Re: a modest proposal [was: Re: [asa] Phil Jones Stepping Down..]

From: Rich Blinne <rich.blinne@gmail.com>
Date: Tue Dec 08 2009 - 14:45:09 EST

On Tue, Dec 8, 2009 at 12:21 PM, Rich Blinne <rich.blinne@gmail.com> wrote:

> The Antarctic data needs to be heavily corrected for a different reason,
> there are so few thermometers on the continent (see Menne and Williams 2005
> and Karl and Williams 1987).
>
>

BTW, the correction is done through a mash up of the more accurate but very
widely spaced land surface stations with the less accurate but less widely
spaced automated weather stations and satellite measurements. Here's an
example of such a synthesis:

http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2FJCLI4236.1

 A Synthesis of Antarctic Temperatures

 William L. Chapman and John E. Walsh

Department of Atmospheric Sciences, University of Illinois at
Urbana-Champaign, Urbana, Illinois

(Manuscript received 24 March 2005, in final form 2 November 2006)

DOI: 10.1175/JCLI4236.1

Monthly surface air temperatures from land surface stations, automatic
weather stations, and ship/buoy observations from the high-latitude Southern
Hemisphere are synthesized into gridded analyses at a resolution appropriate
for applications ranging from spatial trend analyses to climate change
impact assessments. Correlation length scales are used to enhance
information content while limiting the spatial extent of influence of the
sparse data in the Antarctic region. The correlation length scales are
generally largest in summer and over the Antarctic continent, while they are
shortest over the winter sea ice. Gridded analyses of temperature anomalies,
limited to regions within a correlation length scale of at least one
observation, are constructed and validated against observed temperature
anomalies in single-station-out experiments. Trends calculated for the
1958-2002 period suggest modest warming over much of the 60-90S domain.
All seasons show warming, with winter trends being the largest at +0.172C
decade-1 while summer warming rates are only +0.045C decade-1. The 45-yr
temperature trend for the annual means is +0.082C decade-1 corresponding to
a +0.371C temperature change over the 1958-2002 period of record. Trends
computed using these analyses show considerable sensitivity to start and end
dates, with trends calculated using start dates prior to 1965 showing
overall warming, while those using start dates from 1966 to 1982 show net
cooling over the region. Because of the large interannual variability of
temperatures over the continental Antarctic, most of the continental trends
are not statistically significant. However, the statistically significant
warming over the Antarctic Peninsula is the strongest and most seasonally
robust in the spatial patterns of temperature change.

Composite (11-model) global climate model (GCM) simulations for 1958-2002
with forcing from historic aerosol and greenhouse gas concentrations show
warming patterns and magnitudes similar to the corresponding observed trends
for the 45-yr period. GCM projections for the rest of the twenty-first
century, however, *discontinue the pattern of strongest warming over the
Antarctic Peninsula, but instead show the strongest warming over the
Antarctic continent.*
**
Final note: if the bolded sentence is true that means more sea level rise.
The Antarctic Peninsula melting is like an existing ice cube in a drink
melting and doesn't increase sea levels. Continental warming is different.
It's like dropping a new ice cube in your drink.

Rich Blinne
Member ASA

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Received on Tue Dec 8 14:45:44 2009

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