kallend 2,150
kallend 2,150
June 8, 2010 from NSIDC:
Models indicate low ice volume
Ice extent measurements provide a long-term view of the state of Arctic sea ice, but they only show the ice surface. Total ice volume is critical to the complete picture of sea ice decline. Numerous studies indicate that sea ice thickness and volume have declined along with ice extent; unfortunately, there are no continuous, Arctic-wide measurements of sea ice volume. To fill that gap, scientists at the University of Washington have developed regularly updated estimates of ice volume, using a model called the Pan Arctic Ice Ocean Modeling and Assimilation System (PIOMAS).
PIOMAS uses observations and numerical models to make ongoing estimates of changes in sea ice volume. According to PIOMAS, the average Arctic sea ice volume for May 2010 was 19,000 cubic kilometers (46,000 cubic miles), the lowest May volume over the 1979 to 2010 period. May 2010 volume was 42% below the 1979 maximum, and 32% below the 1979 to 2009 May average. The May 2010 ice volume is also 2.5 standard deviations below the 1979 to 2010 linear trend for May (–3,400 cubic kilometers, or -816 cubic miles, per decade).
PIOMAS blends satellite-observed sea ice concentrations into model calculations to estimate sea ice thickness and volume. Comparison with submarine, mooring, and satellite observations help increase the confidence of the model results. More information on the validation methods and results is available on the PIOMAS ice volume Web site.
Models indicate low ice volume
Ice extent measurements provide a long-term view of the state of Arctic sea ice, but they only show the ice surface. Total ice volume is critical to the complete picture of sea ice decline. Numerous studies indicate that sea ice thickness and volume have declined along with ice extent; unfortunately, there are no continuous, Arctic-wide measurements of sea ice volume. To fill that gap, scientists at the University of Washington have developed regularly updated estimates of ice volume, using a model called the Pan Arctic Ice Ocean Modeling and Assimilation System (PIOMAS).
PIOMAS uses observations and numerical models to make ongoing estimates of changes in sea ice volume. According to PIOMAS, the average Arctic sea ice volume for May 2010 was 19,000 cubic kilometers (46,000 cubic miles), the lowest May volume over the 1979 to 2010 period. May 2010 volume was 42% below the 1979 maximum, and 32% below the 1979 to 2009 May average. The May 2010 ice volume is also 2.5 standard deviations below the 1979 to 2010 linear trend for May (–3,400 cubic kilometers, or -816 cubic miles, per decade).
PIOMAS blends satellite-observed sea ice concentrations into model calculations to estimate sea ice thickness and volume. Comparison with submarine, mooring, and satellite observations help increase the confidence of the model results. More information on the validation methods and results is available on the PIOMAS ice volume Web site.
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The only sure way to survive a canopy collision is not to have one.
The only sure way to survive a canopy collision is not to have one.
[Reply]I am still trying to unmuddle my head from the latest Jedi Mind Trick...... Melting ice is not cauded by warmer temperatures
That's not what I wrote. Of course uncreasing the temperature increases the rate at which ice melts - from spring through authumn. As far as the poles are considered, increasing temperature ALSO increases the amount of ice accreted from autumn through spring.
Let's say a 10 pound block of ice is formed at -40 F. Let's put that in the sun at 40 degrees F. Yep. It'll ablate through melting & sublimation.
Now, let's say AGW means that the winter temperature is -35 F. It will create a block of ice in excess of 10 pounds. Put it in the sun at 41 degrees and it'll melt. But AGW's effect is more pronounced with ice formation!
I'm not saying that increasing summer temperature in the Arcric decreases melting. It increases it.
I'm saying that increasing winter temperatures in the Arctic increases ice formation.
This is no Jedi mind trick. This is you reading my writing about ice formation and deciding that I must really mean ice melting. It's understandable because it's not what you want to read.
My wife is hotter than your wife.
kallend 2,150
Quote[Reply]I am still trying to unmuddle my head from the latest Jedi Mind Trick...... Melting ice is not cauded by warmer temperatures
That's not what I wrote. Of course uncreasing the temperature increases the rate at which ice melts - from spring through authumn. As far as the poles are considered, increasing temperature ALSO increases the amount of ice accreted from autumn through spring.
Let's say a 10 pound block of ice is formed at -40 F. Let's put that in the sun at 40 degrees F. Yep. It'll ablate through melting & sublimation.
Now, let's say AGW means that the winter temperature is -35 F. It will create a block of ice in excess of 10 pounds. Put it in the sun at 41 degrees and it'll melt. But AGW's effect is more pronounced with ice formation!
I'm not saying that increasing summer temperature in the Arcric decreases melting. It increases it.
I'm saying that increasing winter temperatures in the Arctic increases ice formation.
This is no Jedi mind trick. This is you reading my writing about ice formation and deciding that I must really mean ice melting. It's understandable because it's not what you want to read.
RIGHT, and when the temperature reaches 50 degrees at the poles the ice will extend all the way to the equator.
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The only sure way to survive a canopy collision is not to have one.
The only sure way to survive a canopy collision is not to have one.
[Reply]
But what is the DOMINANT effect in that particular location?
But what is the DOMINANT effect in that particular location?
I don't know what, as a matter of fact, is the dominant effect. I know that according to AGW theory accretion should predominate over ablation because AGW is to be the dominant forcing when it is cold and dark. Increased accretion, under theory, should be robust. Ablation should increase slightly.
[Reply]PS did you check the effect of ozone depletion on Antarctic ice (like I suggested)?
Not yet. I'll look into it when I'm off my blackberry - which isn't exactly the greatest research tool...
My wife is hotter than your wife.
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Right. Melting versus sublimation.
One thing that is not deniable - even to alarmists - is that adding heat to an atmosphere increases the amount of water vapor that it can hold. Adding MORE heat will cause updrafts to cooler altitudes, where an amount of water vapor will condense into liquid or solid water and fall to the surface.
Because the air in MOST of Antarctica is really cold it is really dry and will not precipitate - which is why Anarctica averages less than an inch of precipitation per year.
If we add AGW through greenhouse gases we have warmer winters and summers that are warmer to a lesser extent. This would mean additional precipitation in the winter (increased accretion) and slightly increased ablation in the summer.
But what is the DOMINANT effect in that particular location?
PS did you check the effect of ozone depletion on Antarctic ice (like I suggested)?
The only sure way to survive a canopy collision is not to have one.