SEMINAR:GEOTOPICS:Dr. Ben Kirtman (10/4 3:15pm)

[Qiong Zhang <qiongzhang87@gmail.com>]

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3:15 PM, Monday,October 4th, 2010
SLAB Seminar Room, S/A 103

Refreshments 3:00 PM

Dr. Ben Kirtman

Professor, Co-Author of NAS report

RSMAS-MPO

bkirtman@rsmas.miami.edu

                "

Resolved Ocean Eddies and Climate Simulations"

The current literature provides compelling evidence suggesting that anâeddy-resolving (as opposed to eddy permitted) ocean component model willâ  significantly impact the simulation of the large-scale climate, althoughâ this has not been fully tested to date in multi-decadal global coupledâclimate simulations. The purpose of this talk is to document how increasedâocean model resolution impacts the simulation of the large-scale climate âvariability. The model used for this study is the NCAR Community ClimateâSystem Model version 3.5 (CCSM3.5) - the forerunner to CCSM4. Twoâ experiments are reported here. The first experiment (i.e., control,âreferred to as LRC) is a 155-year present-day climate simulation of the â0.5Â atmosphere (zonal resolution 0.625Â meridional resolution 0.5Â)â coupled to ocean and sea-ice components with zonal resolution of 1.2Â andâmeridional resolution varying from 0.27Â at the equator to 0.54Â in theâmid-latitudes. The second simulation is carried out in two phases with theâ same atmospheric model coupled to 0.1Â ocean and sea-ice component models.âThe initial condition for the first phase (referred to as HRC03) is theâsame as the control simulation except that the ocean state has been âinterpolated to the 0.1Â grid. The second phase  (referred to as HRC06) âbegins at year-102 of HRC03 using the same resolution and parameters âexcept in this case the polar winds have been filtered to reduce âcomputational instability. This phase of the experiment extends toâ year-155. The simulations are compared in terms of how ocean eddies impactâ the mean and variable climate. Emphasis is placed on the tropical Pacificâand the North Atlantic Ocean, and specifically how the resolved eddies âimpact air-sea feedbacks.

Qiong Zhang

Marine Geology and Geophysics
Rosenstiel School of Marine and Atmospheric Science
University of Miami
4600 Rickenbacker Causeway
Miami Fl 33149