逐层平滑地形的平缓地形追随坐标在高分辨率GRAPES模式中的应用研究  

Application of a smooth terrain-following coordinate with layer-by-layer smoothed terrain on the high resolution GRAPES model

作　　者：李超 陈德辉 李兴良 胡江林 LI Chao;CHEN Dehui;LI Xingliang;HU Jianglin(National Meteorological Centre,Beijing 100081,China)

机构地区：[1]国家气象中心,北京100081

出　　处：《气象学报》2021年第2期300-308,共9页Acta Meteorologica Sinica

基　　金：国家自然科学基金项目(41605080);国家重点研发计划项目(2017YFC1502001、2017YFC1501901)。

摘　　要：高分辨率GRAPES模式如3 km模式对地形的识别程度更高,模式中各高度坐标面可识别的地形坡度也更大,地形作用带来的气压梯度力计算误差和平流输送误差更突出。平缓地形追随坐标可以通过多种方式衰减坐标面上的地形影响进而减小这些计算误差。选择一种逐层平滑地形的平缓地形追随坐标,基于GRAPES-3km模式进行理想试验和批量模拟试验。试验结果显示:逐层平滑地形的平缓地形追随坐标相对其他平缓地形追随坐标对地形重力波模拟更接近解析值;24 h滚动预报月连续模拟试验中逐层平滑地形的平缓地形追随坐标一定程度上能降低高层月平均的温度场、风场的模拟误差,月平均的降水评分也有所提高。逐层平滑地形的平缓地形追随坐标应用于GRAPES-3km模式有较好的模拟效果。The high resolution GRAPES model,such as the GRAPES-3km model,has a higher degree of recognition of the terrain.The slope of the terrain that can be recognized by each coordinate plane in the model is also larger.The calculation errors of the pressure gradient force and mass advection are more prominent.The smooth terrain-following coordinate can attenuate these terrain errors by attenuating the terrain effects on the coordinate plane in a number of ways.The smooth terrain-following coordinate with layer-by-layer smoothed terrain was selected,and ideal test and batch simulation test were carried out based on the GRAPES-3km model.The test results show that using the smooth terrain-following coordinate with layer-by-layer smoothed terrain,model simulations of gravity wave are closer to analytical values compared to simulations using other terrain-following coordinates;monthly average errors for temperature and wind field simulations using the smooth terrain-following coordinate show a certain degree of attenuation,and monthly average precipitation score is also improved.The smooth terrain-following coordinate with layerby-layer smoothed terrain demonstrates better simulation application effects in the GRAPES-3km model.

关 键 词：GRAPES模式 平缓-混合坐标 动力框架 数值模式 

分 类 号：P435.1[天文地球—大气科学及气象学]