AGU Advances最新文献

{"title":"Permafrost-Thaw Driven Acid-Rock Drainage Threatens Arctic Aquatic Ecosystems","authors":"E. K. Skierszkan","doi":"10.1029/2026AV002822","DOIUrl":"https://doi.org/10.1029/2026AV002822","url":null,"abstract":"<p>Scientists continue to document unexpected consequences of post-industrial global warming across Earth systems. In the current issue of <i>AGU Advances</i>, Evinger et al. (<span>2026</span>) documented abrupt onset of acid-rock drainage (ARD) in Arctic rivers affecting hundreds of kilometers of aquatic habitat. Their determined sampling efforts in remote wilderness regions of Alaska's Brooks Range have highlighted major degradation of previously pristine Arctic river networks because of ARD intensification.</p><p>Low-quality ARD is increasingly affecting Arctic water quality as thaw exposes sulfides previously trapped by permafrost to accelerated weathering. Water quality in natural acidic seepages within the Brooks Range and Canada's Yukon is comparable to some of the most severely mine-impacted ARD systems, with elevated metals concentrations and acidity that pose an immediate threat to aquatic ecosystems (Evinger et al., <span>2026</span>; Skierszkan et al., <span>2026a</span>).</p><p>The ARD process produces remarkable “rusting,” discoloration of impacted streams with bright orange or white precipitates. This rusting occurs as pH buffering downstream of ARD point sources drives precipitation of iron and aluminum-rich particles in the water column (Figure 1e). Arctic river rusting can also be caused by a different geochemical pathway, involving mobilization of iron in low-oxygen and neutral pH groundwater (Barker et al., <span>2023</span>; Dial et al., <span>2026</span>). This second pathway is likely less acutely toxic to receiving ecosystems, because of its lower toxic metal and acidity burden.</p><p>The study by Evinger et al. complements a growing body of work documenting emergent ARD affecting the global cryosphere. Earlier this year, we independently documented similarly abrupt ARD onset characterized by extreme water chemistry that drives vegetation dieback, river rusting, and metal mobilization in Yukon's Tombstone Waters Observatory, approximately 1,000 km east of the Brooks Range (Figure 1a; Skierszkan et al., <span>2026a</span>). Both studies build on earlier reports of recent ARD onset in the Brooks Range and Alaska's North Slope (O’Donnell et al., <span>2024</span>).</p><p>These related studies point to a widespread new outcome of permafrost degradation, which is concentrated in mountainous regions underlain by (meta)-sedimentary terranes spanning more than 1 million km<sup>2</sup> in Alaska and northwest Canada (Figure 1a). Here, deep marine sedimentary rocks geologically enriched in sulfide minerals are exposed to accelerated weathering as permafrost retreats (Kwong et al., <span>2009</span>; Lacelle et al., <span>2007</span>; Skierszkan et al., <span>2026a</span>). Exponential rises in sulfate concentrations across major northern rivers in recent decades highlight the breadth of this phenomenon (Figures 1b–1d) (Evinger et al., <span>2026</span>; Skierszkan et al., <span>2026a</span>; Tashiro et al., <span>2026</span>; Toohe","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026AV002822","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impactful Datasets in Earth, Space, and Environmental Sciences: Highlighting the Data That Transform Research","authors":"Joseph Gum,&nbsp;Graziella Caprarelli,&nbsp;Alberto Montanari,&nbsp;Brian Sedora,&nbsp;Shelley Stall,&nbsp;Mathew Biddle,&nbsp;Rachael Blake,&nbsp;Matt Jones,&nbsp;Elizabeth Joyner,&nbsp;Binita KC,&nbsp;Doug Newman,&nbsp;Doug Schuster,&nbsp;Andrea K. Thomer,&nbsp;Bruce Wilson,&nbsp;Lesley Wyborn,&nbsp;Ilse Aben,&nbsp;James Acker,&nbsp;Ebrahim Ahmadisharaf,&nbsp;Weston Anderson,&nbsp;Yosuke Aoki,&nbsp;Christina Arras,&nbsp;Ross Bagwell,&nbsp;Ashley Ballard,&nbsp;Lindsay Barbieri,&nbsp;Sylvain Barbot,&nbsp;Emily Becker,&nbsp;David Berghmans,&nbsp;Justine Blanford,&nbsp;Gil Bohrer,&nbsp;Tobias Braun,&nbsp;Ian Brosnan,&nbsp;Patrick Broxton,&nbsp;Brendan Byrne,&nbsp;Danica Linda Cantarero,&nbsp;Peiyu Cao,&nbsp;Sarah Carter,&nbsp;Rob Casey,&nbsp;Kerry Cawse-Nicholson,&nbsp;Daniel Cayan,&nbsp;K. Dana Chadwick,&nbsp;Kunal Chakraborty,&nbsp;Ernest Cisneros,&nbsp;Alexandru T. Codilean,&nbsp;James Crawford,&nbsp;Noel Cressie,&nbsp;David Crisp,&nbsp;Alfredo A. Cruz,&nbsp;Elisabetta D'Anastasio,&nbsp;Robert E. Daniell Jr.,&nbsp;Fabien Darrouzet,&nbsp;Saswati Das,&nbsp;Kyle Frankel Davis,&nbsp;Ankur R. Desai,&nbsp;Alex de Sherbinin,&nbsp;Catia M. Domingues,&nbsp;Wenhao Dong,&nbsp;Kelsey Druken,&nbsp;Nelia W. Dunbar,&nbsp;Bethany Ehlmann,&nbsp;James S. Eldrett,&nbsp;Shane Elipot,&nbsp;Jing Fang,&nbsp;Nicolas Fernandez,&nbsp;Florence Fetterer,&nbsp;Alison Fritz,&nbsp;Jing Gao,&nbsp;Xueyuan Gao,&nbsp;Sarah Gille,&nbsp;Sven Gilliams,&nbsp;Peter H. Gleick,&nbsp;Christopher R. Hakkenberg,&nbsp;Jonathan B. Hanson,&nbsp;Henry C. Henson,&nbsp;Tracey Holloway,&nbsp;Candice Hopkins,&nbsp;Mark James Hopwood,&nbsp;Faisal Hossain,&nbsp;George J. Huffman,&nbsp;Nicole Jacobs,&nbsp;Daniel Jaffe,&nbsp;Dylan Jones,&nbsp;Apurva P. Joshi,&nbsp;Julie Kalansky,&nbsp;Leander Kallas,&nbsp;Nikita Kaushal,&nbsp;Endalkachew Kebede,&nbsp;Trevor F. Keenan,&nbsp;Gretchen Keppel-Aleks,&nbsp;Tae Kim,&nbsp;Fraser King,&nbsp;Marthe Klöcking,&nbsp;Wouter Knoben,&nbsp;Mark Koenig,&nbsp;Greg Kopp,&nbsp;Gerbrand Koren,&nbsp;Nicholas Kruskamp,&nbsp;Zachary Labe,&nbsp;Anthony Lanati,&nbsp;Matthias Lankhorst,&nbsp;Joshua Laughner,&nbsp;Oana Leahu-Aluas,&nbsp;Christine Lee,&nbsp;Laure Lefevre,&nbsp;Kerstin Lehnert,&nbsp;Einat Lev,&nbsp;Yuan Li,&nbsp;Zhong Liu,&nbsp;Avni Malhotra,&nbsp;Scott Marshall,&nbsp;Landon Marston,&nbsp;Ariadna Martin,&nbsp;Nick Marzolf,&nbsp;Paola Mazzoglio,&nbsp;Art Miller,&nbsp;Sanchit Minocha,&nbsp;Arpita Mondal,&nbsp;Jean-Paul Montagner,&nbsp;Laurent Montesi,&nbsp;Nils Moosdorf,&nbsp;James T. Morris,&nbsp;Md Golam Mostafa,&nbsp;Katelyn Mountjoy,&nbsp;Thiago V. M. do Nascimento,&nbsp;Kiwamu Nishida,&nbsp;Angus Nixon,&nbsp;Ceri Nunn,&nbsp;Martha Cary Eppes,&nbsp;Nasrin Mostafavi Pak,&nbsp;Gerard Gallardo i Peres,&nbsp;Dean Pesnell,&nbsp;Antonio Martínez Picar,&nbsp;Claire Porter,&nbsp;Prithviraj Pramanik,&nbsp;Sara C. Pryor,&nbsp;Marcelo Uriburu Quirno,&nbsp;Federico Rabuffi,&nbsp;Balaji Rajagopalan,&nbsp;Yuhan Rao,&nbsp;A. J. Reiss,&nbsp;Axel D. Renno,&nbsp;Siddharth Rout,&nbsp;Manabendra Saharia,&nbsp;Ricardo Sánchez-Murillo,&nbsp;Tatsuhiko Sato,&nbsp;Erin Satterthwaite,&nbsp;Anna Savage,&nbsp;Ted A. Scambos,&nbsp;Jacob Schaperow,&nbsp;Nirdesh Kumar Sharma,&nbsp;Christine A. Shields,&nbsp;Debjani Sihi,&nbsp;Elizabeth A. Silber,&nbsp;Terry Sohl,&nbsp;Sarath Suresh,&nbsp;James H. Swift,&nbsp;Zoltan Szantoi,&nbsp;Joao Teixeira,&nbsp;Glen Thackray,&nbsp;Anne Tillery,&nbsp;Mike Timmons,&nbsp;Marie Katrine Traun,&nbsp;Martin Vallée,&nbsp;Sara M. Vallejo-Bernal,&nbsp;José Manuel Vaquero,&nbsp;Voltaire A. Velazco,&nbsp;Isabel Wargowsky,&nbsp;Dominique Weis,&nbsp;Nina Welti,&nbsp;Thomas Westerhold,&nbsp;John W. Williams,&nbsp;Ann Windnagel,&nbsp;Ryan J. Woosley,&nbsp;Debra Wunch,&nbsp;Jingfeng Xiao,&nbsp;Ben Zaitchik,&nbsp;Enze Zhang,&nbsp;Xiaoyi Zhao,&nbsp;Li Zhen,&nbsp;Lin Zhiheng,&nbsp;Steven C. Bergman,&nbsp;Daniel Minisini","doi":"10.1029/2026AV002623","DOIUrl":"https://doi.org/10.1029/2026AV002623","url":null,"abstract":"<p>The American Geophysical Union (AGU) announces the new living collection “Impactful Datasets in Earth, Space, and Environmental Sciences” which recognizes the creation and curation of datasets enabling research, analysis, and decision making beyond what is captured by traditional academic impact metrics. The collection highlights datasets through the dimensions of People, Planet, and Prosperity, and includes a curated set of nominated datasets and accompanying special collection of data papers. Developed with the Earth Science Information Partners (ESIP) community, the nomination and review process initially invites contributors from across research, operations, and public service, to nominate datasets important to their work, and then submit a data paper that expands upon the nomination text for inclusion in the special collection. This commentary highlights the rationale for the living collection, and the process of nomination. The collection serves as a living reference that strengthens data culture, supports reproducible geoscience, and provides enduring access to critical information for science and society.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026AV002623","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149047963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"“Young Get Older, But Old Get Younger”: Warming-Induced Circulation Change Explains Contrasting Pattern of Projected Pacific Deoxygenation","authors":"Benjamin A. Taylor,&nbsp;Yassir A. Eddebbar,&nbsp;Yohei Takano,&nbsp;Lynne D. Talley,&nbsp;Shang-Ping Xie","doi":"10.1029/2025AV002278","DOIUrl":"https://doi.org/10.1029/2025AV002278","url":null,"abstract":"<p>Future projections of oxygen and water mass age change in the upper Pacific Ocean show a consistent pattern: strong deoxygenation and increased age in the well-ventilated subtropical gyres, contrasted by weak deoxygenation and younger age in the poorly ventilated tropical oxygen minimum zones. We investigate the underlying dynamics of this pattern by forcing an intermediate-complexity ocean circulation and biogeochemistry model with globally uniform and regionally-distinct idealized warming experiments. We find that this meridional contrast in oxygen and age change arises from a slowdown of vertical velocities driven by a combination of Pacific basin and remote Southern Ocean heat forcing. Warming and stratifying the upper Pacific basin compresses the subtropical gyre circulation into a shallower, flatter layer, thereby reducing ventilation along the base of the North Pacific ventilated thermocline. Warming in the mid-latitude Southern Ocean reduces downwelling locally, but remotely reduces upwelling of old, low-oxygen water in the Tropical and North Pacific via a Kelvin wave-mediated adjustment of the circulation. The combination of these two effects drives the “young get older, but old get younger” response of the Pacific thermocline. Continued monitoring of upper ocean oxygen through the Biogeochemical-Argo float program and improved model representation of mid- and high-latitude ventilation processes are critical to inform how marine ecosystems will adapt to a warmer and more stratified ocean.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025AV002278","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Amplified Cloud-Phase Responses Over Global Mountain Regions Under Climate Warming","authors":"Ying Zhang,&nbsp;Minghuai Wang,&nbsp;Yannian Zhu,&nbsp;Daniel Rosenfeld,&nbsp;Jihu Liu,&nbsp;Xuexu Wu","doi":"10.1029/2026AV002380","DOIUrl":"https://doi.org/10.1029/2026AV002380","url":null,"abstract":"<p>Changes in cloud phase can substantially affect cloud radiative feedbacks and precipitation processes, yet their responses to climate warming remain poorly understood, particularly over mountain regions. Using 20 years of satellite observations together with ERA5 reanalysis data, this study investigates changes in cloud fraction (CF), cloud top temperature, and cloud top height across major mountain regions worldwide and their adjacent lowlands. We find that cloud-phase responses to warming are generally amplified over mountains: ice and warm CF increase, while supercooled CF decreases, at rates exceeding those over global land and ocean. These changes are accompanied by ice cloud tops rising and cooling at rates two to four times faster than over lowlands. Over most mountain and lowland regions, supercooled cloud tops warm and descend, indicating suppressed vertical development. In contrast, the Tibetan Plateau and Andes exhibit pronounced cooling and ascent of supercooled cloud tops, suggesting active supercooled-to-ice phase transitions. Over the Tibetan Plateau, this behavior is associated with enhanced thermal destabilization linked to stronger low-level warming than warming aloft. Over the Andes, a moister mid-tropospheric background environment is consistent with colder and higher supercooled clouds. This stands in contrast to the broader tendency toward atmospheric stabilization under global warming, alongside generally limited changes in relative humidity. These findings highlight distinct and amplified cloud-phase and cloud top responses over high-elevation regions and suggest that mountain cloud changes may represent an important but still insufficiently explored pathway affecting regional radiative response.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026AV002380","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase Transition of CO2-Driven Equatorial Pacific Warming Pattern Governed by Ocean Dynamics and Remote Forcing","authors":"Dirk Olonscheck,&nbsp;Sarah M. Kang","doi":"10.1029/2026AV002437","DOIUrl":"https://doi.org/10.1029/2026AV002437","url":null,"abstract":"<p>Climate models robustly project an El Niño–like warming under rising CO₂, yet recent observations show the opposite with enhanced zonal SST gradients. Whether the long-term projection is relevant for interpreting historical trends remains questionable. Using a large-ensemble of abrupt 4xCO₂ experiment, we identify a two-phase transition in equatorial Pacific warming: an initial gradient strengthening followed by long-term weakening. To isolate the underlying mechanisms, we prescribe CO₂ forcing over discrete latitudinal bands in a model hierarchy that varies the degree to which ocean dynamics are represented. While the initial strengthening is commonly attributed to ocean dynamical thermostat associated with climatological upwelling, our equatorial forcing experiment highlights the role of ocean circulation changes. We further reveal another mechanism involving atmospheric feedbacks via Hadley cell shifts under remote Northern Hemisphere off-equatorial forcing. These fast responses transition to weakened gradients through slow ocean adjustments. In contrast, Southern Hemisphere forcing induces a persistent gradient weakening. Our results suggest that observed SST trends may reflect a fast, forced response to CO₂.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026AV002437","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Ozone Reduction Driven by Dust-Catalyzed Halogen Chemistry","authors":"D. Meidan,&nbsp;A. Bossolasco,&nbsp;C. A. Cuevas,&nbsp;J. Villamayor,&nbsp;R. P. Fernandez,&nbsp;Q. Li,&nbsp;X. Fu,&nbsp;X. Sun,&nbsp;A. Saiz-Lopez","doi":"10.1029/2026AV002453","DOIUrl":"https://doi.org/10.1029/2026AV002453","url":null,"abstract":"<p>Tropospheric ozone (O₃) influences climate and poses risks to human health and crop productivity. Its distribution is shaped by complex interactions between chemical production, transport, and loss processes, including reactions with naturally occurring halogens. Recent studies have shown that mineral dust represents a catalyst for halogen activation, releasing chlorine and iodine radicals that destroy O₃ yet these mechanisms are rarely represented in current atmospheric models. Here, using the Community Earth System Model with explicit chlorine and iodine activation on dust particles, we show that dust-driven halogen chemistry substantially reduces O₃ downwind of major dust source regions. This mechanism drives global annual mean decreases of ∼5% in ground-level O₃ and ∼3% in the tropospheric O₃ column, consistent with observed 3%–6% tropospheric O₃ column reductions over the tropical Atlantic during high-dust conditions. Including this process improves the model's ability to detect the observed spatial pattern of tropospheric O₃ suppression under high-dust conditions, particularly in major dust outflow regions. Dust-driven halogen activation reduces ozone over marine regions, with impacts that propagate inland into agricultural areas. These reductions lower accumulated ozone exposure and improve crop productivity, with the largest improvements (up to 9%) for wheat, rice, and soybeans in southern Asia and North America. Reduced ozone also lowers ozone-attributable mortality, with the strongest benefits occurring in dust-influenced regions of Asia. Our results identify that dust-catalyzed halogen chemistry represents an underrepresented natural ozone sink, with implications for air quality, agricultural productivity, and human health. Projected future increases in dust emissions could further amplify this effect on regional and global ozone budgets.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026AV002453","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148943169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extreme Dry and Humid Heat Seasons Are Changing Asymmetrically","authors":"Catherine C. Ivanovich,&nbsp;Benjamin Cook,&nbsp;Sonali McDermid","doi":"10.1029/2026AV002516","DOIUrl":"https://doi.org/10.1029/2026AV002516","url":null,"abstract":"<p>Climate change is increasing the frequency of extreme heat events, including outside of the expected heat season. Unusually early or late extremes can create outsized impacts as individuals may be less acclimated to intense heat or unprepared to employ cooling strategies. Here we characterize the global seasonality of extreme dry and humid heat and quantify how seasonality is changing over time. We define local baseline heat seasons as the 3 months with the highest fraction of extreme heat events during 1980–1989. This extreme heat season is distinct from meteorological summer for many regions and captures most observed extreme heat days, even in the tropics where the amplitude of temperature seasonality is low. Over the last 45 years, extreme dry and humid heat seasons have significantly expanded over 50% and 48% of the global land area, respectfully, and this expansion is primarily asymmetric. Regions including the western United States, eastern China, northern Africa, and eastern Europe experienced a greater increase in the fraction of extreme dry and humid heat events following the historical extreme heat season, while regions that experienced a larger increase in the fraction of extremes preceding the extreme heat season include western Europe, southern Africa, and northwestern India. These observed asymmetrical changes in extreme heat occurrence in the shoulder seasons are generally not explainable by an intensification of preexisting seasonality driven by annual mean warming. These results highlight the need for extended heat alert systems and prompt further study of compound events where extreme heat seasons are increasingly overlapping with wildfire and hurricane seasons.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026AV002516","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Burn Severity as a Driver of Multi-Year Increases in Gross Primary Production and Solar-Induced Fluorescence Following a Wildfire in Arctic Tundra","authors":"Jinhyuk E. Kim,&nbsp;Rebecca C. Scholten,&nbsp;Rachel Badzioch,&nbsp;Salvatore R. Curasi,&nbsp;Ian Klupar,&nbsp;Alexa A. Salinas,&nbsp;Michael L. Goulden,&nbsp;James T. Randerson,&nbsp;Edward B. Rastetter,&nbsp;Adrian V. Rocha","doi":"10.1029/2025AV001917","DOIUrl":"https://doi.org/10.1029/2025AV001917","url":null,"abstract":"<p>While climate-driven increases in wildfires are altering the composition and function of Arctic ecosystems, the impact of burn severity on longer-term changes in community composition and ecosystem fluxes remains less understood, creating uncertainty in estimates of the biome's carbon storage capacity. Here, we used field and remote sensing observations from the 2007 Anaktuvuk River Fire on Alaska's North Slope to explore post-fire changes in gross primary production (GPP) and solar-induced fluorescence (SIF). A key goal was to develop a mechanistic understanding of the relationships between burn severity, active layer thickness, post-fire plant functional type composition, and GPP, using SIF to explore these linkages at a landscape scale. We measured GPP using eddy covariance flux towers at sites with high and moderate burn severity and at a nearby unburned control site. In high burn severity areas, GPP increased by 38 ± 19% and SIF increased by 48 ± 34% 11–15 years after the fire compared to unburned controls. A positive correlation across space between SIF and post-fire shrub cover within the fire perimeter (<i>r</i> = 0.38, <i>p</i> &lt; 0.01) suggests that shrub expansion (43 ± 22%) was a key driver of the observed pattern of SIF enhancement. Post-fire shrub cover, in turn, was positively correlated to active layer thickness (<i>r</i> = 0.33, <i>p</i> &lt; 0.01) and burn severity (<i>r</i> = 0.76, <i>p</i> &lt; 0.01). Our findings suggest that more frequent and severe Arctic wildfires could accelerate shrub dominance and increases in photosynthesis, trends that are already being driven by climate warming.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025AV001917","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Irreversible Stirring and Mixing of Tracers by Oceanic Internal Gravity Waves","authors":"C. P. Sanjay,&nbsp;Jim Thomas","doi":"10.1029/2026AV002429","DOIUrl":"https://doi.org/10.1029/2026AV002429","url":null,"abstract":"<p>Oceanic internal waves are often thought to be ineffective in stirring and mixing tracer fields such as heat, salt, carbon, and other nutrients. Due to their oscillatory nature, waves are expected to merely displace tracers periodically around their mean position. However, observations of enhanced lateral tracer dispersion at submesoscales (&lt;10 km), where energetic internal waves are abundant, urge better understanding of the role of waves in dispersing oceanic tracers. Using theoretical and numerical methods, this study examines the impact of waves and their amplitudes on the lateral dispersion of passive tracers. We show that two or more waves can irreversibly stir and mix tracers. A broadband spectrum of waves further enhances stirring and mixing. Tracer dispersion in general is seen to become more efficient with increasing amplitude of waves. These findings stem from kinematic non-interacting waves and dynamic nonlinearly interacting waves. Our results highlight the effectiveness of finite-amplitude internal waves in tracer stirring and underscore the need to resolve or parameterize wave-induced lateral mixing in large-scale ocean models.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026AV002429","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Major Space Weather Risks Identified via Coupled Physics-Engineering-Economic Modeling","authors":"Edward J. Oughton,&nbsp;Dennies K. Bor,&nbsp;Robert S. Weigel,&nbsp;C. Trevor Gaunt,&nbsp;Ridvan Dogan,&nbsp;Liling Huang,&nbsp;Jeffrey J. Love,&nbsp;Michael Wiltberger","doi":"10.1029/2026AV002367","DOIUrl":"https://doi.org/10.1029/2026AV002367","url":null,"abstract":"<p>Space weather poses an important but under-quantified threat to society. While severe geomagnetic storms are recognized as potential global catastrophes, their socio-economic impacts remain poorly quantified. We present a novel physics-engineering-economic framework that links geophysical drivers to power grid geoelectric fields, transformer vulnerability, and macroeconomic consequences. Using the United States as an example, we estimate daily economic losses for a 250-year geomagnetic storm from transformer thermal heating of 1.81 billion USD (95 percent confidence interval: 1.65 to 1.96 billion USD), disrupting power for approximately 5.1 million people and 135,000 businesses. These estimates are conservative lower bounds, reflecting only transformer thermal heating effects and excluding voltage collapse, cascading failures, and restoration costs. The true societal risk could be substantially higher. Nonetheless, this contribution provides the first nationwide end-to-end coupling from space physics to potential macroeconomic loss, with quantified uncertainties. Our results demonstrate that coupled socio-economic modeling of space weather is feasible and essential, and the framework is scalable and transferable, offering a template for assessing space weather risk to critical infrastructure in other countries.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"7 6","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026AV002367","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}