npj Climate and Atmospheric Science最新文献

{"title":"Contrasting trends of greening in the waning snowfields of the Hindu-Kush Karakoram Himalaya","authors":"Subhransu Sekhar Gouda, Saket Dubey","doi":"10.1038/s41612-026-01409-5","DOIUrl":"https://doi.org/10.1038/s41612-026-01409-5","url":null,"abstract":"In cold mountain areas, plant growth is limited by temperature and seasonal snow cover, with vegetation activity starting only after snow melts. Earlier snow disappearance extends the snow-free period and exposes plants to warmer conditions, increasing opportunities for vegetation activities. The Hindu Kush–Karakoram–Himalaya (HKKH), one of Asia’s largest and fastest-warming mountain systems, has experienced snow melting earlier by 4.37 ± 3.67 days. Using nearly three decades of Landsat satellite observations combined with ERA5-Land climate data, we measured changes in Snow Melt-Out Date (SMOD; day of year when seasonal snow disappears), annual maximum Normalised Difference Vegetation Index (NDVImax), and Growing Degree Days (GDD; cumulative temperature from SMOD to the end of the study period) across seasonally snow-covered regions above the treeline. Our study shows that approximately 80% of waning snowfields in HKKH shows increasing greenness, especially in pixels that were previously sparsely vegetated. At the same time, heat accumulation during snow-free days has increased by more than 50% due to earlier snowmelt between 1994–2005 and 2013–2024. These results highlight interactions between seasonal snow, temperature, and vegetation, emphasising the importance of including snow dynamics in climate adaptation strategies for mountain ecosystems.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"21 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147709331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global warming intensifies pantropical coupling and its control on northern hemisphere tropical cyclones","authors":"Haikun Zhao, Jun Gao, Philip J. Klotzbach, Xiangbo Feng, Liguang Wu, Suzana J. Camargo, Savin S. Chand, Wenjun Zhang, Krishneel K. Sharma, Chao Wang, Jian Cao","doi":"10.1038/s41612-026-01412-w","DOIUrl":"https://doi.org/10.1038/s41612-026-01412-w","url":null,"abstract":"How tropical cyclone (TC) genesis frequency will change under anthropogenic warming remains one of the most debated questions in climate science. Increasing evidence points to the importance of pantropical climate interactions in shaping extreme weather, yet their influence on TCs and their response to warming are unclear. Here, we show that the linkage between tropical Trans-Basin Variability (TBV, defined as the sea surface temperature gradient between the tropical Atlantic-Indian and Pacific Oceans) and Northern Hemisphere TC genesis has strengthened in recent decades. This intensification arises from the enhanced TBV-driven Walker circulation, which reinforces low-level convergence and ascent conducive to TC formation. Analysis of 29 state-of-the-art climate models indicates that this TBV-TC connection will continue to strengthen under future warming. Our findings suggest that global warming amplifies pantropical coupling and its control on Northern Hemisphere TCs, offering a new pathway through which climate change can modulate TC activity.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"14 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147709301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large direct and indirect impacts of ozone-depleting substances on past Southern Hemisphere atmosphere-ocean trends","authors":"Michael Sigmond, Lorenzo M. Polvani","doi":"10.1038/s41612-026-01403-x","DOIUrl":"https://doi.org/10.1038/s41612-026-01403-x","url":null,"abstract":"The indirect impacts of ozone-depleting substances (ODSs) on past Southern Hemisphere (SH) climate change via their impact on the ozone layer have been widely documented, but their direct radiative impacts remain unexplored. Using 20-member ensembles of historical simulations with a state-of-the-art climate model, we quantify this direct impact and compare it with their indirect impact via ozone depletion, as well as with the impacts of tropospheric ozone, CO2 and aerosols. We find that the radiative impacts of ODSs contributed substantially to annual-mean SH atmosphere and ocean circulation trends between 1955 and 2000, with impacts nearly as large as those of stratospheric ozone, and exceeding those of CO2. ODSs also account for 29% of Southern Ocean warming, several times the individual contributions from stratospheric and tropospheric ozone. Our findings highlight the major role of ODSs in SH climate change and underscore the importance of the Montreal Protocol in mitigating climate change.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"34 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147685152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Longwave radiation responses to cloud property perturbations in blackbody clouds should not be assumed to be negligible","authors":"Adele L. Igel, Lindsay A. Nash, Matthew R. Igel","doi":"10.1038/s41612-026-01414-8","DOIUrl":"https://doi.org/10.1038/s41612-026-01414-8","url":null,"abstract":"The discussion of radiative cooling in cloud dynamics rarely considers quantities aside from the total radiative cooling over a cloud layer, which is constant for blackbody clouds in a given environment. However, here we demonstrate using idealized radiative transfer calculations that the total cooling in the upper part of the cloud increases with liquid water path up to ~100 g m−2, well beyond the threshold liquid water path needed for a cloud to be a blackbody. Moreover, the maximum local cooling rate increases with LWP indefinitely. We then show using high-resolution simulations that the modulation of longwave radiative cooling profiles in blackbody clouds alters the dynamics, free tropospheric entrainment rates, liquid water path, and organization of closed cell stratocumulus clouds. We suggest that the role of longwave radiation in blackbody clouds, particularly in the context of aerosol-cloud interactions, should be given more consideration.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"33 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147685155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physics-guided score-based diffusion for 3D reconstruction of tropical cyclones from sparse observations","authors":"Xinhai Han, Xiaohui Li, Zeyi Niu, Jingsong Yang, Guoqi Han, Jiuke Wang, Wei Tao, Lotfi Aouf, Shaoliang Peng, Dake Chen","doi":"10.1038/s41612-026-01413-9","DOIUrl":"https://doi.org/10.1038/s41612-026-01413-9","url":null,"abstract":"Tropical cyclones (TCs) three-dimensional (3D) structures are crucial for understanding their intensification processes and assessing associated risks. However, observational data remain sparse, especially for complete dynamic and thermodynamic variables. Dropsondes are considered one of the best available in situ observations providing high-quality vertical profiles, but they are extremely sparse in spatial distribution. This study constructs a physics-guided generative AI framework capable of reconstructing complete 3D TC fields, including wind, temperature, and humidity, from sparse dropsonde observations. Our method utilizes a score-based diffusion model, pretrained on global climate simulation data and fine-tuned on high-resolution operational analysis fields, to learn priors of TC structures. By integrating this generative prior with a score-based posterior sampling algorithm and imposing physical constraints of divergence, vorticity, and thermodynamic consistency, we obtain physically consistent TC 3D reconstructions. Results from systematic Observing System Simulation Experiments (OSSEs) and extensive real-world operational cases indicate that our method can reconstruct the complete TC 3D dynamic and thermodynamic structures, providing a data-driven pathway for reconstructing high-dimensional atmospheric states from sparse in situ data.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"9 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147685151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A nationwide radar network reveals typhoon wind profile characteristics in the lower troposphere over China","authors":"Shengming Tang, Yuhui Li, Hui Yu","doi":"10.1038/s41612-026-01404-w","DOIUrl":"https://doi.org/10.1038/s41612-026-01404-w","url":null,"abstract":"Accurate characterization of typhoon wind profiles throughout the lower troposphere remains challenging, as current understanding depends heavily on fragmented observations from shallow layers (<500 m) and isolated case studies. To address this gap, this study analyses a unique nationwide dataset obtained from 186 wind profile radars during 45 typhoons affecting China (2020–2024), enabling a systematic characterization of wind profiles up to 2 km. Statistical analysis identifies four distinct wind profile patterns (Monotonically-increasing, Near-uniform, Jet-like, and others), which are most frequent in the rear-right quadrant and least frequent in the front-left quadrant. Radially, Monotonically-increasing profile types dominate the outer-core region, while Near-uniform and Jet-like types concentrate primarily in the inner-core region. Notably, Monotonically-increasing and Jet-like profiles are more prevalent in intense typhoons than the Near-uniform type. A structured set of fitting parameters for wind profile models is established, categorized by the identified profile patterns, typhoon-relative positions, and terrain types. The findings offer crucial observational benchmarks to support wind profile modeling and engineering applications in typhoon-prone regions.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"2 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147685154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large present-day and future climate forcing due to non-CO2 emissions from global transport","authors":"Johannes Hendricks, Mattia Righi, Sabine Brinkop, Katrin Dahlmann, Mariano Mertens, Christof G. Beer, Volker Grewe, J. Christopher Kaiser, Michael Ponater","doi":"10.1038/s41612-026-01383-y","DOIUrl":"https://doi.org/10.1038/s41612-026-01383-y","url":null,"abstract":"Emissions from land-based transport, aviation, and shipping contribute significantly to climate change. Besides CO2, these emissions include short-lived compounds that affect air quality but are also climatically relevant. We use a global chemistry-climate model to show that the climate effects of these non-CO2 emissions are substantial across all transport sectors both now and in the future. In sum, the non-CO2 impacts result in a cooling, which offsets the positive climate forcing from transport-induced CO2 by around 80% at present and between 25 and 60% in different scenarios for 2050. The trade-off that air pollutants mitigate global warming is strongly reduced in a future scenario with low anthropogenic emissions, where even small remaining amounts of non-CO2 compounds cause significant cooling as they are released in a very clean atmosphere. Our findings emphasize the need to take non-CO2 effects into account when assessing climate protection strategies for the transport sectors.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"1 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147655984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinct sub-period trends in tropospheric ozone column over the East Asian outflow region during 1990-2019","authors":"Zhou Zang, Jane Liu, David Tarasick, Jing M. Chen, Yingjie Li, Lingyun Meng","doi":"10.1038/s41612-026-01406-8","DOIUrl":"https://doi.org/10.1038/s41612-026-01406-8","url":null,"abstract":"Tropospheric ozone, an important greenhouse gas and pollutant, has increased over East Asia in recent decades. However, how this increase evolves temporally remains unclear. Here, we construct a global tropospheric ozone column (TrOC) dataset based on the Trajectory-mapped Ozonesonde dataset for the Stratosphere and Troposphere (TOST). This dataset reveals distinct TrOC sub-period trends over 1990-2019 in the East Asian outflow region: a slow increase (0.07 DU/year, 1990–2002), a rapid increase (1.26 DU/year, 2002–2008), and a non-significant decrease (2008–2019). While lower-tropospheric ozone continues to increase, declining ozone in higher layers drives the TrOC transition after 2008. Ensemble modeling, trajectory analysis, and tagged stratospheric ozone simulations attribute these TrOC changes to increasing chemical production and shifting stratospheric intrusion (SI) from increasing to decreasing, underscoring joint chemical and dynamical roles in shaping regional TrOC, particularly SI variability. Beyond this study, the observationally-constrained and spatially-explicit TOST TrOC would enable broader applications.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"27 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147655983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constraining the intensive absorption properties of ambient organic aerosol particles based on pan-European observations","authors":"Jordi Rovira, Jesús Yus-Díez, Gang I. Chen, Griša Močnik, Martin Gysel-Beer, Wenche Aas, Minna Aurela, John Backman, Sujai Banerji, Benjamin T. Brem, Anna Canals-Angerri, Benjamin Chazeau, Kaspar R. Daellenbach, Joel F. de Brito, Evangelia Diapouli, Konstantinos Eleftheriadis, Mikael Ehn, Olivier Favez, Harald Flentje, Maria I. Gini, Konstantinos Granakis, Asta Gregorič, Roy Harrison, Liine Heikkinen, Christoph Hueglin, Antti Hyvärinen, Matic Ivančič, Hannes Keernik, Eleni Liakakou, Chunshui Lin, Radek Lhotka, Krista Luoma, Marek Maasikmets, Hanna E. Manninen, Manousos Ioannis Manousakas, Nicolas Marchand, Saliou Mbengue, Nikos Mihalopoulos, María Cruz Minguillón, Doina Nicolae, Jarkko V. Niemi, Jurgita Ovadnevaite, Noemí Pérez, Jean-Eudes Petit, Stephen M. Platt, Petra Pokorná, André S. H. Prévôt, Véronique Riffault, Martin Rigler, Matteo Rinaldi, Jaroslav Schwarz, Iasonas Stavroulas, Erik Teinemaa, Kimmo Teinilä, Hilkka Timonen, Anna Tobler, Jeni Vasilescu, Marta Via, Petr Vodička, Stergios Vratolis, Karl Espen Yttri, Naděžda Zíková","doi":"10.1038/s41612-026-01405-9","DOIUrl":"https://doi.org/10.1038/s41612-026-01405-9","url":null,"abstract":"Organic aerosol particles (OA) can absorb solar radiation with varying efficiencies depending on their chemical composition and physical properties. This light-absorbing fraction of OA, commonly referred to as brown carbon (BrC), is difficult to accurately represent in climate models due to the inherent diversity of its optical properties. This variability arises from differences in emission sources and atmospheric processing, as well as from variations in experimental design and the analytical methods used to quantify BrC absorption. As a result, the climate effect of BrC remains uncertain. Here, we studied the light absorption properties of surface ambient OA using measurements from 17 sites across Europe. Combining multi-wavelength absorption measurements from filter-based photometers with OA mass concentrations and source apportionment derived from ACSM/AMS data, we derive empirical estimates of the OA mass absorption cross section (MACOA), its wavelength dependence (AAEOA), the OA density (⍴OA), and the MAC associated with different primary and secondary OA sources. We further develop parameterizations that relate MACOA, AAEOA and ⍴OA to the ambient black carbon-to-organic aerosol ratio (eBC/OA) and propose a corresponding parameterization for the imaginary refractive index (kOA). Given the widespread availability of eBC and OA measurements in global monitoring networks, the framework presented here provides a practical approach for estimating the absorptive properties of surface OA particles under real-world conditions.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"9 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147655985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetric carbon response to the 2019 extreme positive Indian Ocean Dipole","authors":"Zhi Yong Kang, Wee Cheah, Joji Ishizaka, Eko Siswanto, J. Pavan Kumar, TVS Udaya Bhaskar, Yue Fang, Baochao Liu, Tingwei Cui, Mohd Fadzil Firdzaus Mohd Nor, Azizan Abu Samah","doi":"10.1038/s41612-026-01402-y","DOIUrl":"https://doi.org/10.1038/s41612-026-01402-y","url":null,"abstract":"In 2019, one of Indonesia’s most devastating bushfires burned about 3.1 million hectares of forests and peatlands, releasing approximately 708 million tonnes of CO2. The fires were driven by an extreme positive Indian Ocean Dipole (pIOD), which strengthened easterly winds and brought cooler and drier air to the region, creating severe drought conditions. These conditions triggered widespread forest fires across Indonesia. Simultaneously, the same easterly winds displaced warm, nutrient-poor surface waters westward in the eastern equatorial Indian Ocean (EEIO), enhancing upwelling of nutrient-rich deep waters. This process fueled a massive phytoplankton bloom extending over 1000 km. In addition, nutrient deposition from aerosols emitted by the Indonesian fires further enriched the bloom. Together, oceanic upwelling and atmospheric deposition boosted the biomass of large phytoplankton. Satellite estimates suggest that the bloom sequestered approximately 40.19 Tg of carbon, equivalent to 10.1% of the CO2 released by the Indonesian fires, into the deeper ocean. In contrast, air-sea CO2 flux anomalies indicate negligible net atmospheric CO2 uptake, with only 0.05% (0.33 Tg CO2) of the emissions reabsorbed, due to the upwelling-driven dissolved inorganic carbon (DIC)-rich waters. Together, these results highlight a coupled but asymmetric response to climate extremes. The pIOD can simultaneously intensify terrestrial carbon losses through fires, while upwelling enhances the biological pump through blooms. However, the strength of the sequestration was offset by the DIC-rich waters from the upwelling. Understanding this dual impact is crucial for modelling future climate scenarios and assessing the long-term impacts of climate variability on global carbon cycles.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"19 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147630939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}