global cooling is here !!

• From: h erren
• Date: Tue, 13 Nov 2001 00:07:02
• follow the debate on : http://www.eScribe.com/science/ClimateChangeDebate/

Here is a summary of my findings:


1: The current used surface data of CRU and GHCN show homogenity 
problems when compared with radiosonde data. In particular the
climatic shift of 1977 is not reflected in both datasets.

http://members.lycos.nl/ErrenWijlens/co2/ghcnsatsondecru5500.gif


2: To test the claim that global warming is happening, the difference 
was plotted between surface radiosonde data and troposphere radiosonde 
data. Contrary to what greenhouse warming predicts - troposphere warmer 
than surface - there is no warming up to 1991 and then a remarkable 
sharp cooling.

http://members.lycos.nl/ErrenWijlens/co2/radiosonde.gif

I use data from Angell:
http://cdiac.esd.ornl.gov/trends/temp/angell/angell.html


3: To correct for volcanic eruptions, which cause cooling, this was 
removed. The trend is now zero up to 1994, and then again a sharp
cooling. 

http://members.lycos.nl/ErrenWijlens/co2/radiosondeco2diff.gif
(volcanic data from http://climexp.knmi.nl/)


4: The sharp cooling after 1994 is atributed to the effect of 
stratospheric cooling which cools also the lower lying atmospheric 
layers. The data then reveals a slow rising trend which is attributed
to GHG warming. However the CO2 forcing trend is four times larger as predictecd
by IPCC, which could be due to the very crude 3 layer atmosphere that 
was used (Tsurf=15C, Ttrop=-30C, Tstrat=-60C), and the use of an emissivity factor of 1.

http://members.lycos.nl/ErrenWijlens/co2/radiosondevolcstrat.gif


The above method of data reduction is used in exploration geophysics to 
find mineral deposits from gravity observations. Removing what you know 
gives you something to drill into.

I found the following nuggets:

The Global climate trend is dominated by the following factors

- Long term oceanic temperature variations (like Pacific Decadal Oscillation)
- Short term oceanic oscillations (like El Nino Southern Oscillation and North Atlantic Oscillation)
- Stratosphere temperature
- Volcanic cooling
- GHG warming

A nice comparison of PDO and ENSO can be found here:
http://tao.atmos.washington.edu/pdo/img/pdo_enso_comp.gif 
Latest PDO index:
ftp://ftp.atmos.washington.edu/mantua/pnw_impacts/INDICES/PDO.latest 

Currently the effect of stratosphere cooling exceeds by far the effect of GHG warming.
Which is acknowledged elsewhere
http://www-das.uwyo.edu/~geerts/cwx/notes/chap15/future_gcm.html
quote:
Ozone depletion cools the lower stratosphere, troposphere and surface, steepening the tropospheric
temperature lapse rate.
...
If this interpretation is correct, during the next 5-10 years, as ozone-depletion levels out and perhaps 
reverses, warming of the upper troposphere by well-mixed greenhouse gases should become apparent
end quote

So not currently!

Stratospheric cooling correlates nicely with ozone depletion, 
here is the longest historic record from Arosa Switzerland:
http://www.iac.ethz.ch/en/research/chemie/tpeter/totozon.html 

An estimate for ozone recovery is made by Drew Shindell (figure 2):
http://www.giss.nasa.gov/research/intro/shindell_05/


source data for the graphs:

zipped in Excel 5.0/95 format
http://members.lycos.nl/ErrenWijlens/co2/sondeco2pub50.zip

zipped in Excel 2000 format
http://members.lycos.nl/ErrenWijlens/co2/sondeco2pub.zip


Hans Erren

Comment added on 9 August 2002:
The radiative cooling forcing from the stratosphere after 1992 is not realistic:
It would imply that a sparse gas (stratosphere) could radiatively cool a dense gas
(lower troposphere). It is possible, but not in the observed amount.

 


this page:
http://members.lycos.nl/ErrenWijlens/co2/angell.html

homepage:
http://members.lycos.nl/ErrenWijlens