川藏铁路穿越了地形复杂、气候多变的川西高原和青藏高原地区,这些地区的地形和气候对地面风场具有重要影响。本文旨在分析川藏铁路沿线地面风场的变化特征,为铁路的线路设计和工程建设提供参考以及科学依据。本文利用欧洲中期天气预报...川藏铁路穿越了地形复杂、气候多变的川西高原和青藏高原地区,这些地区的地形和气候对地面风场具有重要影响。本文旨在分析川藏铁路沿线地面风场的变化特征,为铁路的线路设计和工程建设提供参考以及科学依据。本文利用欧洲中期天气预报中心(ECMWF)提供的再分析数据集中1950年1月至2023年12月的地面10米风速再分析资料,对川藏铁路沿线地面风场时空分布特征以及变化规律进行分析。结果表明:1) 川藏铁路地区平均风速较大的区域主要集中在铁路的中部和西部,具体位于理塘、昌都以及拉林段铁路两侧;而在雅安周边、昌都部分地区以及林芝东侧和南侧,风速较小。2) 川藏铁路地区平均风速随海拔升高变化情况如下:在0~1500 m范围内,平均风速随海拔升高而降低;在1500~5500 m范围内,风速随海拔升高而升高;在高于5500 m范围内,风速随海拔升高而降低。且海拔在4500~6000 m内时,平均风速较大。3) 1950~2023年平均风速总体呈现上升趋势,其中夏季增速最快,每十年上升0.012 m/s,夏季当中6月份增速最快,每十年增加0.02 m/s。4) 川藏铁路沿线风速较大的月份集中在5月~7月,平均风速超过0.90 m/s,其中6月的平均风速最高,达到约0.95 m/s。风速较小的月份为3月~5月,平均风速低于0.75 m/s,4月的平均风速最低,低于0.70 m/s。从4月份至6月份,风速急速增加,应重点关注。5) 12月至次年4月,即冬季和春季,极大风速波动较大,而在夏季和秋季两季的风速相对较小且平稳。整体来看,各个月的极大风速没有明显变化,但在许多年份存在波动。The Sichuan-Tibet Railway traverses the complex terrain and variable climate of the Sichuan-Western Plateau and Qinghai-Tibet Plateau regions. These regions’ terrain and climate significantly impact the surface wind field. This paper aims to analyze the changing characteristics of the surface wind field along the Sichuan-Tibet Railway, providing reference and scientific basis for railway route design and engineering construction. Utilizing reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) from January 1950 to December 2023, this paper analyzes the temporal and spatial distribution characteristics and change patterns of the surface wind field along the Sichuan-Tibet Railway. The results show: 1) The areas with higher average wind speeds are mainly concentrated in the central and western parts of the railway, specifically on both sides of the Litang, Chamdo, and Lalin sections, while the areas around Ya’an, parts of Chamdo, and the eastern and southern sides of Nyingchi have lower wind speeds. 2) The change in average wind speed with altitude along the Sichuan-Tibet Railway is as follows: in the 0~1500 m range, average wind speed decreases with altitude;in the 1500~5500 m range, wind speed increases with altitude;above 5500 m, wind speed decreases with altitude, with higher average wind speeds occurring in the 4500~6000 m range. 3) From 1950 to 2023, the overall average wind speed shows an upward trend, with the fastest increase in summer, rising by 0.012 m/s per decade, and June showing the fastest increase within summer, rising by 0.02 m/s per decade. 4) The months with higher wind speeds along the Sichuan-Tibet Railway are concentrated from May to July, with average wind speeds exceeding 0.90 m/s, and June having the highest average wind speed at about 0.95 m/s. The months with lower wind speeds are from March to May, with average wind speeds below 0.75 m/s, and April having the lowest average wind speed at about 0.70 m/s. Wind speeds increase rapidly from April to June, warranting close attention. 5) From December to April of the following year, during winter and spring, extreme wind speed fluctuations are larger, while wind speeds are relatively smaller and more stable in summer and autumn. Overall, the extreme wind speeds do not show significant changes throughout the months but exhibit fluctuations in many years.展开更多
随着预报准确度要求以及同化分析循环周期的缩短,具有高时空分辨率的地面观测资料在同化系统中也越来越受到重视,而且一个好的资料同化系统应该能够给出模式近地面动力、热力和湿度状况的合理分析。利用GRAPES区域同化预报系统(GRAPES—...随着预报准确度要求以及同化分析循环周期的缩短,具有高时空分辨率的地面观测资料在同化系统中也越来越受到重视,而且一个好的资料同化系统应该能够给出模式近地面动力、热力和湿度状况的合理分析。利用GRAPES区域同化预报系统(GRAPES——Global and Regional Assimilation and Prediction Enhanced System),在近地层Monin_Obukhov相似理论的基础上,考虑了边界层的动力和湿热力约束,建立新的地面风场观测算子。将此新方案与目前GRAPES系统使用的三次样条插值的地面同化方案进行高度场预报试验、统计试验以及降水预报的TS评分比较,结果表明,加入新方案地面风场资料同化后,预报效果和对降水的预报能力都比旧方案有所提高。展开更多
为了提高郑州市地面风场的精细化预报水平,基于欧洲中期天气预报中心(European centre for medium-range weather forecasts,ECMWF)、日本气象厅(Japan meteorological agency,JMA)、中国气象局(China meterological administration,CM...为了提高郑州市地面风场的精细化预报水平,基于欧洲中期天气预报中心(European centre for medium-range weather forecasts,ECMWF)、日本气象厅(Japan meteorological agency,JMA)、中国气象局(China meterological administration,CMA)3个中心的2012年6月1日-9月30日地面风场3~60h预报资料和郑州加密自动站观测资料,先对郑州市11个站的地面风场进行多模式集成预报试验,再对多模式的集成结果进行统计降尺度研究。针对地面风场预报的难点,分别对地面风场的U、V分量(试验方法1)及全风速和风向(试验方法2)进行试验。最后采用均方根误差对2种试验方法的预报结果进行检验评估。结果表明:在多模式集成的2种试验方法中,对全风速和风向的的试验方法要优于对风场的U、V分量的试验方法,且此试验方法的超级集合集成方案(superensemble forecasts,SUP)预报误差较小,而成为最优的方案。在对多模式集成结果的2种统计降尺度试验中,对全风速和风向的多模式集成结果的方法能够进一步降低预报误差,与对风场的U、V分量的方法相比,是1种较好的方法。与多模式集成的精细化预报相比,统计降尺度预报能够进一步减小预报误差,提高地面风场的预报准确率。展开更多
文摘川藏铁路穿越了地形复杂、气候多变的川西高原和青藏高原地区,这些地区的地形和气候对地面风场具有重要影响。本文旨在分析川藏铁路沿线地面风场的变化特征,为铁路的线路设计和工程建设提供参考以及科学依据。本文利用欧洲中期天气预报中心(ECMWF)提供的再分析数据集中1950年1月至2023年12月的地面10米风速再分析资料,对川藏铁路沿线地面风场时空分布特征以及变化规律进行分析。结果表明:1) 川藏铁路地区平均风速较大的区域主要集中在铁路的中部和西部,具体位于理塘、昌都以及拉林段铁路两侧;而在雅安周边、昌都部分地区以及林芝东侧和南侧,风速较小。2) 川藏铁路地区平均风速随海拔升高变化情况如下:在0~1500 m范围内,平均风速随海拔升高而降低;在1500~5500 m范围内,风速随海拔升高而升高;在高于5500 m范围内,风速随海拔升高而降低。且海拔在4500~6000 m内时,平均风速较大。3) 1950~2023年平均风速总体呈现上升趋势,其中夏季增速最快,每十年上升0.012 m/s,夏季当中6月份增速最快,每十年增加0.02 m/s。4) 川藏铁路沿线风速较大的月份集中在5月~7月,平均风速超过0.90 m/s,其中6月的平均风速最高,达到约0.95 m/s。风速较小的月份为3月~5月,平均风速低于0.75 m/s,4月的平均风速最低,低于0.70 m/s。从4月份至6月份,风速急速增加,应重点关注。5) 12月至次年4月,即冬季和春季,极大风速波动较大,而在夏季和秋季两季的风速相对较小且平稳。整体来看,各个月的极大风速没有明显变化,但在许多年份存在波动。The Sichuan-Tibet Railway traverses the complex terrain and variable climate of the Sichuan-Western Plateau and Qinghai-Tibet Plateau regions. These regions’ terrain and climate significantly impact the surface wind field. This paper aims to analyze the changing characteristics of the surface wind field along the Sichuan-Tibet Railway, providing reference and scientific basis for railway route design and engineering construction. Utilizing reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) from January 1950 to December 2023, this paper analyzes the temporal and spatial distribution characteristics and change patterns of the surface wind field along the Sichuan-Tibet Railway. The results show: 1) The areas with higher average wind speeds are mainly concentrated in the central and western parts of the railway, specifically on both sides of the Litang, Chamdo, and Lalin sections, while the areas around Ya’an, parts of Chamdo, and the eastern and southern sides of Nyingchi have lower wind speeds. 2) The change in average wind speed with altitude along the Sichuan-Tibet Railway is as follows: in the 0~1500 m range, average wind speed decreases with altitude;in the 1500~5500 m range, wind speed increases with altitude;above 5500 m, wind speed decreases with altitude, with higher average wind speeds occurring in the 4500~6000 m range. 3) From 1950 to 2023, the overall average wind speed shows an upward trend, with the fastest increase in summer, rising by 0.012 m/s per decade, and June showing the fastest increase within summer, rising by 0.02 m/s per decade. 4) The months with higher wind speeds along the Sichuan-Tibet Railway are concentrated from May to July, with average wind speeds exceeding 0.90 m/s, and June having the highest average wind speed at about 0.95 m/s. The months with lower wind speeds are from March to May, with average wind speeds below 0.75 m/s, and April having the lowest average wind speed at about 0.70 m/s. Wind speeds increase rapidly from April to June, warranting close attention. 5) From December to April of the following year, during winter and spring, extreme wind speed fluctuations are larger, while wind speeds are relatively smaller and more stable in summer and autumn. Overall, the extreme wind speeds do not show significant changes throughout the months but exhibit fluctuations in many years.
文摘随着预报准确度要求以及同化分析循环周期的缩短,具有高时空分辨率的地面观测资料在同化系统中也越来越受到重视,而且一个好的资料同化系统应该能够给出模式近地面动力、热力和湿度状况的合理分析。利用GRAPES区域同化预报系统(GRAPES——Global and Regional Assimilation and Prediction Enhanced System),在近地层Monin_Obukhov相似理论的基础上,考虑了边界层的动力和湿热力约束,建立新的地面风场观测算子。将此新方案与目前GRAPES系统使用的三次样条插值的地面同化方案进行高度场预报试验、统计试验以及降水预报的TS评分比较,结果表明,加入新方案地面风场资料同化后,预报效果和对降水的预报能力都比旧方案有所提高。
