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Optimal estimation of the surface temperature response to natural and anthropogenic climate forcings over the past century /

Space-time optimal filtering is used to estimate the response

Bibliographic Details
Main Author: Stevens, Mark Joseph, 1955-
Format: Thesis Book
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1997.
Subjects:
Major meteorology.
Online Access:http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739887971&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD
Description
Summary:Space-time optimal filtering is used to estimate the response
of the Earth's surface temperature to both natural and
anthropogenic climate forcings over the past century. A
linear two-dimensional energy balance model with an ocean
mixed-layer is developed to generate the hypothesized space-
time patterns of response to the climate forcings. Optimal
filters are constructed using these space-time patterns along
with estimates of the background climate noise from 1000-year
control runs from three general circulation models (GCMs).
The filters are then applied to 100 years of observed surface
temperature data. The search is limited to the "solar cycle"
frequency band (periods from 7.49 to 16.67 years) to reduce
possible model errors from El Nino-Southern Oscillation
(ENSO) events and low-frequency oscillations from the deeper
ocean. A method is introduced to isolate the response of
each climate forcing from the other three. The surface
temperature response to volcanic aerosols, greenhouse gases,
and tropospheric aerosols is detected with a high level of
confidence. The response to solar cycle forcing is detected
with a moderate level of confidence. The same four climate
forcings are used, along with an estimate of the surface
temperature response to ENSO events, in an investigation of
the forced climate variability over the past 100 years. The
sources of variability in the quasi-decadal frequency band
are examined. It is found that a majority of the variance of
the surface temperature can be explained by the model
response plus the ENSO cycle. This supports the use of the
energy balance model for the generation of the climate
signals. In addition, these results provide information
about the natural (unforced) level of climate variability in
the surface temperature record.
Item Description:Vita.
"Major Subject: Meteorology".
Physical Description:xiv, 157 leaves : illustrations, maps ; 28 cm.
Issued also on microfiche from University Microfilms Inc.
Bibliography:Includes bibliographical references: pages 147-157.