精准的气象场是空气质量模型的基础,本文对中尺度气象模式WRF(The Weather Research and Forecasting)中微物理过程方案、陆面过程方案、行星边界层方案以及积云参数化方案进行组合,设计了24组参数化方案,对2014年5月初四川盆地内一次...精准的气象场是空气质量模型的基础,本文对中尺度气象模式WRF(The Weather Research and Forecasting)中微物理过程方案、陆面过程方案、行星边界层方案以及积云参数化方案进行组合,设计了24组参数化方案,对2014年5月初四川盆地内一次空气重污染过程中的气象场进行了模拟,将模拟输出的10 m风速、2 m温度、2 m相对湿度、水汽混合比廓线及位温廓线与研究区内14个气象站及1个探空站的实测数据进行对比.结果表明,Mellor-Yamada-Janjic(MYJ)边界层方案能更好的模拟出盆地内风速的变化趋势,而Yonsei University(YSU)边界层方案模拟的2 m相对湿度效果更优.第16组参数化方案(由WRF Single-Moment 3-class(WSM3)方案,热扩散(SLAB)方案、Mellor-Yamada-Janjic(MYJ)方案及Grell-Devenyi(GD)方案组合)能够较好地模拟盆地近地面风场的水平分布及风速的日变化规律,模拟的温度日变化规律更贴合实际情况,同时能够模拟出边界层内水汽混合比及位温的垂直分布特征,对边界层内逆温层和混合层的模拟也更加贴近实际,尽管该方案对2m相对湿度的模拟并不是最好,但基本能够模拟出四川盆地气象要素的变化特征,因此认为第16组参数化方案(WSM3,SLAB,MYJ及GD)适用于模拟此次重污染过程的气象场.展开更多
数值模式作为目前最主要的天气预报手段之一,已经广泛应用于极端降雨等强天气过程的预警和预测。在实际预报业务中,数值模式受初始场、边界条件、参数化方案等影响,难以进行长时间精准预报。基于新一代中尺度数值天气预报模式WRF(The We...数值模式作为目前最主要的天气预报手段之一,已经广泛应用于极端降雨等强天气过程的预警和预测。在实际预报业务中,数值模式受初始场、边界条件、参数化方案等影响,难以进行长时间精准预报。基于新一代中尺度数值天气预报模式WRF(The Weather Research and Forecasting Model),交叉组合16套微物理过程和积云对流参数化方案,对闽江流域2021年5月17—24日的一场连续性暴雨过程进行敏感性对比模拟。结果表明,WRF模式基本可以再现本次降雨过程的时空分布特征,但明显高估了暴雨中心的强度和范围,EXP9(Lin-NT组合)整体表现较优。对于初始场质量敏感性试验,基于最优参数化方案组合的模拟结果表明,ERA5(The Fifth-generation Atmospheric Reanalysis of the European Center for Medium-Range Weather Forecasts)对各个量级降雨模拟效果均相对较好,与观测数据的时空特征最吻合,其次为GDAS/FNL(Global Data Assimilation System/Final Operational Global Analysis),而CFS(Climate Forecast System Operational Analysis)表现最差。可为提高极端降雨模拟和预报精度提供方法借鉴。展开更多
利用2010年馆陶站和阿柔站涡动相关仪和自动气象观测资料,运用Yang et al.方法估算空气动力学粗糙度,分析了空气动力学粗糙度的时空变化特征,并将估算值与Brutsaert、Monteith、Zeng andWang、Bastiaanssen and Bandara、Teixeira五种...利用2010年馆陶站和阿柔站涡动相关仪和自动气象观测资料,运用Yang et al.方法估算空气动力学粗糙度,分析了空气动力学粗糙度的时空变化特征,并将估算值与Brutsaert、Monteith、Zeng andWang、Bastiaanssen and Bandara、Teixeira五种参数化方案进行比较。结果表明:(1)空气动力学粗糙度与风向的关系取决于下垫面的非均匀程度;农田下垫面的空气动力学粗糙度随风向变化明显,具有方向性。(2)空气动力学粗糙度的季节性变化取决于下垫面植被(农田和草地)的季节性变化,与植被高度呈显著线性关系,与叶面积指数呈抛物线关系。(3)对于农田、草地下垫面而言,计算结果与Yang et al.方法估算值较为接近的参数化方案分别为Bastiaanssen and Bandara、Brutsaert。展开更多
陆面模式Noah-MP(Noah land surface model with Multi-Parameterizations)为陆面物理过程提供了大量复杂的参数化方案,往往受限于计算量和计算能力,使得利用全组合方案实验,来确定适用的参数化方案难以实现,从而给模式模拟带来不确定...陆面模式Noah-MP(Noah land surface model with Multi-Parameterizations)为陆面物理过程提供了大量复杂的参数化方案,往往受限于计算量和计算能力,使得利用全组合方案实验,来确定适用的参数化方案难以实现,从而给模式模拟带来不确定性。为科学减少实验次数,本文引入正交试验法,选择了影响地表温度模拟较大的5个主要过程,包括动态植被、气孔阻抗过程、控制气孔阻抗的土壤湿度参数过程和表面热交换系数过程以及辐射传输过程等,设计了9次正交试验,利用CLDAS-V2.0(中国气象局陆面数据同化系统)驱动Noah-MP陆面模式对我国东南地区地表温度进行模拟,对参数化方案寻优,以确定其适用的参数化方案组合。结果表明,参数化方案的选择对林地区域的模拟,以及在7月和8月的模拟影响较大。物理过程的敏感性和最优参数化方案同时受到下垫面和季节的影响,多数情况中,动态植被与冠层气孔阻抗过程对模拟影响显著,是较敏感的物理过程。通过对不同下垫面不同季节的最优参数化方案组合的时空尺度分析,经模拟验证,东南地区地表温度模拟的较优方案组合为开启动态植被,Ball-Berry的冠层气孔阻抗方案,Noah的土壤湿度参数方案,M-O的地表热交换系数方案和GAPFVEG的辐射传输方案。展开更多
A set of improved and efficient radiation parameterization schemes for surface radiation balance components under clear- sky conditions was developed by using general surface measurements and MODIS data. The set of sc...A set of improved and efficient radiation parameterization schemes for surface radiation balance components under clear- sky conditions was developed by using general surface measurements and MODIS data. The set of schemes was then adapted for regions similar to the present study sites under different grazing intensities and varying degrees of drought in the semiarid grasslands of Inner Mongolia. Specifically, we mainly improved two schemes for estimating downward shortwave and longwave radiation at the surface, which could be applied to regions with certain degrees of drought. The validation datasets were from ground-based observations at various grazing sites during the growing season （May to September） of different drought years, 2005 and 2006. Through comparisons of parameterized versus measured radiation values, the increased or modified factors in the original schemes demonstrated improved estimation accuracy, and the rationalities of input parameters and variables were analyzed. The regional instantaneous net radiation estimations had root-mean-square errors of less than 30 W m-2 compared with ground measurements at the sites during the study period. The statistical results showed the improved schemes are suitable for estimating surface net radiation in regional semiarid areas during the growing season. Analyses of the sensitivity of the schemes to corresponding variables were conducted to ascertain the major error sources of the schemes and potential variables for improving the performance of the schemes in agreement with observations.展开更多
In the present study, the imitation of heavy rainfall event which occurred over Jharkhand during 18 August 2016 was taken as a case study. Weather Research and Forecasting (WRF) model has been utilized for this study....In the present study, the imitation of heavy rainfall event which occurred over Jharkhand during 18 August 2016 was taken as a case study. Weather Research and Forecasting (WRF) model has been utilized for this study. National Centers for Environmental Prediction (NCEP) analysis data is compared with GSMaP data with different combination of physical parameterization scheme like microphysics (MP) and cumulus parameterization (CP). In the present study, three MP schemes: Kessler scheme, Lin et al. scheme and WRF Single-moment 6-class scheme with combination of three CP schemes: Betts-Miller-Janjic scheme, Multi-scale Kain-Fritsch scheme and New simplified Arakawa-Schubert scheme have been used. The model predicted humidity, temperature and precipitation were compared with the GSMaP product. The model nicely depicted the cloud pattern and recognized the rain event spatially. The obtained result shows that the model overestimates the precipitation for all the schemes.展开更多
文摘数值模式作为目前最主要的天气预报手段之一,已经广泛应用于极端降雨等强天气过程的预警和预测。在实际预报业务中,数值模式受初始场、边界条件、参数化方案等影响,难以进行长时间精准预报。基于新一代中尺度数值天气预报模式WRF(The Weather Research and Forecasting Model),交叉组合16套微物理过程和积云对流参数化方案,对闽江流域2021年5月17—24日的一场连续性暴雨过程进行敏感性对比模拟。结果表明,WRF模式基本可以再现本次降雨过程的时空分布特征,但明显高估了暴雨中心的强度和范围,EXP9(Lin-NT组合)整体表现较优。对于初始场质量敏感性试验,基于最优参数化方案组合的模拟结果表明,ERA5(The Fifth-generation Atmospheric Reanalysis of the European Center for Medium-Range Weather Forecasts)对各个量级降雨模拟效果均相对较好,与观测数据的时空特征最吻合,其次为GDAS/FNL(Global Data Assimilation System/Final Operational Global Analysis),而CFS(Climate Forecast System Operational Analysis)表现最差。可为提高极端降雨模拟和预报精度提供方法借鉴。
文摘利用2010年馆陶站和阿柔站涡动相关仪和自动气象观测资料,运用Yang et al.方法估算空气动力学粗糙度,分析了空气动力学粗糙度的时空变化特征,并将估算值与Brutsaert、Monteith、Zeng andWang、Bastiaanssen and Bandara、Teixeira五种参数化方案进行比较。结果表明:(1)空气动力学粗糙度与风向的关系取决于下垫面的非均匀程度;农田下垫面的空气动力学粗糙度随风向变化明显,具有方向性。(2)空气动力学粗糙度的季节性变化取决于下垫面植被(农田和草地)的季节性变化,与植被高度呈显著线性关系,与叶面积指数呈抛物线关系。(3)对于农田、草地下垫面而言,计算结果与Yang et al.方法估算值较为接近的参数化方案分别为Bastiaanssen and Bandara、Brutsaert。
文摘陆面模式Noah-MP(Noah land surface model with Multi-Parameterizations)为陆面物理过程提供了大量复杂的参数化方案,往往受限于计算量和计算能力,使得利用全组合方案实验,来确定适用的参数化方案难以实现,从而给模式模拟带来不确定性。为科学减少实验次数,本文引入正交试验法,选择了影响地表温度模拟较大的5个主要过程,包括动态植被、气孔阻抗过程、控制气孔阻抗的土壤湿度参数过程和表面热交换系数过程以及辐射传输过程等,设计了9次正交试验,利用CLDAS-V2.0(中国气象局陆面数据同化系统)驱动Noah-MP陆面模式对我国东南地区地表温度进行模拟,对参数化方案寻优,以确定其适用的参数化方案组合。结果表明,参数化方案的选择对林地区域的模拟,以及在7月和8月的模拟影响较大。物理过程的敏感性和最优参数化方案同时受到下垫面和季节的影响,多数情况中,动态植被与冠层气孔阻抗过程对模拟影响显著,是较敏感的物理过程。通过对不同下垫面不同季节的最优参数化方案组合的时空尺度分析,经模拟验证,东南地区地表温度模拟的较优方案组合为开启动态植被,Ball-Berry的冠层气孔阻抗方案,Noah的土壤湿度参数方案,M-O的地表热交换系数方案和GAPFVEG的辐射传输方案。
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Sciences (Grant No.XDA05040201)the National Science and Technology Support Program of China (Grant No.2013CB430104)the Meteorology Project GYHY200906025
文摘A set of improved and efficient radiation parameterization schemes for surface radiation balance components under clear- sky conditions was developed by using general surface measurements and MODIS data. The set of schemes was then adapted for regions similar to the present study sites under different grazing intensities and varying degrees of drought in the semiarid grasslands of Inner Mongolia. Specifically, we mainly improved two schemes for estimating downward shortwave and longwave radiation at the surface, which could be applied to regions with certain degrees of drought. The validation datasets were from ground-based observations at various grazing sites during the growing season （May to September） of different drought years, 2005 and 2006. Through comparisons of parameterized versus measured radiation values, the increased or modified factors in the original schemes demonstrated improved estimation accuracy, and the rationalities of input parameters and variables were analyzed. The regional instantaneous net radiation estimations had root-mean-square errors of less than 30 W m-2 compared with ground measurements at the sites during the study period. The statistical results showed the improved schemes are suitable for estimating surface net radiation in regional semiarid areas during the growing season. Analyses of the sensitivity of the schemes to corresponding variables were conducted to ascertain the major error sources of the schemes and potential variables for improving the performance of the schemes in agreement with observations.
文摘In the present study, the imitation of heavy rainfall event which occurred over Jharkhand during 18 August 2016 was taken as a case study. Weather Research and Forecasting (WRF) model has been utilized for this study. National Centers for Environmental Prediction (NCEP) analysis data is compared with GSMaP data with different combination of physical parameterization scheme like microphysics (MP) and cumulus parameterization (CP). In the present study, three MP schemes: Kessler scheme, Lin et al. scheme and WRF Single-moment 6-class scheme with combination of three CP schemes: Betts-Miller-Janjic scheme, Multi-scale Kain-Fritsch scheme and New simplified Arakawa-Schubert scheme have been used. The model predicted humidity, temperature and precipitation were compared with the GSMaP product. The model nicely depicted the cloud pattern and recognized the rain event spatially. The obtained result shows that the model overestimates the precipitation for all the schemes.
