Thursday, 31 August 2017

A slow down in Arctic melt but temperatures could shoot back up


I read somewhere in the comments on the Arctic sea ice blog forum that the ice will not melt so quickly if it is just sitting in its own melt water.

There is no doubt, due to weather conditions the melt has slowed down despite warm water conditions but it is anyone's bet as to what will happen next.

"Thus Atlantic low pressure system is similar to last year's Fall and December cyclones. This could be the start of a very mild Fall and winter season in the Arctic"


"Cold spikes like the current one are not uncommon. The temperature will reach peak cold soon and then shoot back up."


Arctic ice melt – update – 08/30/2017



forum.arctic-sea-ice.net/index.php/topic,1834.msg127282.html#msg127282 ]

Here are some items from the Arctic sea ice blog





Re: The 2017 melting season
« Reply #3966 on: August 30, 2017, 03:15:01 PM »
Cold spikes like the current one are not uncommon. The temperature will reach peak cold soon and then shoot back up.

Re: The 2017 melting season
« Reply #3977 on: Today at 03:45:56 AM »

Would not take much for most of the ice in that image to disappear
True, but not much action seen out to day 5 in either of our ice thickness and ice boundary predictions systems, ESRL and Hycom, though note the suggestion of CAA garlic press onset in the latter which could potentially break up what little remains of the very thickest ice.

Indeed very little happened by way of trend in the 13-29 Aug 17 time frame for UH AMSR2 sea ice concentration, which mostly wobbles between dispersion, compaction, and bulk ice pack displacement.
I expect it all got thinner however.

Right now, I'm watching the eastern seaboard of North America as I think the first of what will become a regular series of tropical depressions will start sweeping NE to eventually descend on the Barentsz, taking in train massive amounts of moisture.

At some point, the remains of Harvey will emerge from the Mississippi/Ohio watershed and similarly start a more rapid northeasterly trajectory.

If the Cyclone Cannon starts up, that will push the minimum out, possibly quite a ways, as the heat they carry will slow loss to atmosphere and permit more bottom melt.

If it does not, then we may see an "early" start to the refreeze, which may still be bad news, as it will tend to trap more of this season's heat.

Regardless,  anything beyond 2nd year ice will be at historically low levels, and none of it particularly robust, even as it puts a lid on the arctic.


Re: The 2017 melting season
« Reply #3956 on: August 28, 2017, 05:15:20 PM »

"Why would you assume anyone at NSIDC would correct any model? If they changed some model they a) would have published that and b) they would recalculate all previous data also, so a change of models would not start somewhere in between years, that just wouldn't make any sense. The point of those SIE numbers is, that you have a *consistent* record of SIE over multiple decades."

This is the very point the Republican Party policy advisors made recommending for scrapping of F20 satellite as this would help Donald Trump and Congress to cite that the ice measurements are discontinuous, and thus provide inconsistent SIE numbers when once the opportunity rose as F17 failed and F19 too, with nothing to fill the data gap when F18 falters. To help further the cause of uncertainties and discontinuities, the government decided to scrap F20 to break the SIE series.  ;D

Model correction .... or the slippery slope?
The former I think.
Why would you assume anyone at NSIDC would correct any model? If they changed some model they a) would have published that and b) they would recalculate all previous data also, so a change of models would not start somewhere in between years, that just wouldn't make any sense. The point of those SIE numbers is, that you have a *consistent* record of SIE over multiple decades.



The NSIDC numbers are not here to show you some predefined goal, to which SIE should drop and someone is monitoring that and thinks "ice extent is a little slow this year, so just change something in the algorithm". NSIDC extent numbers just show you every day what the ice extent numbers are, calculated from the same satellite data using the same algorithm...

Re: The 2017 melting season
« Reply #3963 on: August 30, 2017, 02:26:43 PM »
I am not often given to posting about the weather - I am able to get it all wrong on other threads.
But weather-forecast.com has a significant system coming into the Arctic from the North Atlantic over the coming days. Are the other weather forecasting systems coming up with something similar?

No comments:

Post a Comment