模式低空急流结构与水汽输送精度的数值试验  

NUMERICAL EXPERIMENTS OF THE STRUCTURE OF LOW LEVEL JET WITH DIFFERENT ACCURATE SCHEMES FOR THE ADVECTION OF MOISTURE

作　　者：李峰[1] 葛孝贞[1] 

机构地区：[1]南京大学大气科学系,南京210093

出　　处：《气象科学》1997年第3期250-257,共8页Journal of the Meteorological Sciences

基　　金：国家自然科学基金!49675266

摘　　要：本文所使用的中尺度模式MM4改进了水汽平流的计算精度，引入了Prather和Bott两种高精度正定平流差分格式。首先探讨了仅考虑模式平流过程的情况下不同平流差分格式的误差特征对模式结果的可能影响。结果显示：MM4中原有的水汽平流差分格式在水汽梯度较大处产生了水汽负值，而引入的高精度格式能正确模拟水汽陡变分市的特征。对不同精度的水汽平流差分格式作了数值试验，不同格式下模式的低空急流结构有较明显差别，水汽输送方案通过对流凝结加热可以影响低空急流的结构。An improved model of MM4 is used in this paper,which includes some high accurate andpositive definite moisture advection schemes:Prather and Bott 4 order. Numerical tests arepresented in order to investigate the possible influence of moisture advection scheme on mod-el results. The influence of moisture transport formulations with different accuracy upon thestructure of low level jet is investigated based on' 82. 6'Heavy rainfall. Obvious differenceare found in the range and intensity of LLJ. The results indicate:1、These differences are found in area with large moisture gradient;2、The possible reason is latent heat.

关 键 词：低空急流 水汽输送 平流方案 气流 数值试验 

分 类 号：P434.5[天文地球—大气科学及气象学]