The 2022 and 2023 western Mediterranean summer temperatures exceeded millennial natural variability, reaching unprecedented anomalies of +3.6 °C and +2.9 °C respectively. We show that anthropogenic climate change may turn extreme heatwaves from a rarity of 1 in 10,000 years into events occurring every 4–75 years, depending on future scenarios. This shift underscores the urgency of implementing adaptive strategies as extreme climate events manifest sooner and more intensely than expected.
{"title":"Recent heatwaves as a prelude to climate extremes in the western Mediterranean region","authors":"Ernesto Tejedor, Gerardo Benito, Roberto Serrano-Notivoli, Fidel González-Rouco, Jan Esper, Ulf Büntgen","doi":"10.1038/s41612-024-00771-6","DOIUrl":"10.1038/s41612-024-00771-6","url":null,"abstract":"The 2022 and 2023 western Mediterranean summer temperatures exceeded millennial natural variability, reaching unprecedented anomalies of +3.6 °C and +2.9 °C respectively. We show that anthropogenic climate change may turn extreme heatwaves from a rarity of 1 in 10,000 years into events occurring every 4–75 years, depending on future scenarios. This shift underscores the urgency of implementing adaptive strategies as extreme climate events manifest sooner and more intensely than expected.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-7"},"PeriodicalIF":8.5,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00771-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142245313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heavy Meiyu-Baiu rainfall can pose threat to the dense population in East Asia by catastrophic flooding. Although previous studies have identified Indian Ocean (IO) warming as the major cause of heavy Meiyu-Baiu rainfall, it failed to predict the record-breaking rainfall in July 2020. Synthesizing observational analysis, large-ensemble climate simulations, and atmospheric simulations, we show that sea-ice loss in the Kara Sea in May can intensify the IO warming-induced heavy Meiyu-Baiu rainfall and well explains the record-breaking rainfall in July 2020. In the precondition of IO warming, sea-ice loss tends to prolong Meiyu-Baiu season and strengthen convective activity over the Meiyu-Baiu region, thereby enhancing the IO warming-induced heavy Meiyu-Baiu rainfall by ~50% and doubling the risk of extreme events comparable to or greater than the one in 2020. A statistical model is further constructed to demonstrate that taking Arctic sea ice into consideration can significantly improve the seasonal prediction of extreme Meiyu-Baiu rainfall.
{"title":"Sea-ice loss in Eurasian Arctic coast intensifies heavy Meiyu-Baiu rainfall associated with Indian Ocean warming","authors":"Xiaodan Chen, Zhiping Wen, Jiping Liu, Wei Mei, Ruonan Zhang, Sihua Huang, Yuanyuan Guo, Juncong Li","doi":"10.1038/s41612-024-00770-7","DOIUrl":"10.1038/s41612-024-00770-7","url":null,"abstract":"Heavy Meiyu-Baiu rainfall can pose threat to the dense population in East Asia by catastrophic flooding. Although previous studies have identified Indian Ocean (IO) warming as the major cause of heavy Meiyu-Baiu rainfall, it failed to predict the record-breaking rainfall in July 2020. Synthesizing observational analysis, large-ensemble climate simulations, and atmospheric simulations, we show that sea-ice loss in the Kara Sea in May can intensify the IO warming-induced heavy Meiyu-Baiu rainfall and well explains the record-breaking rainfall in July 2020. In the precondition of IO warming, sea-ice loss tends to prolong Meiyu-Baiu season and strengthen convective activity over the Meiyu-Baiu region, thereby enhancing the IO warming-induced heavy Meiyu-Baiu rainfall by ~50% and doubling the risk of extreme events comparable to or greater than the one in 2020. A statistical model is further constructed to demonstrate that taking Arctic sea ice into consideration can significantly improve the seasonal prediction of extreme Meiyu-Baiu rainfall.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-12"},"PeriodicalIF":8.5,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00770-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extreme events with increasing frequency and intensity are significantly affecting the permafrost environment. Analysis using the ERA5-Land reanalysis data revealed that the permafrost region of the central Qinghai-Tibet Plateau (QTP) experienced the summer heat wave in 2022. Four active layer sites experienced maximum active layer thicknesses (ALT) in 2022 (mean: 207.7 cm), which was 20% higher than the mean ALT during 2000–2021 (mean: 175.9 cm). The mean annual ground temperature (MAGT) observed in 2022 was also the highest, exceeding the average of the previous years by 10%. The contribution fraction of heat wave to the seasonal thaw depth of active layer was quantified using Stefan model with ranging from 6.6% to 13.6%, and the maximum contribution fraction occurs in 2022. These findings are helpful to better understand the impact processes of extreme events on the active layer and permafrost.
频率和强度不断增加的极端事件正在对冻土环境产生重大影响。利用ERA5-Land再分析数据进行的分析表明，青藏高原中部的冻土区在2022年经历了夏季热浪。2022年，四个活动层站点出现了最大活动层厚度（平均：207.7厘米），比2000-2021年的平均活动层厚度（平均：175.9厘米）高出20%。2022 年观测到的年平均地面温度（MAGT）也是最高的，比前几年的平均值高出 10%。利用 Stefan 模型量化了热浪对活动层季节性解冻深度的贡献率，其范围为 6.6% 至 13.6%，最大贡献率出现在 2022 年。这些发现有助于更好地理解极端事件对活动层和冻土的影响过程。
{"title":"Summer heat wave in 2022 led to rapid warming of permafrost in the central Qinghai-Tibet Plateau","authors":"Xiaofan Zhu, Tonghua Wu, Jie Chen, Xiaodong Wu, Pengling Wang, Defu Zou, Guangyang Yue, Xuchun Yan, Xin Ma, Dong Wang, Peiqing Lou, Amin Wen, Chengpeng Shang, Weiying Liu","doi":"10.1038/s41612-024-00765-4","DOIUrl":"10.1038/s41612-024-00765-4","url":null,"abstract":"Extreme events with increasing frequency and intensity are significantly affecting the permafrost environment. Analysis using the ERA5-Land reanalysis data revealed that the permafrost region of the central Qinghai-Tibet Plateau (QTP) experienced the summer heat wave in 2022. Four active layer sites experienced maximum active layer thicknesses (ALT) in 2022 (mean: 207.7 cm), which was 20% higher than the mean ALT during 2000–2021 (mean: 175.9 cm). The mean annual ground temperature (MAGT) observed in 2022 was also the highest, exceeding the average of the previous years by 10%. The contribution fraction of heat wave to the seasonal thaw depth of active layer was quantified using Stefan model with ranging from 6.6% to 13.6%, and the maximum contribution fraction occurs in 2022. These findings are helpful to better understand the impact processes of extreme events on the active layer and permafrost.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-15"},"PeriodicalIF":8.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00765-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142175028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1038/s41612-024-00758-3
Christos Xenofontos, Matthias Kohl, Samuel Ruhl, João Almeida, Hannah M. Beckmann, Lucía Caudillo-Plath, Sebastian Ehrhart, Kristina Höhler, Milin Kaniyodical Sebastian, Weimeng Kong, Felix Kunkler, Antti Onnela, Pedro Rato, Douglas M. Russell, Mario Simon, Leander Stark, Nsikanabasi Silas Umo, Gabriela R. Unfer, Boxing Yang, Wenjuan Yu, Marcel Zauner-Wieczorek, Imad Zgheib, Zhensen Zheng, Joachim Curtius, Neil M. Donahue, Imad El Haddad, Richard C. Flagan, Hamish Gordon, Hartwig Harder, Xu-Cheng He, Jasper Kirkby, Markku Kulmala, Ottmar Möhler, Mira L. Pöhlker, Siegfried Schobesberger, Rainer Volkamer, Mingyi Wang, Stephan Borrmann, Andrea Pozzer, Jos Lelieveld, Theodoros Christoudias
During summer, ammonia emissions in Southeast Asia influence air pollution and cloud formation. Convective transport by the South Asian monsoon carries these pollutant air masses into the upper troposphere and lower stratosphere (UTLS), where they accumulate under anticyclonic flow conditions. This air mass accumulation is thought to contribute to particle formation and the development of the Asian Tropopause Aerosol Layer (ATAL). Despite the known influence of ammonia and particulate ammonium on air pollution, a comprehensive understanding of the ATAL is lacking. In this modelling study, the influence of ammonia on particle formation is assessed with emphasis on the ATAL. We use the EMAC chemistry-climate model, incorporating new particle formation parameterisations derived from experiments at the CERN CLOUD chamber. Our diurnal cycle analysis confirms that new particle formation mainly occurs during daylight, with a 10-fold enhancement in rate. This increase is prominent in the South Asian monsoon UTLS, where deep convection introduces high ammonia levels from the boundary layer, compared to a baseline scenario without ammonia. Our model simulations reveal that this ammonia-driven particle formation and growth contributes to an increase of up to 80% in cloud condensation nuclei (CCN) concentrations at cloud-forming heights in the South Asian monsoon region. We find that ammonia profoundly influences the aerosol mass and composition in the ATAL through particle growth, as indicated by an order of magnitude increase in nitrate levels linked to ammonia emissions. However, the effect of ammonia-driven new particle formation on aerosol mass in the ATAL is relatively small. Ammonia emissions enhance the regional aerosol optical depth (AOD) for shortwave solar radiation by up to 70%. We conclude that ammonia has a pronounced effect on the ATAL development, composition, the regional AOD, and CCN concentrations.
夏季，东南亚的氨排放会影响空气污染和云的形成。南亚季风的对流输送将这些污染气团带入对流层上部和平流层下部（UTLS），并在反气旋流动条件下积聚。这种气团积聚被认为有助于粒子的形成和亚洲对流层顶气溶胶层（ATAL）的发展。尽管氨和微粒铵对空气污染的影响众所周知，但对 ATAL 却缺乏全面的了解。本模拟研究评估了氨对颗粒物形成的影响，重点是 ATAL。我们使用了 EMAC 化学-气候模型，其中纳入了从欧洲核子研究中心 CLOUD 实验室的实验中得出的新颗粒物形成参数。我们的昼夜周期分析证实，新粒子的形成主要发生在白天，形成率增加了 10 倍。与不含氨的基线情景相比，这种增加在南亚季风UTLS中尤为突出，因为深层对流会从边界层引入高浓度的氨。我们的模型模拟显示，这种由氨驱动的粒子形成和增长导致南亚季风地区成云高度的云凝结核（CCN）浓度增加高达 80%。我们发现，氨通过粒子生长对 ATAL 中的气溶胶质量和组成产生了深远影响，与氨排放相关的硝酸盐含量的数量级增长就表明了这一点。然而，氨驱动的新颗粒形成对 ATAL 气溶胶质量的影响相对较小。氨的排放使区域气溶胶光学深度（AOD）对短波太阳辐射的影响提高了 70%。我们的结论是，氨对 ATAL 的发展、组成、区域 AOD 和 CCN 浓度都有明显的影响。
{"title":"The impact of ammonia on particle formation in the Asian Tropopause Aerosol Layer","authors":"Christos Xenofontos, Matthias Kohl, Samuel Ruhl, João Almeida, Hannah M. Beckmann, Lucía Caudillo-Plath, Sebastian Ehrhart, Kristina Höhler, Milin Kaniyodical Sebastian, Weimeng Kong, Felix Kunkler, Antti Onnela, Pedro Rato, Douglas M. Russell, Mario Simon, Leander Stark, Nsikanabasi Silas Umo, Gabriela R. Unfer, Boxing Yang, Wenjuan Yu, Marcel Zauner-Wieczorek, Imad Zgheib, Zhensen Zheng, Joachim Curtius, Neil M. Donahue, Imad El Haddad, Richard C. Flagan, Hamish Gordon, Hartwig Harder, Xu-Cheng He, Jasper Kirkby, Markku Kulmala, Ottmar Möhler, Mira L. Pöhlker, Siegfried Schobesberger, Rainer Volkamer, Mingyi Wang, Stephan Borrmann, Andrea Pozzer, Jos Lelieveld, Theodoros Christoudias","doi":"10.1038/s41612-024-00758-3","DOIUrl":"10.1038/s41612-024-00758-3","url":null,"abstract":"During summer, ammonia emissions in Southeast Asia influence air pollution and cloud formation. Convective transport by the South Asian monsoon carries these pollutant air masses into the upper troposphere and lower stratosphere (UTLS), where they accumulate under anticyclonic flow conditions. This air mass accumulation is thought to contribute to particle formation and the development of the Asian Tropopause Aerosol Layer (ATAL). Despite the known influence of ammonia and particulate ammonium on air pollution, a comprehensive understanding of the ATAL is lacking. In this modelling study, the influence of ammonia on particle formation is assessed with emphasis on the ATAL. We use the EMAC chemistry-climate model, incorporating new particle formation parameterisations derived from experiments at the CERN CLOUD chamber. Our diurnal cycle analysis confirms that new particle formation mainly occurs during daylight, with a 10-fold enhancement in rate. This increase is prominent in the South Asian monsoon UTLS, where deep convection introduces high ammonia levels from the boundary layer, compared to a baseline scenario without ammonia. Our model simulations reveal that this ammonia-driven particle formation and growth contributes to an increase of up to 80% in cloud condensation nuclei (CCN) concentrations at cloud-forming heights in the South Asian monsoon region. We find that ammonia profoundly influences the aerosol mass and composition in the ATAL through particle growth, as indicated by an order of magnitude increase in nitrate levels linked to ammonia emissions. However, the effect of ammonia-driven new particle formation on aerosol mass in the ATAL is relatively small. Ammonia emissions enhance the regional aerosol optical depth (AOD) for shortwave solar radiation by up to 70%. We conclude that ammonia has a pronounced effect on the ATAL development, composition, the regional AOD, and CCN concentrations.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-12"},"PeriodicalIF":8.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00758-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142175032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1038/s41612-024-00761-8
Akintomide A. Akinsanola, Ziming Chen, Gabriel J. Kooperman, Vishal Bobde
We investigate 21st-century hydroclimate changes over the United States (US) during winter and the sources of projection uncertainty under three emission scenarios (SSP2–4.5, SSP3–7.0, and SSP5–8.5) using CMIP6 models. Our study reveals a robust intensification of winter precipitation across the US, except in the Southern Great Plains, where changes are very small. By the end of the 21st century, winter precipitation is projected to increase by about 2–5% K−1 over most of the US. The frequency of very wet winters is also expected to increase, with 6–7 out of 30 winters exceeding the very wet threshold under the different scenarios. Our results suggest that the enhancement of future winter precipitation is modulated largely by coupled dynamic and thermodynamic responses, though partly offset by thermodynamic responses. Overall, our results highlight a high likelihood of increasing impacts from winter precipitation due to climate change.
{"title":"Robust future intensification of winter precipitation over the United States","authors":"Akintomide A. Akinsanola, Ziming Chen, Gabriel J. Kooperman, Vishal Bobde","doi":"10.1038/s41612-024-00761-8","DOIUrl":"10.1038/s41612-024-00761-8","url":null,"abstract":"We investigate 21st-century hydroclimate changes over the United States (US) during winter and the sources of projection uncertainty under three emission scenarios (SSP2–4.5, SSP3–7.0, and SSP5–8.5) using CMIP6 models. Our study reveals a robust intensification of winter precipitation across the US, except in the Southern Great Plains, where changes are very small. By the end of the 21st century, winter precipitation is projected to increase by about 2–5% K−1 over most of the US. The frequency of very wet winters is also expected to increase, with 6–7 out of 30 winters exceeding the very wet threshold under the different scenarios. Our results suggest that the enhancement of future winter precipitation is modulated largely by coupled dynamic and thermodynamic responses, though partly offset by thermodynamic responses. Overall, our results highlight a high likelihood of increasing impacts from winter precipitation due to climate change.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-11"},"PeriodicalIF":8.5,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00761-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142160844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1038/s41612-024-00760-9
Hong Wang, Zhisheng An, Xu Zhang, Peixian Shu, Feng He, Weiguo Liu, Hongxuan Lu, Guodong Ming, Lin Liu, Weijian Zhou
The last glacial maximum (LGM) is widely acknowledged as the most recent cold period representing maximum global ice conditions. However, substantial warming is observed over Northern Hemisphere. Here, we show that the LGM climate shifted from very cold to fairly warm, followed by less cold conditions in the early Heinrich Stadial 1 (HS1) phases. Our synthesis of accurate AMS 14C dates refines the exact timing of Laurentide Ice Sheet (LIS) advances during the early LGM/HS1, constraining the chronology of the LIS decay during the late LGM. The summertime soil temperatures near ice fronts were found to increase by 1.3 °C from the early to late LGM and to decrease by 0.5 °C to the early HS1 phases, consistent with the cold-warm-cool climate patterns. The early/late LGM and early HS1 climates are found to be characterized by frequent cold/warm summers and cold winters since the world’s largest LIS began to decay.
{"title":"Westerly and Laurentide ice sheet fluctuations during the last glacial maximum","authors":"Hong Wang, Zhisheng An, Xu Zhang, Peixian Shu, Feng He, Weiguo Liu, Hongxuan Lu, Guodong Ming, Lin Liu, Weijian Zhou","doi":"10.1038/s41612-024-00760-9","DOIUrl":"10.1038/s41612-024-00760-9","url":null,"abstract":"The last glacial maximum (LGM) is widely acknowledged as the most recent cold period representing maximum global ice conditions. However, substantial warming is observed over Northern Hemisphere. Here, we show that the LGM climate shifted from very cold to fairly warm, followed by less cold conditions in the early Heinrich Stadial 1 (HS1) phases. Our synthesis of accurate AMS 14C dates refines the exact timing of Laurentide Ice Sheet (LIS) advances during the early LGM/HS1, constraining the chronology of the LIS decay during the late LGM. The summertime soil temperatures near ice fronts were found to increase by 1.3 °C from the early to late LGM and to decrease by 0.5 °C to the early HS1 phases, consistent with the cold-warm-cool climate patterns. The early/late LGM and early HS1 climates are found to be characterized by frequent cold/warm summers and cold winters since the world’s largest LIS began to decay.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-10"},"PeriodicalIF":8.5,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00760-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142166159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1038/s41612-024-00762-7
Wen Xing, Chunzai Wang, Lei Zhang, Baiyang Chen, Heng Liu
The rainfall variabilities of the West African and South American summer monsoons, pivotal for local and global climate systems, are strongly influenced by tropical Atlantic sea surface temperature anomalies. This study investigates the impacts of two recently identified Atlantic Niño types, central and eastern Atlantic Niño (CAN and EAN), on these monsoon systems using observational data and numerical experiments. During boreal summer, EAN events exhibit increased rainfall over West Africa compared to CAN events, indicating a strengthened West African summer monsoon. Enhanced moisture flux convergence from eastern Atlantic warming drives these wetting conditions during EAN events. Conversely, CAN events have a more pronounced influence on South American monsoon rainfall during austral summer, causing a rainfall anomaly dipole between the Amazon and eastern Brazil, suggesting an eastward shift in the South American summer monsoon rainfall belt. These rainfall changes are linked to cyclonic circulation anomalies over the southwest Atlantic Ocean, attributed to central Atlantic warming during CAN events. Furthermore, a statistical model assesses hindcast skills of rainfall variability in the two summer monsoon regions, affirming the benefits of separating Atlantic Niño into CAN and EAN events for improved seasonal climate predictions.
西非和南美洲夏季季风的降雨量变化对当地和全球气候系统至关重要，受到热带大西洋海面温度异常的强烈影响。本研究利用观测数据和数值实验研究了最近确定的两种大西洋尼诺现象类型，即大西洋中部和东部尼诺现象（CAN 和 EAN）对这些季风系统的影响。在北半球夏季，EAN 事件与 CAN 事件相比，西非降雨量增加，表明西非夏季季风得到加强。在 EAN 事件期间，大西洋东部变暖带来的水汽通量辐合增强推动了这些湿润条件。相反，CAN 事件对南美洲夏季季风降雨的影响更为明显，在亚马逊和巴西东部之间造成降雨异常偶极，表明南美洲夏季季风降雨带向东移动。这些降雨量变化与大西洋西南部的气旋环流异常有关，而气旋环流异常则归因于 CAN 事件期间大西洋中部的变暖。此外，一个统计模型评估了两个夏季季风区域降雨量变化的后报技能，肯定了将大西洋尼诺现象分为 CAN 和 EAN 事件对改进季节性气候预测的益处。
{"title":"Influences of Central and Eastern Atlantic Niño on the West African and South American summer monsoons","authors":"Wen Xing, Chunzai Wang, Lei Zhang, Baiyang Chen, Heng Liu","doi":"10.1038/s41612-024-00762-7","DOIUrl":"10.1038/s41612-024-00762-7","url":null,"abstract":"The rainfall variabilities of the West African and South American summer monsoons, pivotal for local and global climate systems, are strongly influenced by tropical Atlantic sea surface temperature anomalies. This study investigates the impacts of two recently identified Atlantic Niño types, central and eastern Atlantic Niño (CAN and EAN), on these monsoon systems using observational data and numerical experiments. During boreal summer, EAN events exhibit increased rainfall over West Africa compared to CAN events, indicating a strengthened West African summer monsoon. Enhanced moisture flux convergence from eastern Atlantic warming drives these wetting conditions during EAN events. Conversely, CAN events have a more pronounced influence on South American monsoon rainfall during austral summer, causing a rainfall anomaly dipole between the Amazon and eastern Brazil, suggesting an eastward shift in the South American summer monsoon rainfall belt. These rainfall changes are linked to cyclonic circulation anomalies over the southwest Atlantic Ocean, attributed to central Atlantic warming during CAN events. Furthermore, a statistical model assesses hindcast skills of rainfall variability in the two summer monsoon regions, affirming the benefits of separating Atlantic Niño into CAN and EAN events for improved seasonal climate predictions.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-10"},"PeriodicalIF":8.5,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00762-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142166158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1038/s41612-024-00764-5
Xiaoye Yang, Cheng shen, Irfan Ullah, Julia Curio, Deliang Chen
The southern Himalayas, characterized by its dense population and hot, humid summers, are confronted with some of the world’s most severe heat stress risks. This study uses the hourly ERA5 dataset (1979–2022) and CMIP6 projections (2005–2100) to evaluate past and future heat stress based on the Wet Bulb Globe Temperature (WBGT). This has significant implications for the management of occupational workloads in the southern Himalayas. Heat stress levels are classified into 6 categories (0 to 5) using WBGT threshold intervals of 23 °C, 25 °C, 28 °C, 30 °C, and 33 °C. With heat stress surpassing level 3 for almost half of the time, people are constrained to engage in less than moderate workloads to ensure their health remains uncompromised. Flow-analogous algorithm is employed to contextualize the unprecedented heat stress case in the summer of 2020 and the associated atmospheric circulation patterns from historical and future perspectives. The results show that over 80% of the time in 2020, heat stress levels were at 3 and 4. The identified circulation pattern explains 27.6% of the extreme intensity, and such an extreme would have been nearly impossible in pre-21st-century climate conditions under the identified pattern. Future projections under SSP2-4.5 and SSP5-8.5 scenarios indicate that heat stress similar to what was experienced in 2020 will likely become a common occurrence across the southern Himalayas. Under a similar circulation pattern, the heat stress levels by the end of the 21st century would be elevated by at least one category compared to the climatic baseline in over 70% of the region, leading to an additional 120.5 (420.1) million daily population exposed to the highest heat stress level under the SSP2-4.5 (SSP5-8.5) scenario.
{"title":"Evaluating heat stress and occupational risks in the Southern Himalayas under current and future climates","authors":"Xiaoye Yang, Cheng shen, Irfan Ullah, Julia Curio, Deliang Chen","doi":"10.1038/s41612-024-00764-5","DOIUrl":"10.1038/s41612-024-00764-5","url":null,"abstract":"The southern Himalayas, characterized by its dense population and hot, humid summers, are confronted with some of the world’s most severe heat stress risks. This study uses the hourly ERA5 dataset (1979–2022) and CMIP6 projections (2005–2100) to evaluate past and future heat stress based on the Wet Bulb Globe Temperature (WBGT). This has significant implications for the management of occupational workloads in the southern Himalayas. Heat stress levels are classified into 6 categories (0 to 5) using WBGT threshold intervals of 23 °C, 25 °C, 28 °C, 30 °C, and 33 °C. With heat stress surpassing level 3 for almost half of the time, people are constrained to engage in less than moderate workloads to ensure their health remains uncompromised. Flow-analogous algorithm is employed to contextualize the unprecedented heat stress case in the summer of 2020 and the associated atmospheric circulation patterns from historical and future perspectives. The results show that over 80% of the time in 2020, heat stress levels were at 3 and 4. The identified circulation pattern explains 27.6% of the extreme intensity, and such an extreme would have been nearly impossible in pre-21st-century climate conditions under the identified pattern. Future projections under SSP2-4.5 and SSP5-8.5 scenarios indicate that heat stress similar to what was experienced in 2020 will likely become a common occurrence across the southern Himalayas. Under a similar circulation pattern, the heat stress levels by the end of the 21st century would be elevated by at least one category compared to the climatic baseline in over 70% of the region, leading to an additional 120.5 (420.1) million daily population exposed to the highest heat stress level under the SSP2-4.5 (SSP5-8.5) scenario.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-12"},"PeriodicalIF":8.5,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00764-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142158954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-08DOI: 10.1038/s41612-024-00754-7
Youngji Joh, SeonJu Lee, Young-Gyu Park, Thomas L. Delworth, Gyundo Pak, Liwei Jia, William F. Cooke, Colleen McHugh, Young-Ho Kim, Hyung-Gyu Lim
The East/Japan Sea (EJS), a marginal sea of the Northwestern Pacific, is one of the ocean regions showing the most rapid warming and greatest increases in ocean heatwaves over the last several decades. Predictability and skillful prediction of the summer season EJS variability are crucial, given the increasing severity of ocean temperature events impacting fisheries and reinforcing climate conditions like the East Asian rainy season, which in turn affects adjacent high-population density areas over East Asia. We use observations and the Geophysical Fluid Dynamics Laboratory (GFDL) Seamless System for Prediction and Earth System Research (SPEAR) seasonal forecast system to investigate the summertime EJS Sea Surface Temperature (SST) predictability and prediction skill. The observations and seasonal prediction system show that the summer season EJS SST can be closely linked to the previous winter air-sea coupling and predictable 8–9 months in advance. The SPEAR seasonal prediction system demonstrates skillful forecast of EJS SST events from summer to late fall, with added skill for long-lead forecasts initialized in winter. We find that winter large-scale atmospheric circulations linked to Barents Sea variability can induce persistent surface wind anomalies and corresponding northward Ekman heat transport over the East China Sea. The ocean advection anomalies that enter the EJS in prior seasons appear to play a role in developing anomalous SST during summer, along with instantaneous atmospheric forcing, as the source of long-lead predictability. Our findings provide potential applications of large-scale ocean-atmosphere interactions in understanding and predicting seasonal variability of East Asian marginal seas.
{"title":"Predictability and prediction skill of summertime East/Japan Sea surface temperature events","authors":"Youngji Joh, SeonJu Lee, Young-Gyu Park, Thomas L. Delworth, Gyundo Pak, Liwei Jia, William F. Cooke, Colleen McHugh, Young-Ho Kim, Hyung-Gyu Lim","doi":"10.1038/s41612-024-00754-7","DOIUrl":"10.1038/s41612-024-00754-7","url":null,"abstract":"The East/Japan Sea (EJS), a marginal sea of the Northwestern Pacific, is one of the ocean regions showing the most rapid warming and greatest increases in ocean heatwaves over the last several decades. Predictability and skillful prediction of the summer season EJS variability are crucial, given the increasing severity of ocean temperature events impacting fisheries and reinforcing climate conditions like the East Asian rainy season, which in turn affects adjacent high-population density areas over East Asia. We use observations and the Geophysical Fluid Dynamics Laboratory (GFDL) Seamless System for Prediction and Earth System Research (SPEAR) seasonal forecast system to investigate the summertime EJS Sea Surface Temperature (SST) predictability and prediction skill. The observations and seasonal prediction system show that the summer season EJS SST can be closely linked to the previous winter air-sea coupling and predictable 8–9 months in advance. The SPEAR seasonal prediction system demonstrates skillful forecast of EJS SST events from summer to late fall, with added skill for long-lead forecasts initialized in winter. We find that winter large-scale atmospheric circulations linked to Barents Sea variability can induce persistent surface wind anomalies and corresponding northward Ekman heat transport over the East China Sea. The ocean advection anomalies that enter the EJS in prior seasons appear to play a role in developing anomalous SST during summer, along with instantaneous atmospheric forcing, as the source of long-lead predictability. Our findings provide potential applications of large-scale ocean-atmosphere interactions in understanding and predicting seasonal variability of East Asian marginal seas.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-14"},"PeriodicalIF":8.5,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00754-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142152382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Global warming has accelerated alpine glacier melting and led to an increased risk of glacial lake outburst floods (GLOFs). This paper extracted glacial lake boundaries in the Tienshan Mountains of Central Asia from 1990 to 2023, analyzed their spatiotemporal variations and evaluated their risk levels under current and future scenarios. The results show that glacial lakes are predominantly distributed in the Central and Western Tienshan, accounting for 75% of the total number in the Tienshan region. The number and area of glacial lakes increased by 148% (from 1837 to 4557) and 71.83% (from 119.73 to 205.73 km2) during 1990 to 2023, with moraine lake expansion predominating. In the Western Tienshan, the high or very high risk of GLOF is 3–4 times that of other areas. By the middle of the twenty-first century, GLOF risk will continue to increase, especially in the Western Tienshan. This study can provide scientific foundation for disaster mitigation in the downstream areas.
{"title":"Risk assessment of glacial lake outburst flood in the Central Asian Tienshan Mountains","authors":"Man Chen, Yaning Chen, Gonghuan Fang, Guoxiong Zheng, Zhi Li, Yupeng Li, Ziyang Zhu","doi":"10.1038/s41612-024-00755-6","DOIUrl":"10.1038/s41612-024-00755-6","url":null,"abstract":"Global warming has accelerated alpine glacier melting and led to an increased risk of glacial lake outburst floods (GLOFs). This paper extracted glacial lake boundaries in the Tienshan Mountains of Central Asia from 1990 to 2023, analyzed their spatiotemporal variations and evaluated their risk levels under current and future scenarios. The results show that glacial lakes are predominantly distributed in the Central and Western Tienshan, accounting for 75% of the total number in the Tienshan region. The number and area of glacial lakes increased by 148% (from 1837 to 4557) and 71.83% (from 119.73 to 205.73 km2) during 1990 to 2023, with moraine lake expansion predominating. In the Western Tienshan, the high or very high risk of GLOF is 3–4 times that of other areas. By the middle of the twenty-first century, GLOF risk will continue to increase, especially in the Western Tienshan. This study can provide scientific foundation for disaster mitigation in the downstream areas.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":" ","pages":"1-13"},"PeriodicalIF":8.5,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00755-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142143886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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