为给通过地形复杂,缺少气象资料的西南艰险山区的铁路研究风吹雪易发性提供方法,以位于该区域的四川省康定市为例,采用中尺度数值天气预报模式(The Weather Research and Forecasting Mode,WRF)对该区域气象要素的时空分布进行模拟.基于...为给通过地形复杂,缺少气象资料的西南艰险山区的铁路研究风吹雪易发性提供方法,以位于该区域的四川省康定市为例,采用中尺度数值天气预报模式(The Weather Research and Forecasting Mode,WRF)对该区域气象要素的时空分布进行模拟.基于WRF模式中各种参数的特点,设计4种参数方案进行计算,采用双层网格嵌套达到降尺度模拟,为了高精度解析大气边界层过程,在竖直方向、近地面1.5km高度内加密为15层,提取康定站计算结果与观测结果进行比较.结果表明,WRF模式的计算结果符合康定市气候特征,气象要素的相关系数均高于0.5;风吹雪发生概率从高到低的区域依次为康定市东部和南部边缘的贡嘎山区,内部的大雪山段,以及位于101.7°E~102.0°E位置处的铁路线路,概率分别为19%、14%和12%,其他区域的概率低于4%.展开更多
WRF(weather research and forecasting)模式中参数化方案的选择与近地面风场的仿真模拟结果关系密切。为解决新疆北部不同地形地区风场模拟准确性的问题,采用WRF中尺度气象模式,探究4类参数化方案(边界层、微物理、陆面过程、近地面层...WRF(weather research and forecasting)模式中参数化方案的选择与近地面风场的仿真模拟结果关系密切。为解决新疆北部不同地形地区风场模拟准确性的问题,采用WRF中尺度气象模式,探究4类参数化方案(边界层、微物理、陆面过程、近地面层)以及次网格地形方案对新疆北部不同地形地区风场模拟结果的影响。结果表明:每组试验均能模拟出风速的变化趋势;陆面过程RUC(rapid update cycle)方案和微物理Lin(Purdue Lin)方案对平原地区模拟结果较好,陆面过程Noah方案和微物理WSM6(WRF single moment 6 class)方案对山区地形模拟结果较好,且对于平原和山谷地形,次网格地形方案对模拟地区均能起到较好的修正作用。展开更多
利用中尺度数值模式WRF研究积云对流参数化方案和模式分辨率对青藏高原玉树地区夏季的一次层状云降水的影响。通过模拟结果分析表明:采用WRF模拟高原降水结果普遍偏大,三种积云参数化方案中GD方案模拟结果比较理想,不同方案对降水模拟...利用中尺度数值模式WRF研究积云对流参数化方案和模式分辨率对青藏高原玉树地区夏季的一次层状云降水的影响。通过模拟结果分析表明:采用WRF模拟高原降水结果普遍偏大,三种积云参数化方案中GD方案模拟结果比较理想,不同方案对降水模拟比较敏感,相同方案下不同网格分辨率模拟降水分布基本相同。所用设计方案模拟的结果基本反映此次降水的实况和云图特征。在模拟实况温度和露点温度时,5 km分辨率的BMJ方案模拟效果相对于同分辨率其他两种方案明显更好。结合物理量场以及卫星云图分析本次层状云降水是由环流形势稳定、水汽充足、高原风切变共同影响。利用高分辨率的日本葵花8号卫星分析8 um和11 um红外通道分析云辐射亮温和水汽情况,降水时段玉树地区上空存在片状层云,并且水汽条件充足,环流背景场上玉树地区位于槽前,积云对流旺盛。此外,夜间露点温度差减小有利于形成较厚的云系导致高原夜间降水频繁。云图上发现,上升流场维持层状云团的发展和移动,高原夜间低层出现小而多的水汽云团,较小的云团混合生成较大的降水云系。The mesoscale numerical model WRF was used to study the effects of cumulus convection scheme and model resolution on the precipitation of stratiform clouds in Yushu over the Qinghai-Xizang Plateau in summer. Analysis of simulation results shows that WRF tends to overestimate precipitation over the plateau. Among the three cumulus parameterization schemes, the GD scheme yields relatively ideal simulation results, and different schemes exhibit sensitivity in precipitation simulation. Under the same scheme, different grid resolutions yield similar precipitation distributions. The simulated results using the designated schemes generally reflect the actual conditions and cloud features of this precipitation event. When simulating observed temperature and dew point temperature, the BMJ scheme at 5km resolution performs significantly better compared to the other two schemes at the same resolution. Combining physical field analysis and satellite cloud images, it is concluded that the stratiform cloud precipitation during this event is influenced by stable circulation patterns, abundant moisture, and wind shear over the plateau. High-resolution data from the Japanese Himawari-8 satellite’s 8um and 11um infrared channels reveal cloud radiative temperatures and moisture conditions. During the precipitation period, patchy stratiform clouds are present over the Yushu area with sufficient moisture, and the circulation background places Yushu ahead of a trough, promoting vigorous cumulus convection. Additionally, the reduced temperature-dew point temperature difference at night favors the formation of thick cloud systems, leading to frequent nighttime precipitation over the plateau. Analysis of cloud images indicates that the updraft field sustains the development and movement of stratiform cloud clusters, while small and numerous water vapor cloud clusters appear in the lower atmosphere at night, mixing to form larger precipitation cloud systems.展开更多
青藏高原是全球气候变化的敏感地区,该地区的降水变化对全球及区域气候系统影响深远。运用WRF模型对高原的降水状况进行模拟研究,可以揭示降水形成机制和变化规律。但目前缺少利用WRF模式的不同组合改进青藏高原降水高估。为了改善降水...青藏高原是全球气候变化的敏感地区,该地区的降水变化对全球及区域气候系统影响深远。运用WRF模型对高原的降水状况进行模拟研究,可以揭示降水形成机制和变化规律。但目前缺少利用WRF模式的不同组合改进青藏高原降水高估。为了改善降水高估的问题,本研究利用区域气候站逐时降水实况资料和NCEP 0.25度的3小时全球再分析格点资料,采用WRF4.0,对2019年7月28日发生在玉树地区的降水事件进行了对比分析,涉及多种积云对流方案与分辨率的组合。通过比较各种方案对降水量及降水分布的模拟效果,从而得到了相关的研究结论:不同积云对流参数化方案对降水落区和强度模拟的影响显著,GD方案在降水区域模拟上效果最好,与实际降水空间分布相似性最大,而BMJ方案效果最差。总体来看,各方案均普遍高估降水量,提高模式水平分辨率可以提高降水模拟精度,但对雨带走向和范围影响不大。模式能很好地模拟降水演变过程及其后的温度、露点、CAPE和风场等物理量,除NKF-5 km方案外,其余方案的CAPE模拟结果基本与实际一致。NKF方案倾向于产生更高的CAPE,这可能是其降水模拟效果较差的原因。The Tibetan Plateau is a sensitive region for global climate change, and variations in precipitation in this area have far-reaching impacts on both global and regional climate systems. Conducting simulation studies on precipitation conditions in the plateau using the WRF model can reveal mechanisms and patterns of precipitation formation. However, there is currently a lack of research utilizing different combinations of the WRF model to improve the overestimation of precipitation on the Tibetan Plateau. To address this overestimation issue, this study utilized hourly precipitation data from regional climate stations and 3-hourly global reanalysis grid data from NCEP with a resolution of 0.25 degrees. The WRF model was employed to conduct comparative analyses of a precipitation event that occurred in the Yushu region on July 28, 2019, involving various combinations of cumulus convection schemes and resolutions. By comparing the simulation effects of different schemes on precipitation amount and distribution, the study drew relevant conclusions: different cumulus convection schemes significantly affect the simulation of precipitation regions and intensity. The GD scheme performed the best in simulating precipitation areas, exhibiting the highest similarity to the actual spatial distribution of precipitation, while the BMJ scheme performed the worst. Overall, all schemes tended to overestimate precipitation amounts. Increasing the model’s horizontal resolution can enhance precipitation simulation accuracy but has a minimal impact on the direction and extent of rain belts. The model effectively simulates the evolution of precipitation and subsequent physical quantities such as temperature, dew point, CAPE, and wind fields. With the exception of the NKF-5 km scheme, the CAPE simulation results of the other schemes were generally consistent with actual observations. The NKF scheme tends to produce higher CAPE, which may be a contributing factor to its poorer precipitation simulation performance.展开更多
风场是影响林火蔓延行为最关键的因素之一。许多林火发生在地形复杂多变的山区,会产生复杂的局部风场。为探究动态风场对林火蔓延预测的影响,以“3·30”西昌泸山森林火灾为研究对象,利用WRF(weather research and forecasting)模...风场是影响林火蔓延行为最关键的因素之一。许多林火发生在地形复杂多变的山区,会产生复杂的局部风场。为探究动态风场对林火蔓延预测的影响,以“3·30”西昌泸山森林火灾为研究对象,利用WRF(weather research and forecasting)模式模拟动态风场,并与林火蔓延模型耦合。分别将模拟风场和均一风场分别输入林火蔓延模型,基于林火蔓延过程中实际火场范围数据,分析动态风场对林火蔓延模型预测结果的影响。结果表明,耦合WRF模式和林火蔓延模型考虑了分辨率更高、且更为准确的局部风场,能够实现对森林火灾蔓延的动态模拟。预测得到的火场范围和均一风场相比,与实际范围具有更高的相似度。展开更多
基于中尺度气象数值模式WRF(Weather Research and Forecasting),分别对我国广东、浙江、山东这3个近海典型风能资源储备区域进行了45组物理参数化方案组合连续1 M的敏感性试验,对试验中多要素的模拟结果进行综合评估,分别确定了适用于...基于中尺度气象数值模式WRF(Weather Research and Forecasting),分别对我国广东、浙江、山东这3个近海典型风能资源储备区域进行了45组物理参数化方案组合连续1 M的敏感性试验,对试验中多要素的模拟结果进行综合评估,分别确定了适用于3个风能资源储备区各自排名前3的物理参数化方案组合,并对其模拟性能较优的原因进行分析。为了测试3个风能资源储备区筛选得到的物理参数化方案组合的适用性,利用不同于敏感性试验时段的模拟结果,结合海上测风塔和海洋气象站的实测数据开展进一步评估。结果表明,优选得到的物理参数化方案组合具有较好的适用性,其对近海的风速模拟性能较优,具有实际业务应用价值。展开更多
本文利用WRF(Weather Research and Forecasting)模式耦合Noah陆面过程模式,对比研究了使用不同精度陆面资料:WRF默认陆面资料、中国1 km分辨率数字高程模型数据集、2006年MODIS(MODerate-resolution Imaging Spectroradiometer)土地利...本文利用WRF(Weather Research and Forecasting)模式耦合Noah陆面过程模式,对比研究了使用不同精度陆面资料:WRF默认陆面资料、中国1 km分辨率数字高程模型数据集、2006年MODIS(MODerate-resolution Imaging Spectroradiometer)土地利用和植被覆盖度资料,WRF模式对兰州地区冬季气象场模拟结果的差异。结果表明,近地面气温对陆面资料的精度非常敏感,而风场对陆面资料的精度不敏感,WRF模式对气温的模拟效果好于对风场模拟。采用高精度且时效性好的陆面资料后,WRF模拟的近地面气温准确率提高了15.8%,模拟的夜间气温改进幅度较白天大。陆面资料可影响整个边界层温度场分布,准确的陆面资料对提高WRF模式模拟近地面乃至整个边界层气象场至关重要。尽管风速模拟误差较大,但总体上WRF模式能较准确地模拟出研究区的风场演变特征。使用新的陆面资料后WRF模拟的风速误差略有减小,风向误差略有增加。干旱半干旱区冬季数值模拟需要注意土壤湿度初值和模式初始积分时刻对模拟结果的影响。展开更多
文摘为给通过地形复杂,缺少气象资料的西南艰险山区的铁路研究风吹雪易发性提供方法,以位于该区域的四川省康定市为例,采用中尺度数值天气预报模式(The Weather Research and Forecasting Mode,WRF)对该区域气象要素的时空分布进行模拟.基于WRF模式中各种参数的特点,设计4种参数方案进行计算,采用双层网格嵌套达到降尺度模拟,为了高精度解析大气边界层过程,在竖直方向、近地面1.5km高度内加密为15层,提取康定站计算结果与观测结果进行比较.结果表明,WRF模式的计算结果符合康定市气候特征,气象要素的相关系数均高于0.5;风吹雪发生概率从高到低的区域依次为康定市东部和南部边缘的贡嘎山区,内部的大雪山段,以及位于101.7°E~102.0°E位置处的铁路线路,概率分别为19%、14%和12%,其他区域的概率低于4%.
文摘WRF(weather research and forecasting)模式中参数化方案的选择与近地面风场的仿真模拟结果关系密切。为解决新疆北部不同地形地区风场模拟准确性的问题,采用WRF中尺度气象模式,探究4类参数化方案(边界层、微物理、陆面过程、近地面层)以及次网格地形方案对新疆北部不同地形地区风场模拟结果的影响。结果表明:每组试验均能模拟出风速的变化趋势;陆面过程RUC(rapid update cycle)方案和微物理Lin(Purdue Lin)方案对平原地区模拟结果较好,陆面过程Noah方案和微物理WSM6(WRF single moment 6 class)方案对山区地形模拟结果较好,且对于平原和山谷地形,次网格地形方案对模拟地区均能起到较好的修正作用。
文摘利用中尺度数值模式WRF研究积云对流参数化方案和模式分辨率对青藏高原玉树地区夏季的一次层状云降水的影响。通过模拟结果分析表明:采用WRF模拟高原降水结果普遍偏大,三种积云参数化方案中GD方案模拟结果比较理想,不同方案对降水模拟比较敏感,相同方案下不同网格分辨率模拟降水分布基本相同。所用设计方案模拟的结果基本反映此次降水的实况和云图特征。在模拟实况温度和露点温度时,5 km分辨率的BMJ方案模拟效果相对于同分辨率其他两种方案明显更好。结合物理量场以及卫星云图分析本次层状云降水是由环流形势稳定、水汽充足、高原风切变共同影响。利用高分辨率的日本葵花8号卫星分析8 um和11 um红外通道分析云辐射亮温和水汽情况,降水时段玉树地区上空存在片状层云,并且水汽条件充足,环流背景场上玉树地区位于槽前,积云对流旺盛。此外,夜间露点温度差减小有利于形成较厚的云系导致高原夜间降水频繁。云图上发现,上升流场维持层状云团的发展和移动,高原夜间低层出现小而多的水汽云团,较小的云团混合生成较大的降水云系。The mesoscale numerical model WRF was used to study the effects of cumulus convection scheme and model resolution on the precipitation of stratiform clouds in Yushu over the Qinghai-Xizang Plateau in summer. Analysis of simulation results shows that WRF tends to overestimate precipitation over the plateau. Among the three cumulus parameterization schemes, the GD scheme yields relatively ideal simulation results, and different schemes exhibit sensitivity in precipitation simulation. Under the same scheme, different grid resolutions yield similar precipitation distributions. The simulated results using the designated schemes generally reflect the actual conditions and cloud features of this precipitation event. When simulating observed temperature and dew point temperature, the BMJ scheme at 5km resolution performs significantly better compared to the other two schemes at the same resolution. Combining physical field analysis and satellite cloud images, it is concluded that the stratiform cloud precipitation during this event is influenced by stable circulation patterns, abundant moisture, and wind shear over the plateau. High-resolution data from the Japanese Himawari-8 satellite’s 8um and 11um infrared channels reveal cloud radiative temperatures and moisture conditions. During the precipitation period, patchy stratiform clouds are present over the Yushu area with sufficient moisture, and the circulation background places Yushu ahead of a trough, promoting vigorous cumulus convection. Additionally, the reduced temperature-dew point temperature difference at night favors the formation of thick cloud systems, leading to frequent nighttime precipitation over the plateau. Analysis of cloud images indicates that the updraft field sustains the development and movement of stratiform cloud clusters, while small and numerous water vapor cloud clusters appear in the lower atmosphere at night, mixing to form larger precipitation cloud systems.
文摘青藏高原是全球气候变化的敏感地区,该地区的降水变化对全球及区域气候系统影响深远。运用WRF模型对高原的降水状况进行模拟研究,可以揭示降水形成机制和变化规律。但目前缺少利用WRF模式的不同组合改进青藏高原降水高估。为了改善降水高估的问题,本研究利用区域气候站逐时降水实况资料和NCEP 0.25度的3小时全球再分析格点资料,采用WRF4.0,对2019年7月28日发生在玉树地区的降水事件进行了对比分析,涉及多种积云对流方案与分辨率的组合。通过比较各种方案对降水量及降水分布的模拟效果,从而得到了相关的研究结论:不同积云对流参数化方案对降水落区和强度模拟的影响显著,GD方案在降水区域模拟上效果最好,与实际降水空间分布相似性最大,而BMJ方案效果最差。总体来看,各方案均普遍高估降水量,提高模式水平分辨率可以提高降水模拟精度,但对雨带走向和范围影响不大。模式能很好地模拟降水演变过程及其后的温度、露点、CAPE和风场等物理量,除NKF-5 km方案外,其余方案的CAPE模拟结果基本与实际一致。NKF方案倾向于产生更高的CAPE,这可能是其降水模拟效果较差的原因。The Tibetan Plateau is a sensitive region for global climate change, and variations in precipitation in this area have far-reaching impacts on both global and regional climate systems. Conducting simulation studies on precipitation conditions in the plateau using the WRF model can reveal mechanisms and patterns of precipitation formation. However, there is currently a lack of research utilizing different combinations of the WRF model to improve the overestimation of precipitation on the Tibetan Plateau. To address this overestimation issue, this study utilized hourly precipitation data from regional climate stations and 3-hourly global reanalysis grid data from NCEP with a resolution of 0.25 degrees. The WRF model was employed to conduct comparative analyses of a precipitation event that occurred in the Yushu region on July 28, 2019, involving various combinations of cumulus convection schemes and resolutions. By comparing the simulation effects of different schemes on precipitation amount and distribution, the study drew relevant conclusions: different cumulus convection schemes significantly affect the simulation of precipitation regions and intensity. The GD scheme performed the best in simulating precipitation areas, exhibiting the highest similarity to the actual spatial distribution of precipitation, while the BMJ scheme performed the worst. Overall, all schemes tended to overestimate precipitation amounts. Increasing the model’s horizontal resolution can enhance precipitation simulation accuracy but has a minimal impact on the direction and extent of rain belts. The model effectively simulates the evolution of precipitation and subsequent physical quantities such as temperature, dew point, CAPE, and wind fields. With the exception of the NKF-5 km scheme, the CAPE simulation results of the other schemes were generally consistent with actual observations. The NKF scheme tends to produce higher CAPE, which may be a contributing factor to its poorer precipitation simulation performance.
文摘风场是影响林火蔓延行为最关键的因素之一。许多林火发生在地形复杂多变的山区,会产生复杂的局部风场。为探究动态风场对林火蔓延预测的影响,以“3·30”西昌泸山森林火灾为研究对象,利用WRF(weather research and forecasting)模式模拟动态风场,并与林火蔓延模型耦合。分别将模拟风场和均一风场分别输入林火蔓延模型,基于林火蔓延过程中实际火场范围数据,分析动态风场对林火蔓延模型预测结果的影响。结果表明,耦合WRF模式和林火蔓延模型考虑了分辨率更高、且更为准确的局部风场,能够实现对森林火灾蔓延的动态模拟。预测得到的火场范围和均一风场相比,与实际范围具有更高的相似度。
文摘基于中尺度气象数值模式WRF(Weather Research and Forecasting),分别对我国广东、浙江、山东这3个近海典型风能资源储备区域进行了45组物理参数化方案组合连续1 M的敏感性试验,对试验中多要素的模拟结果进行综合评估,分别确定了适用于3个风能资源储备区各自排名前3的物理参数化方案组合,并对其模拟性能较优的原因进行分析。为了测试3个风能资源储备区筛选得到的物理参数化方案组合的适用性,利用不同于敏感性试验时段的模拟结果,结合海上测风塔和海洋气象站的实测数据开展进一步评估。结果表明,优选得到的物理参数化方案组合具有较好的适用性,其对近海的风速模拟性能较优,具有实际业务应用价值。
文摘本文利用WRF(Weather Research and Forecasting)模式耦合Noah陆面过程模式,对比研究了使用不同精度陆面资料:WRF默认陆面资料、中国1 km分辨率数字高程模型数据集、2006年MODIS(MODerate-resolution Imaging Spectroradiometer)土地利用和植被覆盖度资料,WRF模式对兰州地区冬季气象场模拟结果的差异。结果表明,近地面气温对陆面资料的精度非常敏感,而风场对陆面资料的精度不敏感,WRF模式对气温的模拟效果好于对风场模拟。采用高精度且时效性好的陆面资料后,WRF模拟的近地面气温准确率提高了15.8%,模拟的夜间气温改进幅度较白天大。陆面资料可影响整个边界层温度场分布,准确的陆面资料对提高WRF模式模拟近地面乃至整个边界层气象场至关重要。尽管风速模拟误差较大,但总体上WRF模式能较准确地模拟出研究区的风场演变特征。使用新的陆面资料后WRF模拟的风速误差略有减小,风向误差略有增加。干旱半干旱区冬季数值模拟需要注意土壤湿度初值和模式初始积分时刻对模拟结果的影响。
