Final 2010 Arctic Sea Ice Summary – Sea Ice News #30

UPDATE: Peter Sinclair shows his true crock colors, and refuses to correct his errors in “crock of the week” even after they’ve been clearly pointed out. Some “journalist”, see update screencap posted below. -Anthony

I’m a bit late in getting this posted, as I’ve had a number of distractions the past week. But here it is, the post mortem report on 2010 Arctic Sea ice minimum. Of course the most interesting aspect is how well did the forecasts from the various scientists and groups do at predicting the 2010 minimum? This graph from the SEARCH report (in entirety below) sums it up pretty well:

The yellow highlight shows that Steve Goddard, who supplied sea ice commentary for WUWT over the past year before starting his own blog here, did better than many of the scientists and groups who made forecasts submitted to Study of Environmental ARctic CHange (SEARCH). His forecast at 5.1 million square kilometers (as seen in the SEARCH graph above) wasn’t that far off, was in the middle of the pack, and certainly better than the other ends of the forecast spectrum.

Forecasting is always a risk, and the closer you get to the target point, the better your skill will be. Forecasts made further out always have a greater chance of missing the mark, such as this one by NSIDC’s Dr. Mark Serreze did on Climate Progress on May 24, 2010:

As Arctic sea ice shrinks faster than 2007, NSIDC director Serreze says, “I think it’s quite possible” we could “break another record this year.”

Well, no new record was set, and sea ice certainly didn’t go higher than 2009 as we talked about here, so there were errors on both sides.The ground truth nature provided was in the middle.

Of course, nobody likes to admit such errors, in fact it seems that some will go to great lengths to hide them by projecting, such as video hack turned Al Gore trained environmentalist “Greenman3610” aka Peter Sinclair.  He videocasts from his home studio with sophisticated Mac slide show effects producing a YouTube feature called “Climate Denial Crock of the Week”. It’s a crock, there’s no doubting that, since he only shows one side of the 2010 sea ice forecast story, and focuses on a couple of words in a sentence for one WUWT blog post to prove his point. It’s hilarious for its sheer spinmastery, and a must watch for entertainment value:

The lead text posted by Greenman3610 starts with a false premise, and he carries that through the whole video.

In early summer 2010, the pseudo science blog Watts up with that informed it’s discriminating readers that this summer would decisively show that northern polar ice had ended a long term decline. They guaranteed it.

Now what’s hilarious about that spinmastery is the blog post he focused on, which was a two parter about Joe Bastardi’s AccuWeather sea ice report (which I summarized) followed by a technical summary written by Steve Goddard. You can read it here.

Greenman’s video opens with and focuses on a sentence and three words of ebullience from Goddard in that post, “you bet ya”, along with making the false claim of “They guaranteed it“.

Um, well, sadly no. We didn’t say “guarantee” nor that the long term trend would reverse, that’s your spinning words. Search that WUWT article for the word guarantee or variances of it and you won’t find it. In fact you won’t find any reference to a “guarantee” for a sea ice forecast anywhere on WUWT. But you will find a caveat using the word guarantee from Sea Ice News #8 on June 6th, 2010

Conclusion : Based on current ice thickness, we should expect September extent/area to come in near the top of the JAXA rankings (near 2003 and 2006.) However, unusual weather conditions like those from the summer of 2007 could dramatically change this. There is no guarantee, because weather is very variable.

And also on June 3rd in a post called “The Undeath Spiral” Goddard uses the word again:

Anyone betting on the minimum extent needs to recognize that summer weather can dramatically effect the behaviour of the ice. The fact that the ice is thicker now is no guarantee that it won’t shrink substantially if the summer turns out to be very warm, windy or sunny. Joe Bastardi believes that it will be a warm summer in the Arctic. I’m not a weather forecaster and won’t make any weather predictions.

Yup, weather during late melt season is a big factor, even NSIDC’s Dr. Walt Meir points that out in his guest post here, wind and weather is a big factor. He wrote:

NSIDC’s June estimate was too high compared to what actually happened.

…

First, when the thicker, older ice is in broken up floes, it is more easily “attacked” on all sides by the ocean heat and can potentially be melted completely. Second, the less consolidated ice is more easily pushed around by the ice and more susceptible to winds pushing the ice together – in other words, the effect of the wind is amplified. I think this is a major reason why a lot of the forecasts were too high.

…

To be sure, some of this could be attributed to luck, because there is always the wildcard of what the weather will do over the summer.

Certainly at that time of the WUWT post that Greenman focuses on it looked like 2010 would come out a bit ahead of 2009. But even though NSIDC’s forecasts were also initially too high (so was WUWT’s) and NSIDC director Serreze goes out on a limb in May and says:

As Arctic sea ice shrinks faster than 2007, NSIDC director Serreze says, “I think it’s quite possible” we could “break another record this year.”

You won’t see either of those NSIDC forecasts that didn’t come true mentioned in Peter Sinclair’s “crock” video, as they don’t fit his narrative of denigration. But you will hear that tired old Serreze maxim of “death spiral“.

And finally, here’s the complete SEARCH forecast summary report that Peter Sinclair and his merry band of crockers don’t want you to see, even though it has some nice “crock ready” graphics in it. He doesn’t want to let slip that some other scientists did worse in sea ice forecasts than what was posted here on WUWT, and he certainly doesn’t want to let slip that NSIDC’ Dr. Walt Meir posts here (and gets accolades) and that their forecasts were initially high too. No, can’t have that, it would upset the faithful and just wouldn’t be good television. 😉

But I suppose I’m grateful for all the attention, after all, if WUWT wasn’t the leading blog on climate with traffic that in a single day dwarfs the number of total views that Greenman gets on his videos in their life cycle, I wouldn’t be the big target. The fact that it irritates him enough to do a hit piece pleases me greatly.

But, I invite readers to compare facts from the video to what is presnted above and below. I also invite other skeptical bloggers to repost this in entirety on their own blogs.

UPDATE: Here’s the comments from “Greenman3610” aka Peter Sinclair on YouTube after being informed of the rebuttal:

It seems he’s enjoying the traffic WUWT sent, but is uninterested in correcting the errors pointed out. – Anthony

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From SEARCH (November 12th, 2010)

INTRODUCTION

A request was sent to the contributors of the 2010 SEARCH Sea Ice Outlook to summarize the 2010 arctic sea ice season. We asked:

• What were the main factors driving the 2010 summer sea ice?
• What additional data would be useful for improving future Outlooks?
• What are the implications for future arctic sea ice?

We appreciate the contribution by all participants and reviewers who made the 2010 Outlook effort a continued success. The Sea Ice Outlook provides a forum for researchers to evaluate their understanding of the state of arctic sea ice and for the community to jointly assess a range of factors that contribute to arctic summer sea ice minima. The Sea Ice Outlook is not a formal consensus forecast or prediction for arctic sea ice extent, nor is it intended as a replacement for existing efforts or centers with operational responsibility. Additional background material about the Outlook effort can be found on the background page.

SUMMARY

The sea ice monthly extent for September 2010 was 4.9 million square kilometers, based on National Snow and Ice Data Center (NSIDC) estimates. This was the third lowest behind 2008 (4.7 million square kilometers) and 2007 (4.3 square kilometers). It should be noted that the NSIDC value is a monthly averaged estimate and it is dependent on a particular passive microwave algorithm for sea ice. Other satellites, composites, or passive microwave analyses will have slightly different numbers. A review of the differences amongst algorithms and sensors is discussed in a brief report by the Climate and Cryosphere Project’s (CliC, http://www.climate-cryosphere.org/en/) Arctic Sea Ice Working Group (also available in the “additional information” section at the bottom of this page). The point here is not which is the “correct” value, but to acknowledge that there will be understandable differences between estimates. We take the NSIDC value as the “operational definition.”

It is also important to note that although recent sea ice values have not reached the extreme minimum of 2007, the sea ice minimum has remained well below the long-term “norm” (Figure 1). This may imply that in the present warmer climate conditions, September ice extents below 5 million square kilometers will become the norm.

Outlook estimates for September 2010 based on May data had a mean value of 5.0 million square kilometers compared to the observed minimum of 4.9 million square kilometers (Figure 2a). Quartile values were 4.7 and 5.4 million square kilometers. Outlook estimates based on June data had a mean value of 4.8 million square kilometers and Quartile values were 4.2 and 5.4 million square kilometers (Figure 2b). The August report (based on July data, Figure 2c) gave a mean of 4.9 million square kilometers, with Quartile values of 4.6 and 5.4 million square kilometers. The drop in estimate values between the two first Outlooks reflected in part record ice loss rates observed in June. However, ice loss slowed substantially in July and Outlook projections based on July data increased to 4.9 million square kilometers. This illustrates the importance of the summer circulation pattern on the ice cover, and provides a limitation on accuracy of estimates made earlier in the season.

SUMMER SEA ICE AND METEOROLOGICAL CONDITIONS

Figure 3 is a sea ice analysis combined with shipboard observations for the end of summer 2010 provided by Jenny Hutchings. Figure 4 is a sea ice age plot for the end of September provide by Jim Maslanik. While the 2010 melt season started with more multi-year ice (MYI) in the Beaufort and Chukchi seas than seen in recent years and an overall greater percentage of MYI arctic-wide, by the end of August nearly all of this MYI had melted out or ice concentration had fallen below 40%. In the Chukchi Sea, none of the ice greater than two years of age remained, and 97% of the second-year ice was gone. In the East Siberian Sea, there was a 65% reduction in the amount of second-year ice between the end of April and the end of August. A remarkable feature that was captured by satellite imagery was a corridor of low ice concentrations that allowed the Chinese vessel Xuelong, an icebreaker with a low ice class, to reach above 88˚N of latitude. Howell and colleagues recorded open water conditions in the Northwest Passage.

Several contributors, including Walt Meier and Hiroki Shibata, note that there was considerable sea ice present at the end of the spring season. NSIDC reported that the 2010 seasonal sea ice maximum was quite late (31 March compared to the climatological date of 26 February) and the total maximum ice extent approached the climatological mean. This increase was dominated by higher than normal ice extent in the Bering Sea, while ice extent remained below normal elsewhere. The increase in the Bering Sea was perhaps related to the strong negative Arctic Oscillation (AO)/North Atlantic Oscillation (NAO) pattern of winter 2009-2010. It was strongly negative in December and February; the February value was the third lowest NAO in160 years, and strong winds in the Bering Sea led to new ice formation. Community-based observations and field data for the Bering Sea ice cover summarized in the Sea Ice for Walrus Outlook (SIWO) indicate that even though Bering Sea ice was extensive, it was thinner than in past decades and hence susceptible to rapid retreat. Thus, after the winter maximum, pan-arctic ice extent quickly declined, with record daily average ice loss rates for the Arctic as a whole in May and June, and a new record low ice extent for June. This rapid rate of decline likely reflects a combination of thin ice and an atmospheric circulation pattern favoring ice loss. Julienne Stroeve (personal communication) noted that the total loss of sea ice area for 2010 was actually greater than the loss in 2007, based on a greater starting amount in 2010.

An important meteorological pattern is that the summers of the last four years have been dominated by the Arctic Dipole Anomoly (DA) atmospheric climate pattern. This pattern results in high sea level pressure on one side of the Arctic Basin (in this case North America) and low sea level pressure on the other. Because winds tend to blow parallel to lines of constant pressure, this provides sea ice advection generally poleward from the Bering Strait region. These winds also pick up heat and moisture from open water areas in the southern arctic (Chukchi region), transport it northward, and release the heat there. The normal sea level pressure climatology for the summer Arctic has been a flat field or a weak monthly mean low pressure center over the Arctic. In 2007 the DA was present all summer and contributed to record low sea ice conditions. In 2009 the DA was strong in June and July, suggesting a near record sea ice loss for that year, but by August the DA pressure pattern was replaced by the more normal low pressure center. In 2010 the summer started with a strong DA pattern in June, contributing to rapid sea ice loss (see Figure 1). However, the DA was replaced by a low pressure pattern in July (Figure 5), slowing down the rate of summer sea ice loss. But a major surprise for 2010 was that the DA pattern returned in August (Figure 6). We also saw continued above-normal ocean temperatures in ice-free regions at the end of summer (Figure 7).

CONCLUSIONS AND LESSONS

The mean estimates for the 2010 September Sea Ice Outlook based on May, June, and July data were close to the observed value with a rather small quartile distribution (as a measure of deviation from the mean). Most investigators, using a variety of methods, settled on a value slightly below 5.0 million square kilometers. This may represent an interim (or potentially longer-term) state for an Arctic that is now dominated by first-year sea ice.

Thickness surveys and drifting buoys that are part of the Arctic Observing Network (AON) suggest that much of the growth of first-year sea ice in the Pacific sector approaches an end-of-season thickness of around 1.7 m, independent of the starting time of freeze-up in the fall (H. Eicken, personal communication). As one goes further north toward the North Pole, the length of the shortwave radiation season is shortened with less ability to melt out multi-year sea ice (D. Perovich, personal communication). Could the last four years be a plateau state? What would it take to have another major sea ice loss down to a level of 3.5-4.0 million square kilometers? In regards to the first question, J. Stroeve (personal communication) notes that in the present warmer climate state, the tendency for a negative AO winter pattern to promote increased transport of ice into the western Beaufort/Chukchi seas—a pattern that historically has helped to reduce summer ice loss—actually enhances summer ice loss.

Another wild card is the presence of the Arctic Dipole pressure pattern in summer. It seems like it is a necessary feature to maintain current summer sea ice conditions. Yet the reason for its continued year-to-year presence in unknown. Is a return to more climatological flat summer sea level pressure patterns more probable than a continuation of the DA pattern?