Pub Date : 2025-06-12DOI: 10.1016/j.aosl.2025.100662
Rongwang Zhang , Yujie Cheng , Xin Wang
The frequency of marine heatwaves (MHWs) in the South China Sea (SCS) has increased recently. However, the relative roles of thermal and dynamic processes regulating the changes of SCS MHWs remain an open question. This study examines all long-lived MHWs (> 10 days) in the SCS from 1982 to 2021, categorizing them into intensified and attenuated MHWs based on the overall trend of sea surface temperature during an MHW event. A mixed-layer heat budget analysis reveals that the thermal processes primarily driven by the latent heat flux are crucial in modulating the SCS MHWs, particularly for attenuated MHWs. However, under intensified conditions, the proportions of dynamically dominated MHWs (40 %) is approximately comparable to that of thermally dominated ones (47 %). This study highlights the significance of dynamic processes in shaping SCS MHWs and discusses the potential impacts induced by tropical cyclones on these MHWs.
{"title":"Classification of marine heatwaves in the South China Sea and their thermodynamic features","authors":"Rongwang Zhang , Yujie Cheng , Xin Wang","doi":"10.1016/j.aosl.2025.100662","DOIUrl":"10.1016/j.aosl.2025.100662","url":null,"abstract":"<div><div>The frequency of marine heatwaves (MHWs) in the South China Sea (SCS) has increased recently. However, the relative roles of thermal and dynamic processes regulating the changes of SCS MHWs remain an open question. This study examines all long-lived MHWs (> 10 days) in the SCS from 1982 to 2021, categorizing them into intensified and attenuated MHWs based on the overall trend of sea surface temperature during an MHW event. A mixed-layer heat budget analysis reveals that the thermal processes primarily driven by the latent heat flux are crucial in modulating the SCS MHWs, particularly for attenuated MHWs. However, under intensified conditions, the proportions of dynamically dominated MHWs (40 %) is approximately comparable to that of thermally dominated ones (47 %). This study highlights the significance of dynamic processes in shaping SCS MHWs and discusses the potential impacts induced by tropical cyclones on these MHWs.</div><div>摘要</div><div>近年来南海海洋热浪发生频率显著上升, 但调控其变化的热力与动力过程的相对作用尚不明确. 本研究分析了1982至2021年的南海海洋热浪事件, 根据海洋热浪期间海表温度的变化趋势将其划分为增强型和减弱型两类. 混合层热收支分析表明, 由潜热通量主导的热力过程对调控南海海洋热浪 (尤其是衰减型) 至关重要. 然而, 在增强型海洋热浪中, 动力过程主导的事件比例 (40 %) 与热力主导型 (47 %) 近乎相当. 本研究强调了动力过程在塑造南海海洋热浪中的重要性, 并探讨了热带气旋对南海海洋热浪可能产生的影响.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"19 2","pages":"Article 100662"},"PeriodicalIF":3.2,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The year 2024 witnessed remarkable climatic anomalies across China, characterized by pronounced warm and wet conditions. The annual mean temperature soared to a record high since 1951, with seasonal temperatures in spring, summer, and autumn all exceeding historical extremes. Meanwhile, the annual precipitation ranked as the fourth highest on record, with all four seasons experiencing above-average rainfall. Notably, the Yangtze River Basin and Jiangnan region encountered their most intense precipitation event since 1961. Extreme weather events were particularly striking: An unusually early and severe heatwave swept through central and eastern China, becoming the second most intense high-temperature event in recorded history. Autumn typhoon activity also displayed exceptional intensity, with Typhoon Yagi triggering significant impacts in Hainan, Guangdong, and Guangxi. Although drought conditions were generally mild overall, notable seasonal and regional disparities emerged, especially in the winter–spring droughts affecting southwestern China. Conversely, cold outbreaks occurred more frequently than usual, and convective weather events exhibited heightened activity. Moreover, dust storm activity remained relatively limited.
{"title":"State of China’s climate in 2024","authors":"Yundi Jiang, Lin Zhao, Xiucang Li, Xianyan Chen, Xukai Zou, Yiran Wang, Hongling Zeng, Tong Cui, Hailing Zhong","doi":"10.1016/j.aosl.2025.100661","DOIUrl":"10.1016/j.aosl.2025.100661","url":null,"abstract":"<div><div>The year 2024 witnessed remarkable climatic anomalies across China, characterized by pronounced warm and wet conditions. The annual mean temperature soared to a record high since 1951, with seasonal temperatures in spring, summer, and autumn all exceeding historical extremes. Meanwhile, the annual precipitation ranked as the fourth highest on record, with all four seasons experiencing above-average rainfall. Notably, the Yangtze River Basin and Jiangnan region encountered their most intense precipitation event since 1961. Extreme weather events were particularly striking: An unusually early and severe heatwave swept through central and eastern China, becoming the second most intense high-temperature event in recorded history. Autumn typhoon activity also displayed exceptional intensity, with Typhoon Yagi triggering significant impacts in Hainan, Guangdong, and Guangxi. Although drought conditions were generally mild overall, notable seasonal and regional disparities emerged, especially in the winter–spring droughts affecting southwestern China. Conversely, cold outbreaks occurred more frequently than usual, and convective weather events exhibited heightened activity. Moreover, dust storm activity remained relatively limited.</div><div>摘要</div><div>2024年中国气候异常特征显著, 呈现突出的暖湿气候态势. 全国平均气温创1951年以来历史新高, 春, 夏, 秋三季气温均为历史最高; 年降水量位列历史第四高位, 四季降水均偏多, 其中长江流域和江南地区降水量更创1961年以来最强纪录, 极端天气事件尤为突出: 中东部地区遭遇历史罕见的早发强高温天气, 高温强度居历史第二; 秋季台风活动异常活跃, 台风\"摩羯\"给海南, 广东, 广西带来显著影响. 尽管全年干旱总体偏轻, 但季节性和区域性差异明显, 西南地区冬春连旱尤为显著. 与此同时, 冷空气过程较常年偏多, 强对流天气呈现高发态势, 而沙尘天气则相对偏少.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 5","pages":"Article 100661"},"PeriodicalIF":2.3,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-08DOI: 10.1016/j.aosl.2025.100660
Yanjin Mao , Ping Li , Xianchun Chen , Libin Huang , Xiaorui Niu
This study provides potential climate projections for Central Asia (CA) based on multi-regional climate model (RCM) outputs from the Coordinated Regional Climate Downscaling Experiment for Central Asia (CORDEX-CA-II). Despite some systematic biases, all RCMs effectively capture the main features of observed temperature and precipitation means and extremes over CA, with notable variations in model performance due to differences in the driving global climate models and the RCMs themselves. Overall, REMO consistently outperforms ALARO in simulating temperature-related indices, and ALARO-0 provides more accurate simulations for precipitation-related indices, and the multimodel ensemble (MME) tends to outperform individual RCMs. Under the representative concentration pathway (RCP) scenarios of RCP2.6 and RCP8.5, the MME results indicate a clear warming trend across CA for all temperature-related indices, except for the diurnal temperature range, with annual temperatures projected to increase by 0.15 °C/10 yr and 0.53 °C/10 yr, respectively. Both scenarios exhibit similar spatial distributions in projected annual precipitation, characterized by peak increases of ∼0.2 mm per day in northern CA. The number of consecutive dry days is projected to slightly increase under RCP8.5, while it is expected to slightly decrease under RCP2.6. This study improves our understanding of the applicability of RCMs in CA and provides reliable projections of future climate change.
本研究基于中亚协调区域气候降尺度试验（CORDEX-CA-II）的多区域气候模式（RCM）输出提供了中亚（CA）的潜在气候预估。尽管存在一些系统偏差，但所有rcm都有效地捕获了观测到的温度和降水平均值以及在CA上的极端值的主要特征，由于驱动全球气候模式和rcm本身的差异，模式性能存在显著差异。总体而言，REMO在模拟温度相关指数方面始终优于ALARO， ALARO-0对降水相关指数的模拟更为精确，多模式集合（MME）有优于单个rcm的趋势。在RCP2.6和RCP8.5的代表性浓度路径（RCP）情景下，MME结果表明，除日温范围外，所有温度相关指数都有明显的变暖趋势，年气温分别上升0.15°C/10 yr和0.53°C/10 yr。两种情景的年预估降水空间分布相似，其特征是CA北部的峰值增加约0.2 mm / d。在RCP8.5情景下，预估连续干旱日数略有增加，而在RCP2.6情景下，预估连续干旱日数略有减少。该研究提高了我们对rcm在CA中的适用性的理解，并提供了对未来气候变化的可靠预测。摘要本文基于CORDEX-CA-II中的多区域气候模式(rcm)对中亚未来气候变化进行预估分析。结果表明,所有RCM均能再现温度和降水的主要气候态分布及极端事件,其中雷莫在温度相关指标模拟方面表现更好,而Alaro-0在降水相关指标方面更具优势,且多模式集合平均(MME)结果优于单个RCM。在RCP2.6和RCP8.5排放情景下,除日较差外,中亚地区的温度相关指标均呈现出一致的上升趋势,而年均降水变化的空间分布也较为相似,高纬度地区增幅最为显著。rcp2.6, rcp2.6, rcp2.6, rcp2.6。
{"title":"Climate change projections in Central Asia based on the CORDEX-CA-II high-resolution simulations","authors":"Yanjin Mao , Ping Li , Xianchun Chen , Libin Huang , Xiaorui Niu","doi":"10.1016/j.aosl.2025.100660","DOIUrl":"10.1016/j.aosl.2025.100660","url":null,"abstract":"<div><div>This study provides potential climate projections for Central Asia (CA) based on multi-regional climate model (RCM) outputs from the Coordinated Regional Climate Downscaling Experiment for Central Asia (CORDEX-CA-II). Despite some systematic biases, all RCMs effectively capture the main features of observed temperature and precipitation means and extremes over CA, with notable variations in model performance due to differences in the driving global climate models and the RCMs themselves. Overall, REMO consistently outperforms ALARO in simulating temperature-related indices, and ALARO-0 provides more accurate simulations for precipitation-related indices, and the multimodel ensemble (MME) tends to outperform individual RCMs. Under the representative concentration pathway (RCP) scenarios of RCP2.6 and RCP8.5, the MME results indicate a clear warming trend across CA for all temperature-related indices, except for the diurnal temperature range, with annual temperatures projected to increase by 0.15 °C/10 yr and 0.53 °C/10 yr, respectively. Both scenarios exhibit similar spatial distributions in projected annual precipitation, characterized by peak increases of ∼0.2 mm per day in northern CA. The number of consecutive dry days is projected to slightly increase under RCP8.5, while it is expected to slightly decrease under RCP2.6. This study improves our understanding of the applicability of RCMs in CA and provides reliable projections of future climate change.</div><div>摘要</div><div>本文基于CORDEX-CA-II中的多区域气候模式 (RCMs) 对中亚未来气候变化进行预估分析. 结果表明, 所有RCM均能再现温度和降水的主要气候态分布及极端事件, 其中REMO在温度相关指标模拟方面表现更好, 而Alaro-0在降水相关指标方面更具优势, 且多模式集合平均 (MME) 结果优于单个RCM. 在RCP2.6和RCP8.5排放情景下, 除日较差外, 中亚地区的温度相关指标均呈现出一致的上升趋势, 而年均降水变化的空间分布也较为相似, 高纬度地区增幅最为显著. 此外, 在RCP8.5情景下, 连续干燥日数预计将略有增加, 而在RCP2.6情景下则略有减少.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"19 2","pages":"Article 100660"},"PeriodicalIF":3.2,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-06DOI: 10.1016/j.aosl.2025.100659
Yuliang Zhou, Wentao Jia, Weimin Zhang, Huizan Wang
In this study, based on MERRA-2 reanalysis data and a multi-algorithm integrated atmospheric river (AR) identification method, the authors reveal the cross-seasonal regulation mechanism of El Niño–Southern Oscillation (ENSO) on winter–spring AR activities in East Asia. The results show that ENSO asymmetrically modulates AR activity through teleconnection and hysteresis effects, and has significant enhancement/inhibition effects on ARs in different regions. At the onset of El Niño, enhanced southwesterly flow at the western edge of the western Pacific subtropical high (WPSH) leads to enhanced AR activity in the western Pacific, and anomalous southerly winds in the Indian Ocean promote northward transport of water vapor in the Arabian Sea and Bay of Bengal. With a three-month lag, the weakening and eastward retreat of the WPSH weakens the low-latitude AR activity, but persistent southerly winds in the Bay of Bengal maintain the AR activity over Southwest China. The mid- to high-latitude AR response exhibits delayed dynamics, initially dominated by the synergistic effect of the southward deviation of the upper-air rapids and the low-level convergence (double-rapid-flow effect) and later modulated by the Pacific–North American teleconnection (PNA)-triggered East Asian ridge, which enhances the precipitation efficiency through prolonged frontal activity and enhanced cold–warm airmass convergence. Overall, El Niño promotes the development of low- and midlatitude AR activity in East Asia, while La Niña promotes (maritime continental) AR activity in the tropics. This study establishes the “ENSO teleconnection → circulation adjustment → East Asian AR response” chain, revealing a cross-seasonal lagged response mechanisms of East Asian AR activity, and provides a theoretical basis for winter and spring climate prediction and extreme precipitation forecasting.
{"title":"Mechanisms of ENSO’s cross-seasonal modulation of winter–spring atmospheric river activity over East Asia","authors":"Yuliang Zhou, Wentao Jia, Weimin Zhang, Huizan Wang","doi":"10.1016/j.aosl.2025.100659","DOIUrl":"10.1016/j.aosl.2025.100659","url":null,"abstract":"<div><div>In this study, based on MERRA-2 reanalysis data and a multi-algorithm integrated atmospheric river (AR) identification method, the authors reveal the cross-seasonal regulation mechanism of El Niño–Southern Oscillation (ENSO) on winter–spring AR activities in East Asia. The results show that ENSO asymmetrically modulates AR activity through teleconnection and hysteresis effects, and has significant enhancement/inhibition effects on ARs in different regions. At the onset of El Niño, enhanced southwesterly flow at the western edge of the western Pacific subtropical high (WPSH) leads to enhanced AR activity in the western Pacific, and anomalous southerly winds in the Indian Ocean promote northward transport of water vapor in the Arabian Sea and Bay of Bengal. With a three-month lag, the weakening and eastward retreat of the WPSH weakens the low-latitude AR activity, but persistent southerly winds in the Bay of Bengal maintain the AR activity over Southwest China. The mid- to high-latitude AR response exhibits delayed dynamics, initially dominated by the synergistic effect of the southward deviation of the upper-air rapids and the low-level convergence (double-rapid-flow effect) and later modulated by the Pacific–North American teleconnection (PNA)-triggered East Asian ridge, which enhances the precipitation efficiency through prolonged frontal activity and enhanced cold–warm airmass convergence. Overall, El Niño promotes the development of low- and midlatitude AR activity in East Asia, while La Niña promotes (maritime continental) AR activity in the tropics. This study establishes the “ENSO teleconnection → circulation adjustment → East Asian AR response” chain, revealing a cross-seasonal lagged response mechanisms of East Asian AR activity, and provides a theoretical basis for winter and spring climate prediction and extreme precipitation forecasting.</div><div>摘要</div><div>本研究基于MERRA-2再分析数据及多算法融合的AR识别方法, 揭示ENSO通过遥相关效应对东亚冬春季大气河活动的跨季节调控机制. 厄尔尼诺初期, 西太平洋副高西侧增强的西南风激发西太平洋AR活动, 同时印度洋偏南风异常促进阿拉伯海-孟加拉湾水汽北输; 滞后3个月后, WPSH东退削弱低纬AR, 但孟加拉湾持续南风维持西南地区AR活动. 中高纬AR响应初期受高空急流南偏与低层辐合 (双急流效应) 协同作用, 后期由PNA遥相关触发的东亚脊调制, 通过延长锋面活动及增强冷暖空气辐合提升降水效率. 总体而言, 厄尔尼诺促进东亚中低纬AR发展, 拉尼娜则增强热带海洋性大陆AR活动. \"ENSO遥相关-环流调整-东亚AR响应\"机制链为冬春季气候预测及极端降水预报提供理论基础.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"19 1","pages":"Article 100659"},"PeriodicalIF":3.2,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145610574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-29DOI: 10.1016/j.aosl.2025.100656
Wenjing Cheng , Daoyong Yang , Lingkun Ran , Kuo Zhou , Yanli Chu
The enhanced mountain-to-plain convective storms in Beijing on 22 May 2021 were simulated using the high-resolution Weather Research and Forecasting model, enabling detailed analyses of convective instability characteristics and underlying causes of stability variations. Generalized potential temperature outperformed traditional potential temperature and equivalent potential temperature in capturing instability variations associated with mid-level latent heating and near-surface evaporative cooling. Local instability variance was primarily governed by potential divergence and the advection of potential instability, with these factors exhibiting out-of-phase distributions. Prior to the onset of heavy precipitation, intense downdrafts transported unstable air from higher levels into more stable regions at lower levels, increasing local near-surface instability, which contributed to the formation of heavy precipitation. During the heavy precipitation stage, vertical divergence between slantwise updrafts and downdrafts in the low–middle stable layers led to destabilization, supporting sustained convective development within the precipitation area. At the leading edge of the heavy precipitation, instability enhancement was primarily driven by vertical advection, and less stable air in the lower levels was transported upward, enhancing instability at higher levels.
{"title":"Analysis of an enhanced mountain-to-plain convective storm based on potential divergence and the advection of potential instability","authors":"Wenjing Cheng , Daoyong Yang , Lingkun Ran , Kuo Zhou , Yanli Chu","doi":"10.1016/j.aosl.2025.100656","DOIUrl":"10.1016/j.aosl.2025.100656","url":null,"abstract":"<div><div>The enhanced mountain-to-plain convective storms in Beijing on 22 May 2021 were simulated using the high-resolution Weather Research and Forecasting model, enabling detailed analyses of convective instability characteristics and underlying causes of stability variations. Generalized potential temperature outperformed traditional potential temperature and equivalent potential temperature in capturing instability variations associated with mid-level latent heating and near-surface evaporative cooling. Local instability variance was primarily governed by potential divergence and the advection of potential instability, with these factors exhibiting out-of-phase distributions. Prior to the onset of heavy precipitation, intense downdrafts transported unstable air from higher levels into more stable regions at lower levels, increasing local near-surface instability, which contributed to the formation of heavy precipitation. During the heavy precipitation stage, vertical divergence between slantwise updrafts and downdrafts in the low–middle stable layers led to destabilization, supporting sustained convective development within the precipitation area. At the leading edge of the heavy precipitation, instability enhancement was primarily driven by vertical advection, and less stable air in the lower levels was transported upward, enhancing instability at higher levels.</div><div>摘要</div><div>针对2021年5月22日发生在北京地区的一次雷暴下山增强的过程, 利用WRF模式进行高分辨率数值模拟. 在成功模拟下山对流发生, 增强和移动的基础上, 对该过程中位势不稳定特征以及引起位势稳定度变化的原因进行诊断分析. 研究结果表明, 广义位温在识别由潜热加热与蒸发冷却引起的不稳定性变化方面, 优于传统的位温和相当位温. 通过对位势稳定度趋势方程的诊断分析发现, 局地位势不稳定的变化主要受位势散度和位势不稳定平流的主导, 两者在空间呈反位相分布. 在强降水开始前, 强烈的下沉气流将高层的不稳定空气输送到较为稳定的低层, 导致近地面不稳定性增加, 为强降水的形成提供了有利条件. 在强降水阶段, 低中层大气层结稳定, 同时倾斜上升气流和下沉气流之间的垂直辐散导致了大气向不稳定变化, 维持了对流的持续发展. 在强降水的前沿, 主要由垂直平流驱动不稳定性增加, 低层不稳定空气被向上输送, 增强了高层的不稳定性.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"19 2","pages":"Article 100656"},"PeriodicalIF":3.2,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-26DOI: 10.1016/j.aosl.2025.100655
Ming Cheng , Ziniu Xiao , Xinyi Lai , Jingjing Xu , Siyu Lu , Baorong Zhou , Weisi Deng
This study investigates the distinct impacts of eastern Pacific (EP) and central Pacific (CP) El Niño events on winter shortwave solar radiation (SSR) in southern China, revealing different spatial distributions and underlying mechanisms. The results show that, during the developing winter of EP El Niño, significant SSR reductions occur in southwestern China and the east coast of southern China due to a strong, zonally extended Northwest Pacific anticyclone that transports moisture from the tropical Northwest Pacific and North Indian Ocean, while the northeast of southern China experiences a weak increase in SSR. In contrast, during the developing winter of CP El Niño, SSR decreases in the east of southern China with a significant decrease in the lower basin of the Yangtze River but an increase in the west of southern China with a remarkable increase in eastern Yunnan. The pronounced east–west dipole pattern in SSR anomalies is driven by a meridionally elongated Northwest Pacific anticyclone, which enhances northward moisture transport to the east of southern China while leaving western areas drier. Further research reveals that distinct moisture anomalies during the developing winter of EP and CP events result in divergent SSR distributions across southern China, primarily through modulating the total cloud cover. These findings highlight the critical need to differentiate between El Niño types when predicting medium and long-term variability of radiation in southern China.
本文研究了东太平洋（EP）和中太平洋（CP） El Niño事件对中国南方冬季短波太阳辐射（SSR）的不同影响，揭示了不同的空间分布及其机制。结果表明，在EP El Niño冬季发展过程中，由于西北太平洋强反气旋输送来自热带西北太平洋和北印度洋的水汽，中国西南和华南东海岸的SSR显著减少，而华南东北部的SSR微弱增加。在CP El Niño发展冬季，华南东部SSR减少，长江下游流域显著减少，而华南西部SSR增加，云南东部显著增加。一个经向拉长的西北太平洋反气旋驱动了SSR异常中明显的东西偶极子型，该气旋增强了华南东部向北的水汽输送，同时使西部地区更加干燥。进一步研究表明，EP和CP事件发展冬季的明显湿度异常，主要通过调节总云量导致了华南地区SSR分布的差异。这些发现强调了在预测中国南方中期和长期辐射变化时区分El Niño类型的关键必要性。摘要东部型(EP)和中部型(CP)厄尔尼诺发展年冬季中国南方地区地表太阳短波辐射(SSR)的空间分布特征存在明显差异。在EP厄尔尼诺发展年冬季,受西北太平洋反气旋异常西伸的影响,来自热带西北太平洋和北印度洋的水汽输送增强,导致中国西南和华南沿海SSR明显减少,中国南方东北部SSR微弱增加;在CP厄尔尼诺事件发展年冬季,中国南方东部SSR减少(长江下游流域尤为显著),而西部SSR增加(滇东地区增幅突出),该偶极型异常分布与经向延伸的西北太平洋反气旋加强了中国南方东部的水汽北向输送有关。研究指出,两类厄尔尼诺事件发展年冬季水汽异常存在明显差异,并通过调控总云量导致中国南方SSR空间分布的差异。
{"title":"Different effects of eastern and central Pacific El Niño events on the surface shortwave radiation over southern China in winter","authors":"Ming Cheng , Ziniu Xiao , Xinyi Lai , Jingjing Xu , Siyu Lu , Baorong Zhou , Weisi Deng","doi":"10.1016/j.aosl.2025.100655","DOIUrl":"10.1016/j.aosl.2025.100655","url":null,"abstract":"<div><div>This study investigates the distinct impacts of eastern Pacific (EP) and central Pacific (CP) El Niño events on winter shortwave solar radiation (SSR) in southern China, revealing different spatial distributions and underlying mechanisms. The results show that, during the developing winter of EP El Niño, significant SSR reductions occur in southwestern China and the east coast of southern China due to a strong, zonally extended Northwest Pacific anticyclone that transports moisture from the tropical Northwest Pacific and North Indian Ocean, while the northeast of southern China experiences a weak increase in SSR. In contrast, during the developing winter of CP El Niño, SSR decreases in the east of southern China with a significant decrease in the lower basin of the Yangtze River but an increase in the west of southern China with a remarkable increase in eastern Yunnan. The pronounced east–west dipole pattern in SSR anomalies is driven by a meridionally elongated Northwest Pacific anticyclone, which enhances northward moisture transport to the east of southern China while leaving western areas drier. Further research reveals that distinct moisture anomalies during the developing winter of EP and CP events result in divergent SSR distributions across southern China, primarily through modulating the total cloud cover. These findings highlight the critical need to differentiate between El Niño types when predicting medium and long-term variability of radiation in southern China.</div><div>摘要</div><div>东部型 (EP) 和中部型 (CP) 厄尔尼诺发展年冬季中国南方地区地表太阳短波辐射 (SSR) 的空间分布特征存在明显差异. 在EP厄尔尼诺发展年冬季, 受西北太平洋反气旋异常西伸的影响, 来自热带西北太平洋和北印度洋的水汽输送增强, 导致中国西南和华南沿海SSR明显减少, 中国南方东北部SSR微弱增加; 在CP厄尔尼诺事件发展年冬季, 中国南方东部SSR减少 (长江下游流域尤为显著), 而西部SSR增加 (滇东地区增幅突出), 该偶极型异常分布与经向延伸的西北太平洋反气旋加强了中国南方东部的水汽北向输送有关. 研究指出, 两类厄尔尼诺事件发展年冬季水汽异常存在明显差异, 并通过调控总云量导致中国南方SSR空间分布的差异.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"19 1","pages":"Article 100655"},"PeriodicalIF":3.2,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145610623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-26DOI: 10.1016/j.aosl.2025.100653
Congqi Cao , Ze Sun , Lanshu Hu , Liujie Pan , Yanning Zhang
Deep learning-based methods have become alternatives to traditional numerical weather prediction systems, offering faster computation and the ability to utilize large historical datasets. However, the application of deep learning to medium-range regional weather forecasting with limited data remains a significant challenge. In this work, three key solutions are proposed: (1) motivated by the need to improve model performance in data-scarce regional forecasting scenarios, the authors innovatively apply semantic segmentation models, to better capture spatiotemporal features and improve prediction accuracy; (2) recognizing the challenge of overfitting and the inability of traditional noise-based data augmentation methods to effectively enhance model robustness, a novel learnable Gaussian noise mechanism is introduced that allows the model to adaptively optimize perturbations for different locations, ensuring more effective learning; and (3) to address the issue of error accumulation in autoregressive prediction, as well as the challenge of learning difficulty and the lack of intermediate data utilization in one-shot prediction, the authors propose a cascade prediction approach that effectively resolves these problems while significantly improving model forecasting performance. The method achieves a competitive result in The East China Regional AI Medium Range Weather Forecasting Competition. Ablation experiments further validate the effectiveness of each component, highlighting their contributions to enhancing prediction performance.
{"title":"A novel deep learning-based framework for five‐day regional weather forecasting","authors":"Congqi Cao , Ze Sun , Lanshu Hu , Liujie Pan , Yanning Zhang","doi":"10.1016/j.aosl.2025.100653","DOIUrl":"10.1016/j.aosl.2025.100653","url":null,"abstract":"<div><div>Deep learning-based methods have become alternatives to traditional numerical weather prediction systems, offering faster computation and the ability to utilize large historical datasets. However, the application of deep learning to medium-range regional weather forecasting with limited data remains a significant challenge. In this work, three key solutions are proposed: (1) motivated by the need to improve model performance in data-scarce regional forecasting scenarios, the authors innovatively apply semantic segmentation models, to better capture spatiotemporal features and improve prediction accuracy; (2) recognizing the challenge of overfitting and the inability of traditional noise-based data augmentation methods to effectively enhance model robustness, a novel learnable Gaussian noise mechanism is introduced that allows the model to adaptively optimize perturbations for different locations, ensuring more effective learning; and (3) to address the issue of error accumulation in autoregressive prediction, as well as the challenge of learning difficulty and the lack of intermediate data utilization in one-shot prediction, the authors propose a cascade prediction approach that effectively resolves these problems while significantly improving model forecasting performance. The method achieves a competitive result in The East China Regional AI Medium Range Weather Forecasting Competition. Ablation experiments further validate the effectiveness of each component, highlighting their contributions to enhancing prediction performance.</div><div>摘要</div><div>深度学习逐渐替代传统数值天气预报 (NWP) 系统, 但在数据有限的中期天气预报中仍面临挑战。为此, 本文提出三项创新: 首先, 引入语义分割模型增强时空特征捕捉能力, 提高预测精度; 其次, 设计可学习的高斯噪声机制, 解决过拟合问题并突破传统噪声增强的局限性; 最后, 提出级联预测方法, 平衡预测精度与误差控制, 缓解自回归预测的误差累积问题。该方法在华东区域AI中期气象预报竞赛中表现优异, 实验验证了各模块的有效性, 其中语义分割降低温度预测误差9.3%, 噪声机制提升降水预测F1-score 6.8%, 级联策略减少风速预测均方误差12.5%。此研究为数据受限的区域气象预报提供了新路径。</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"19 1","pages":"Article 100653"},"PeriodicalIF":3.2,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145610583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-26DOI: 10.1016/j.aosl.2025.100654
Fei Yang , Jing Ma , Hongxia Lan , Bin Mu , Shijin Yuan , Jing-Jia Luo
The Northwest Pacific subtropical high (NWPSH) significantly affects East Asian weather and climate, rendering the prediction of its intensity and location critically important. This study aims to evaluate the performance of the Convolutional Long and Short-Term Memory (ConvLSTM) model for predicting the summertime 500 hPa geopotential height and NWPSH intensity and area at a lead time of three months, and to compare it with the dynamical models of the Nanjing University of Information Science and Technology Climate Forecast System (NUIST-CFS1.0) and the Canadian Seasonal to Interannual Prediction System Version 2 (CanSIPSv2). The mean latitude-weighted RMSE (RMSEw), anomaly correlation coefficient (ACC), and NWPSH indices are used as evaluation metrics. For both summer mean and monthly prediction, the ConvLSTM model outperforms the two dynamical models in terms of RMSEw and ACC for the 500 hPa geopotential height over the western Pacific region. The correlation coefficients between the NWPSH intensity index predicted by the ConvLSTM model and the observations are higher than those obtained from the two dynamical models. Regarding the NWPSH area index, the ConvLSTM model shows more stable performance. Particularly in August, the improvement of the ConvLSTM model compared to the two dynamical models is more significant, indicating the robust capability in capturing late-summer circulation patterns. Therefore, the ConvLSTM model demonstrates significant potential for summer NWPSH prediction, offering a new perspective and approach for climate prediction in this region.
{"title":"Prediction of the summertime Northwest Pacific subtropical high based on ConvLSTM","authors":"Fei Yang , Jing Ma , Hongxia Lan , Bin Mu , Shijin Yuan , Jing-Jia Luo","doi":"10.1016/j.aosl.2025.100654","DOIUrl":"10.1016/j.aosl.2025.100654","url":null,"abstract":"<div><div>The Northwest Pacific subtropical high (NWPSH) significantly affects East Asian weather and climate, rendering the prediction of its intensity and location critically important. This study aims to evaluate the performance of the Convolutional Long and Short-Term Memory (ConvLSTM) model for predicting the summertime 500 hPa geopotential height and NWPSH intensity and area at a lead time of three months, and to compare it with the dynamical models of the Nanjing University of Information Science and Technology Climate Forecast System (NUIST-CFS1.0) and the Canadian Seasonal to Interannual Prediction System Version 2 (CanSIPSv2). The mean latitude-weighted RMSE (RMSE<sub>w</sub>), anomaly correlation coefficient (ACC), and NWPSH indices are used as evaluation metrics. For both summer mean and monthly prediction, the ConvLSTM model outperforms the two dynamical models in terms of RMSE<sub>w</sub> and ACC for the 500 hPa geopotential height over the western Pacific region. The correlation coefficients between the NWPSH intensity index predicted by the ConvLSTM model and the observations are higher than those obtained from the two dynamical models. Regarding the NWPSH area index, the ConvLSTM model shows more stable performance. Particularly in August, the improvement of the ConvLSTM model compared to the two dynamical models is more significant, indicating the robust capability in capturing late-summer circulation patterns. Therefore, the ConvLSTM model demonstrates significant potential for summer NWPSH prediction, offering a new perspective and approach for climate prediction in this region.</div><div>摘要</div><div>西北太平洋副热带高压 (NWPSH) 对东亚天气和气候具有重要影响, 其强度和位置的预测至关重要. 本研究旨在评估卷积长短期记忆 (ConvLSTM) 模型提前3个月对夏季500 hPa位势高度及NWPSH强度和面积的预测性能, 并将其与动力模式南京信息工程大学气候预测系统1.0版 (NUIST-CFS1.0) 和加拿大季节–年际预测系统第2版 (CanSIPSv2) 预测结果对比. 评估指标为纬度加权均方根误差 (RMSE<sub>w</sub>) , 异常相关系数 (ACC) 和NWPSH指数. 在夏季平均和逐月预测中, ConvLSTM模型对西太平洋地区500 hPa位势高度的RMSEw和ACC预测技巧均优于动力模式. ConvLSTM模型预测的NWPSH强度指数与观测值的相关系数高于动力模式结果, 预测的NWPSH面积指数也表现出更稳定的性能. 与两个动力学模式相比, ConvLSTM模型在8月的改进更为显著, 表明其对夏季末期环流形势具有更强的捕捉能力. 因此, ConvLSTM模型在夏季NWPSH的预测中具有较好的应用潜力, 为该区域的气候预测提供了新的视角和方法.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"19 2","pages":"Article 100654"},"PeriodicalIF":3.2,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-24DOI: 10.1016/j.aosl.2025.100652
Shanshan Li , Lei Chen , Xihui Gu
Based on datasets from the International Best-Track Archive for Climate Stewardship (IBTrACS) and the fifth major global reanalysis produced by ECMWF (ERA5), the authors found that 29% of tropical cyclones (TCs) in the western North Pacific underwent extratropical transition (ET) from 1979 to 2022, with the frequency of ET events showing a slow decreasing trend. The extratropical transition tropical cyclones (ETCs) are classified into four clusters using the k-means clustering method based on their track patterns: recurving ETCs, westward ETCs, northwestward ETCs, and abnormal track ETCs. The transition process of recurving ETCs mostly occurs after the recurvature is completed, while 63.7% of the westward ETCs complete their transition after landfall. Abnormal track ETCs undergo transition over high-latitude oceans. Northwestward ETCs have the longest duration and slowest transition speed during the ET period, resulting in a prolonged impact. The ET process occurs at the edges of the western Pacific subtropical high (WPSH), with higher frequency during westward extension and lower during eastward retreat. While westward ETCs transition through surface friction effects, others complete ET in the northwest baroclinic zone of the WPSH.
{"title":"Climatological characteristics of the extratropical transition of tropical cyclones along different tracks in the western North Pacific (1979–2022)","authors":"Shanshan Li , Lei Chen , Xihui Gu","doi":"10.1016/j.aosl.2025.100652","DOIUrl":"10.1016/j.aosl.2025.100652","url":null,"abstract":"<div><div>Based on datasets from the International Best-Track Archive for Climate Stewardship (IBTrACS) and the fifth major global reanalysis produced by ECMWF (ERA5), the authors found that 29% of tropical cyclones (TCs) in the western North Pacific underwent extratropical transition (ET) from 1979 to 2022, with the frequency of ET events showing a slow decreasing trend. The extratropical transition tropical cyclones (ETCs) are classified into four clusters using the <em>k</em>-means clustering method based on their track patterns: recurving ETCs, westward ETCs, northwestward ETCs, and abnormal track ETCs. The transition process of recurving ETCs mostly occurs after the recurvature is completed, while 63.7% of the westward ETCs complete their transition after landfall. Abnormal track ETCs undergo transition over high-latitude oceans. Northwestward ETCs have the longest duration and slowest transition speed during the ET period, resulting in a prolonged impact. The ET process occurs at the edges of the western Pacific subtropical high (WPSH), with higher frequency during westward extension and lower during eastward retreat. While westward ETCs transition through surface friction effects, others complete ET in the northwest baroclinic zone of the WPSH.</div><div>摘要</div><div>本研究基于国际气候管理最佳路径档案(IBTrACS)和欧洲中期天气预报中心第五代再分析数据集(ERA5), 发现1979−2022年间西北太平洋有29%的热带气旋经历了温带变性(ET)过程, 且ET事件的发生频率呈缓慢下降趋势. 通过<em>k</em>-means聚类方法, 将变性的热带气旋(ETCs)按路径特征划分为四类: 转向路径ETCs, 西移路径ETCs, 西北移路径ETCs和异常路径ETCs. 转向路径ETCs主要在完成转向后开始变性. 西移路径ETCs大多数在登陆后完成变性(63.7%). 异常路径ETCs通常在高纬度洋面完成变性. 西北移路径ETCs在变性期间所用时间最长, 移动速度较慢, 因此影响持续时间较长. ET过程均发生在西太平洋副热带高压(WPSH)边缘, WPSH西伸时ET频率较高, 东退时频率较低. 除西移路径ETCs受地表摩擦主导外, 其他类型多在WPSH西北侧的强斜压区完成转变.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"19 2","pages":"Article 100652"},"PeriodicalIF":3.2,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-24DOI: 10.1016/j.aosl.2025.100651
Jinfeng Huang , Shuai Yang , Yuanfa Gong
Typhoon Bebinca in 2024 experienced a nearshore outbreak (a rapid intensification (RI) near the coast), making accurate forecasting of unpredictable tracks and intensities highly challenging. The AI model is superior to the numerical model for typhoon track prediction but performs worse for intensity forecasting. Vortex initialization is an effective approach to further improve numerical prediction via cycle assimilation, accounting for multiple relocating TC centers and adjusting the typhoon initial structure. In addition, by integrating numerical runs with an AI weather model through real-time dynamic weight correction of the forecast, the predictive skill is further improved. For example, it can reduce the deviation of 72-h track forecasting by 25 % compared with the numerical model and decrease the intensity deviation by 2 % and 56 % relative to the numerical run and AI forecasts, respectively. On the basis of the best-performing forecasting, the inner-core convective burst (CB) characteristics are illuminated. The attributions of the nearshore outbreak and RI of Typhoon Bebinca are examined. From the viewpoint of bottom-up convection growth, the CB is associated with the energy supply from the high-boundary-layer CAPE, the following upward-developing secondary circulation, and accompanying latent heat release of hydrometeors. The contracted radius of maximum winds (RMW) and increased inertial stability within the inner core region effectively prevent the escape of the high-energy atmosphere and favor rapid intensification and maintenance of the offshore burst of a typhoon. The intensifying secondary circulation further promotes the primary circulation of the TC and RI processes through the gradient wind balance.
{"title":"Exploring typhoon prediction and convective bursts through integration of a numerical model after vortex initialization with AI weather forecasting","authors":"Jinfeng Huang , Shuai Yang , Yuanfa Gong","doi":"10.1016/j.aosl.2025.100651","DOIUrl":"10.1016/j.aosl.2025.100651","url":null,"abstract":"<div><div>Typhoon Bebinca in 2024 experienced a nearshore outbreak (a rapid intensification (RI) near the coast), making accurate forecasting of unpredictable tracks and intensities highly challenging. The AI model is superior to the numerical model for typhoon track prediction but performs worse for intensity forecasting. Vortex initialization is an effective approach to further improve numerical prediction via cycle assimilation, accounting for multiple relocating TC centers and adjusting the typhoon initial structure. In addition, by integrating numerical runs with an AI weather model through real-time dynamic weight correction of the forecast, the predictive skill is further improved. For example, it can reduce the deviation of 72-h track forecasting by 25 % compared with the numerical model and decrease the intensity deviation by 2 % and 56 % relative to the numerical run and AI forecasts, respectively. On the basis of the best-performing forecasting, the inner-core convective burst (CB) characteristics are illuminated. The attributions of the nearshore outbreak and RI of Typhoon Bebinca are examined. From the viewpoint of bottom-up convection growth, the CB is associated with the energy supply from the high-boundary-layer CAPE, the following upward-developing secondary circulation, and accompanying latent heat release of hydrometeors. The contracted radius of maximum winds (RMW) and increased inertial stability within the inner core region effectively prevent the escape of the high-energy atmosphere and favor rapid intensification and maintenance of the offshore burst of a typhoon. The intensifying secondary circulation further promotes the primary circulation of the TC and RI processes through the gradient wind balance.</div><div>摘要</div><div>2024年强台风贝碧嘉近岸爆发快速增强, 预报极具挑战. 将数值预报和AI模型相结合, 并融入涡旋初始化循环同化预报技术, 以及动态权重释用预报技术等, 可在不同程度上提升台风路径和强度预报. 比如, 72h路径预报偏差较数值模式降低25%, 强度偏差较AI预报降低56%. 基于预报分析, 发现台风近岸爆发快速增强, 与内核对流爆发, 次级环流增强促进主环流发展, 边界层高CAPE, 深对流潜热加热持续供能, 内核惯性稳定度增加防止高能大气外逸等有关.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"19 2","pages":"Article 100651"},"PeriodicalIF":3.2,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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