The Effect of Topography on Storm Track Intensity in Relatively Simple General Circulation Model

The effect of topography on the intensity of storm tracks is examined with a relatively simple general circulation model. This effect is found to be crucially dependent on the latitudinal structure of the zonal background flow impinging on the topography. If the background flow consists of a double jet, larger topography leads to an intensification of the storm track downstream of the mountain, consistent with enhanced baroclinicity in this region. However, if the background flow consists of a single jet, topography weakens the storm track, despite the fact that the baroclinicity downstream of the mountain is again enhanced. This different impact of topography on the storm track intensity arises from the fundamentally different wave structure in the two reference flows, which we will present in some detail together with a discussion on how these results can be helpful in understanding the mid-winter suppression of the Pacific storm track.