Izvorni znanstveni članak
EFFECTS OF MOIST FROUDE NUMBER AND OROGRAPHIC ASPECT RATIO ON A CONDITIONALLY UNSTABLE FLOW OVER A MESOSCALE MOUNTAIN
Shu-Hua Chen
; Department of LAWR, University of California, Davis, CA 95616-8627
Yuh-Lang Lin
; Department of MEAS, North Carolina State University, Raleigh, NC 27695
Zhan Zhao
; Department of LAWR, University of California, Davis, CA 95616-8627
Heather Dawn Reeves
; Department of MEAS, North Carolina State University, Raleigh, NC 27695
Sažetak
A series of idealized simulations for an unsaturated, conditionally unstable flow over a two-dimensional mountain ridge were performed to investigate how the unsaturated moist Froude number (Fw) and the aspect ratio of mountain height to half-width (h/a), affect the propagation, cloud type and rainfall amount of orographically induced precipitation systems. The moist Froude number (Fw) was varied by increasing or decreasing the basic state wind speed (U) while the aspect ratio was varied by increasing or decreasing the mountain half-width (a). For low Fw flows, the flow is in an upstream propagating regime and shows little or no sensitivity to changes in a. For moderate or large values of Fw, the flow shifts more toward a downstream propagating regime as a is decreased (i. e. as h/a is increased). The domain integrated accumulated precipitation was not sensitive to the aspect ratio. For a fixed h/a,
the flow shifts more toward a downstream propagating flow regime as Fw is increased, a result that is consistent with previous research. Additionally, the results show that there is an increase in the domain integrated precipitation as Fw is increased.
Ključne riječi
Hrčak ID:
64662
URI
Datum izdavanja:
15.12.2005.
Posjeta: 684 *