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 eddy-resolving global ocean component for CCSM to address these questions.

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Polar Climate StudiesFactors 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 ~ 30S). The slow propagation toward the equator offers the possibility of predicting near equatorial anomalies years in advance.

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 1C 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 .

WITH DC (BLUE)WITHOUT DC (BLACK)

Multi-Century Coupled Carbon/Climate Multi-Century Coupled Carbon/Climate

SimulationsSimulations

Net CO2 Flux (Pg C/yr)-2.0

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• 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: 01 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

Surface Temp.13.6

14.1

10000 year 0 1000year