Yes Neil the daytime temperatures in the 50s have certainly hastened the surface melting. The radar animation is quite interesting too, up until last night the fast ice extended out to about 5km but overnight it has cracked about 2km offshore and started to move. Presumably one of the offshore pressure ridges that held it in place has melted enough to release. Phil.

Andy Celsius himself set 0ºC as the boiling point of tap water and 100ºC as the freezing point. "Other way 'round my friend, other way 'round." No the original poster is correct, after Celsius's death Linneus reversed it! Strange but true.

Hi guys, I just saw this on CNN and thought it may be of interest. Does anyone have any more details? Phil. http://www.cnn.com/2013/03/29/world/europe/latvia-ice-stranded/index.html?hpt=hp_t2

If you think about PIOMAS, if the ice cracks and spreads by say 1%, initially you have the same SIA, but once the ice in the cracks freezes the SIA will increase by 1%. As regards volume as the cracks freeze the volume must also increase, but the growth rate will be faster because the build up of surface ice will be faster than growth under the existing ice for thermodynamic reasons. Phil.

Based on the Barrow site it's ~1ºC/0.1m of ice, so the fresh cracks should be about 0.7m thinner, assuming no snow. Thermal conductivity of ice is ~2.3W/m K so I make that ~23W/m^2 conducted through the ice. Phil.

A-Team, Wow, this is a great and very detailed image! If I am reading it right, it seems many of the "fresh" cracks have a temperature of -22.5C, while neighboring ice is 7-9 degrees colder. I was wondering with the ice temperatures displaying like this, if it would be possible to calculate how much heat convection/freezing is going on in those cracks, or if it would be necessary to have air temperatures to assess the heat release? If you know the conductivity of ice it should be possible to calculate the difference in thickness for example as well as the heat loss. Phil.

I am far from a global warming denier. You can look at my other posts. I believe in following the facts though. Nobody on this forum predicted we would have record volume gain this winter. This is an unexpected fact. Hardly unexpected, it was virtually inevitable following a record minimum! Failure to do so would have severe implications for this summer. Phil.

Wet ther that looks like a beautiful example of a Von Karmann vortex street, well spotted! Phil.

SATire, your blind faith in the market economy to achieve the optimum solution is touching but unrealistic. I find the idea that the German population is divided between those who only drive their cars in cities and those who only drive on the autobahns surprising.

SATire, read what I said, a diesel hybrid, I did not mention an SUV. From your description of driving in Germany such a hybrid would be perfect

SATire regenerative braking will increase efficiency regardless of the power source as a result what's needed on the autobahns are diesel hybrids with the same benefits as are obtained by gasoline hybrids. Phil.

Should divide by number of points of course, I.e. RMS. Sorry Phil.

Andrew for combining the uncertainties the usual procedure is to take the square root of the sum of the squared uncertainties. HTH Phil.

Regarding Tommi's comments about Wipneus's calculations, what he's describing reminds me of the reaction-diffusion models, whereby the state of neighboring cells influence their neighbors. Would it be possible to incorporate a step whereby an empty cell increased the melt rate of its neighbor (and vice-versa)? Phil.

Donald, for anyone using a Mac just cntrl click on the fig and select 'Open Image in new window'.

Looking at the remaining N pole webcam (cam2) now sailing through the Fram it looks like a lot of churned up ice nearby also no sign of the posts. Phil.

Lord Soth camera buoy #1 was picked up by the research vessel from the edge of the ice. Camera buoy #2 caught the approaching search light on an image! Phil.

Curious how 3.28% distance variance causes 7% more [or less] watts to arrive at TOA. Seke the reason for this is the inverse square law. http://en.wikipedia.org/wiki/Inverse-square_law Phil.

bluesky they quote Serreze, Stroeve, Maslowski and Steele, estimates range from 2016 to 2030. Here's the last para: "Serreze and others think Maslowski’s volume extrapolation exaggerates the problem. “It could happen [by 2016],” Serreze says. “I just don’t think so. I think he’s being too aggressive.” There is, however, a hint that enhanced pessimism may be appropriate. Stroeve is just back from a cruise to 83°N, beyond northern Greenland. She saw only 30% to 40% ice cover there. “We never expected that,” she says, because satellite data had not suggested it."

That's because km^2 isn't correct SI usage, in SI the prefix is applied after the primary unit raised to the appropriate power. Therefore Gm^2 is correctly G(m^2). Remember that the prefix is shorthand for the associated powers of ten so Gm^2 represents 10^12 m^2. Phil.

Lowest extent observed there, I don't have access to a computer at present so I can't link it. If you go to the 30 day report for the Western Arctic on their site you'll find it. Phil.

Another Domino not mentioned before, also a navigational site, is the Canadian Ice Service. They have also declared this year to be a record in their western region. Phil.

That should be Tm^2 of course. :-) It makes the calculation of thickness really simple: 3 Tm^3/ 2.5 Tm^2 = 1.2 m Phil.

In response to Wipneus the use of multiple prefixes is an abomination and it would be much better if the standard SI practices were followed. However in this field the use of the km as the base unit seems unshakeable! For example the proper unit for reporting the area should be the Gm^2 (= million km^2) and for volume Gm^3 (=km^3). Phil.

Yes Lodger, with no more melt and no refreeze the SIE could in the limit be compacted to the area value, I.e. ~2.75 Gm^2 Phil.