Transcript Oceanography Section Highlights 2004 (PowerPoint

Mesoscale Ocean Processes
• What role do mesoscale
ocean processes play in
establishing the mean
climate, its variability, and
the response to climate
forcing?
• Developing an eddyresolving global ocean
component for CCSM to
address these questions.
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Polar Climate Studies
Factors influencing the polar
amplification of climate change
Shown is the zonally averaged surface
air temperature change simulated in a
number of coupled models
The role of the ocean, sea ice and
coupled feedbacks in the climate
variability of the southern ocean
Shown is the regression of
absorbed solar radiation on the
leading mode of sea ice variability
in CCSM2
Hindcast of the formation and propagation of South Pacific salinity
anomalies of 0 = 25.5 from 1966 to 1974.
Model results have given
insights into the process (late
winter vertical mixing below
the mixed-layer) that injects
positive anomalies onto deep
isopycnals downstream
(north) of their wintertime
surface outcrops (solid
contour across ~ 30S).
The slow propagation toward
the equator offers the
possibility of predicting near
equatorial anomalies years in
advance.
WITH DC (BLUE)
WITHOUT DC (BLACK)
In CCSM3, the ocean model exchanges information with the coupler once a day.
Thus, the diurnal cycle (DC) is not explicitly resolved. Instead, its effects are
included in solar heating within the ocean model. The simulations produce a diurnal
cycle in vertical mixing in the upper ocean in agreement with observations. The
figure shows that the Equatorial Pacific mean SST is about 1C warmer with the DC
parameterization than without one, in better agreement with the Reynolds and Smith
(1994) climatology. Additionally, NINO3.4 standard deviation improves dramatically
(0.81 vs. 1.12 C with and without DC, respectively), matching the observational
value of about 0.82 C .
Multi-Century Coupled Carbon/Climate Simulations
+2.0
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13.6
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Surface Temp.
year
1000 0
-2.0
Net CO2 Flux (Pg C/yr)
year
Fully prognostic land/ocn BGC and carbon/radiation
Atm-Land CO2 flux: 70 PgC/yr ; Atm-Ocean CO2 flux: 90 PgC/yr 
Net Land+ocean CO2 flux: 01 PgC/yr
“Stable” carbon cycle and climate over 1000y
Baseline for : Projection of climate change on natural modes, Detection &
attribution, Future climate projections/fossil fuel perturbations
• Joint work with UC-Berkeley, WHOI
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