GRAPES对流尺度集合预报模式中不同尺度初始扰动能量的演变特征  

Evolution Characteristics of Initial Perturbation Energy at Different Scales in Convection-Permitting Ensemble Prediction of GRAPES

作　　者：马雅楠 陈静[2] 徐致真 王婧卓 刘昕 MA Yanan;CHEN Jing;XU Zhizhen;WANG Jingzhuo;LIU Xin(Chinese Academy of Meteorological Sciences,Beijing 100081;Center for Earth System Modeling and Prediction of China Meteorological Administration,Beijing 100081;Chengdu University of Information Technology,Chengdu 610225)

机构地区：[1]中国气象科学研究院,北京100081 [2]中国气象局地球系统数值预报中心,北京100081 [3]成都信息工程大学,成都610225

出　　处：《大气科学》2023年第5期1541-1556,共16页Chinese Journal of Atmospheric Sciences

基　　金：国家重点研发计划项目2021YFC3000902。

摘　　要：对流尺度数值预报对初始场的微小扰动非常敏感,且初始扰动的演变具有模式依赖、环流依赖和尺度依赖特征,如何构建合理的初始扰动场是国内外对流尺度集合预报领域尚未解决的难点问题和研究前沿。本文基于中国气象局3 km水平分辨率的GRAPES(Global/Regional Assimilation and Prediction Enhanced System)对流尺度模式,利用其同化分析系统的背景误差和一个二维随机型,构建大、中、小三个尺度的初始扰动场,并选取中国夏季一次典型的多区域强降水天气个例,开展对流尺度集合预报试验,对比分析了大、中、小尺度初始扰动能量的时空演变和谱分解特征,以期为构建适用于GRAPES对流尺度集合预报的初始扰动场提供依据。研究结果表明,在GRAPES 3 km对流尺度模式中:(1)大、中、小尺度初始扰动总能量的增长过程具有明显差异。大尺度初始扰动总能量随着模式积分呈增长趋势,尤以对流层中高层的持续增长为甚;而中、小尺度初始扰动总能量随着模式积分以日变化为主,表现为下午至傍晚(夜晚至清晨),扰动总能量显著增加(减小),且扰动总能量小尺度分量的日变化占主导,这可能是由于太阳辐射引起地表加热,使得白天的对流活动比夜晚活跃,且对流直接影响了扰动总能量小尺度分量的变化。此外,大、中、小尺度初始扰动总能量增长均以扰动动能增长为主,扰动位能在对流层低层的增长不可忽略。(2)大、中、小尺度初始扰动总能量增长具有环流依赖特征。对北支气流控制的中高纬天气区,在斜压不稳定较强的低槽区,大尺度初始扰动总能量增长突出,而在槽后西北气流区,大、中、小尺度初始扰动总能量均不增长;对南北气流交汇区,仍以大尺度初始扰动总能量增长最为明显;对南海夏季风影响区,大、中、小尺度初始扰动总能量发展均较弱,扰动位能增长与区域降水大值率演�Convective-scale numerical weather prediction is sensitive to minor IPs(initial perturbations),and the evolution of these perturbations is model-,flow-,and scale-dependent.Constructing reasonable IPs for convectionpermitting ensemble prediction systems has always been challenging.The authors use GRAPES(Global/Regional Assimilation and Prediction System)3-km convective-scale model from the Center for Earth System Modeling and Prediction of the China Meteorological Administration.The authors employ a two-dimensional random function and background error of assimilation system in GRAPES 3-km to construct large-,meso-,and small-scale stochastic initial perturbation fields.Using these different-scale IPs,the authors conduct three convective-scale ensemble forecast experiments on a typical multiregional heavy precipitation weather process during summer in China.The authors analyze the spatiotemporal evolution and spectral decomposition characteristics of perturbation energy in these three experiments to elucidate the evolution characteristics of different-scale initial perturbations in a convective-scale model.This analysis provides a reference for constructing optimal initial perturbations in GRAPES convection-permitting ensemble prediction systems.The results reveal the following:(1)There are significant differences in the evolution of DTE(difference total energy)among the three IP experiments.The DTE of the large-scale IP increases with model integration,particularly in the middle and upper troposphere.However,the DTE evolution of the meso-and small-scale IP experiments exhibits an apparent diurnal cycle characteristic.In particularly,it exhibits a significant increase(decrease)during the period ranging from afternoon to evening(from night to morning)when convection is active(passive).The diurnal cycle is primarily caused by the small-scale component of DTE.The diurnal cycle of DTE may be due to the surface heating caused by solar short-wave radiation,which facilitates more active convection during the daytime than a

关 键 词：GRAPES 3 KM 对流尺度模式 集合预报 不同尺度初始扰动 扰动能量演变 环流依赖 

分 类 号：P456[天文地球—大气科学及气象学]