Geoscience Reference
In-Depth Information
Recent Research at GFDL on Surface
Temperature Trends and Simulations
of Tropical Cyclone Activity in the
Indian Ocean Region
Thomas R. Knutson*, Fanrong Zeng, Andrew Wittenberg,
Hyeong-Seog Kim, Joseph Sirutis, Morris Bender,
Ming Zhao and Robert Tuleya
Geophysical Fluid Dynamics Laboratory/NOAA
Princeton, New Jersey, U.S.A.
*e-mail: tom.knutson@noaa.gov
1. Introduction and Overview
In this extended abstract, we report on progress in two areas of research at
GFDL relating to Indian Ocean regional climate and climate change. The first
topic is an assessment of regional surface temperature trends in the Indian
Ocean and surrounding region. Here we illustrate the use of a multi-model
approach (CMIP3 or CMIP5 model ensembles) to assess whether an
anthropogenic warming signal has emerged in the historical data, including
identification of where the observed trends are consistent or not with current
climate models. Trends that are consistent with All Forcing runs but inconsistent
with Natural Forcing Only runs are ones which we can attribute, at least in
part, to anthropogenic forcing.
This topic is quite relevant to the topic of Indian Ocean tropical cyclone
(TC) activity, since long-term sea surface temperature warming could be an
important environmental change for Indian Ocean tropical cyclones. The second
topic in our abstract is a status report on our attempts to dynamically simulate
Indian Ocean tropical cyclone activity for the current climate using observed
SSTs alone as input to the model. We adopt a two-step procedure, which includes
a second dynamical downscaling step—which is an attempt to produce a realistic
simulation of very intense tropical cyclone activity. The inputs to the higher
resolution model are storm cases from a 27-yr simulation of a global model
that used prescribed interannual varying observed SSTs as input.
Search WWH ::
Custom Search