摘要
云微物理的参数化对天气及气候的准确模拟至关重要,其中云粒子谱分布特征通过改变云演化发展和云辐射效应,必然进一步影响气候模拟.目前广泛使用的双参数云微物理方案,无法预报云粒子谱分布的谱形参数,阻碍了气候模式对云物理过程的准确描述.鉴于此,本文在单柱大气模式SCAM5.3(Single Column Atmosphere Model,Version 5.3)中增加雷达反射率因子的预报方程,构建了三参数冰相云微物理方案,实现了冰晶粒子谱分布谱形参数的预报.利用该模式,模拟了大气辐射观测计划在1997年夏季实施的为期29 d的观测个例(ARM97),分析了双、三参数方案对云量和辐射的模拟差异.结果表明:首先,三参数方案预报的冰晶粒子谱的谱形参数主要集中在0~4,峰值在2左右,至少有85%的μ都大于默认的0.其次,与双参数方案相比,三参数方案对云量的模拟更接近观测;利用辐射通量密度的观测值进行评估,发现无论是短波还是长波辐射通量密度,三参数方案的误差都比双参数方案小.最后,揭示了三参数方案对云量和辐射模拟效果的改进机理:主要是因为三参数方案减弱了冰晶到雪的自动转化过程,增强了冰晶凝华增长过程,从而增大了冰晶浓度和冰云云量.本文构建的三参数冰相云微物理方案,将有利于增强模式对云-气候反馈等过程的模拟能力.
Parameterization of cloud microphysics is critical for accurate simulation of weather and climate,in which the characteristics of cloud particle spectrum inevitably further affect climate simulation by changing the cloud evolution and cloud radiation effects.The popular currently used double-moment cloud microphysics schemes in numerical models can predict the intercept(N0)and slope(λ)parameters of cloud particle spectrum but cannot predict the spectral shape parameter(μ),which hinders accurate description of cloud physical processes in climate models.Therefore,in the present study,we built upon the ideas of previously developed triple-moment cloud microphysics scheme,considered radar reflectivity factor as the third predictor in addition to number and mass concentration,and introduced its related prediction equation to the Single Column Atmosphere Model Version 5.3(SCAM5.3).Moreover,the relevant microphysical process formulas in the model were revised,and a triple-moment ice-cloud microphysics scheme was constructed to predict theμof ice particle spectrum.Based on this model,a 29-day case of the Atmospheric Radiation Measurement Program in the summer of 1997(ARM97)was simulated,and the differences in cloud fraction and radiation simulations between the double-and triple-moment schemes were analysed.Theμof ice particle spectrum predicted by the triple-moment scheme mainly ranged from 0 to 4;the peak value was around 2,and at least 85%of theμvalues were greater than the default 0.Therefore,theμ=0 setting in the double-moment scheme is unreasonable.Moreover,the developed triple-moment icecloud microphysics scheme yielded a narrower ice particle spectrum,which was closer to the observation results of previous studies,than the double-moment cloud microphysics scheme(e.g.,height=233 hPa).Furthermore,compared with the double-moment scheme,the triple-moment scheme achieved closer simulations of the cloud fraction observations,particularly for ice clouds in the upper levels.Considering the close association between
作者
贺欣
陆春松
史湘军
张文韬
朱磊
徐晓齐
李君俊
李丹
Xin He;Chunsong Lu;Xiangjun Shi;Wentao Zhang;Lei Zhu;Xiaoqi Xu;Junjun Li;Dan Li(Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration,Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing 210044,China;School of Atmospheric Sciences,Nanjing University of Information Science and Technology,Nanjing 210044,China;Nanjing Joint Institute for Atmospheric Sciences,Nanjing 210008,China;Chongqing Research Institute of Big Data,Peking University,Chongqing 400000,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2023年第15期1971-1984,共14页
Chinese Science Bulletin
基金
国家重点研发计划(2019YFA0606803)
国家自然科学基金(42175099,42027804,42075073,41775095)
2021年江苏省研究生科研创新计划(KYCX21_0951)
2022年江苏省研究生科研创新计划(KYCX22_1168)资助。
关键词
谱形参数
三参数方案
微物理
单柱大气模式
spectral shape parameter
triple-moment scheme
microphysics
Single Column Atmosphere Model
