Naked Science Forum

Life Sciences => The Environment => Topic started by: CliffordK on 20/01/2011 00:00:24

Title: Is the specific heat, or enthalpy of fusion, of water a major climate buffer?
Post by: CliffordK on 20/01/2011 00:00:24
I've been looking at some of the climate charts, and have been struck at the temperature swings in Canada and Russia.

http://www.ncdc.noaa.gov/sotc/global/2010
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.ncdc.noaa.gov%2Fsotc%2Fservice%2Fglobal%2Fmap-blended-mntp%2F201011.gif&hash=35bed9694ac0cbc19ae65f33705a274f)(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.ncdc.noaa.gov%2Fsotc%2Fservice%2Fglobal%2Fmap-blended-mntp%2F201012.gif&hash=fdc00b44478e11dfcfbff65fa06c3a7b)

Above are two successive months of temperature anomalies.  Many of the anomalies in Canada/Russia bounce around at +/- 5°C or more.

The Specific Heat of Fusion, or Enthalpy of Fusion of water is about 80 cal/cm³.  Thus, it takes the equivalent amount of energy to freeze/thaw 1 cm³ of water as it takes to raise or lower the equivalent amount of liquid or solid water about 80°C.

This effect would be shared across different forms of water, snow, rain, hail, high altitude clouds, etc.

Thus, the non-permafrost regions should have the winter temperatures moderated by the specific heat of fusion. 

Permafrost regions wouldn't have it, and thus would logically show much higher temperature swings.  Of course, one would still expect a random distribution of temperature swings which isn't happening.

I think northern Africa suffers by the same thing with less temperature moderation from water and vegetation on both ends of the scale, and also frequently looks very hot.

Keep in mind for the calculations, this square grid is weighted for the spherical shape of the globe.  Obviously what is happening in Canada and Russia is important to the world.  But, are they being weighted too much?

Oh...
Also, is NOAA systematically skipping one of the continents in the global warming calculations?

Title: Re: Is the specific heat, or enthalpy of fusion, of water a major climate buffer?
Post by: JP on 20/01/2011 07:27:05
Quote
Oh...
Also, is NOAA systematically skipping one of the continents in the global warming calculations?
Antarctica?  They don't have data for the arctic either.

I can't find an obvious statement of how they got the data.  They link to a paper about it, but I'm not interested enough to wade through it.  The data is a blending of measurements from land stations and sea surface temperatures.  The land data for December, for example, looks like
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.ncdc.noaa.gov%2Fsotc%2Fservice%2Fglobal%2Fmap-land-sfc-mntp%2F201012.gif&hash=b3bee2b1934e1b606e6fba5d265a3b69)

I suspect that since there are apparently only a few land stations in the polar regions and since there isn't generally free water in the arctic, they just don't have enough data to say anything much about those regions... 
Title: Re: Is the specific heat, or enthalpy of fusion, of water a major climate buffer?
Post by: Geezer on 20/01/2011 07:45:29
As Jerry Lee Lewis put it -

"There's a whole lotta 'strapolatn goin' on"
Title: Re: Is the specific heat, or enthalpy of fusion, of water a major climate buffer?
Post by: CliffordK on 20/01/2011 08:58:53
It appears as if most of the Antarctic anomalies are smaller than the northern anomalies too, and go in both directions.  Perhaps historical data is also a problem.  I saw a study doing boreholes in Antarctica, I think 30 meters down.  The idea was that it would give a good indication of the average annual temperature.  But, that study needs to be repeated periodically.  Since ice accumulates, one can't just leave the sensors in place.

They apparently have a lot of troubles with satellite temperatures readings in the arctic, perhaps due to the cloud cover, but there may be other issues too.

There are a lot of data points that are being interpolated in Canada and Russia.  It is probably ok, although there were questions on whether there would be an "Urban Effect", even in the small communities as they modernize.