We present recent results from the design of the GFDL ocean circulation model for the Cedar multicluster architecture. The model simulates the basic aspects of largescale, baroclinic ocean circulation, including treatment of irregular bottom topography. We concentrate on several modifications and versions of the code that are designed to exploit the memory and computational hierarchy of Cedar, ...

Impacts of mixing driven by barotropic tides in a coupled climate model are investigated by using an atmosphere–ocean–ice–land coupled climate model, the GFDL CM2.0. We focus on oceanic conditions of the Northern Atlantic. Barotropic tidal mixing effects increase the surface salinity and density in the Northern Atlantic and decrease the RMS error of the model surface salinity and temperature fi...

IRD), Paris, France, and Walker Institute, University of Reading, Reading, United Kingdom; WittenberG—GFDL, Princeton, New Jersey; Fedorov—Yale University, New Haven, Connecticut; Collins—Met Office, Hadley Centre, Exeter, United Kingdom; WanG—NOAA/AOML, Miami, Florida; Capotondi—University of Colorado, and NOAA, Boulder, Colorado; oldenborGh—KNMI, De Bilt, Netherlands; stoCkdale—ECMWF, Reading...

AFFILIATIONS: Guilyardi—LOCEAN/IPSL, Paris, France, and National Centre for Atmospheric Science–Climate, University of Reading, Reading, United Kingdom; wittEnbErG—NOAA/GFDL, Princeton, New Jersey; balMasEda—ECMWF, Reading, United Kingdom; cai—CSIRO, Aspendale, Victoria, Australia; collins— University of Exeter, Exeter, United Kingdom; McPhadEn— NOAA/PMEL, Seattle, Washington; watanabE—Universi...

Underestimated rainfall over Amazonia was a common problem for the Coupled Model Intercomparison Project phase 3 (CMIP3) models. We investigate whether it still exists in the CMIP phase 5 (CMIP5) models and, if so, what causes these biases? Our evaluation of historical simulations shows that some models still underestimate rainfall over Amazonia. During the dry season, both convective and large...

The Atlantic Multidecadal Oscillation (AMO) is a pronounced signal of climate variability in the North Atlantic sea-surface temperature field. In this paper, we propose an explanation of the physical processes responsible for the timescale and the spatial pattern of the AMO. Our approach involves the analysis of solutions of a hierarchy of models. In the lowest member of the model hierarchy, wh...

Optimal signal detection theory has been applied in a search through 100 yr of surface temperature data for the climate response to four specific radiative forcings. The data used comes from 36 boxes on the earth and was restricted to the frequency band 0.06–0.13 cycles yr21 (16.67–7.69 yr) in the analysis. Estimates were sought of the strengths of the climate response to solar variability, vol...

[1] Weather forecasts started from realistic initial conditions are used to diagnose the large warm and dry bias over the United States Southern Great Plains simulated by the GFDL climate model. The forecasts exhibit biases in surface air temperature and precipitation within 3 days which appear to be similar to the climate bias. With the model simulating realistic evaporation but underestimated...

Wildfire risks for California under four climatic change scenarios were statistically modeled as functions of climate, hydrology, and topography. Wildfire risks for the GFDL and PCM global climate models and the A2 and B1 emissions scenarios were compared for 2005–2034, 2035–2064, and 2070–2099 against a modeled 1961–1990 reference period in California and neighboring states. Outcomes for the G...

This paper presents a quantitative methodology for evaluating air–sea fluxes related to ENSO from different atmospheric products. A statistical model of the fluxes from each atmospheric product is coupled to an ocean general circulation model (GCM). Four different products are evaluated: reanalyses from the National Centers for Environmental Prediction (NCEP) and the European Centre for Medium-...