Atmospheric and Oceanic Science Letters最新文献

{"title":"Interannual variability of short rains in Tanzania and the influences from ENSO and the Indian Ocean Dipole","authors":"Issa Rwambo ,&nbsp;Yi Fan ,&nbsp;Peilong Yu ,&nbsp;Changyu Chu ,&nbsp;Matthews Nyasulu ,&nbsp;Philemon King'uza","doi":"10.1016/j.aosl.2025.100614","DOIUrl":"10.1016/j.aosl.2025.100614","url":null,"abstract":"<div><div>Tanzania is mainly subject to a bimodal rainfall pattern, characterized by two distinct seasons: the long rains, occurring from March to May, and the short rains, which typically take place from October to December (OND). Short rains are usually less intense but still significantly influence local agriculture. Therefore, with station-based observations and reanalysis data, the current paper examines the interannual variability of OND precipitation in Tanzania from 1993 to 2022 and explores the possible impacts from El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) as well as the mechanisms. It is found that the Tanzania OND precipitation is above (below) normal in 1997, 2006, 2011, and 2019 (1993, 1998, 2005, and 2016). The composite difference between wet (dry) years and the climatology indicates that the anomalous lower-level convergence (divergence) and upward (downward) motion are the critical circulation characters for above (below) precipitation. Further analysis indicates ENSO and the IOD are the two main oceanic systems modulating OND precipitation in Tanzania. El Niño and a positive IOD could induce easterly anomalies and weaken the Walker circulation over the Indian Ocean, consequently leading to lower-level convergence in water vapor flux, upward anomalies, and more than normal precipitation in Tanzania. In contrast, La Niña and a negative IOD produce opposite circulation anomalies and less than normal precipitation over Tanzania. Moreover, through partial correlation and Generalized Equilibrium Feedback Analysis, the individual contributions of ENSO and the IOD to circulation are investigated. It is found that although both the IOD and ENSO impact the Walker circulation, the feedback to the IOD is stronger than ENSO. These results provide critical insights into the oceanic drivers and their mechanistic pathways underlying precipitation anomalies in Tanzania.</div><div>摘要</div><div>坦桑尼亚降水模态呈现双峰型, 其显著特征为两个不同的雨季: 长雨季 (3月至5月) 和短雨季 (10月至12月 (OND)). 短雨季降水强度通常较弱, 但对当地农业仍具有重要影响. 基于站点观测和再分析数据, 本文研究了1993–2022年坦桑尼亚OND降水的年际变化特征, 并探讨了厄尔尼诺-南方涛动 (ENSO) 和印度洋偶极子 (IOD) 的可能影响及其机制. 研究发现, 坦桑尼亚OND降水在1997, 2006, 2011和2019年偏多 (1993, 1998, 2005和2016年偏少) . 降水偏多 (偏少) 年与气候态之间的差值场合成分析表明, 异常低层辐合 (辐散) 和上升 (下沉) 运动是降水偏多 (偏少) 的关键环流特征. 进一步分析发现, ENSO和IOD是调控坦桑尼亚OND降水年际变化的主要海洋系统. 厄尔尼诺事件和正位相IOD会引发印度洋低层东风异常并削弱其上空Walker环流, 从而导致坦桑尼亚水汽通量在低层辐合, 上升运动异常和降水增多. 相反, 拉尼娜事件和负位相IOD会引起相反的环流异常, 导致该地区降水减少. 通过偏相关分析和广义平衡反馈方法, 本文量化了ENSO和IOD对环流的独立贡献. 结果表明, 虽然IOD和ENSO均会影响Walker环流, 但IOD的作用强于ENSO. 这些发现为理解坦桑尼亚降水异常的海洋驱动因子及其机理路径提供了重要科学依据.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 6","pages":"Article 100614"},"PeriodicalIF":3.2,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903212","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":"Principal modes of summer NDVI in eastern Siberia and its climate prediction schemes","authors":"Yuqing Tian ,&nbsp;Ke Fan ,&nbsp;Hongqing Yang ,&nbsp;Zhiqing Xu","doi":"10.1016/j.aosl.2025.100611","DOIUrl":"10.1016/j.aosl.2025.100611","url":null,"abstract":"<div><div>Based on a normalized difference vegetation index (NDVI) dataset for 1982–2021, this work investigates the principal modes of interannual variability in summer NDVI over eastern Siberia using the year-to-year increment method and empirical orthogonal function (EOF) analysis. The first three principal modes (EOF1–3) of the year-to-year increment of summer NDVI (NDVI_DY) exhibit a regionally consistent mode, a western–eastern dipole mode, and a northern–southern dipole mode, respectively. Further analysis shows that sea surface temperature (SST) in the tropical Indian Ocean in February–March and western Siberian soil moisture in April could influence EOF1. EOF2 is modulated by April Northwest Pacific SST and western Siberian soil moisture in May. May North Atlantic SST and sea ice in the Kara Sea in the preceding October significantly affect EOF3. Using the year-to-year increment method and multiple linear regression analysis, prediction schemes for EOF1–3 are developed based on these predictors. To assess the predictive skill of these schemes, one-year-out cross-validation and independent hindcast methods are employed. The temporal correlation coefficients between observed EOF1–3 and the cross-validation results are 0.62, 0.46, and 0.37, respectively, exceeding the 95 % confidence level. In addition, reconstructed schemes for summer NDVI are developed using predicted NDVI_DY and the observed principal modes of NDVI_DY. Independent hindcasts of NDVI anomalies during 2019–2021 also present consistent distributions with the observed results.</div><div>摘要</div><div>本文基于1982–2021年的归一化植被指数 (Normalized Difference Vegetation Index, NDVI) 数据集, 利用年际增量法和经验正交函数方法提取了夏季东西伯利亚地区NDVI的年际变化主模态. NDVI年际增量 (NDVI_DY) 的前3个主模态 (EOF1–3) 分别呈全区一致, 东西偶极子和南北偶极子变化特征. 进一步分析影响其主模态变化的影响因子显示, 前期2–3月热带印度洋海温和4月西西伯利亚土壤湿度是全区一致模态的关键影响因子, 东西偶极子模态受前期4月西北太平洋海温和5月西西伯利亚土壤湿度的调控, 前期5月北大西洋海温和前一年10月喀拉海海冰与南北偶极子模态相联. 本文利用上述前期关键影响因子, 基于多元线性回归分析和年际增量方法建立了夏季东西伯利亚地区NDVI_DY主模态的预测模型. 其中, 观测的EOF1–3对应的时间序列与各模态交叉检验结果的时间相关系数分别为0.62, 0.46和0.37, 均超过了95 %的置信水平. 此外, 利用预测的各模态对应时间序列和观测的主模态, 本文进一步建立了夏季东西伯利亚地区NDVI的场重建预测模型. 2019–2021年夏季东西伯利亚地区独立后报的NDVI距平的空间分布也与观测一致.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 6","pages":"Article 100611"},"PeriodicalIF":3.2,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903348","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":"Attribution of regional Hadley circulation intensity changes in the Northern Hemisphere","authors":"Yi Zheng ,&nbsp;Bo Sun ,&nbsp;Wanling Li ,&nbsp;Siyu Zhou ,&nbsp;Jiarui Cai ,&nbsp;Huixin Li ,&nbsp;Shengping He","doi":"10.1016/j.aosl.2025.100613","DOIUrl":"10.1016/j.aosl.2025.100613","url":null,"abstract":"<div><div>The discrepancy in the trends of the global zonal mean (GZM) intensity of the Hadley circulation (HCI) between reanalysis data and model simulations has been a problem for understanding the changes in HCI and the influence of external forcings. To understand the reason for this discrepancy, this study investigates the trends of intensity of regional HCI of the Northern Hemisphere over the eastern Pacific (EPA), western Pacific (WPA), Atlantic (ATL), Africa (AFR), the Indian Ocean (IDO), and residual area (RA), based on six reanalysis datasets and 13 CMIP6 models. In reanalysis data, the trends in regional HCI over EPA and ATL (WPA and AFR) contribute to (partially offset) the increasing trend in GZM HCI, while the trends in regional HCI over IDO are different in different reanalysis data. The CMIP6 models skillfully reproduce the trends in regional HCI over EPA, ATL, WPA, and AFR, but simulate notable decreasing trends in regional HCI over IDO, which is a key reason for the opposite trends in GZM HCI between reanalysis data and models. The discrepancy in IDO can be attributed to differences in the simulation of diabatic heating and zonal friction between reanalysis data and models. Optimal fingerprint analysis indicates that anthropogenic (ANT) and non-greenhouse gas (NOGHG) forcings are the dominant drivers of the HCI trends in the EPA and ATL regions. In the WPA (AFR) region, NOGHG (ANT) forcing serves as the primary driver. The findings contribute to improving the representation of regional HCI trends in models and improving the attribution of external forcings.</div><div>摘要</div><div>基于6套再分析资料和13个CMIP6模式, 研究发现模式能够较好地再现北半球东太平洋, 西太平洋, 大西洋和非洲的哈德来环流强度变化趋势. 但在印度洋区域, 再分析数据与模式模拟的趋势存在较大差异. 这一差异主要归因于模式与再分析数据在非绝热加热和纬向摩擦力模拟上的不同表现. 最优指纹法分析表明, 人为强迫和非温室气体强迫是北半球局地哈德来环流强度变化的主要驱动因素. 本研究揭示了人类活动对北半球不同区域哈德来环流变化的重要影响, 并阐明了再分析资料与CMIP6模式中北半球哈德来环流变化差异的原因.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 6","pages":"Article 100613"},"PeriodicalIF":3.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903349","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}

{"title":"Theory and prediction of tropical cyclones and induced precipitation","authors":"Lili Lei ,&nbsp;Jianfang Fei ,&nbsp;Wen Zhou","doi":"10.1016/j.aosl.2025.100608","DOIUrl":"10.1016/j.aosl.2025.100608","url":null,"abstract":"","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 2","pages":"Article 100608"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643422","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":"Westward shift of western North Pacific tropical cyclones in CMIP6-HighResMIP models","authors":"Zhuoying Li ,&nbsp;Wen Zhou","doi":"10.1016/j.aosl.2025.100594","DOIUrl":"10.1016/j.aosl.2025.100594","url":null,"abstract":"<div><div>Against the backdrop of climate change, the activity of tropical cyclones (TCs) has captured widespread attention. Observational datasets indicate a declining trend in the genesis longitude of western North Pacific (WNP) TCs. This study investigates the zonal changes of WNP TCs with CMIP6-HighResMIP models. These models capture the genesis density of WNP TCs fairly well. The results reveal a westward shift in TC genesis longitude. This trend is associated with the significant reduction in the TC frequency over the southeastern WNP. The study also discusses changes in large-scale circulation patterns and the impact of the strengthening Pacific Walker circulation.</div><div>摘要</div><div>在全球变暖背景下, 热带气旋的活动变化引起广泛关注. 观测数据表明, 西北太平洋热带气旋年平均生成经度呈减小趋势. 本研究利用CMIP6-HighResMIP模式对西北太平洋热带气旋活动的经度变化进行研究, 这些高分辨率模式较好地捕捉了西北太平洋热带气旋的生成密度. 研究显示西北太平洋地区热带气旋生成经度呈现西移的趋势, 这一趋势与西北太平洋地区东南部热带气旋频率的显著减少有关. 本研究还讨论了大尺度环流模式的变化以及太平洋沃克环流的加强所造成的影响.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 2","pages":"Article 100594"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643432","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}