Carinthians Latest Arctic Reports

[Filski]

If the ice is broken up it will be prone to the heating effects of friction as it moves around, the weather will affect it more, effects of water, etc.

Think of a glass of water with a 5cm thick ice sheet across the top and another glass with 5cm of ice cubes. If you pick both up and shake at the same rate which will melt first?

[Chris Knight]

Indeed TWS I will come and eat humble pie if I'm wrong, have no fear

Genuine question to all and sundry . I'm going to challenge what seems to be an assumption that " multiyear ice " is somehow more resistent to melting than single year ice. For a given thickness, I don't see why that should be the case. Anyone have any hard evidence on this ? Facts please, not opinions

From what I have read, MY ice has less salt content than SY ice due to brine expulsion and consolidation of ice crystals during subsequent seasonal melts and refreezes.

Almost everything you may like to know is here.

The process has analogies to the tempering of metals by heating, reworking and quenching to strengthen the crystal microstructure to provide tougher, harder and less brittle products.

[Mr Sleet]

From what I have read, MY ice has less salt content than SY ice due to brine expulsion and consolidation of ice crystals during subsequent seasonal melts and refreezes.

Almost everything you may like to know is here.

The process has analogies to the tempering of metals by heating, reworking and quenching to strengthen the crystal microstructure to provide tougher, harder and less brittle products.

Cheers Chris.

That seems plausible.

[Gray-Wolf]

If the ice is broken up it will be prone to the heating effects of friction as it moves around, the weather will affect it more, effects of water, etc.

Think of a glass of water with a 5cm thick ice sheet across the top and another glass with 5cm of ice cubes. If you pick both up and shake at the same rate which will melt first?

The melting has more to do ,I believe, with the surface area exposed. If you think of all of those 'edges' in shattered ice compared to a sheet of ice exposed to both the atmosphere and the unfrozen water in which it sits then you can see how the shattered pack melts faster.

In the arctic of course the 'dark water' that is exposed between the ice also absorbs something like 80% of the suns energy as opposed to the ice reflecting back 80% of the suns energy leading to more warming and more melt.

In as far as this season goes we are now getting to the time of year that the rapid melt begins. This time last year (weather aside) a sizable proportion of the melt was tough perennial ice, which of course is now melted, so one might imagine that the rest of the summer melt will be 'easier' to achieve than last year.

The predictions for a repeat of last years melt levels have more to do with the fact that much of the ice to melt is single year ,and not perennial , so is no longer dependant on 'freak' weather conditions to achieve the min. of 2007.

On the brighter side some of the single year ice, beyond 75N, may well last through the melt season due to the lower levels of incoming solar radiation up there so we may well have some gains on the 'perennial' ice front!

[oldsnowywizard]

On the brighter side some of the single year ice, beyond 75N, may well last through the melt season due to the lower levels of incoming solar radiation up there so we may well have some gains on the 'perennial' ice front!

GW? is that you? that has to be the first "positive" comment i think i have read from you. well done that man!

provided conditions continue to be favourable hopefully we will not see a record low year.

there is a forecasted polar low which is likely to bring cold conditions to the artic with snow of course early next week..

[shuggee]

Fresh news on the BBC:

http://news.bbc.co.uk/1/hi/sci/tech/7461707.stm

[oldsnowywizard]

Fresh news on the BBC:

http://news.bbc.co.uk/1/hi/sci/tech/7461707.stm

although the latest nsidc chart shows that melt rates are moving slowly away from last years levels... how long for who knows.. it will all probably catch up again.. it all depends on snow fall, ssts, 2m temps etc etc

[Stu_London]

although the latest nsidc chart shows that melt rates are moving slowly away from last years levels... how long for who knows.. it will all probably catch up again.. it all depends on snow fall, ssts, 2m temps etc etc

agree

if its below zero and snowing like it is forecast to be in the next few days, the ice will melt a lot slower than if it is sunny and 15C - like last year.

[reef]

We could see some major melting during next week around the North-west passage though. GFS still has the 10C 850hPa isotherm moving northwards way into the Arctic ocean, not to mention the land of parts of the Canadian archipelago reaching well into the mid-20s.

The main Arctic basin still looks good though as all remnants of sub -5C air remain locked up there, along with the polar vortex, meaning sunshine amounts will be minimal. The extra snowfall wont harm anything either.

[Gray-Wolf]

You have to remember Reef that once the fringing ice has gone the ice beyond 75N is at the mercy of wind and current (it being a floating mass) so ,though temps/conditions may be conducive to ice retention the ice might just bugger off into less conducive conditions.

[Mr Sleet]

Melt rate slowing down :

[oldsnowywizard]

totally agree with you GW.. something that may help this not to happen is if the sea ice pack continues to be held to the russian sectors... although granted there will be areas of free ice in places. the rate of melt is quite constant at the moment.. the next 2 months or so the 850s below 0 will reduce to a pin prick sized area and the +5s and 10s will run riot.. of course 2 m temps will vary. however i would expect the rate of decline to speed up.. whether this rate is faster than the mean, only time will tell. one would expect this to be the case due to all the thinner ice.

at least the polar vortex seems to be sticking around, which will help bring snowfall to areas.. which of course will contribute to ice creation.

interesting watching over the next few months..

[Optimus Prime]

Current situation compared to last year

2008

2007

2001

[Gray-Wolf]

I think we are now beginning to see the rapid decline in the Canadian Archipelago sea ice in line with the forecast opening of the 'deep Channel' in early Aug.

[BLAST FROM THE PAST]

Current situation compared to last year

2008

2007

2001

Generally much more widespread cold...good.

BFTP

[Gray-Wolf]

http://nsidc.org/data/seaice_index/images/...ation_hires.png

The link above takes you to the NSIDC image from June 21st. You'll readily see how poorly the ice in the Canadian Archipelago is faring and also , like last year, the ice facing Bering (north of Alaska and on to the Pole) is now starting to fail en-mass.

If ,like last year, we see a similar pattern of circulation once the ice is free moving we can discount the H.P. hypothesis from last year as being the primary driver for the melt and concentrate on influx of waters from the Pacific driving a new 'Polar Current' with waters entering through Bering and exiting via NW Greenland.

The opening of the 'Deep channel' NW Passage would also provide both a shortcut for such a flow but also give us a reason why the ice in those areas has failed so completely over the last few years leaving the weak single year ice as the only cover through winter.

One section of the 'passage' did have section of multiyear drift in before refreeze last year so it will be interesting to see how quickly these chunks fail (compared to the Canadian Coastguards predictions for their 'melt time') to also assess if warm water influx is starting to play a role in the final meltdown of sea ice (as BFTP notes there is still some cold still in the polar region).

[Gray-Wolf]

http://news.bbc.co.uk/1/hi/sci/tech/7461707.stm

Mean't to post this last week but ........

The beeb are also running a 'special' news prog on a trip up to the arctic with a team measuring the changes so have a look around after you've read the article.

[Mr Sleet]

http://nsidc.org/data/seaice_index/images/...ation_hires.png

The link above takes you to the NSIDC image from June 21st. You'll readily see how poorly the ice in the Canadian Archipelago is faring and also , like last year, the ice facing Bering (north of Alaska and on to the Pole) is now starting to fail en-mass.

If ,like last year, we see a similar pattern of circulation once the ice is free moving we can discount the H.P. hypothesis from last year as being the primary driver for the melt and concentrate on influx of waters from the Pacific driving a new 'Polar Current' with waters entering through Bering and exiting via NW Greenland.

The opening of the 'Deep channel' NW Passage would also provide both a shortcut for such a flow but also give us a reason why the ice in those areas has failed so completely over the last few years leaving the weak single year ice as the only cover through winter.

One section of the 'passage' did have section of multiyear drift in before refreeze last year so it will be interesting to see how quickly these chunks fail (compared to the Canadian Coastguards predictions for their 'melt time') to also assess if warm water influx is starting to play a role in the final meltdown of sea ice (as BFTP notes there is still some cold still in the polar region).

Still above last year but probably not for long.

NH area loss speeded up a bit now. Got the humble pie from Waitrose yesterday but it is still firmly in the tin.

[Iceberg]

A few temperature reports from around the Arctic most show an above average temperature recently if not quite as above as last year.

[Gray-Wolf]

After reading through the Canadian coastgaurds forcasts it would seem that there are only the areas to the north of 75 degrees than can expect 'normal' temps through 'till Aug at least.

With the predominance of single year ice and the early break up of the pack it isn't looking good for those of us who did not wish a repeat, or worse, of last years melt.

[Interitus]

A few temperature reports from around the Arctic most show an above average temperature recently if not quite as above as last year.

Not sure what the Mohe, China graph is doing there..

[Iceberg]

um that might have slipped from something else my Chinese/Russian Geography is not good.

[Gray-Wolf]

Click the image for a high-resolution version.

Ice concentrations through the 'deep channel' of the NW Passage appear to be already in their final stages of melt. The forcast was for it to be fully open by early Aug but they may prove to have been a little conservative in nature.

[oldsnowywizard]

2m temps predicted to be between +10 and 27 degrees along the coast next week of Canadian/Alaskan sectors.. not sure if this is normal.. it may of course be.. the impact of course on the thin ice will be very rapid. colder air still over much of the Russian side of the Arctic.. perhaps it will be a story of two sides of the artic this year?

[Gray-Wolf]

2m temps predicted to be between +10 and 27 degrees along the coast next week of Canadian/Alaskan sectors.. not sure if this is normal.. it may of course be.. the impact of course on the thin ice will be very rapid. colder air still over much of the Russian side of the Arctic.. perhaps it will be a story of two sides of the Arctic this year?

As it was last year with the Eastern passage blocked by drifted multiyear ice . This year the Eastern passage is also forecast to be open by August so we'll just have to sit back and watch. If it is then that's another batch of perennial turned back into water .