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Author Topic: Basic questions and discussions about melting physics  (Read 24098 times)

binntho

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Re: Basic questions and discussions about melting physics
« Reply #150 on: June 15, 2020, 04:42:35 AM »
very interesting!
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Tor Bejnar

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Re: Basic questions and discussions about melting physics
« Reply #151 on: June 15, 2020, 06:17:30 PM »
Indeed!  While the graphs are 'above my pay grade', the explanations were fully within my grasp.
Arctic ice is healthy for children and other living things.

Freegrass

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Re: Basic questions and discussions about melting physics
« Reply #152 on: June 17, 2020, 08:41:15 AM »
It would be great to get an answer from somebody who studies this stuff.
I agree, but it looks like nobody is home today...  :(
Is anyone seeing this?

Freethinkers are those who are willing to use their minds without prejudice and without fearing to understand things that clash with their own customs, privileges, or beliefs. This state of mind is not common, but it is essential for right thinking.

Human Habitat Index

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Re: Basic questions and discussions about melting physics
« Reply #153 on: June 17, 2020, 08:59:49 AM »
Anecdotally we have had clear unusually chilly nights in southern Australia, consistent with the effect of less aerosols in the atmosphere.
There is a principle which is a bar against all information, which cannot fail to keep a man in everlasting ignorance. That principle is contempt prior to investigation. - Herbert Spencer

Phoenix

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Re: The 2020 melting season
« Reply #154 on: July 07, 2020, 09:13:36 AM »

I can feel freezing in winter when standing in the shadows, and then walk out into the sunshine and start feeling warmer after just a few seconds.  The air has not got any warmer (and BTW I doubt I would be able to tell the difference between .5C or 2C).  But I do know that the sunlight hitting my jacket and pants and skin and hat is being converted to heat and the effect is considerable, despite the uniform coldness of the air around me..

Take two full and frozen ice cube trays out of your freezer. Put one in your refrigerator which might be cooled to 5C and shut the door so its dark inside. Take the other tray and put it a dark space like a closet which is at room temperature, say 23C or so. Check on them both after an hour.

Light (or lack thereof) is constant. Both are above 0C and will melt. Will they melt at the same rate ? No. The tray in your closet will melt faster.

Your personal example of stepping out of the shade is not reliable because your body sensors can't easily differentiate between the simultaneous experience of direct solar radiation and thermal radiation emitted from the sun baked earth you are now moving over.




pleun

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Re: Re: The 2020 melting season
« Reply #155 on: July 07, 2020, 09:18:24 AM »

Light (or lack thereof) is constant. Both are above 0C and will melt. Will they melt at the same rate ? No. The tray in your closet will melt faster.

Yet the temperature just above the icecubes will be the same in both cases. You just took down your own argument...

El Cid

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Re: Re: The 2020 melting season
« Reply #156 on: July 07, 2020, 09:24:39 AM »
Take two full and frozen ice cube trays out of your freezer. Put one in your refrigerator which might be cooled to 5C and shut the door so its dark inside.

And now take that ice cube and put it out into the full sun. See what happens. And how fast

oren

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Re: Basic questions and discussions about melting physics
« Reply #157 on: July 07, 2020, 01:33:08 PM »
To whom it may concern, let it be known. A large region of sea ice will keep surface air temperatures pegged near the melting point, due to the energy soaked up by the phase change of ice into water. Thus surface air temperatures are often not very informative during the Arctic summer.

Tony Mcleod

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Re: Basic questions and discussions about melting physics
« Reply #158 on: July 07, 2020, 02:05:09 PM »
To whom it may concern, let it be known. A large region of sea ice will keep surface air temperatures pegged near the melting point, due to the energy soaked up by the phase change of ice into water. Thus surface air temperatures are often not very informative during the Arctic summer.

These anomaly graphs http://ocean.dmi.dk/arctic/meant80n_anomaly.uk.php clearly show how Arctic temps have climbed in autumn, winter and spring but have been flat as a pancake in summer.

Phoenix

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Re: The 2020 melting season
« Reply #159 on: July 07, 2020, 05:24:49 PM »

The surface temperature of melting ice is always going to be zero until the ice has melted and turned into water - that's thermodynamics -

Attached is the latest DMI 80N temperature chart. It shows the 2m temps coming down from an above normal peak. The forecast calls for a further decline in a few days. If it's not clear, I'm referring to temps at 2m, not at 0m.

http://ocean.dmi.dk/arctic/meant80n.uk.php

sedziobs

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Re: Re: The 2020 melting season
« Reply #160 on: July 07, 2020, 05:33:29 PM »
Attached is the latest DMI 80N temperature chart.
This chart tells us next to nothing about energy transfer to ice, especially under high pressure.

igs

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Re: Re: The 2020 melting season
« Reply #161 on: July 07, 2020, 06:30:56 PM »

The surface temperature of melting ice is always going to be zero until the ice has melted and turned into water - that's thermodynamics -

Attached is the latest DMI 80N temperature chart. It shows the 2m temps coming down from an above normal peak. The forecast calls for a further decline in a few days. If it's not clear, I'm referring to temps at 2m, not at 0m.

http://ocean.dmi.dk/arctic/meant80n.uk.php

It's not relevant at this time of the year and current conditions. More info would be too long to read but you can find it if you search for DMI and for DMI above 80N especially.

DMI is special in itself somehow and DMI above 80N in Summer has been discussed and explained dozens if not hundreds of times.

On of the best chances to find such entries other than using a search tool ist in the melting season threads of each year in posts ranging from 15. of June to the end of July.

Also i think i remember there is a DMI above 80N thread somewhere, just in case you're interested to find info WHY it is as it is  ;)
Knowledge that does not increase every day will decrease every day !

Viggy

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Re: Re: The 2020 melting season
« Reply #162 on: July 07, 2020, 06:54:37 PM »

The surface temperature of melting ice is always going to be zero until the ice has melted and turned into water - that's thermodynamics -

Attached is the latest DMI 80N temperature chart. It shows the 2m temps coming down from an above normal peak. The forecast calls for a further decline in a few days. If it's not clear, I'm referring to temps at 2m, not at 0m.

http://ocean.dmi.dk/arctic/meant80n.uk.php

What exactly is the value of this insanity? Temperature at 0m is the around 0C (in the summer) because there is ice at 0m.

Temperature at 2m is close enough to the ice to be anchored around a very tight range around 0C during the summer months. You clearly know and understand this based on previous posts. Yea, there may be tiny fluctuations but there is absolutely zero analytical value in looking at a snapshot of 1 week and calling peaks and declines.

Stop attempting to derail constructive conversation because you are bored at home during Covid or whatever your affliction is.
« Last Edit: July 07, 2020, 07:00:22 PM by Viggy »