第30回 ESCセミナー

Establishing Equivalent Resolutions for Global Atmospheric Model Dynamical Cores

日時
2007年11月12日(月) 10:00-11:00
場所
横浜研究所 シミュレータ研究棟1階 大会議室
講演者
David L. Williamson (National Center for Atmospheric Research)
使用言語
英語

要旨

The equivalent resolutions for two different global dynamical coresare established when they are coupled to the sub-grid scale parameterization suite of the Community Atmosphere Model (CAM3). One core adopts the common spectral transform formalism, the other adopts a finite volume approach. The equivalent resolutions are established over a range of resolutions employed today for climate models. The comparison is done in the context of the Aqua Planet Experiment. Thus it is based on the characteristics of free, unforced motions, due in large part to the dynamical component driven by the parameterized processes and explicit dissipation. The forced component arising from surface orography and land-ocean-sea-ice contrasts is not considered.

The resolution equivalences are demonstrated for a number of model fields. These include selected time averaged, global and zonal averaged fields, the meridional structure of eddy kinetic energy and eddy temperature variance, the mean meridional eddy transports, the characteristics of tropical wave propagation, and probability density functions of precipitation. These fields indicate that the 2 degree finite volume model is equivalent to T42 spectral transform model, 1 degree is equivalent to T85, and 0.5 degree is equivalent to T170.

This proportional relationship does not hold at lower resolutions.

問い合わせ先

地球シミュレータセンター
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