Journal article

Further sensitivities of orographic precipitation to terrain geometry in idealized simulations

CD Watson, TP Lane

Journal of the Atmospheric Sciences | American Meteorological Society | Published : 2014

Abstract

This study examines how variations to the nondimensional mountain height Ĥ and the horizontal aspect ratio β of a straight ridge and a concave ridge influence orographic precipitation. An idealized threedimensional model is used to simulate a moist flow impinging upon these two ridges with Ĥ 50.66-2.0 and β 5 1.0-8.0. The concave ridge generates substantially more precipitation than the straight ridge via an established precipitation-enhancing funneling mechanism near the ridge vertex when the flow is unblocked. Based on previous work, it was hypothesized that when the approaching flow becomes blocked, the strength of the precipitation enhancement by the concave ridge relative to the straigh..

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University of Melbourne Researchers

Grants

Awarded by Australian Research Council


Awarded by ARC Centre of Excellence for Climate System Science


Funding Acknowledgements

Campbell Watson was supported by a Melbourne Research Scholarship, and Todd Lane was supported by the Australian Research Council's Future Fellowships Scheme (Grant FT0990892). Computing was performed at the Victorian Partnership for Advanced Computing (VPAC) facility and at the National Computational Infrastructure (NCI) facility. The work benefitted from computational support provided by the ARC Centre of Excellence for Climate System Science (Grant CE110001028). We would also like to thank Dan Kirshbaum and Alison Nugent for their comments on an earlier version of the paper, Rich Rotunno for the useful discussion in the early parts of the study and feedback, and two anonymous reviewers.