Maximising asif skills using near real time Mosaic data

[uniquorn]

t58 since oct2, no traumatic events, just thickening. These aren't the melting profiles I was expecting. Maybe jdallen is watching.

[uniquorn]

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

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.

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.

[oren]

Very interesting.

[uniquorn]

All the mosaic temp_procs I could find back to back, jun1-15.
Much quicker for me this way.

[SimonF92]

Very interesting, had no idea about "flushing"

[uniquorn]

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]

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

[uniquorn]

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]

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]

t78 and t81 heat120 temps
t78 has some odd features

[uniquorn]

t78 and t81 temp proc

[oren]

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]

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.

[uniquorn]

latest t78 and t81. T78 is an algo nightmare

[uniquorn]

example of ice/ocean interface

[uniquorn]

tbuoy update

[uniquorn]

tbuoy update. The quick 'refreeze' on T78 might be the porous layer at the bottom cooling.

[uniquorn]

Very interesting, had no idea about "flushing"

Could be that many of our assumptions about ice melting and refreeze need confirming.

For the time being, instead of having a set value of -1.8 I just set ice bottom as the thermistor below which the temp is 0.2degC less than whatever the ocean temp is at that measurement time.
''
ice_thermistors=ice_or_water_thermistors.where(ice_or_water_thermistors<mean_ocean_heat-0.2)
''

Looks good if my ice temperature doubts turn out to be wrong.

17 older tbuoys deployment report update

[SimonF92]

Very interesting, had no idea about "flushing"

Could be that many of our assumptions about ice melting and refreeze need confirming.

For the time being, instead of having a set value of -1.8 I just set ice bottom as the thermistor below which the temp is 0.2degC less than whatever the ocean temp is at that measurement time.
''
ice_thermistors=ice_or_water_thermistors.where(ice_or_water_thermistors<mean_ocean_heat-0.2)
''

Looks good if my ice temperature doubts turn out to be wrong.

17 older tbuoys deployment report update

I have been spending most of my time working on the HEAT data as I agree there are probably issues in the TEMP data. The former is in some ways more powerful for estimating thickness,
and i suspect when they eventually publish their own method it will centre on HEAT not TEMP, or maybe a combination.

In my opinion its more powerful because you will never see a flat profile through the chain in HEAT, but you do sometimes see it in TEMP.

Its good they are providing their top ice thermistor now, that make things easier.

 If i get anything solid ill send you a message with the code and you can take a look.