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The effect of rotation on the pressure drag force produced by flow around long mountain ridges
Author(s) -
Wells Helen,
Webster Stuart,
Brown Andrew
Publication year - 2005
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1256/qj.04.37
Subject(s) - drag , ridge , orographic lift , mechanics , rotation (mathematics) , parasitic drag , geology , orography , flow (mathematics) , drag coefficient , physics , meteorology , geometry , mathematics , precipitation , paleontology
Abstract The impact of rotation on the orographic drag experienced by air flowing around a wide mountain is investigated. The work builds on numerical modelling studies performed by Ólafsson and Bougeault, who investigated the effect of rotation and surface friction on the drag experienced by flow around a single elongated mountain perpendicular to the direction of the flow. The region of parameter space they explored is extended by performing a series of idealized model experiments with a larger range of ridge lengths. The drag force in these simulations is compared with the predictions of a heuristic flow‐blocking model devised by Shutts. The results show that Shutts's model overestimates the effect of rotation upon the drag force. However we find that Shutts's model predicts both the drag force exerted on the upstream side of the ridge and the upstream features reasonably well. Finally the implications of the results for NWP parametrizations of subgrid‐scale orographic drag are discussed. Copyright © 2005 Royal Meteorological Society