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Re: [Phys-l] The Cause of Global Warming. What's the Proof the hypothesis' and models are right?

The statement about the retreat of the polar ice cap refers to the minimum solar ice cover during the yearly cycle.

It is quite true that a fair amount of data processing is necessary to convert microwave data to visual images. The same is true in many other instances. Other good examples are MRIs and CAT scans.

Mark


-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu on behalf of Stefan Jeglinski
Sent: Sun 5/20/2007 10:35 PM
To: Forum for Physics Educators
Subject: Re: [Phys-l] The Cause of Global Warming. What's the Proof the hypothesis' and models are right?

For those who are interested in how NASA researchers measure the
extent of sea ice in the polar regions, I suggest the following link:

http://polynya.gsfc.nasa.gov/seaice_links.html


In particular, see

http://nsidc.org/data/docs/daac/nsidc0002_ssmi_seaice.gd.html

I think questions about models and simulations are quite relevant in
light of this. The processing required to convert the microwave data
to an "image" that one can see in the animations is immense, and has
required a bit of massaging to correct errors that were discovered
along the way. The analysis is quite candid regarding the sources of
error. It is clear that a number of simplifications had to be made to
get anywhere at all.

With respect to the assertion that the north polar ice cap (um, is
that summer or winter?) is retreating at about 9% per decade, I'd
love to see some error bars on that (still googling), in light of the
assumptions that had to go into this stuff. See for example

http://en.wikipedia.org/wiki/Polar_ice_packs.

Or, beat me about the head with:

http://nsidc.org/news/press/20070430_StroeveGRL.html


Mine is not a criticism of the science per se. It's obviously a tough
analysis, with the final images highly distanced from the raw data.


Stefan Jeglinski


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