[ RadSafe ] Arctic Ice

[KARAM, PHILIP]

There are so many factors - many of them cyclical - affecting the Earth's temperature and the amount of ice at the poles that it's hard to keep track of them all. Solar output is variable, with a generally increasing trend over hundreds of millions of years. So there's the 11-year solar activity cycle, plus much longer-amplitude cycles over millennia and longer. But overall (i.e. the life of the solar system) the sun has been getting hotter - today it produces about 30% more energy (give or take) than it did a few billion years ago. Anyhow - the take-home message from that part is that solar activity is variable on many time-scales and this variability certainly has an effect on Earth's temperature.

Add to that the variability in the earth's orbit etc. that we learned about in middle school or high school - the earth precesses on its axis, the tilt varies, the orbit becomes more and less circular, and so forth - all of these influence the amount of solar radiation that reaches the surface as well. Couple these variabilities with those of the sun's output and you get a fairly complex function. What we're doing to the planet comes on top of all of these natural factors (including what's mentioned below). The question is whether or not our influence is significant and whether or not it can be sorted out from all of the innate natural variabilities.

Andy

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of JPreisig at aol.com
Sent: Monday, September 23, 2013 1:23 PM
To: radsafe at health.phys.iit.edu
Subject: Re: [ RadSafe ] Arctic Ice

Radsafe:
 
     Of course.  In terms of Earth orientation  (with respect to the Sun) 
1998 was a polar motion amplitude high (strongly  dipping towards the Sun), 
while 2020 will be like 1976 (rather low polar motion  amplitude).  I've 
asked Chopo Ma (NASA Goddard) to plot the polar motion  amplitude with respect 
to time and/or Arctic/Antarctic Sea Ice percentage, and  we'll see if such a 
data plot will show up one day soon.  A good data plot  (with good fitting) 
should give some resolution to this question NOW.
 
    The VLBI earth orientation data are available from NASA  Goddard's Very 
Long Baseline Interferometry website, and someone else at NASA  has the 
Arctic/Antarctic ice percentage data.  Someone with a few weeks  available (at 
Sandia, Los Alamos or elsewhere) could do the World a service by  doing this 
calculation.  Good books on Earth Orientation are Munk and  MacDonald, 
Lambeck I and Lambeck II (Space Geodesy).  This stuff isn't  simple though.  Get 
Cranking???
 
 
     Joe Preisig
 
 
 
 
In a message dated 9/23/2013 10:05:28 A.M. Eastern Daylight Time,  
mmiller at sandia.gov writes:

Worth  noting, of course.  However, one data point does not a trend make.   
Stay tuned for a decade or two.


-----Original Message-----
From:  JPreisig at aol.com [mailto:JPreisig at aol.com] 
Sent: Saturday, September 21,  2013 10:32 AM
To: radsafe at health.phys.iit.edu
Subject: [ RadSafe ] Fwd:  Arctic Ice





____________________________________
From: JPreisig at aol.com
To:  dickman at binghamton.edu
Sent: 9/21/2013  12:30:01 P.M. Eastern Daylight  Time
Subj: Arctic Ice


Dr. Dickman/Steve:

News item today on Google News.

Sea  ice in the Arctic Ocean underwent a sharp  recovery this year from the 
 record-low levels of 2012, with  50 percent  more ice surviving the  
summer melt season, scientists said Friday.

Will  this trend continue???

Thus endeth Global  Warming????


Joe  Preisig







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