus the amount transported out has to be zero. Otherwise the ice would either be hundreds of feet thick or non-existent.
Jeopardy? … bzzzt (presses buzzer) … I know this one Alex …
What happens when you switch on the satellite and begin measuring ice extent in January 1979 immediately after a mini ice-age and continue measuring into warmer decades?
The question I have is this. Would it be at all possible to find a more cherry picked date for the AGW cultists to use as the starting point?
Julienne: every one of you and Serreze’s propaganda press releases should have a disclaimer on the bottom that says: PLEASE NOTE: satellite data began in 1979 at the end of a cold phase after two decades or more of cooling. Consequently comparing the early data with more recent data from warmer decades may lead to idiotic conclusions. Thank you. NSIDC.
But since you never do anything that approaches that slightly humorous disclaimer, and instead use terms like: since the records began, and your sycophants use terms like: since recorded history, well I think you are purposefully misleading the public.
Surely you understand my point?
BBC now says “Arctic ‘tipping point’ may not be reached” Well knock me over with a feather!
http://www.bbc.co.uk/news/science-environment-14408930
Andy, but that is not what happened in 2007 when you had thicker ice than today. This goes to show that while thin ice plays a role in shaping the end of summer extent, so does the atmospheric circulation pattern. 2007 saw persistence of the Beaufort Sea High coupled with Eurasian Low. Both are important, and I am confident that if we saw the same summer pattern as in 2007, this year would see a new record low.
Julienne, many thanks for your input, I am still gathering comprehension and understanding and you are helping greatly along many others.
However I think you should think again about the following:-
“I am confident that if we saw the same summer pattern as in 2007, this year would see a new record low.”
Last time I heard the like was on a football terrace:- “that would have been a good goal if it had gone in”. I think it was a Chelsea supporter (the Chelsea bit is just for Steven)
It is 2011, therefore it is 2011’s weather, maybe tomorrow the wind changes and consolidation/compaction changes the whole scene? But calling on earlier “gods” to make your case… will and can only be seen as not becoming of you. It is only a matter of time before somebody points to their particular earlier “god” when the ice was non existant.
Please, please keep joining in, many thanks
Green, the point I’m trying to make (and perhaps not very well), is that the low extent in 2007 was driven by a combination of unusual summer circulation pattern and a thinning of the ice cover. A thin ice cover was somewhat of a prerequisite, so that the anomalous atmospheric forcing could remove so much ice. Since evidence shows thinner ice today than at the start of the 2007 melt season, if the same atmospheric forcing were to be applied to the ice cover today, you would get even more ice loss than observed in 2007. You may not recall buoy observations from 2007 that showed parts of the Arctic with more than 2m of basal melt. If you had that kind of basal melt happening this summer (and I’m looking forward to seeing how much basal melt has happened from the buoy observations), I’m positive 2011 would set a new record low during the satellite data record.