Aqua-planet configurationof the Unified Model |
Centre for Global Atmospheric Modelling
The University of Reading |
Various studies have made use of aqua-planet versions of GCMs to study aspects of atmospheric phenomena such as the Madden-Julian Oscillation (Hayashi and Sumi, J. Met. Soc. Japan, 1986) and the ITCZ (Goswami et al., JAS, 1984). Woolnough et al. (QJRMS, 2001) used an aqua-planet version of the Unified Model to investigate the organization of tropical convection by SST anomalies which propagated around the equator at speeds equivalent to the MJO.
For an aqua-planet GCM it is difficult to define a "correct" circulation pattern as there is no observed climatology with which to compare results. However, theoretical ideas such as the zonal mean response to equator-pole temperature gradients (Held and Hou, JAS, 1980) and equatorial trapped wave modes (Matsuno, J. Met. Soc. Japan, 1966) give us an understanding of how the atmosphere should respond to various simple forcing scenarios such as zonally symmetric SST fields. An aqua-planet GCM is particularly useful for looking at how the GCM responds to changes in some aspect of the model formulation where it is the difference between the various experiments that is more important than comparison with climatology.
email: pete@met.reading.ac.uk phone: 0118 3785583