复杂地形风电机组建设时易形成高边坡地形,可能严重影响机组的发电量和疲劳寿命。以重庆市某复杂山地风电场为例,基于CDRFG(Consistent Discretizing Random Flow Generation)方法生成大气边界层湍流入口,采用大涡模拟技术重现高边坡复...复杂地形风电机组建设时易形成高边坡地形,可能严重影响机组的发电量和疲劳寿命。以重庆市某复杂山地风电场为例,基于CDRFG(Consistent Discretizing Random Flow Generation)方法生成大气边界层湍流入口,采用大涡模拟技术重现高边坡复杂地形的湍流风场分布,并根据激光测风雷达和测风塔实测数据验证大涡模拟结果的准确性;对比分析了风机平台开挖导致的3种不同高边坡地形下,风机机位湍流风场的差异性,提出了风机平台开挖影响评估指标,深入分析了高边坡地形对风电机组发电效益和安全运行的影响。研究为复杂地形风机平台建设提供了科学保障。展开更多
Predicting monsoon climate is one of the major endeavors in climate science and is becoming increasingly challenging due to global warming. The accuracy of monsoon seasonal predictions significantly impacts the lives ...Predicting monsoon climate is one of the major endeavors in climate science and is becoming increasingly challenging due to global warming. The accuracy of monsoon seasonal predictions significantly impacts the lives of billions who depend on or are affected by monsoons, as it is essential for the water cycle, food security, ecology, disaster prevention, and the economy of monsoon regions. Given the extensive literature on Asian monsoon climate prediction, we limit our focus to reviewing the seasonal prediction and predictability of the Asian Summer Monsoon (ASM). However, much of this review is also relevant to monsoon predictions in other seasons and regions. Over the past two decades, considerable progress has been made in the seasonal forecasting of the ASM, driven by an enhanced understanding of the sources of predictability and the dynamics of seasonal variability, along with advanced development in sophisticated models and technologies. This review centers on advances in understanding the physical foundation for monsoon climate prediction (section 2), significant findings and insights into the primary and regional sources of predictability arising from feedback processes among various climate components (sections 3 and 4), the effects of global warming and external forcings on predictability (section 5), developments in seasonal prediction models and techniques (section 6), the challenges and limitations of monsoon climate prediction (section 7), and emerging research trends with suggestions for future directions (section 8). We hope this review will stimulate creative activities to enhance monsoon climate prediction.展开更多
The global monsoon system,encompassing the Asian-Australian,African,and American monsoons,sustains two-thirds of the world’s population by regulating water resources and agriculture.Monsoon anomalies pose severe risk...The global monsoon system,encompassing the Asian-Australian,African,and American monsoons,sustains two-thirds of the world’s population by regulating water resources and agriculture.Monsoon anomalies pose severe risks,including floods and droughts.Recent research associated with the implementation of the Global Monsoons Model Intercomparison Project under the umbrella of CMIP6 has advanced our understanding of its historical variability and driving mechanisms.Observational data reveal a 20th-century shift:increased rainfall pre-1950s,followed by aridification and partial recovery post-1980s,driven by both internal variability(e.g.,Atlantic Multidecadal Oscillation)and external forcings(greenhouse gases,aerosols),while ENSO drives interannual variability through ocean-atmosphere interactions.Future projections under greenhouse forcing suggest long-term monsoon intensification,though regional disparities and model uncertainties persist.Models indicate robust trends but struggle to quantify extremes,where thermodynamic effects(warming-induced moisture rise)uniformly boost heavy rainfall,while dynamical shifts(circulation changes)create spatial heterogeneity.Volcanic eruptions and proposed solar radiation modification(SRM)further complicate predictions:tropical eruptions suppress monsoons,whereas high-latitude events alter cross-equatorial flows,highlighting unresolved feedbacks.The emergent constraint approach is booming in terms of correcting future projections and reducing uncertainty with respect to the global monsoons.Critical challenges remain.Model biases and sparse 20th-century observational data hinder accurate attribution.The interplay between natural variability and anthropogenic forcings,along with nonlinear extreme precipitation risks under warming,demands deeper mechanistic insights.Additionally,SRM’s regional impacts and hemispheric monsoon interactions require systematic evaluation.Addressing these gaps necessitates enhanced observational networks,refined climate models,and interdisciplinary efforts to disentangle multiscale drivers,ultimately improving resilience strategies for monsoon-dependent regions.展开更多
本文基于2014~2016年华南前汛期(4~6月)广东省(简称粤)阳江市海陵岛风廓线雷达观测资料、地面自动观测站降水资料和ERA5再分析数据集,分析了粤西海岸低空急流的结构特征、日变化特征及其形成机制,并探讨了不同强度边界层低空急流对广东...本文基于2014~2016年华南前汛期(4~6月)广东省(简称粤)阳江市海陵岛风廓线雷达观测资料、地面自动观测站降水资料和ERA5再分析数据集,分析了粤西海岸低空急流的结构特征、日变化特征及其形成机制,并探讨了不同强度边界层低空急流对广东三个关键区域的地形降水时空分布影响。研究表明:(1)基于本文提出的低空急流四个等级判定标准,低空急流累计发生概率为21.2%,其中以1~3级低空急流为主,4级低空急流较为罕见。大部分(77.1%)低空急流的风速不超过14 m s^(-1),84.7%的低空急流风向为西南风,低空急流中心最大风速下方的风速垂直切变大多介于(5~25)×10^(-3)s^(-1)。低空急流最大风速出现的高度呈现出双峰结构,大部分低空急流出现在1 km以内的边界层。(2)天气尺度系统相关的低空急流日内发生频数表现为夜间单峰结构,而边界层急流发生频数为昼夜双峰结构。边界层急流夜间主峰值出现在上半夜至早晨,与局地海陆风触发的惯性振荡机制有关,白天次峰值主要出现在下午。近地面附近的低纬亚洲大陆低压与西北太平洋洋面高压两个高低值系统间的压力差对不同强度边界层急流形成起着关键的作用,白天大陆低压发展是强边界层急流午后峰值形成的主要原因。(3)边界层急流对广东地形降水分布和强度的影响机制复杂。粤中北部内陆和粤东沿海区域均以大尺度山脉迎风坡地形降水为主,边界层急流越强,地形降水越强;粤东沿海强地形降水落区稳定,而粤中北部内陆地形降水中心随边界层急流增强而西北移。粤西海岸带中小尺度地形的迎(背)风坡及尾流辐合区均可产生明显地形降水,强地形降水需在合适的低空入流风速背景下发生。(4)在地形降水日变化方面,粤中北部内陆区域降水在不同强度边界层急流影响下均出现了下午和早晨双峰结构,下午峰强度约为早晨峰的两倍,双峰强度随急流加强而增大;粤东沿海区域降水随着急流强度增强,降水由日内双峰结构演变为三峰结构;粤西海岸区域降水在较弱急流影响下为双峰,在4级强急流影响下为三峰结构,而在3级中等偏强急流影响下表现为中午单峰结构。展开更多
考虑到山谷气流的复杂性,我们在山地云雾物理研究和人工影响天气作业中,需要更加关注低层风廓线及垂直气流的观测研究。本文针对我国庐山云雾试验站的山谷地形及其与庐山气象站的85 m高度落差特点,利用2019年11、12月云雾试验站测风激...考虑到山谷气流的复杂性,我们在山地云雾物理研究和人工影响天气作业中,需要更加关注低层风廓线及垂直气流的观测研究。本文针对我国庐山云雾试验站的山谷地形及其与庐山气象站的85 m高度落差特点,利用2019年11、12月云雾试验站测风激光雷达的40~260 m高度风廓线和气象站10 m风的联合观测,分析了山谷低层风廓线特征、垂直运动与水平气流的关系及其影响因素。结果表明:(1)云雾试验站80 m高度与气象站10 m高度的风速和风向相关性较好,该高度的垂直速度和水平风速分别以±0.5 m s^(-1)、2~4 m s^(-1)为主。(2)云雾试验站所处山谷的平均风速随高度递增,白天风速在各高度上均低于夜间;昼夜风速差随高度增大,80 m(40 m)高度的昼夜风速差分别为-1 m s^(-1)(-0.2 m s^(-1))。(3)山谷低层垂直运动的方向主要与山谷开口方向及气流来向有关,与气流强度的关系不大;垂直速率大小与水平风速成正比。如云雾试验站80 m高度偏南风(风向112.5°~247.5°)上升气流占主导,其余风向下沉气流占主导,该关系可延展到260 m高度。(4)山谷低层气流弱风向切变可导致垂直运动分层,反映了山谷地形气流比平原更复杂。展开更多
文摘复杂地形风电机组建设时易形成高边坡地形,可能严重影响机组的发电量和疲劳寿命。以重庆市某复杂山地风电场为例,基于CDRFG(Consistent Discretizing Random Flow Generation)方法生成大气边界层湍流入口,采用大涡模拟技术重现高边坡复杂地形的湍流风场分布,并根据激光测风雷达和测风塔实测数据验证大涡模拟结果的准确性;对比分析了风机平台开挖导致的3种不同高边坡地形下,风机机位湍流风场的差异性,提出了风机平台开挖影响评估指标,深入分析了高边坡地形对风电机组发电效益和安全运行的影响。研究为复杂地形风机平台建设提供了科学保障。
基金supported by the National Natural Science Foundation of China(Grant No.U2342208)support from NSF/Climate Dynamics Award#2025057。
文摘Predicting monsoon climate is one of the major endeavors in climate science and is becoming increasingly challenging due to global warming. The accuracy of monsoon seasonal predictions significantly impacts the lives of billions who depend on or are affected by monsoons, as it is essential for the water cycle, food security, ecology, disaster prevention, and the economy of monsoon regions. Given the extensive literature on Asian monsoon climate prediction, we limit our focus to reviewing the seasonal prediction and predictability of the Asian Summer Monsoon (ASM). However, much of this review is also relevant to monsoon predictions in other seasons and regions. Over the past two decades, considerable progress has been made in the seasonal forecasting of the ASM, driven by an enhanced understanding of the sources of predictability and the dynamics of seasonal variability, along with advanced development in sophisticated models and technologies. This review centers on advances in understanding the physical foundation for monsoon climate prediction (section 2), significant findings and insights into the primary and regional sources of predictability arising from feedback processes among various climate components (sections 3 and 4), the effects of global warming and external forcings on predictability (section 5), developments in seasonal prediction models and techniques (section 6), the challenges and limitations of monsoon climate prediction (section 7), and emerging research trends with suggestions for future directions (section 8). We hope this review will stimulate creative activities to enhance monsoon climate prediction.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFA0608904)the International Partnership Program of the Chinese Academy of Sciences(Grant Nos.060GJHZ2023079GC and 134111KYSB20160031)+1 种基金supported by the Office of Science,U.S.Department of Energy(DOE)Biological and Environmental Research as part of the Regional and Global Model Analysis program area through the Water Cycle and Climate Extremes Modeling(WACCEM)scientific focus areaoperated for DOE by Battelle Memorial Institute under contract DE-AC05-76RL01830。
文摘The global monsoon system,encompassing the Asian-Australian,African,and American monsoons,sustains two-thirds of the world’s population by regulating water resources and agriculture.Monsoon anomalies pose severe risks,including floods and droughts.Recent research associated with the implementation of the Global Monsoons Model Intercomparison Project under the umbrella of CMIP6 has advanced our understanding of its historical variability and driving mechanisms.Observational data reveal a 20th-century shift:increased rainfall pre-1950s,followed by aridification and partial recovery post-1980s,driven by both internal variability(e.g.,Atlantic Multidecadal Oscillation)and external forcings(greenhouse gases,aerosols),while ENSO drives interannual variability through ocean-atmosphere interactions.Future projections under greenhouse forcing suggest long-term monsoon intensification,though regional disparities and model uncertainties persist.Models indicate robust trends but struggle to quantify extremes,where thermodynamic effects(warming-induced moisture rise)uniformly boost heavy rainfall,while dynamical shifts(circulation changes)create spatial heterogeneity.Volcanic eruptions and proposed solar radiation modification(SRM)further complicate predictions:tropical eruptions suppress monsoons,whereas high-latitude events alter cross-equatorial flows,highlighting unresolved feedbacks.The emergent constraint approach is booming in terms of correcting future projections and reducing uncertainty with respect to the global monsoons.Critical challenges remain.Model biases and sparse 20th-century observational data hinder accurate attribution.The interplay between natural variability and anthropogenic forcings,along with nonlinear extreme precipitation risks under warming,demands deeper mechanistic insights.Additionally,SRM’s regional impacts and hemispheric monsoon interactions require systematic evaluation.Addressing these gaps necessitates enhanced observational networks,refined climate models,and interdisciplinary efforts to disentangle multiscale drivers,ultimately improving resilience strategies for monsoon-dependent regions.
文摘本文基于2014~2016年华南前汛期(4~6月)广东省(简称粤)阳江市海陵岛风廓线雷达观测资料、地面自动观测站降水资料和ERA5再分析数据集,分析了粤西海岸低空急流的结构特征、日变化特征及其形成机制,并探讨了不同强度边界层低空急流对广东三个关键区域的地形降水时空分布影响。研究表明:(1)基于本文提出的低空急流四个等级判定标准,低空急流累计发生概率为21.2%,其中以1~3级低空急流为主,4级低空急流较为罕见。大部分(77.1%)低空急流的风速不超过14 m s^(-1),84.7%的低空急流风向为西南风,低空急流中心最大风速下方的风速垂直切变大多介于(5~25)×10^(-3)s^(-1)。低空急流最大风速出现的高度呈现出双峰结构,大部分低空急流出现在1 km以内的边界层。(2)天气尺度系统相关的低空急流日内发生频数表现为夜间单峰结构,而边界层急流发生频数为昼夜双峰结构。边界层急流夜间主峰值出现在上半夜至早晨,与局地海陆风触发的惯性振荡机制有关,白天次峰值主要出现在下午。近地面附近的低纬亚洲大陆低压与西北太平洋洋面高压两个高低值系统间的压力差对不同强度边界层急流形成起着关键的作用,白天大陆低压发展是强边界层急流午后峰值形成的主要原因。(3)边界层急流对广东地形降水分布和强度的影响机制复杂。粤中北部内陆和粤东沿海区域均以大尺度山脉迎风坡地形降水为主,边界层急流越强,地形降水越强;粤东沿海强地形降水落区稳定,而粤中北部内陆地形降水中心随边界层急流增强而西北移。粤西海岸带中小尺度地形的迎(背)风坡及尾流辐合区均可产生明显地形降水,强地形降水需在合适的低空入流风速背景下发生。(4)在地形降水日变化方面,粤中北部内陆区域降水在不同强度边界层急流影响下均出现了下午和早晨双峰结构,下午峰强度约为早晨峰的两倍,双峰强度随急流加强而增大;粤东沿海区域降水随着急流强度增强,降水由日内双峰结构演变为三峰结构;粤西海岸区域降水在较弱急流影响下为双峰,在4级强急流影响下为三峰结构,而在3级中等偏强急流影响下表现为中午单峰结构。
文摘考虑到山谷气流的复杂性,我们在山地云雾物理研究和人工影响天气作业中,需要更加关注低层风廓线及垂直气流的观测研究。本文针对我国庐山云雾试验站的山谷地形及其与庐山气象站的85 m高度落差特点,利用2019年11、12月云雾试验站测风激光雷达的40~260 m高度风廓线和气象站10 m风的联合观测,分析了山谷低层风廓线特征、垂直运动与水平气流的关系及其影响因素。结果表明:(1)云雾试验站80 m高度与气象站10 m高度的风速和风向相关性较好,该高度的垂直速度和水平风速分别以±0.5 m s^(-1)、2~4 m s^(-1)为主。(2)云雾试验站所处山谷的平均风速随高度递增,白天风速在各高度上均低于夜间;昼夜风速差随高度增大,80 m(40 m)高度的昼夜风速差分别为-1 m s^(-1)(-0.2 m s^(-1))。(3)山谷低层垂直运动的方向主要与山谷开口方向及气流来向有关,与气流强度的关系不大;垂直速率大小与水平风速成正比。如云雾试验站80 m高度偏南风(风向112.5°~247.5°)上升气流占主导,其余风向下沉气流占主导,该关系可延展到260 m高度。(4)山谷低层气流弱风向切变可导致垂直运动分层,反映了山谷地形气流比平原更复杂。
