Bering Strait: Cryosphere Today vs Real World

Thanks to NASA’s Earth Observatory site, a (rare?) opportunity to compare Arctic sea ice extension as shown on Cryosphere Today with the real world (as seen by the Terra satellite).

DISCLAIMER: The following should in no way be interpreted as suggesting anything untoward is being done at Cryosphere Today

The Earth Observatory’s “Image of the Day” for Jan 16, 2010 shows “Ice and Clouds in the Bering Strait“.

Ice and Clouds in the Bering Strait
Fig. 1 - Ice and Clouds in the Bering Strait

What are we looking at? The shapes of the islands clearly indicate it’s the sea between the Russian and Alaska coasts just to the South of St Lawrence Island.

St Lawrence Island
Fig. 2 - St Lawrence Island
Part of the Bering Strait (from Google Maps)
Fig. 3 - Part of the Bering Strait (from Google Maps)
Part of the Bering Strait (from Google Maps)
Fig. 4 - Part of the Bering Strait (from Google Maps)

Let’s take now the sea ice extent image from Cryosphere Today, for Jan 16, 2010, and zoom in to the area described above:

Cryosphere Today, Jan 16, 2010
Fig. 5 -Cryosphere Today, Jan 16, 2010
Detail from Cryosphere Today, Jan 16, 2010
Fig. 6 - Detail from Cryosphere Today, Jan 16, 2010
Detail from Cryosphere Today, Jan 16, 2010
Fig. 7 - Detail from Cryosphere Today, Jan 16, 2010

We can finally compare Fig. 7 with Fig. 1.

Ice and Clouds in the Bering Strait
Fig. 1 - Ice and Clouds in the Bering Strait

What is evident is that the Cryosphere Today processing eliminates the kind of ice that can be found right at the edge of the pack (visible as “dendrils” after a suitable magnification). The neat sea ice – open water distinction is a computational illusion.

"wavy tendrils—newly formed, thin sea ice"
Fig. 8 - "wavy tendrils—newly formed, thin sea ice"

Other evidence of missing sea ice from the Cryosphere Today image is along the Alaskan coast, for example in the black, apparently ice-free “shadow” of Nunivak island

Nunivak Island
Fig. 9 - Nunivak Island
Cryosphere Today, around Nunivak Island
Fig. 10 - Cryosphere Today, around Nunivak Island
Nunivak Island, Jan 16, 2010
Fig. 11 - Nunivak Island, Jan 16, 2010

Seemingly, the ice around the island is “broken up” by its presence, and for some reason disappears in a restricted area in the Cryosphere Today image.

So the question is…how much of this “marginal” ice is lost in Cryosphere Today compared to the real world?

0 Replies to “Bering Strait: Cryosphere Today vs Real World”

  1. I have been monitoring Crosphere Today for some time. After blowing up the images to examine the dithering patterns of presented sea ice. I had questions about the amount of anomaly in the regression of current sea ice patterns when compared to the velosity of shinkage and then rapid growth.

    The irregular behavior was ecpected with the Gulf Oil situation. The Tades where quite elevated and skewed North for months no doout in an attempt to avert weather compications.

    However I feel that there should have been a far greater scattering of the data than presented. I fin the coastal patterns to regular and inconsistant with landfall images. I have a basis of 25 years in computer science and feel that my analysis is sound. Still, in checking my thoughts and findings against those of other observers, I stubled rather quickly on your post.

    You may note:

    That Island is in the loose vicinity of a newly consigned joint U.S. Canadian under water Naval facility to be competed in 2012 ? (Reports say it’s been delayed)

    That may explain allot, or it may not. But either way personally I’m going to find another source for my data…

    Do you have knowledge of other sites, non-North Americab preferred, that present sea ice conditions, and/or sea temperatures in any form?

    Thank you,

    -Tony

  2. “So the question is…how much of this “marginal” ice is lost in Cryosphere Today compared to the real world.”

    You could ask: mailto:cryosphere-data@atmos.uiuc.edu

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