风场预报是智能网格预报的重要支撑,提高风场预报准确率,能够为风能预报提供核心保障。在综合评估2023年汛期CMA-MESO 3 km(China Meteorological Administration Mesoscale Model at 3 km resolution)模式在山西逐小时10 m风预报能力...风场预报是智能网格预报的重要支撑,提高风场预报准确率,能够为风能预报提供核心保障。在综合评估2023年汛期CMA-MESO 3 km(China Meteorological Administration Mesoscale Model at 3 km resolution)模式在山西逐小时10 m风预报能力的基础上,基于自适应Kalman滤波方法,开展针对纬向风(U)、经向风(V)的客观订正,以期建立适应山西复杂地形特征的客观预报方案,促进国产模式本地化业务应用。结果表明:①全风速预报偏大,预报误差呈“单峰型”日变化,峰值出现在18:00-20:00,正偏差主要位于忻定和太原盆地以及山西南部。②U、V预报误差与预报值呈显著正相关,需考虑不同强度预报风速误差随时效变化的特征,避免订正不足或过订正。③Kalman滤波方案(KM)订正幅度小且不稳定,订正后均方根误差R MSE削减不足6%,准确率提升不足2%。④基于动态分级的改进方案(CBKM)突破KM订正瓶颈,更准确地估计系统误差并有效订正,更好再现不同地区风速日变化,平均误差M E趋近0,R MSE削减32.8%,风向、风速预报准确率分别提升8.29%、7.92%,峰值时刻订正率达83.49%。展开更多
0 INTRODUTION The Kuqa Depression,situated along the northern margin of the Tarim Basin,holds substantial geological significance due to its intricate sedimentary burial history,tectonic history,and the evolution of h...0 INTRODUTION The Kuqa Depression,situated along the northern margin of the Tarim Basin,holds substantial geological significance due to its intricate sedimentary burial history,tectonic history,and the evolution of hydrocarbon source rocks(Jiang et al.,2024;Zhang et al.,2023;Huang et al.,2019;Yang et al.,2017;Jia et al.,2003;Hendrix,2000).展开更多
Vector winds play a crucial role in weather and climate,as well as the effective utilization of wind energy resources.However,limited research has been conducted on treating the wind field as a vector field in the eva...Vector winds play a crucial role in weather and climate,as well as the effective utilization of wind energy resources.However,limited research has been conducted on treating the wind field as a vector field in the evaluation of numerical weather prediction models.In this study,the authors treat vector winds as a whole by employing a vector field evaluation method,and evaluate the mesoscale model of the China Meteorological Administration(CMA-MESO)and ECMWF forecast,with reference to ERA5 reanalysis,in terms of multiple aspects of vector winds over eastern China in 2022.The results show that the ECMWF forecast is superior to CMA-MESO in predicting the spatial distribution and intensity of 10-m vector winds.Both models overestimate the wind speed in East China,and CMA-MESO overestimates the wind speed to a greater extent.The forecasting skill of the vector wind field in both models decreases with increasing lead time.The forecasting skill of CMA-MESO fluctuates more and decreases faster than that of the ECMWF forecast.There is a significant negative correlation between the model vector wind forecasting skill and terrain height.This study provides a scientific evaluation of the local application of vector wind forecasts of the CMA-MESO model and ECMWF forecast.展开更多
重构GRAPES(Global/Regional Assimilation and Prediction System)全球、区域一体化变分同化系统中的极小化控制变量,提升中、小尺度同化分析能力,为中国气象局业务区域数值预报系统CMA-MESO提供千米尺度适用的同化方案。新方案用纬向...重构GRAPES(Global/Regional Assimilation and Prediction System)全球、区域一体化变分同化系统中的极小化控制变量,提升中、小尺度同化分析能力,为中国气象局业务区域数值预报系统CMA-MESO提供千米尺度适用的同化方案。新方案用纬向风速(u)和经向风速(v)替代原有流函数和势函数作为新的风场控制变量,采用温度和地面气压(T,ps)替代原有非平衡无量纲气压作为新的质量场控制变量,同时不再考虑准地转平衡约束,而是采用连续方程弱约束保证分析平衡。背景误差参数统计和数值试验结果表明,采用重构后的极小化控制变量,观测信息传播更加局地,分析结构更加合理,避免了原方案在中、小尺度应用时存在的虚假相关问题。连续方程弱约束的引入,限制了同化分析中辐合、辐散的不合理增长,帮助新方案在分析更加局地的同时保证分析平衡。为期1个月的连续同化循环和预报试验结果表明,新方案可以减小风场和质量场分析误差,CMAMESO系统地面降水和10 m风场的预报评分显著提升。展开更多
利用2020年夏季(6~8月)CMA-MESO模式逐日08:00(北京时,下同)起报的12~36 h逐时降水预报数据和地面—卫星—雷达三源融合逐时降水产品,着眼于小时尺度降水特征,细致评估了CMA-MESO对四川盆地及周边地区的降水预报性能。结果表明,CMA-MES...利用2020年夏季(6~8月)CMA-MESO模式逐日08:00(北京时,下同)起报的12~36 h逐时降水预报数据和地面—卫星—雷达三源融合逐时降水产品,着眼于小时尺度降水特征,细致评估了CMA-MESO对四川盆地及周边地区的降水预报性能。结果表明,CMA-MESO较好把握了夏季降水的空间分布特征,即小时平均降水量和降水频率的大值区位于四川盆地西部、北部和东部的高海拔山区,而降水强度大值区主要位于山脉迎风坡一侧,但CMA-MESO预报的降水量和频率大值区位置较观测偏南。CMA-MESO合理描述了研究区域内降水量和频率峰值时间位相自西向东逐步滞后的特征,能够把握区域平均的降水量和频率清晨主峰、傍晚次峰的双峰形态以及降水强度的单峰特征,但预报的降水日变化位相超前于观测。CMA-MESO预报的逐时降水量均大于观测,明显的降水量预报正偏差发生于夜间(21:00至次日03:00)和午后至傍晚(14:00~20:00),分别由一般性降水(0.1~10 mm h-1)预报偏差和强降水(≥10 mm h-1)预报偏差主导,其偏差大值区分别位于青藏高原东南缘至四川盆地西部和四川盆地以东、以南地区,模式对热力和动力场的预报偏差结合地形的影响是降水量预报偏差的成因。展开更多
All nuclei in mesophyll cells of Artemisia marschalliana are located in vacuoles and occupy up to 90% of their volume. The ultrastructural organization of chromatin in nuclei shows different degrees of its decondensat...All nuclei in mesophyll cells of Artemisia marschalliana are located in vacuoles and occupy up to 90% of their volume. The ultrastructural organization of chromatin in nuclei shows different degrees of its decondensation, up to complete separation of DNA from histones. It is possible that the separation of DNA from histones enables Artemisia to grow in soils with high salinity.展开更多
文摘风场预报是智能网格预报的重要支撑,提高风场预报准确率,能够为风能预报提供核心保障。在综合评估2023年汛期CMA-MESO 3 km(China Meteorological Administration Mesoscale Model at 3 km resolution)模式在山西逐小时10 m风预报能力的基础上,基于自适应Kalman滤波方法,开展针对纬向风(U)、经向风(V)的客观订正,以期建立适应山西复杂地形特征的客观预报方案,促进国产模式本地化业务应用。结果表明:①全风速预报偏大,预报误差呈“单峰型”日变化,峰值出现在18:00-20:00,正偏差主要位于忻定和太原盆地以及山西南部。②U、V预报误差与预报值呈显著正相关,需考虑不同强度预报风速误差随时效变化的特征,避免订正不足或过订正。③Kalman滤波方案(KM)订正幅度小且不稳定,订正后均方根误差R MSE削减不足6%,准确率提升不足2%。④基于动态分级的改进方案(CBKM)突破KM订正瓶颈,更准确地估计系统误差并有效订正,更好再现不同地区风速日变化,平均误差M E趋近0,R MSE削减32.8%,风向、风速预报准确率分别提升8.29%、7.92%,峰值时刻订正率达83.49%。
基金supported by the National Key Research and Development Project(No.2019YFA0708601)the National Natural Science Foundation of China(No.4231101056)the Chinese Academy of Geological Sciences Basic Research Fund(No.JKYZD202402)。
文摘0 INTRODUTION The Kuqa Depression,situated along the northern margin of the Tarim Basin,holds substantial geological significance due to its intricate sedimentary burial history,tectonic history,and the evolution of hydrocarbon source rocks(Jiang et al.,2024;Zhang et al.,2023;Huang et al.,2019;Yang et al.,2017;Jia et al.,2003;Hendrix,2000).
基金primarily supported by the National Key R&D Program of China[grant number 2021YFC3000904]the Jiangsu Provincial Key Technology R&D Program[grant number BE2022851]National Natural Science Foundation of China[grant number 42405035]。
文摘Vector winds play a crucial role in weather and climate,as well as the effective utilization of wind energy resources.However,limited research has been conducted on treating the wind field as a vector field in the evaluation of numerical weather prediction models.In this study,the authors treat vector winds as a whole by employing a vector field evaluation method,and evaluate the mesoscale model of the China Meteorological Administration(CMA-MESO)and ECMWF forecast,with reference to ERA5 reanalysis,in terms of multiple aspects of vector winds over eastern China in 2022.The results show that the ECMWF forecast is superior to CMA-MESO in predicting the spatial distribution and intensity of 10-m vector winds.Both models overestimate the wind speed in East China,and CMA-MESO overestimates the wind speed to a greater extent.The forecasting skill of the vector wind field in both models decreases with increasing lead time.The forecasting skill of CMA-MESO fluctuates more and decreases faster than that of the ECMWF forecast.There is a significant negative correlation between the model vector wind forecasting skill and terrain height.This study provides a scientific evaluation of the local application of vector wind forecasts of the CMA-MESO model and ECMWF forecast.
文摘利用2020年夏季(6~8月)CMA-MESO模式逐日08:00(北京时,下同)起报的12~36 h逐时降水预报数据和地面—卫星—雷达三源融合逐时降水产品,着眼于小时尺度降水特征,细致评估了CMA-MESO对四川盆地及周边地区的降水预报性能。结果表明,CMA-MESO较好把握了夏季降水的空间分布特征,即小时平均降水量和降水频率的大值区位于四川盆地西部、北部和东部的高海拔山区,而降水强度大值区主要位于山脉迎风坡一侧,但CMA-MESO预报的降水量和频率大值区位置较观测偏南。CMA-MESO合理描述了研究区域内降水量和频率峰值时间位相自西向东逐步滞后的特征,能够把握区域平均的降水量和频率清晨主峰、傍晚次峰的双峰形态以及降水强度的单峰特征,但预报的降水日变化位相超前于观测。CMA-MESO预报的逐时降水量均大于观测,明显的降水量预报正偏差发生于夜间(21:00至次日03:00)和午后至傍晚(14:00~20:00),分别由一般性降水(0.1~10 mm h-1)预报偏差和强降水(≥10 mm h-1)预报偏差主导,其偏差大值区分别位于青藏高原东南缘至四川盆地西部和四川盆地以东、以南地区,模式对热力和动力场的预报偏差结合地形的影响是降水量预报偏差的成因。
文摘All nuclei in mesophyll cells of Artemisia marschalliana are located in vacuoles and occupy up to 90% of their volume. The ultrastructural organization of chromatin in nuclei shows different degrees of its decondensation, up to complete separation of DNA from histones. It is possible that the separation of DNA from histones enables Artemisia to grow in soils with high salinity.
