Predicting Coupled Ocean-Atmosphere Modes with a Climate Modeling Hierarchy - ID:121

Project Description

An exploration of aspects of climate predictability associated with Atlantic tropical-extratropical interactions on interannual-to-interdecadal time scales, with special emphasis given to Northeast Brazil and West Africa.

Goals and Objectives

Goal: To determine mid-latitude climate predictability over the tropical Atlantic sector associated with tropical-extratropical interactions on interannual-to-interdecadal time scales.

Objectives:

• Develop probabilistic network (PN) models (i.e. hidden Markov models, HMMs) to diagnose interannual-to-interdecadal variability in GCM-based climate models.
• Analyze atmospheric tropical-extratropical teleconnections over the North Pacific and North Atlantic on interannual-to-interdecadal time scales in the NCAR Parallel Climate Model (PCM). Determine the extent of nonlinearity. Quantify the potential predictability.
• Build a simplified coupled ocean-atmosphere model of the Atlantic Ocean-global atmosphere and use it, in conjunction with the GCM through PN-techniques, to test the hypothesis that coupled ocean-atmosphere interactions involving the thermohaline circulation give rise to predictable modes of decadal climate variability over the North Atlantic.
• Determine the influence of greenhouse-gas increases on these modes in the PCM simulations.

Outputs

Currently Available Outputs:

Kondrashov, D., S. Kravtsov, A. W. Robertson and M. Ghil, 2005: A hierarchy of data-based ENSO models. J. Climate, 18, 4425-4444.

Robertson, A. W., S. Kirshner, and P. Smyth, 2006: Subseasonal-to-Interdecadal Variability of the Australian Monsoon Over North Queensland. Quart. J. Royal Meteor. Soc., 132, 519-542.

Koo, S., A. W. Robertson, and M. Ghil, 2002: Multiple regimes and low-frequency oscillations in the Southern Hemisphere's zonal-mean flow. J. Geophys. Res., doi: 10.1029/2001JD001353.

Kravtsov, S., and A. W. Robertson, 2002: Midlatitude ocean-atmosphere interaction in an idealized coupled model. Climate Dynamics, 19, 693-711.

Kravtsov, S., A. W. Robertson and M. Ghil, 2005: Bimodal Behavior in the Zonal Mean Flow of a Baroclinic Beta-Channel Model. J. Atmos. Sci., 62, 1746-1769.

Lott, F., A. W. Robertson, and M. Ghil, 2004a: Mountain torques and Northern Hemisphere low-frequency variability. Part I: Hemispheric and oscillatory aspects. J. Atmos. Sci., 61, 1259-1271.

Lott, F., A. W. Robertson, and M. Ghil, 2004b: Mountain torques and Northern Hemisphere low-frequency variability. Part II: Regional and episodic aspects. J. Atmos. Sci., 61, 1272-1283.

DoE Energy Citations Database Final Report


Kirshner, S., P. Smyth, and A. W. Robertson, 2004b: Conditional Chow-Liu Tree Structures for Modeling Discrete-Valued Vector Time Series. Technical Report, ICS-TR 04-04. Dept. Information and Computer Science, University of California, Irvine, CA.