npj Climate and Atmospheric Science最新文献

{"title":"Controls of the global overturning circulation of the ocean","authors":"Fabien Roquet, Michael J. Bell, Agatha M. de Boer, David Ferreira, C. Spencer Jones, Joseph H. LaCasce, Casimir de Lavergne, David P. Marshall, David R. Munday, Jonas Nycander, Malin Ödalen","doi":"10.1038/s41612-025-01185-8","DOIUrl":"https://doi.org/10.1038/s41612-025-01185-8","url":null,"abstract":"<p>The global overturning circulation (GOC) is the largest scale component of the ocean circulation, associated with a global redistribution of key tracers such as heat and carbon. The GOC generates decadal to millennial climate variability, and will determine much of the long-term response to anthropogenic climate perturbations. This review aims at providing an overview of the main controls of the GOC. By controls, we mean processes affecting the overturning structure and variability. We distinguish three main controls: mechanical mixing, convection, and wind pumping. Geography provides an additional control on geological timescales. An important emphasis of this review is to present how the different controls interact with each other to produce an overturning flow, making this review relevant to the study of past, present and future climates as well as to exoplanets’ oceans.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"37 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144851660","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":"Amplified impacts of multi-year La Niñas on soil moisture compared to single-year La Niñas","authors":"Tingting Zhu, Jin-Yi Yu, Min-Hui Lo","doi":"10.1038/s41612-025-01175-w","DOIUrl":"https://doi.org/10.1038/s41612-025-01175-w","url":null,"abstract":"<p>This study examines December-January-February (DJF) soil moisture responses to multi-year (MY) and single-year (SY) La Niñas using a 2200-year CESM1 simulation, AGCM experiments, and observational data. Four regions where MY La Niñas amplify SY La Niñas’ impacts on soil moisture were identified: North America, Australia, the Middle East, and the Sahel. SY La Niñas typically cause soil moisture drying in the Middle East and North America and wetting in Australia and the Sahel. MY La Niñas enhance these effects in the second DJF due to the strengthening of precipitation anomalies or the accumulation of precipitation-induced soil moisture anomalies, except in the Sahel where wetting is driven in part by evapotranspiration anomalies. Soil moisture variations are linked to La Niña-induced sea surface temperature changes in the Indian Ocean (for Australia and the Middle East) and the Pacific Ocean (for North America). These amplified effects are largely supported by the observed MY La Niña events from 1948 to 2022. These findings emphasize the need to integrate MY La Niñas into regional agriculture and water resource management strategies to better anticipate and mitigate their impacts.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"52 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144840003","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":"Interpretable ensemble learning unveils main aerosol optical properties in predicting cloud condensation nuclei number concentration","authors":"Nan Wang, Yuying Wang, Chunsong Lu, Bin Zhu, Xing Yan, Yele Sun, Jialu Xu, Junhui Zhang, Zhuoxuan Shen","doi":"10.1038/s41612-025-01181-y","DOIUrl":"https://doi.org/10.1038/s41612-025-01181-y","url":null,"abstract":"<p>Variations in cloud condensation nuclei number concentration (<i>N</i>_CCN) significantly influence cloud microphysics, yet direct <i>N</i>_CCN measurements remain challenging. Here, we present an <i>N</i>_CCN ensemble learning (NEL) model utilizing ensemble learning and interpretability analysis on aerosol optical parameters. Validated at two land sites, two ocean sites and one polar site within the Atmospheric Radiation Measurement program, the mean absolute percentage error range of the NEL model across different environments is from 12% to 36%, demonstrating high accuracy. Key findings reveal that aerosol optical parameters can serve as predictors for <i>N</i>_CCN. Aerosol scattering and backscattering coefficients, absorption coefficient, backscatter fraction (BSF), and Ångström exponent (AE) are positively correlated with <i>N</i>_CCN, while single scattering albedo shows negative correlations. <i>N</i>_CCN prediction at land sites is highly sensitive to BSF, largely driven by the backscattering coefficient, as fine particles dominate in these sites. At ocean sites, <i>N</i>_CCN prediction is more sensitive to AE, primarily influenced by the scattering coefficient, due to the higher proportion of larger particles. At the polar site, <i>N</i>_CCN prediction shows sensitivity to both BSF and AE, mainly driven by the scattering coefficient, as polar sites are cleaner and contain larger particles. These differences reflect the variation in particle size and number concentration across different environments.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"5 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144851661","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":"Fine and coarse aerosols control of cloud water by evaporation-precipitation dynamics","authors":"Fan Liu, Zengxin Pan, Daniel Rosenfeld, Lin Zang, Wei Gong, Guy Pulik, Feiyue Mao","doi":"10.1038/s41612-025-01193-8","DOIUrl":"https://doi.org/10.1038/s41612-025-01193-8","url":null,"abstract":"<p>Fine aerosols (FA, radius &lt;1 µm) may enhance cloud albedo for a given liquid water path (LWP), thereby partially offsetting greenhouse gas-induced warming. However, the aerosol-driven LWP adjustment is currently heavily debated due to conflicting observations. Here, we observationally found that both FA and coarse sea spray aerosols (CSA, radius &gt; 1 µm) exhibit bidirectional regulation on LWP adjustments through precipitation-evaporation competition. In marine stratocumulus with moderate thickness, under dry cloud-top environments (RH &lt; 20%) where evaporation dominates, FA decreases LWP by ~15% while CSA induces a slight ~8% increase. Conversely, in humid cloud-top environments (RH &gt; 80%) favoring precipitation processes, the addition of FA more than doubles LWP, whereas the addition of CSA nearly halves it. Thin cloud LWP changes are primarily driven by droplet evaporation, while deep cloud LWP changes are dominated by precipitation. Our findings underscore the necessity to resolve precipitation-evaporation dynamics and opposing FA and CSA effects for credible aerosol-cloud interaction simulations.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"95 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144825496","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":"Energetic processes underlying the interannual variability of South Asian summer monsoon","authors":"Tong Lu, Kaiming Hu, Gang Huang, Sang-Wook Yeh, Ya Wang","doi":"10.1038/s41612-025-01143-4","DOIUrl":"https://doi.org/10.1038/s41612-025-01143-4","url":null,"abstract":"<p>The South Asian summer monsoon (SASM) interannual variability significantly impacts regional climates, with its first mode featuring a lower-level anomalous anticyclone over the northern Bay of Bengal (BOB) and the second mode displaying an anomalous anticyclone over central-northern India. Here, we diagnose the energy budget of these two SASM modes. Barotropic energy conversion supplies eddy kinetic energy (EKE) to the first mode from lower-level climatological confluent westerlies downstream of the Somali Jet and over the BOB–western North Pacific. In contrast, the second mode derives EKE from the subtropical westerly confluence induced by Tibetan Plateau topography. Baroclinic energy conversion, extracting eddy available potential energy (EAPE) from the mean thermal structure, sustains the second mode while dampening the first. Convective heating generates EAPE for both modes, acting as feedback. Further analyses suggest these modes likely stem from internal dynamics. Our findings highlight the importance of internal energetic processes in SASM modulation.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"145 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144839998","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":"Climate effects of a future net forestation scenario in CMIP6 models","authors":"James L. Gomez, Robert J. Allen, Larry W. Horowitz, Steven T. Turnock, Rosie A. Fisher, Olivia E. Clifton, Bryan K. Mignone, Elena Shevliakova, Sergey Malyshev","doi":"10.1038/s41612-025-01127-4","DOIUrl":"https://doi.org/10.1038/s41612-025-01127-4","url":null,"abstract":"<p>Forestation may reduce temperatures by lowering atmospheric CO₂. However, biogeophysical changes from forestation may weaken this cooling. We use twelve Coupled Model Intercomparison Project (CMIP6) models to quantify the biogeochemical (carbon cycle) and biogeophysical (non-carbon cycle) effects of net forestation, as quantified as the difference between the end of two future scenarios: ssp370-ssp126Lu and ssp370. Biogeochemical effects have an inferred global multi-model mean cooling (−0.08 ± 0.02 K). Changes in fires have no significant effect on land carbon storage globally. In contrast with studies indicating biogeophysical impacts counteract biogeochemical impacts by up to 50%, we find that biogeophysical effects lead to insignificant global mean cooling (−0.002 ± 0.041 K). Tropical land shows cooling (−0.058 ± 0.058 K) with eight of twelve models indicating cooling, consistent with prior studies. Using the Surface Energy Balance Decomposition, we find cooling is primarily from increased evapotranspiration and decreased downwelling solar radiation related to clouds and aerosols.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"27 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144797381","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":"Trans-basin interaction sustains multi-year marine heatwaves in the Gulf of Alaska","authors":"Yu Zhao, Jin-Yi Yu, Huang-Hsiung Hsu, I-I Lin, Song Yang, Chunzai Wang, Jian Shi, Yan Du, Xin Wang, Tao Lian, Sang-Wook Yeh","doi":"10.1038/s41612-025-01187-6","DOIUrl":"https://doi.org/10.1038/s41612-025-01187-6","url":null,"abstract":"<p>Multi-year marine heatwaves (MHWs) in the Gulf of Alaska (GOA) are major climate events with lasting ecological and economic effects. Though often seen as local Pacific phenomena, our study shows their persistence depends on trans-basin interactions between the North Pacific and North Atlantic. Using observational data and climate model experiments, we find that prolonged MHWs occur as sequential warming episodes triggered by atmospheric wave trains crossing ocean basins. These wave trains alter surface heat flux, initiating MHWs in the GOA and changing North Atlantic sea surface temperatures (SSTs). In turn, Atlantic SST anomalies reinforce wave activity, fueling subsequent MHW episodes in a feedback loop. This mechanism appears in historical events (1949–52, 1962–65, 2013–16, and 2018–22), highlighting MHWs as a trans-basin phenomenon. Our findings link GOA MHWs to trans-basin atmospheric wave dynamics and identify North Atlantic SSTs as a potential predictor of their duration.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"17 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144797377","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":"In-situ baseline calibration approach for enhanced data quality of large-scale air sensor monitoring networks","authors":"Han Mei, Peng Wei, Ya Wang, Meisam Ahmadi Ghadikolaei, Nirmal Kumar Gali, Zhi Ning","doi":"10.1038/s41612-025-01184-9","DOIUrl":"https://doi.org/10.1038/s41612-025-01184-9","url":null,"abstract":"<p>As dense sensor networks for air quality monitoring become increasingly prevalent, effective calibration remains a critical yet challenging component of their operation, particularly for large-scale networks. Conventional calibration methods, which rely heavily on co-locating sensors with reference monitors for learning and training, often face significant scalability challenges, rendering them impractical for post-deployment recalibration. To address this limitation, we propose an in-situ baseline calibration method (b-SBS) that calibrates sensors remotely without the need for direct co-location. This approach is grounded in the physical characteristics of electrochemical sensors and is informed by statistical analyses of calibration coefficients across a large group of similar sensors. Through preliminary field tests conducted on a batch of sensors for NO₂, NO, CO, and O₃, two key linear calibration coefficients, sensitivity and baseline, were systematically investigated. Sensitivity analysis of over 100 short-term calibration samples for each gas revealed coefficients clustered within 20% variation, enabling universal parameterization. Long-term baseline drift remained stable within ±5 ppb for NO₂, NO, and O₃, and ±100 ppb for CO over 6 months, supporting semi-annual recalibration. Applying the b-SBS calibration approach to 73 NO₂ sensors in a large-scale Shanghai network yielded pronounced data quality improvements compared to their original measurements (initially calibrated before deployment): the median <i>R</i>² increased by 45.8% (from 0.48 to 0.70), and RMSE decreased by 52.6% (from 16.02 to 7.59 ppb), as validated against nearby reference stations. The Shanghai application, while showing the method’s potential for large-scale deployments, awaits further real-time validation to confirm its robustness under diverse operational conditions. This study is a valuable advancement in calibration strategies, offering a cost-effective solution that reduces operational costs while ensuring accurate measurements across numerous sensors and long-term network deployments.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"113 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144797186","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":"Bridging large-scale and coastal variability to improve seasonal sea level predictions along the U.S. and Canadian West Coast","authors":"Qinxue Gu, Liwei Jia, Liping Zhang, Thomas L. Delworth, Xiaosong Yang, Nathaniel C. Johnson, Feiyu Lu, Colleen E. McHugh, William F. Cooke","doi":"10.1038/s41612-025-01182-x","DOIUrl":"https://doi.org/10.1038/s41612-025-01182-x","url":null,"abstract":"<p>Coastal communities are increasingly vulnerable to long-term sea level rise and fluctuations driven by climate variability. While recent advances in coupled climate models enable sea level predictions several months in advance, further efforts are needed to assess and enhance seasonal prediction of coastal sea level. In this study, we evaluate seasonal prediction skill for large-scale and coastal sea level along the U.S. and Canadian West Coast using multiple forecast systems. Prediction skill peaks in the tropical Indo-Pacific and extends into the eastern North Pacific, declining from south to north along the coast. Using self-organizing maps (SOMs), a machine learning technique, we identify sources of large-scale sea level variability and predictability in the eastern tropical and North Pacific, closely linked to the El Niño–Southern Oscillation. Finally, we improve coastal sea level predictions from dynamical models by leveraging the connection between large-scale and coastal sea level through SOM-reconstructed and model-analog approaches.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"16 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144792715","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":"Weakened relationship between November Barents-Kara sea ice and January Arctic Oscillation after the mid-1990s","authors":"Shuai Zheng, Peilong Yu, Bo Sun, Huijun Wang, Xiaopei Lin, Minghao Yang, Yudi Liu","doi":"10.1038/s41612-025-01186-7","DOIUrl":"https://doi.org/10.1038/s41612-025-01186-7","url":null,"abstract":"<p>The Arctic Oscillation (AO) is a dominant atmospheric mode in the Northern Hemisphere, influencing weather and climate. Its variations are driven by numerous factors, including Arctic sea ice, particularly autumn Barents-Kara Sea ice concentration (SIC), which can significantly impact the AO through planetary wave dynamics. However, the interdecadal stability of this relationship remains unclear. This study detected the weakened November Barents-Kara SIC-January AO connection after the mid-1990s. Observational and model analysis showed that from 1979 to 1994, their relationship was driven by the North Atlantic tripole (NAT) sea surface temperature (SST) anomalies, which influenced storm track activities over North Atlantic and Eurasia, thus inducing a wave train resembling the Scandinavian pattern. After the mid-1990s, weakened interannual variability of the NAT SST anomalies disrupted this mechanism. These findings highlight the critical role of mid-latitude ocean-atmosphere interactions in Arctic climate variability and emphasize the need for further research on long-term AO-SIC linkages.</p>","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":"32 1","pages":""},"PeriodicalIF":9.0,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144792716","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}