Tag Archives: Chukchi

Arctic melt ponds get media spotlight as Laptev Sea ice hits an 11 year high

PolarBearCV1_USGS_2009

Walt Meier, sea ice scientist at NASA Goddard, made a statement yesterday about this year’s ice conditions [2016 Climate Trends Continue to Break Records: July 19, 2016]:

“It has been a record year so far for global temperatures, but the record high temperatures in the Arctic over the past six months have been even more extreme,” Meier said. “This warmth as well as unusual weather patterns have led to the record low sea ice extents so far this year. [my bold]

Well, except for Davis Strait/Labrador Sea this spring. And Western Hudson Bay/Foxe Basin this month – plus the fact that late July sea ice in the Laptev Sea is higher than it’s been for more than a decade (more on that below).

r04_Laptev_Sea_ts_4km 2016 July 19

I guess totals matter for some things – just not for polar bears. However, it’s nice to see the issue of melt ponds get some attention, since they are such a prominent feature of polar bear habitat during the summer melt season.

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Challenging Alaska polar bear research sound bites and bewildering ESA status

Beaufort Sea male polar bear USGS_2005 Amstrup photo

It’s easy to take polar bear research papers at face value but it’s not very scientific. The snappy sound bites provided for the benefit of the media – whether they’re embedded in press releases or in published abstracts – don’t cut it with trained scientists. Trained scientists read the whole report, critically examine the evidence it contains and assess that evidence within the context of previous knowledge. That’s what they are trained to do.

I challenge the superficial summary on the status of Alaskan polar bear populations provided by FactCheck.org journalist Vanessa Schipani.  Schipani disputed a comment made by Alaska Senator Lisa Murkowski that, according to the latest research Alaskan polar bear population numbers are strong and healthy. I’m not especially interested in the political context of the statement, only Schipani’s bald claim that Murkowski’s declaration is false.

I’ve read all the relevant papers in full and I contend that the evidence supports Murkowski’s statement. Schipani is confusing the issue by regurgitating ‘facts’ that don’t tell the truth of the matter. By the sum of accounts, Alaskan polar bear populations are indeed healthy and strong – whether or not this status will continue is an entirely different question. Continue reading

Summer refuge for polar bears in Arctic Basin only 0.3 mkm2 below its possible maximum

At the seasonal minimum 2015, the Arctic Basin was still almost full of sea ice, down only 0.3 mkm2 below the maximum it could ever be.

Healy Aug 24 2015 Polar-Bear III Tim Kenna

Remember that spending the summer in the Arctic Basin for most polar bears is just like sitting on the western shore of Hudson Bay – they are all waiting for the refreeze. In either location, they might find something to eat, they might not.

Below are NSIDC MASIE sea ice maps for 10 April 2015 (as big as it gets, basin filled) vs. 17 September 2015: Continue reading

Designated critical habitat for Alaskan polar bears offers no protection from thick spring ice deaths

The Obama administration is apparently attempting to overturn a previous ruling that rejected proposed Alaskan “critical habitat” for polar bears in 2013 – as if “critical habitat” would protect the bears from the repeated episodes of thick spring ice that develop in this region every 10 years or so.

Polar_Bear_male on sea ice_Alaska Katovik Regehr photo_April 29, 2005_sm labeled

According to a Reuters report today (5 May 2015):

Seeking to reverse a ruling throwing out its designation of critical habitat for polar bears, the Obama administration has defended its decision to list large swathes of the Arctic as necessary for the conservation of the threatened species.

A coalition of oil industry groups and Alaska Natives, represented by Stoel Rives and Holland & Hart, successfully persuaded the U.S. District Court for Alaska to vacate the government’s polar bear habitat designation in 2013.” [my bold]

If they succeed, it would put most of the north coast of Alaska under special ESA rules, as the map below shows (click to enlarge).

Critical habitat Polar Bears US_NorthSlopeOrg map_labeled_PolarBearScience

As I commented previously, regarding the Obama administration’s recommendation to congress that they approve a proposed Arctic wildlife refuge area on Alaska’s North Slope, this move (if implemented) would not protect polar bears from the starvation deaths due to thick spring ice conditions that have occurred in this region for 2-3 years out of every 10 since 1960 at least.

The other issue is how much additional, biologically meaningful protection a critical habitat designation would provide for Southern Beaufort and Chukchi Sea polar bears – over and above that already provided by the Marine Mammal Protection Act.
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Chukchi-Beaufort sea ice atlas: check out polar bear habitat 1850-2013

It’s here – as promised and right on schedule — the sea ice atlas put together by University of Alaska Fairbanks (UAF) now has ice concentration maps for Alaska going back to 1850 — and for every year up to 2013. 

Several examples are included below: August 1850 vs August 1870, and April 1850 vs. April 1920 and April 2012.

For background, see my post announcing the site preview, which was then limited to 1953-2012 data, when it became available in late January.

Sea ice atlas_1850_Aug
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Graphing polar bear population estimates over time

I’ve already commented on the 2013 update of polar bear population status released by the IUCN Polar Bear Specialist Group (PBSG).

However, I thought it might be interesting to graph the changes in global population estimates over time (from 1981-2013) — not just the actual estimates from PBSG status tables (with their min/max error ranges) but those totals plus the so-called “inaccurate” estimates that the PBSG have dropped from their accounts in recent (2005-2013) assessments: Chukchi Sea, East Greenland, Queen Elizabeth Islands (now known as the “Arctic Basin”), and Laptev Sea.

In 2001, those “inaccurate” estimates contributed 5,000-5,400 bears to the global total, but now they’re gone — no bears from those regions contribute to the official totals listed on recent PBSG status tables.

Adding those dropped estimates back into the global totals makes it possible to generate a graph in which the global estimates are truly comparable over time.

To see how the dropped estimates influenced the perception of population change over time, I’ve also graphed the estimates given by the PBSG in their status tables. I’ve combined the two into one image (Fig. 1, click to enlarge) to make comparison easy.

UPDATE 5 December 2014: Links to more recent posts relevant to this issue added below. The most recent numbers, added 31 May 2015, are here.
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Polar bear habitat update for October 31, 2013

Here’s the ground-truth follow-up to my suggestion of what polar bear habitat would likely look like 6 weeks after the minimum extent was reached this year – which was looking then like it would mirror 2009.

You’ll find my discussion, posted on September 22, here. At that point (September 13), ice extent was 5.1 million square kilometers; now it is 9.1 million square kilometers (Fig.1).

Figure 1. Oct 30 2013 Maisie sea ice extent, 9.1 mkm2. This does not take thickness or concentration into account.

Figure 1. Oct 30 2013 Maisie sea ice extent, 9.1 mkm2. Click to enlarge.

Have a look at the maps below: Fig. 2 to see how ice extent at October 31st compares to ice extent at the end of October 2009, and Fig. 3 to see what ice concentrations looked like in the Canadian Arctic.

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