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Andrew Xnn

Could you explain the average daily melt numbers?

Why is 2010 so low compared to the other years when the current area is so much lower?

I thought 2010 started from a fairly large area during the winter max.

Thanks for the blog,


The ice-bridge in NWP is breaking (cloud cover just moved).

You started looking at melt in specific parts of the arctic, which is the way to go: what matters in September is how much ice melted from the arctic basin, elsewhere very little is left. Seems this year there will be less ice towards Sxandinavi/Svalbard then in 2007, but towards the Chukchi sea, Beaufort and East Siberian there was a large melt in 2007, probably less this year, a bit early to tell.

Due to the unusual amount of thick ice in the East Siberian, the North East Pass may open later than the NWP, which to me seems a big surprise.



A large chunk of ice maybe 40x20km? has detached from the shore off Alert (west of the top of Nares Strait):

Kevin McKinney

. . . and 2007 edges ahead on the prelim, with today's result around 66k.


Andrew Xnn, I apologize, I wasn't clear. The average melt numbers are for the month of July. I've adjusted the text, thanks for pointing it out.

Andrewt, good catch! I'm so focussed on Petermann Glacier that I didn't catch that one.

Yep, 2007 is taking the lead and will probably expand it straight away the coming few days.


Speaking of Petermann, I like that preoccupation. I have updated the online post on the Petermann Glacier to reflect a new published velocity map from Joughin et al., (2010). It indicates how far inland the high velocity region of this glacier extends compared to neighboring NW Greenland glaciers. The Petermann is quite susceptible to sea ice changes, compared to Jakobshavn which at this time of the year fills its fjord with icebergs.


Ah, fjord. That was the word I was looking for when I commented on your blog the other day and referred to it as 'canyon'. It's a good thing I can laugh at my own silliness.

One thing I notice when looking at the Petermann Glacier is that so much ice from the Lincoln Sea is transported through Nares Strait. It makes me think it is slowing the break-up the sea ice in front of Petermann, but that's just a gut feeling.

I think I'm going to make that Jakobshavn Glacier animation tonight. If only for this news:

NASA-funded researchers monitoring Greenland's Jakobshavn Isbrae glacier report that a 7 square kilometer (2.7 square mile) section of the glacier broke up on July 6 and 7, as shown in the image above. The calving front – where the ice sheet meets the ocean – retreated nearly 1.5 kilometers (a mile) in one day and is now further inland than at any time previously observed. The chunk of lost ice is roughly one-eighth the size of Manhattan Island, New York.

Steve Bloom

I suppose someone should collect some of that ice and market it to restaurants in Manhattan. On these hot days it would come in handy for cooling drinks. :)


Andrew, I believe that large chuck off Alert is due to the flow reversal in the Nares Straits that started yesterday.


The speed of reverse flow of much warmer water from the Straits back into the Arctic basin is 14km a day (point 16 to point 17). Each day this continues, I would expect significant melting within 30km radius from the mouth of the Straits, growing each day as roughly 500km2 area of water is pushed back into the Arctic.

Alert is within 20km of the Straits entrance. and this is first time I've see a reverse flow this year(it may have occurred I just haven't spotted it, no buoy data to verify it)

Nevan, over prior days, i've been pondering your prior query regarding historical flow, regarding historical flow, sorry about the delay I'm somewhat cautious on estimates of this nature, these figures are preliminary and based on my own basic knowledge and review of the data, so please don't use this as definitive data in any way. with that disclaimer..

– had 61 days (of ice flow) = 30k (km2) total flow though the straits (using linear daily flow rate of 480km2).

Note: 2009 was somewhat unusual, the Straits were clear for a couple months before the ice started to flow, indicating that a lot ticker multi-year ice at the entrance didn't break and start to flow up until day 194.
Compare that with 2010 ice flow started on day 100, 94 days earlier then last year.

Ice Flow Start – day194 http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r03c03.2009194.terra.500m.jpg

Ice Flow End – day255 http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r03c03.2009255.terra.500m.jpg

Estimate of ice flow - 155 days = 99k (km2)
Current Julian day: 190 - Est. 58k ice flow (compared to ~zero flow 2009 at this time)

2010 – 90 days (of ice flow),
Ice Flow Start – day 100 http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r03c03.2010100.terra.500m.jpg

Ice Flow End – ~day 255
Will the Flow End date be the same as 2009?, my own prediction is that this will be extended by at least a week due to the thinner ice now permeating in the Arctic basin around north of Greenland.

It will be interesting to watch how this flow reversal will affect the region in the coming days, if it persists.
another candidate for an short animation, I reckon, or am i being presumptuous?.

The ice must flow.


correction on 2010 Nares Strait predictions (old estimates)..

> normal flow out : 480km2/day
> estimate on amount of Out Flow - 190 days
> total ice outflow over 2010 period - 91,200

now deduct any reverse flow days.

note - reverse flow has a bigger impact on ice extent in Arctic basin then normal out flow at this time of year due to the pumping of 500km2 of warm water back into the basin region. how to quantify 'bigger impact' will be seen over coming days.


blog comments are stuck on bold tag.. this should clear it


Thanks, Peter! Coincidentally, I have uploaded an animation showing the flow reversal in Nares Strait. If it's okay I'll repost your stuff over there.

What's with the bold?


i used html bold tags, but the closing tag was missing a backslash, resulting in two open bold tags.. this second close tag should sort it out.

thanks for reposting on the relevant new blog entry. Bouy 7440 data for today should be out in 2 or 3 hours time - should be interesting to see if it exceeds the 14km reverse speed from yesterday.


After Uni Bremen it's now Cryosphere Today that is acting weird, with ice concentration maps stuck on 7/7 and sea ice area graphs not being updated yet today. Are these weird weather conditions freaking out the satellite sensors, or what?


Sea ice area graphs have been updated on CT, but ice concentration map is still showing 7/7. Uni Bremen website is acting weird again, I've had to remove it from the Arctic sea ice graph page.

Another relatively low melt reported by IJIS, but at least the revision stayed below 10K today. I have decided to do the SIE updates every 3 days again. It's not much fun like this. ;-)


Anyway.where is Polarmet35.mps.ohio-state.edu/MODIS/250m/n/2010/
data gone for year 2010.Please ,can anyone help with that.(data ,pictures about petermann glacier.for this season)


Meelis, I'm not sure what you mean but when I copypasted the link in your comment in my browser I was directed here.

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