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Author Topic: Maximising asif skills using near real time Mosaic data  (Read 11366 times)

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #200 on: June 14, 2020, 04:54:04 PM »
t58 since oct2, no traumatic events, just thickening. These aren't the melting profiles I was expecting. Maybe jdallen is watching.

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #201 on: June 14, 2020, 10:48:41 PM »
Yeah I didn't notice the numbers. 80cm of top melt in 4 days is impossible. But once the ice reaches 0C I think melt progress should be rapid nonetheless.
I still wonder how 0C can propagate so deeply if the ice is solid, especially considering it's supposed to be somewhat salty. Above my pay grade unfortunately.
It could be 'flushing'
https://www.cambridge.org/core/journals/annals-of-glaciology/article/on-the-thermodynamics-of-melting-sea-ice-versus-melting-freshwater-ice/B88EBD53A0209295EA0662825C48EBAE/core-reader
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The simulations show clearly that after the onset of surface warming, flushing sets in, which transports cold and salty brine from higher up in the ice to the region close to the ice-ocean interface.
Still frozen, fresher ice.     or something else completely.
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One final notable feature related to the evolution of internal temperature in our experiments is the signature of a localized flushing event (ellipse in Fig. 5a): Around 25 hours after we raised the air temperature, the ice temperature increased strongly and subsequently decreased again in the upper two-thirds of the ice within a few hours. The measured temperature reaches 0°C and even higher. The sudden onset and short duration of this event point towards a localized flushing event, where penetrating comparably fresh meltwater from the surface desalinates a small region of ice quickly. The rapid desalination leads to a short release of latent heat, as a fraction of the percolated water freezes in order to reach thermal equilibrium. Once the desalination ends, much of the percolated freshwater refreezes in the interior of the ice due to heat diffusion from the colder surrounding ice which was not desalinated by the localized flushing event.

 In our set-up, it is likely that the thermistor chain sticking in the ice supported or even induced this localized flushing event due to additional heat conduction that let the ice melt around the chain. After the flushing event the measured temperatures stay above 0°C in the upper 0.02-0.03 m of the ice, which indicates that the thermistors are no longer in contact with the ice, but instead with comparably warm meltwater. Note, however, that a similar flushing event was observed by Pringle and others (2007) in a set-up with only horizontal thermistor strings.
« Last Edit: June 14, 2020, 10:58:06 PM by uniquorn »

oren

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Re: Maximising asif skills using near real time Mosaic data
« Reply #202 on: June 14, 2020, 11:08:54 PM »
Very interesting.

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #203 on: June 15, 2020, 11:12:06 AM »
All the mosaic temp_procs I could find back to back, jun1-15.
Much quicker for me this way.

SimonF92

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Re: Maximising asif skills using near real time Mosaic data
« Reply #204 on: June 15, 2020, 11:27:03 AM »
Very interesting, had no idea about "flushing"
Im working on a satellite-miner to detect changes in small ice-caps/ snow-fields. Send me recommendations to optimise the program with.

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #205 on: June 15, 2020, 02:52:39 PM »
https://www.essoar.org/pdfjs/10.1002/essoar.10503129.1

platelets and supercooling. A bit late for the freezing season but a good read.

SimonF92

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Re: Maximising asif skills using near real time Mosaic data
« Reply #206 on: June 15, 2020, 06:39:19 PM »
https://www.essoar.org/pdfjs/10.1002/essoar.10503129.1

platelets and supercooling. A bit late for the freezing season but a good read.

Normally get a brain-drain reading arctic papers because of the physics, but that was a good read
Im working on a satellite-miner to detect changes in small ice-caps/ snow-fields. Send me recommendations to optimise the program with.

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #207 on: July 03, 2020, 01:51:06 PM »
Hate to say this, so decided to wait a few days before I did.
I really cant see a way of getting th(ocean) anymore. Uniquorn I believe if you run the code on your end youll see what i mean. The temps at the ocean:ice interface are just too variable now.
That being said, if anyone has any data they would like to see graphed, let me know
I had another look at the heat120 data. It's possible that as the ocean warms we might still be able to retrieve thickness data from some of the buoys. Perhaps the last few weeks has been a tricky transition period. Of course, they may not last much longer.

T67 floating in open water?

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #208 on: September 10, 2020, 10:11:10 PM »
continuing from mosaic thread
squared up the grid and added some labels. Looking at adding some distances but tracking them is difficult as the delaunay lines move around. It is in the code somewhere though.

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #209 on: September 14, 2020, 12:34:11 PM »
t78 and t81 heat120 temps
t78 has some odd features

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #210 on: September 15, 2020, 04:32:35 PM »
t78 and t81 temp proc

oren

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Re: Maximising asif skills using near real time Mosaic data
« Reply #211 on: September 15, 2020, 06:52:28 PM »
Thanks for these updates uniquorn.
It appears that at least for T78 bottom melt has been halted at last, and the ice core temp has equalized and soon hopefully to be inverted.

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #212 on: September 15, 2020, 08:15:32 PM »
They were probably just spam on the mosaic thread.
@SimonF92 is it possible to take surface temperature into account when using the heat files in the algo?So that it amplifies the stdev in some way.
« Last Edit: September 15, 2020, 08:20:48 PM by uniquorn »

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #213 on: September 16, 2020, 12:07:02 PM »
latest t78 and t81. T78 is an algo nightmare

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #214 on: September 16, 2020, 09:42:30 PM »
example of ice/ocean interface

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #215 on: September 19, 2020, 10:42:08 PM »
tbuoy update
« Last Edit: September 19, 2020, 10:51:45 PM by uniquorn »

uniquorn

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Re: Maximising asif skills using near real time Mosaic data
« Reply #216 on: September 23, 2020, 09:43:09 PM »
tbuoy update. The quick 'refreeze' on T78 might be the porous layer at the bottom cooling.