Atmospheric and Oceanic Science Letters最新文献

{"title":"State of the climate over the Three Gorges Region of the Yangtze River basin in 2024","authors":"Hongling Zeng,&nbsp;Xianyan Chen,&nbsp;Yundi Jiang,&nbsp;Xukai Zou,&nbsp;Tong Cui,&nbsp;Qiang Zhang,&nbsp;Linhai Sun","doi":"10.1016/j.aosl.2025.100664","DOIUrl":"10.1016/j.aosl.2025.100664","url":null,"abstract":"<div><div>The Three Gorges Region (TGR) of the Yangtze River basin exhibited warm and dry climatic characteristics in 2024. The annual mean temperature in the TGR was 18.6 °C, which was 1.2 °C above normal and marked the highest level since 1961. All four seasons were warmer than normal, with spring and autumn both recording their highest temperatures since 1961. Additionally, the TGR recorded 57.2 high-temperature days in 2024, reaching a historic high since 1961 and exceeding the previous record set in 2022 by 2.4 days. Annual rainfall was 11.2 % below normal, with spring, summer, and autumn all being drier than normal. However, the number of heavy rain days was slightly higher than normal. The annual mean wind speed in the TGR ranked as the second-highest since 1961, only slightly lower than in 2022. The annual mean relative humidity was below normal and the number of fog days across large areas of the TGR decreased compared to 2023. In 2024, the TGR experienced extreme high-temperature events characterized by exceptional intensity and prolonged duration, accompanied by generally severe meteorological drought conditions. During the year, the TGR also experienced frequent and intense cooling events, an early onset of heavy rainfall (including severe convective weather), and exceptionally extreme rainstorm events.</div><div>摘要</div><div>2024年长江三峡地区的气候呈暖干特征, 年平均气温创下新的纪录, 达到18.6 °C, 较常年偏高1.2 °C. 四季气温均偏高, 其中春秋季平均气温均为1961年以来历史同期最高. 高温日数为57.2天, 也为1961年以来最多. 年降水量较常年偏少11.2 %, 春, 夏, 秋三季降水均偏少, 但暴雨日数较常年略偏多. 年平均风速为1961年以来第二大, 仅略低于2022年. 年平均相对湿度偏小, 大部地区雾日数较2023年有所减少. 2024年, 三峡地区经历极端高温事件, 高温强度强, 持续时间长, 气象干旱总体偏重; 强降温频次多, 强度强; 强降水 (强对流) 天气过程偏早, 暴雨极端性强.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 5","pages":"Article 100664"},"PeriodicalIF":2.3,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696952","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}

{"title":"State of China’s climate in 2024","authors":"Yundi Jiang,&nbsp;Lin Zhao,&nbsp;Xiucang Li,&nbsp;Xianyan Chen,&nbsp;Xukai Zou,&nbsp;Yiran Wang,&nbsp;Hongling Zeng,&nbsp;Tong Cui,&nbsp;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}

{"title":"Compound extreme events and health risks in China: A review","authors":"Haosu Tang ,&nbsp;Gang Huang ,&nbsp;Kaiming Hu ,&nbsp;Jun Wang ,&nbsp;Cunrui Huang ,&nbsp;Xianke Yang","doi":"10.1016/j.aosl.2025.100647","DOIUrl":"10.1016/j.aosl.2025.100647","url":null,"abstract":"<div><div>Against the backdrop of global warming, China has been facing increasingly frequent and severe extreme weather and climate events, with a prominent risk of compound extreme events induced by interactions among multiple climate drivers and/or hazards. The present study first reviews the definition and classification of compound extreme events in China. Then, it summarizes research progress on the evolutionary characteristics, formation mechanisms, and future projections of different types of compound extreme events. The potential risks and possible impact pathways of three specific event types—namely, continuous day–night hot extremes, temperature–humidity compound events, and high-temperature–ozone compound events—on the health of the Chinese population are then explored. Finally, a framework for assessing the hazard risk of compound extreme events is constructed, accompanied by response strategies based on carbon neutrality targets. Building on existing research achievements, five future research directions are proposed: (1) identifying the risk chains of compound events; (2) addressing the constraints of observational records and coupled model performances; (3) attributing and understanding the drivers of compound extreme events; (4) finding optimal pathways for carbon reduction and air quality improvement; and (5) promoting inter-disciplinary, multi-regional, and cross-sectoral collaboration. Strengthening research in these directions will deepen our understanding of compound extreme events and provide technological support for climate change adaptation and health risk responses in China.</div><div>摘要</div><div>在全球变暖的背景下, 中国面临着日益频繁和严峻的极端天气气候事件, 其中以多种气候驱动因子和/或灾害相互作用而形成的复合型极端事件风险尤为突出. 本文首先回顾了中国区域复合型极端事件的定义与分型; 然后综述了不同类型复合型极端事件的演变特征, 形成机制以及未来预估等方面的研究进展; 随后, 探讨了日夜持续型极端高温事件, 温湿复合事件以及高温–臭氧复合事件等三类事件对我国人群健康的潜在风险及可能的影响途径; 最后, 阐述了复合型极端事件灾害风险评估框架, 并在此基础上提出了基于碳中和目标的应对策略. 在总结既有研究成果的基础上, 提出了五个未来亟需关注的研究方向: (1)复合事件灾害风险链的识别问题; (2)观测资料和耦合模式性能的制约问题; (3)复合型极端事件的归因与成因问题; (4)碳减排与空气质量改善的最优路径问题; (5)多学科, 多区域, 多部门的合作问题. 加强上述方向的研究有助于深化对复合型极端事件的理解, 并为我国气候变化适应和健康风险应对提供科技支撑.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 5","pages":"Article 100647"},"PeriodicalIF":2.3,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696949","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}

{"title":"The strongest early-summer drought–flood abrupt alternation event over the Huang–Huai–Hai River Basin in 2024 since the 1980s: Perspective of anomalous subseasonal circulation evolution","authors":"Zhiheng Chen,&nbsp;Zhihai Zheng","doi":"10.1016/j.aosl.2025.100648","DOIUrl":"10.1016/j.aosl.2025.100648","url":null,"abstract":"<div><div>Since the 21st century, the Huang–Huai–Hai River Basin (HHHRB) in China has experienced increased frequency and severity of drought–flood abrupt alternation (DFAA) events during early summer, characterized by droughts in June followed by floods in July. The 2024 event was the most severe since 1981. This study demonstrates that such compound extreme events are closely linked to anomalous subseasonal evolution of large-scale atmospheric circulation. During the drought phase, the East Asian subtropical westerly jet (EAJ) shifts southward, and the western Pacific subtropical high (WPSH) exhibits anomalous strengthening with its western ridge line displaced southward. The flood phase is characterized by acceleration of the EAJ, westward extension of the WPSH, and enhanced southwestern moisture transport from the western Pacific. Beyond these typical features, the 2024 early summer circulation exhibited unique characteristics: Anomalous northeastward intensification of the WPSH facilitated merged moisture influx from both the Indian Ocean and the western Pacific along the southeast pathway into the HHHRB in July, resulting in the highest net moisture inflow at the southern boundary of the HHHRB since 1981. The synergistic effects of multiple factors primarily explain the exceptionally intense DFAA event in 2024.</div><div>摘要</div><div>21世纪以来, 中国黄淮海地区初夏旱涝急转事件 (6月旱–7月涝) 呈频次增多, 强度增强趋势, 2024年事件为1981年以来最强. 研究表明, 此类复合极端事件与大尺度环流的季节内异常演变密切相关, 其中旱期表现为东亚副热带西风急流的位置偏南, 西太副高的强度偏强但西段脊线偏南; 涝期表现为东亚副热带西风急流增速, 西太副高西伸脊点偏西与西南路径西太水汽的增多. 除上述典型特征外, 2024年初夏的环流演变兼具特殊性——初夏西太副高向东北方向的异常加强, 导致7月印度洋水汽和东南路径的西太水汽合并汇入黄淮海地区, 造成其南边界水汽净流入量达1981年以来峰值. 以上多要素协同是2024年黄淮海地区旱涝急转事件强度异常偏强的重要原因.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 5","pages":"Article 100648"},"PeriodicalIF":2.3,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696950","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}

{"title":"Trends and characteristics of global CH4 emissions: Insights from UNFCCC greenhouse gas inventories","authors":"Dong Gao ,&nbsp;Wenkang Gao ,&nbsp;Zhanyun Ma ,&nbsp;Lingyun Zhu ,&nbsp;Jiajing Tian ,&nbsp;Shule Liu ,&nbsp;Yangchun Yu ,&nbsp;Guozhong Zhang ,&nbsp;Qingxian Gao","doi":"10.1016/j.aosl.2025.100637","DOIUrl":"10.1016/j.aosl.2025.100637","url":null,"abstract":"<div><div>The trends and characteristics of global CH₄ emissions were analyzed using greenhouse gas data reported by both Annex I and non-Annex I countries under the United Nations Framework Convention on Climate Change (UNFCCC) from 1990 to 2021. The results show the following: (1) In 2021, the cumulative CH₄ emissions from the 42 nations listed in Annex I of the UNFCCC amounted to 1871521.79 kt CO₂ eq. The top 10 countries account for 82.0 % of the total CH₄ emissions. (2) Most Annex I countries showed a gradual decline in CH₄ emissions over the period. In contrast, emissions from non-Annex I countries have increased year by year. Notably, CH₄ emissions in the United States, the European Union, the Russian Federation, and Ukraine decreased by 14.0 %, 37.4 %, 24.0 %, and 60.9 %, respectively. (3) In 2020, the CH₄ emissions of the agriculture, energy, waste treatment and LULUCF (land use, land-use change and forestry) sectors in Annex I countries were 72240.43, 63863.51, 41573.08, and 889019 million tons of CO₂ eq, accounting for 38.6 %, 34.1 %, 22.2 %, and 4.8 %, respectively. Among non-Annex I countries, the main CH₄ sources vary by country. In China and Mexico, energy and agriculture were the largest contributors, accounting for 44.8 % and 40.2 % in China, and 34.4 % and 43.3 % in Mexico, respectively. In India, Brazil, Nigeria, Argentina, and Vietnam, agriculture dominated, contributing 73.8 %, 75.8 %, 59.7 %, 60.3 %, and 58.5 % of total emissions, respectively. Indonesia was an exception, with waste treatment being the primary source, accounting for 64.8 % of its total CH₄ emissions.</div><div>摘要</div><div>基于《联合国气候变化框架公约》 (UNFCCC) 附件一国家提交的 1990 年至最新清单年份 (2021 年) 温室气体排放数据, 探讨了附件一和非附件一国家排放现状, 演变趋势和关键排放源. 结果表明: 2021年UNFCCC附件一中42个国家CH₄总排放量为1871521.79 kt CO₂当量. 排在前10位的国家占CH₄总排放量的82.0 %. (2)大多数附件一国家的CH₄排放量呈逐渐下降趋势, 非附件一国家的CH₄排放量呈逐年增加趋势, 其中最大的排放源的美国, 欧盟(公约), 俄罗斯联邦和乌克兰排放量分别下降了13.96 %, 37.44 %, 24.01 %和60.89 %. 乌克兰, 英国, 意大利和罗马尼亚与1990年相比, 2021年的排放量减少了60 %以上. (3) 2020年, 附件一国家农业, 能源, 废物处理和LULUCF行业的CH₄排放量分别为72240.43, 63863.51, 41573.08和889.19亿吨CO₂当量, 占比分别为38.60 %, 34.11 %, 22.21 %和4.75 %. 在UNFCCC非附件一国家中, 能源和农业部门是中国和墨西哥最主要的CH₄排放源, 分别占中国总排放量的44.77 %和40.23 %, 占墨西哥总排放量的34.44 %和43.29 %. 在印度, 巴西, 尼日利亚, 阿根廷和越南, 农业部门是最主要的排放源, 分别占总排放量的73.75 %, 75.78 %, 59.66 %, 60.29 %和58.47 %. 印度尼西亚以废物处理部门为主, 占总排放量的64.79 %.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 5","pages":"Article 100637"},"PeriodicalIF":2.3,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696948","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}

{"title":"Spatiotemporal characteristics of Universal Thermal Climate Index during five-year return period extreme heat events in the Beijing–Tianjin–Hebei region","authors":"Yiguo Xu ,&nbsp;Liqing Tian ,&nbsp;Tingru Cui ,&nbsp;Jun Zhang ,&nbsp;Hui Zhang ,&nbsp;Yating Wang ,&nbsp;Rui Wang","doi":"10.1016/j.aosl.2025.100612","DOIUrl":"10.1016/j.aosl.2025.100612","url":null,"abstract":"<div><div>Frequent extreme heat events exacerbated by global warming pose a significant threat to human health. However, the dynamic changes in human thermal comfort during such regional extremes remain understudied. This study investigates the spatiotemporal characteristics of the Universal Thermal Climate Index (UTCI) during 5-year return period extreme heat events across the Beijing–Tianjin–Hebei (BTH) region of China, utilizing 40 years of meteorological data from 174 stations. A non-stationary Generalized Extreme Value distribution model with a location parameter link function was identified as the optimal model (for 65.3 % of stations) through the Akaike Information Criterion, capturing 16 regional extreme heat events. Results indicate that extreme heat thresholds rise with increasing return periods, with the highest thresholds concentrated around Beijing and Shijiazhuang. Air temperature and mean radiant temperature were found to be the dominant factors influencing UTCI, with daytime air temperature contributing 47.03 % to 50.64 % and nighttime mean radiant temperature contributing up to 48.55 %. Spatially, “extreme heat stress” conditions, as defined by UTCI, were predominantly observed in the southeastern plains of Beijing and southern Hebei Province. Diurnally, UTCI peaked between 1200 and 1600 BT (Beijing time), generally returning to “no heat stress” levels across most areas between 0000 and 0600 BT. These findings provide crucial insights into the dynamics of human thermal comfort during extreme heat events in the BTH region, offering valuable scientific support for developing targeted heat mitigation and adaptation strategies.</div><div>摘要</div><div>本研究旨在探讨京津冀地区五年一遇极端高温事件期间通用热气候指数的时空特征, 弥补极端高温条件下人类热舒适度动态变化研究的不足. 基于40年174站点数据, 采用非平稳广义极值 (GEV) 分布模型, 通过赤池信息准则选取最优模型, 识别出16次极端高温事件. 结果表明, 极端高温阈值随重现期延长而升高, 北京, 石家庄周边最高. 气温和平均辐射温度是UTCI主导因素, 极端高温热应力主要分布于北京东南部平原及河北南部, UTCI在12至16时达峰值, 00至06时降至“无热应力”水平. 本研究为高温应对提供了科学支撑.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 3","pages":"Article 100612"},"PeriodicalIF":2.3,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868276","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}

{"title":"Changes in tropical cyclone response to the Boreal Summer Intraseasonal Oscillation in the western North Pacific under global warming in EC-Earth3P-HR","authors":"Zhefan Gao ,&nbsp;Chaoxia Yuan","doi":"10.1016/j.aosl.2024.100482","DOIUrl":"10.1016/j.aosl.2024.100482","url":null,"abstract":"<div><div>EC-Earth3P-HR reproduces well the observed Boreal Summer Intraseasonal Oscillation (BSISO) and its impacts on tropical cyclone genesis (TCG) in the western North Pacific (WNP). Hence, the historical simulation (1950–1979) and future projection under the SSP5-8.5 scenario (2020–2049) in EC-Earth3P-HR are adopted to explore possible changes in the BSISO's modification of WNP TCG under global warming to enhance the understanding of TC activities in the WNP. Results show that the BSISO circulation in the WNP shifts northeastward under global warming. This leads to enhanced convection in a northwest–southeast-oriented band crossing the WNP. Along the band, the BSISO-related TCG anomalies are enhanced. Analyses of genesis potential index show that changes in the BSISO-related mid-tropospheric relative humidity play the dominant role in modifying the BSISO's impacts on WNP TCG under global warming. The enhanced BSISO convection in the band moistens the middle troposphere, which helps reduce the entrainment of generally dry mid-tropospheric air in the updrafts and the modification of the boundary layer by the downdraft of generally dry mid-tropospheric air, leading to enhanced TCG.</div><div>摘要</div><div>北半球夏季季内振荡 (BSISO) 对西北太平洋 (WNP) 热带气旋形成 (TCG) 有显著的影响, 并且为TC的次季节预报提供重要依据, 因此研究其在全球变暖下的变化有重要意义. EC-Earth3P-HR模式较好地再现了观测到的BSISO及其对TCG的影响. 因此, 采用EC-Earth3P-HR的历史模拟 (1950–1979) 和SSP5-8.5情景 (2020–2049) 下的未来预估, 探讨全球变暖下BSISO对WNP上TCG调制的可能变化. 结果表明, 在全球变暖影响下, WNP上的BSISO环流向东北方向移动, 表现为西北-东南方向分布的增强对流带. 在对流带上, BSISO相关的TCG异常增强. 成因潜力指数分析表明, 全球变暖背景下, 与BSISO相关的对流层中部相对湿度的变化对BSISO对TCG的调制起主导作用. 带内增强的BSISO对流使对流层中部空气变湿润, 这有利于减少上升气流对通常干燥的对流层空气的夹带以及下沉气流对边界层的修正, 从而导致TCG的增强.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 2","pages":"Article 100482"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140464770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Statistical seasonal forecasting of tropical cyclone landfalls on Taiwan Island","authors":"Ziqing Chen ,&nbsp;Kelvin T.F. Chan ,&nbsp;Zawai Luo","doi":"10.1016/j.aosl.2024.100554","DOIUrl":"10.1016/j.aosl.2024.100554","url":null,"abstract":"<div><div>Forecasting tropical cyclone (TC) activities has been a topic of great interest and research. Taiwan Island (TW) is one of the key regions that is highly exposed to TCs originated from the western North Pacific. Here, the authors utilize two mainstream reanalysis datasets for the period 1979–2013 and propose an effective statistical seasonal forecasting model—namely, the Sun Yat-sen University (SYSU) Model—for predicting the number of TC landfalls on TW based on the environmental factors in the preseason. The comprehensive predictor sampling and multiple linear regression show that the 850-hPa meridional wind over the west of the Antarctic Peninsula in January, the 300-hPa specific humidity over the open ocean southwest of Australia in January, the 300-hPa relative vorticity over the west of the Sea of Okhotsk in March, and the sea surface temperature in the South Indian Ocean in April, are the most significant predictors. The correlation coefficient between the modeled results and observations reaches 0.87. The model is validated by the leave-one-out and nine-fold cross-validation methods, and recent 9-yr observations (2014–2022). The Antarctic Oscillation, variabilities of the western Pacific subtropical high, Asian summer monsoon, and oceanic tunnel are the possible physical linkages or mechanisms behind the model result. The SYSU Model exhibits a 98% hit rate in 1979–2022 (43 out of 44), suggesting an operational potential in the seasonal forecasting of TC landfalls on TW.</div><div>摘要</div><div>本文利用1979–2013年的两个主流再分析数据集, 提出了一个中山大学 (SYSU) 热带气旋统计季节预报模型, 基于4个季前环境因子对登陆台湾岛的热带气旋数量进行预报. 模型通过了留一法, 九折交叉验证法和近9年观测数据 (2014–2022) 的验证, 模型结果与实际观测的相关系数达0.87. 南极涛动, 西太平洋副热带高压变化, 亚洲夏季风和海洋通道是模型潜在的物理联系或机制. SYSU模型在1979–2022年期间的预报准确率为98%, 表现出其业务应用价值.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 2","pages":"Article 100554"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation of size contraction of Typhoon Cempaka (2021)","authors":"Lingfeng Sun ,&nbsp;Qingqing Li","doi":"10.1016/j.aosl.2024.100533","DOIUrl":"10.1016/j.aosl.2024.100533","url":null,"abstract":"<div><div>In 2021, Cempaka, a tiny tropical cyclone, made landfall in China. As the TC intensified prior to landfall, the tropical cyclone size measured with precipitation decreased significantly. A numerical simulation was conducted to examine the possible processes modulating the storm size. Azimuthally mean potential vorticity (PV) was found to decrease mainly in the middle to upper troposphere between 50- and 80-km radii. The PV budget results indicate that the advection and generation of mean PV associated with asymmetric processes, rather than the symmetric processes, primarily contributed to the decrease in mean PV. These asymmetric processes leading to a negative PV tendency were likely associated with inactive outer rainbands. In contrast, the tangential winds simultaneously expanded radially outward, possibly related to inner-core diabatic heating. The findings here emphasize the importance of outer rainband activity in tropical cyclone size change.</div><div>摘要</div><div>2021年台风“查帕卡”增强过程中风场向外扩张, 但卫星云图显示降水范围减小. 高分辨率数值模拟结果显示, “查帕卡”降水范围减小对应着50–80km半径处对流层中层位涡的减小. 位涡诊断结果表明, 非对称过程是导致上述位涡减小的关键物理过程, 而非对称过程主要同外雨带活动减弱有关. 上述结果强调了外雨带活动对热带气旋尺度变化的潜在重要影响.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 2","pages":"Article 100533"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141393846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Collaborative assimilation experiment of Beidou radiosonde and drone-dropped radiosonde based on CMA-TRAMS","authors":"Qiushi Wen ,&nbsp;Xuefen Zhang ,&nbsp;Sheng Hu ,&nbsp;Peitao Zhao ,&nbsp;Shuixin Zhong ,&nbsp;Zhenyu Liu ,&nbsp;Zhongkuo Zhao ,&nbsp;Jiahao Liang ,&nbsp;Guangfeng Dai ,&nbsp;Chenzhong Zhang ,&nbsp;Mengjie Li ,&nbsp;Ling Huang","doi":"10.1016/j.aosl.2024.100555","DOIUrl":"10.1016/j.aosl.2024.100555","url":null,"abstract":"<div><div>Based on the China Meteorological Administration's Tropical Regional Atmosphere Model for the South China Sea (CMA-TRAMS), the authors conducted a collaborative assimilation forecasting experiment utilizing both Beidou radiosonde and drone-dropped (HAIYAN-I) radiosonde data in September 2023. Three assimilation experimental groups were designed as follows: Beidou radiosonde assimilation, drone-dropped radiosonde assimilation, and collaborative assimilation of Beidou and drone-dropped radiosonde data (hereinafter referred to as “Beidou-drop”). Additionally, a control group of operational forecasts without these data assimilations was set up. The results indicate that the operational forecast path in the control group deviated northward from the actual path. Besides, the Beidou-drop group showed the most significant improvement in terms of forecasting the typhoon path at 60 to 90 h lead times. Specifically, the 72 h and 90 h path errors were reduced by 66.8 and 82.4 km, respectively, resulting in a much more accurate forecast of Typhoon Haikui's landing point, at the coastal junction of Fujian and Guangdong. Furthermore, the collaborative assimilation revealed a notable impact on improving the forecast of wind and rain associated with Haikui's landfall, aligning more closely with the real case. A marked rise was also seen in the precipitation score of the Beidou-drop group, where the 50 mm TS (threat score) of the 72 h lead time increased from 0.33 in the control experiment to 0.75, and the 100 mm TS rose from 0.18 to 0.39.</div><div>摘要</div><div>基于中国气象局南海台风模式CMA-TRAMS, 开展了北斗探空和无人机下投探空协同同化预报试验, 分别开展了北斗探空同化, 无人机下投探空同化, 北斗和下投探空 (beidou-drop) 协同同化试验. 结果表明, CMA-TRAMS业务预报路径较实况偏北, 协同同化了北斗和下投探空的路径预报改进效果最显著, 对60–90小时路径预报均有改进, 72小时和90小时路径误差分别较减小66.8 km和82.4 km, 且台风海葵的登陆区域更趋于向实况 (闽粤沿海交界处); 协同同化了北斗和下投探空对台风“海葵”登陆风雨影响更为显著, 与实况更加吻合, 降水评分提升明显, 72小时预报的50 mm TS评分由对照试验的0.33提高至0.75; 100 mm降水TS评分由对照试验的0.18提高至0.39.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 2","pages":"Article 100555"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}