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Nick Barnes

You might want to rethink the words "north of the North Hole", by which I think you mean "south along 180W".


Sure, but which one would Alfred Hitchcock choose?

Just kidding, you are entirely correct. All that looking at flat maps of the Arctic makes me forget that the Earth is round.

Artful Dodger

No, Neven is right. The earth is flat, and the sea ice is recovering... once you finally realize that "Black is White" ;^)

Artful Dodger

Neven, there are at least 73,790 km^2 of open water in the 'North Hole' image for Sep 7. That represent 23.4% of the area within the dashed circle in image 2 above.

Artful Dodger

Only 4 more days until the last Sunset of the year at the N. Pole. Sep 12, 2010 (day 255) will be the last visible band MODIS image of the Pole until Sunshine returns in Spring 2011. So hopefully the open patch will drift over the Pole within that time.

Lord Soth

The MODIS mosaic created by NASA are polar stereographic projections with the scaling latitude (no distortion) at 70 degrees north not 90 degrees north.

To properly count pixels; you will need to convert to an equal area projection such as lambert azimuthal equal area which accurately treats each pixel as equal area, regardless of location on the projection.

You won't need to redo your work however; as the distortion at the pole is only 6%


Lord Soth the 6% is the linear dimension right? So area will be ~12% out?

Andrew Xnn

It sure is beginning to look like 2010 will be within a few days of reaching the same sea ice minimum as 2008 (or least that is what it appears to me).

Peter Ellis

The area of each pixel will be out by ~12%, yes. However, that's irrelevant to the calculations being made.

The pixel-counting process gives the sea ice fraction as a percentage of the total Pole Hole region in the MODIS photo. This percentage is independent of the distortion, and so should be a true measure of the ice coverage within the Hole. This percentage is then multiplied by the true size of the Pole Hole in order to calculate the sea ice area.

Artful Dodger

Lord Soth / MeYah / Peter: The projection error was handled in the previous thread (read down to "Projection"). That's why Neven's Polar circle is now 328 pixels instead of 314 pixels.

Don't gripe: The maximum error is 3% at the Pole, not 6%. The error gets less the closer you get to 70N, the standard latitude for the projection. 70 N is 2233 km from the Pole, so it's not even 1 pixel avg difference in the size of the error for the 'Pole Hole'.


Hi Neven, I have a friend who is so concerned about the melting polar ice caps that she is taking some urgent action next week - trekking to the magnetic North Pole! Charged with purity of heart, clear intention and willingness to serve, Canadian musical artist and yogi Parvati is making this courageous journey to a small, desolate island in the Arctic Ocean known as Ward Hunt Island, where less than one month ago, a chunk of ice the size of Bermuda spontaneously calved off the glacier. She will become the first ever to perform at the magnetic North Pole, and will offer her songs to help raise awareness of the global ecological impact of the melting polar ice caps. Learn more at www.parvati.ca


Hi All - Firstly, these images are astounding. Thank you so much for sharing them. Secondly, I'm also friends with Parvati, the electronic dance pop musician that Eringoestoparis is talking about. She's trying to raise awareness of this by taking some social action. She is going to be the first singer to ever perform at the North Pole. Kinda crazy! But the thing I really like about her awareness campaign is that it is based on the fact that we can create positive change. It is not doom and gloom and focused on the negative. Your approach is hope-based. I really resonate with and respect that. If you're curious, her web site is http://www.parvati.ca . It is a really interesting mission, to say the least. Best to you all.

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