頁籤選單縮合
題 名 | Precipitation Parameterization in a Simulated Mei-Yu Front=梅雨鋒面數值模擬之降水參數方法研究 |
---|---|
作 者 | 楊明仁; 簡芳菁; 鄭明典; | 書刊名 | Terrestrial, Atmospheric and Oceanic Sciences |
卷 期 | 11:2 2000.06[民89.06] |
頁 次 | 頁393-422 |
分類號 | 328.63 |
關鍵詞 | 梅雨; 鋒面; 降水參數方法; Quantitative precipitation forecast; Numerical simulation; Cumulus parameterization; Microphysics parameterization; |
語 文 | 英文(English) |
英文摘要 | Observational and numerical studies have consistently shown the im-portance of latent heat release associated with frontal precipitation in thedevelopment of a Mei-Yu front. However, a systematic evaluation of pre-cipitation parameterization in the simulation of a Mei-Yu front has beenrare in the literature. In order to enhance our understanding on precipita-tion parameterization of Mei-Yu fronts, this study conducts numerical ex-periments to evaluate the performance of subgrid-scale cumulus schemesand resolvable-scale microphysics schemes to simulate the Mei-Yu frontalsystem on 4-5 June 1998 at grid resolutions of 45 km and 15 km, using thePenn State/NCAR mesoscalc model MM5. Principal findings are summa-rized here. ● The horizontal extent and intensity of precipitation, the partitioningof precipitation into grid-resolvable and subgrid-scale portions, the verti-cal thermodynamic profile in the precipitation region and the embeddedmesoscale structure are extremely sensitive to the choice of cumulus pa-rameterization schemes. This is true for both the 45- and 15-km grids. ● The partitioning of precipitation into subgrid scale and resolvablescale is sensitive to the particular cumulus parameterization that is used inthe model, but it is nearly the same on both the 45- and 15-km grids for agiven cumulus parameterization. ● The detailed ice-phase microphysical processes do not have a signifi-cant impact on the rainfall pattern on either the 45- and 15-km grids. How-ever, the inclusion of cloud ice-snow-graupel microphysical processes in-creases the total surface precipitation amount by 30 compared to theamount with only warm rain processes. ● Variations in the subgrid-scale cumulus parameterization have a muchlarger impact on the distribution and amount of Mei-Yu frontal precipita- tion than do variations in the resolvable-scale microphysics parameteriza-tion at mesoscale grid resolutions of 10-50 km. |
本系統中英文摘要資訊取自各篇刊載內容。