AGU Advances最新文献_第7页

Carbon-Water Tradeoffs in Old-Growth and Young Forests of the Pacific Northwest 西北太平洋老林和幼林的碳水权衡

IF 8.3

AGU Advances Pub Date : 2024-07-18 DOI: 10.1029/2024AV001188

Michael D. Farinacci, Julia Jones, Lucas C. R. Silva

{"title":"Carbon-Water Tradeoffs in Old-Growth and Young Forests of the Pacific Northwest","authors":"Michael D. Farinacci, Julia Jones, Lucas C. R. Silva","doi":"10.1029/2024AV001188","DOIUrl":"https://doi.org/10.1029/2024AV001188","url":null,"abstract":"Despite much interest in relationships among carbon and water in forests, few studies assess how carbon accumulation scales with water use in forested watersheds with varied histories. This study quantified tree growth, water use efficiency, and carbon-water tradeoffs of young versus mature/old-growth forest in three small (13–22 ha) watersheds in the H.J. Andrews Experimental Forest, Oregon, USA. To quantify and scale carbon-water tradeoffs from trees to watersheds, tree-ring records and greenness and wetness indices from remote sensing were combined with long-term vegetation, climate, and streamflow data from young forest watersheds (trees ∼45 years of age) and from a mature/old-growth forest watershed (trees 150–500 years of age). Biomass production was closely related to water use; water use efficiency (basal area increment per unit of evapotranspiration) was lower; and carbon-water tradeoffs were steeper in young forest plantations compared with old-growth forest for which the tree growth record begins in the 1850s. Greenness and wetness indices from Landsat imagery were not significant predictors of streamflow or tree growth over the period 1984 to 2017, and soil C and N did not differ significantly among watersheds. Multiple lines of evidence show that mature and old-growth forest watersheds store and accumulate more carbon, are more drought resistant, and better sustain water availability compared to young forests. These results provide a basis for reconstructions and predictions that are potentially broadly applicable, because first-order watersheds occupy 80%–90% of large river basins and study watersheds are representative of forest history in the Pacific Northwest region.","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 4","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001188","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141730213","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}

引用次数: 0

Challenges Facing Scientific Publishing in the Field of Earth & Space Sciences 地球与空间科学领域科学出版面临的挑战

IF 8.3

AGU Advances Pub Date : 2024-07-17 DOI: 10.1029/2024AV001334

AGU Editorial Network

{"title":"Challenges Facing Scientific Publishing in the Field of Earth & Space Sciences","authors":"AGU Editorial Network","doi":"10.1029/2024AV001334","DOIUrl":"https://doi.org/10.1029/2024AV001334","url":null,"abstract":"The scientific publishing landscape is evolving rapidly. This evolution is driven by a confluence of internal and external forces, including the growth of metrics-based evaluation of scientists; an increasing volume of manuscripts combined with expectations for rapid review and publication; an increasing number of journals, including for-profit Open Access publications; and the adoption of preprint servers across a growing range of disciplines. Many of these forces are contributing to personal anxiety and fatigue for authors, reviewers, and editors. Collectively, they are placing substantial stress on scientific publishing, which is a foundational pillar of the scientific enterprise. As editors of American Geophysical Union journals and books, we remain confident in the fundamental foundations of scientific publishing, but we are concerned about the impact of these increasing stressors. By affirming and investing in editorial values, respecting scientific integrity and credibility, and committing to accessibility, transparency, and accountability, we can fortify the foundations of the scientific enterprise during a time of rapid change.","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 4","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001334","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141639520","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}

引用次数: 0

Permafrost Formation in a Meandering River Floodplain 蜿蜒河流洪泛区的冻土形成

IF 8.3

AGU Advances Pub Date : 2024-07-05 DOI: 10.1029/2024AV001175

Madison M. Douglas, Gen K. Li, A. Joshua West, Yutian Ke, Joel C. Rowland, Nathan Brown, Jon Schwenk, Preston C. Kemeny, Anastasia Piliouras, Woodward W. Fischer, Michael P. Lamb

{"title":"Permafrost Formation in a Meandering River Floodplain","authors":"Madison M. Douglas, Gen K. Li, A. Joshua West, Yutian Ke, Joel C. Rowland, Nathan Brown, Jon Schwenk, Preston C. Kemeny, Anastasia Piliouras, Woodward W. Fischer, Michael P. Lamb","doi":"10.1029/2024AV001175","DOIUrl":"https://doi.org/10.1029/2024AV001175","url":null,"abstract":"Permafrost influences 25% of land in the Northern Hemisphere, where it stabilizes the ground beneath communities and infrastructure and sequesters carbon. However, the coevolution of permafrost, river dynamics, and vegetation in Arctic environments remains poorly understood. As rivers meander, they erode the floodplain at cutbanks and build new land through bar deposition, creating sequences of landforms with distinct formation ages. Here we mapped these sequences along the Koyukuk River floodplain, Alaska, analyzing permafrost occurrence, and landform and vegetation types. We used radiocarbon and optically stimulated luminescence (OSL) dating to develop a floodplain age map. Deposit ages ranged from modern to 10 ka, with more younger deposits near the modern channel. Permafrost rapidly reached 50% areal extent in all deposits older than 200 years then gradually increased up to ∼85% extent for deposits greater than 4 Kyr old. Permafrost extent correlated with increases in black spruce and wetland abundance, as well as increases in permafrost extent within wetland, and shrub and scrub vegetation classes. We developed an inverse model to constrain permafrost formation rate as a function of air temperature. Permafrost extent initially increased by ∼25% per century, in pace with vegetation succession, before decelerating to <10% per millennia as insulating overbank mud and moss slowly accumulated. Modern permafrost extent on the Koyukuk floodplain therefore reflects a dynamic balance between widespread, time-varying permafrost formation and rapid, localized degradation due to cutbank erosion that might trigger a rapid loss of permafrost with climatic warming.","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 4","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001175","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536993","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}

引用次数: 0

Characteristics of the Fault Damage Zone From High-Resolution Seismic Imaging Along the Palos Verdes Fault, California 加利福尼亚州帕洛斯维第斯断层沿线高分辨率地震成像显示的断层破坏带特征

IF 8.3

AGU Advances Pub Date : 2024-07-03 DOI: 10.1029/2023AV001155

Travis Alongi, Emily E. Brodsky, Jared Kluesner, Daniel Brothers

{"title":"Characteristics of the Fault Damage Zone From High-Resolution Seismic Imaging Along the Palos Verdes Fault, California","authors":"Travis Alongi, Emily E. Brodsky, Jared Kluesner, Daniel Brothers","doi":"10.1029/2023AV001155","DOIUrl":"https://doi.org/10.1029/2023AV001155","url":null,"abstract":"The distribution and intensity of fault damage zones provides insight into fault activity and its relationship to fluid flow in the crust. Presently, measures of the in-situ distribution of fault damage remain limited and along-strike studies are rare. This study focuses on an offshore section Palos Verdes Fault damage zone that spans 28 km, near Los Angeles, California. To investigate the previously unresolved shallow (∼400 m below the seafloor) fault damage zone we use densely spaced (∼500 m line separation) newly collected sparker multichannel seismic lines and sub-bottom profiles. The combination of high-resolution acquisition methods and specialized seismic processing workflows provide improved imaging of shallow faulting. We apply a multi-trace similarity technique to identify discontinuities in the seismic data that may be attributed to faults and fractures. This fault detection approach reveals diverse fault damage patterns on adjacent seismic profiles. However, a discernible damage zone pattern emerges by stacking multiple damage detection profiles along strike. We find that peak damage identified in this way corresponds to the active main fault strand, confirmed in this study, and thus the technique may be useful for identifying active fault strands elsewhere. Additionally, we observe that the variable width of the damage zone along strike is controlled by fault obliquity. Furthermore, our observations reveal a correlation between fault damage and seafloor fluid seeps visible in the water column, suggesting that damage plays a role in controlling fluid flow around the fault.","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 4","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023AV001155","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141536924","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}

引用次数: 0

Evolving Subduction Zone Thermal Structure Drives Extensive Forearc Mantle Wedge Hydration 不断演化的俯冲带热力结构推动了广泛的弧前地幔楔水合作用

IF 8.3

AGU Advances Pub Date : 2024-06-29 DOI: 10.1029/2023AV001121

G. S. Epstein, C. B. Condit, R. K. Stoner, A. F. Holt, V. E. Guevara

{"title":"Evolving Subduction Zone Thermal Structure Drives Extensive Forearc Mantle Wedge Hydration","authors":"G. S. Epstein, C. B. Condit, R. K. Stoner, A. F. Holt, V. E. Guevara","doi":"10.1029/2023AV001121","DOIUrl":"https://doi.org/10.1029/2023AV001121","url":null,"abstract":"Hydration of the subduction zone forearc mantle wedge influences the downdip distribution of seismicity, the availability of fluids for arc magmatism, and Earth's long term water cycle. Reconstructions of present-day subduction zone thermal structures using time-invariant geodynamic models indicate relatively minor hydration, in contrast to many geophysical and geologic observations. We pair a dynamic, time-evolving thermal model of subduction with phase equilibria modeling to investigate how variations in slab and forearc temperatures from subduction infancy through to maturity contribute to mantle wedge hydration. We find that thermal state during the intermediate period of subduction, as the slab freely descends through the upper mantle, promotes extensive forearc wedge hydration. In contrast, during early subduction the forearc is too hot to stabilize hydrous minerals in the mantle wedge, while during mature subduction, slab dehydration dominantly occurs beyond forearc depths. In our models, maximum wedge hydration during the intermediate phase is 60%–70% and falls to 20%–40% as quasi-steady state conditions are approached during maturity. Comparison to global forearc H2O capacities reveals that consideration of thermal evolution leads to an order of magnitude increase in estimates for current extents of wedge hydration and provides better agreement with geophysical observations. This suggests that hydration of the forearc mantle wedge represents a potential vast reservoir of H2O, on the order of 3.4–5.9 × 1021 g globally. These results provide novel insights into the subduction zone water cycle, new constraints on the mantle wedge as a fluid reservoir and are useful to better understand geologic processes at plate margins.","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 4","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023AV001121","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489024","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}

引用次数: 0

When a Plateau Suppresses a Plume: Disappearance of the Samoan Plume Under the Ontong Java Plateau 当高原抑制烟羽时：翁通爪哇海台下萨摩亚烟羽的消失

IF 8.3

AGU Advances Pub Date : 2024-06-26 DOI: 10.1029/2023AV001079

M. G. Jackson, V. A. Finlayson, Bernhard Steinberger, Kevin Konrad

{"title":"When a Plateau Suppresses a Plume: Disappearance of the Samoan Plume Under the Ontong Java Plateau","authors":"M. G. Jackson, V. A. Finlayson, Bernhard Steinberger, Kevin Konrad","doi":"10.1029/2023AV001079","DOIUrl":"https://doi.org/10.1029/2023AV001079","url":null,"abstract":"The Samoan hotspot generated an age-progressive volcanic track that can be traced back to 24 Ma at Alexa Bank, but the trace of the older portion (>24 Ma) of the hotspot track is unclear. We show that six seamounts located in and around the Magellan Seamount chain—north of the Ontong-Java Plateau (OJP)—have ages (87–106 Ma), geochemistry, and locations consistent with absolute plate motion model reconstructions of the Samoan hotspot track in the late Cretaceous, and three additional seamounts have geochemistry and locations consistent with a Samoan origin. However, a large segment of the Samoan hotspot (24–87 Ma) remains unidentified. Absolute plate motion models show that, from ∼60 to 30 Ma, the OJP passed over the Samoan plume. The exceptional thickness of the OJP lithosphere may have largely suppressed Samoan plume melting because the inferred volcanic trace of the Samoan hotspot wanes, and then disappears, on the OJP. Fortunately, 44 Ma volcanism at Malaita Island, located on the southern margin of the OJP, has a location, age, and geochemistry consistent with a Samoan plume origin, and provides a “missing link” bridging the younger and older segments of the Samoan hotspot. Our synthesis of geochemical, geochronological, and plate motion model evidence reveals that Samoa exhibits a clear hotspot age progression for over 100 Myr. Passage of ancient plateaus over young plumes—here called “plume-plateau” interaction—may be relatively common: the OJP also passed over the putative Rarotonga hotspot, and the Society and Pitcairn hotspots were overtopped by the Manihiki Plateau.","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 4","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023AV001079","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488841","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}

引用次数: 0

The Spillover of Tropospheric Ozone Increases Has Hidden the Extent of Stratospheric Ozone Depletion by Halogens 对流层臭氧增加的溢出效应掩盖了卤素对平流层臭氧的消耗程度

AGU Advances Pub Date : 2024-06-09 DOI: 10.1029/2023AV001154

Michael J. Prather

引用次数: 0

Unraveling the Atmospheric Energy Input and Ionization Due To EMIC-Driven Electron Precipitation From ELFIN Observations 从 ELFIN 观测中揭示 EMIC 驱动的电子沉降引起的大气能量输入和电离作用

AGU Advances Pub Date : 2024-06-07 DOI: 10.1029/2023AV001096

L. Capannolo, R. Marshall, W. Li, G. Berland, K. Duderstadt, N. Sivadas, D. L. Turner, V. Angelopoulos

{"title":"Unraveling the Atmospheric Energy Input and Ionization Due To EMIC-Driven Electron Precipitation From ELFIN Observations","authors":"L. Capannolo, R. Marshall, W. Li, G. Berland, K. Duderstadt, N. Sivadas, D. L. Turner, V. Angelopoulos","doi":"10.1029/2023AV001096","DOIUrl":"https://doi.org/10.1029/2023AV001096","url":null,"abstract":"Energetic electron precipitation (EEP) from the radiation belts into Earth's atmosphere leads to several profound effects (e.g., enhancement of ionospheric conductivity, possible acceleration of ozone destruction processes). An accurate quantification of the energy input and ionization due to EEP is still lacking due to instrument limitations of low-Earth-orbit satellites capable of detecting EEP. The deployment of the Electron Losses and Fields InvestigatioN (ELFIN) CubeSats marks a new era of observations of EEP with an improved pitch-angle (0°–180°) and energy (50 keV–6 MeV) resolution. Here, we focus on the EEP recorded by ELFIN coincident with electromagnetic ion cyclotron (EMIC) waves, which play a major role in radiation belt electron losses. The EMIC-driven EEP (∼200 keV–∼2 MeV) exhibits a pitch-angle distribution (PAD) that flattens with increasing energy, indicating more efficient high-energy precipitation. Leveraging the combination of unique electron measurements from ELFIN and a comprehensive ionization model known as Boulder Electron Radiation to Ionization (BERI), we quantify the energy input of EMIC-driven precipitation (on average, ∼3.3 × 10−2 erg/cm2/s), identify its location (any longitude, 50°–70° latitude), and provide the expected range of ion-electron production rate (on average, 100–200 pairs/cm3/s), peaking in the mesosphere—a region often overlooked. Our findings are crucial for improving our understanding of the magnetosphere-ionosphere-atmosphere system as they accurately specify the contribution of EMIC-driven EEP, which serves as a crucial input to state-of-the-art atmospheric models (e.g., WACCM) to quantify the accurate impact of EMIC waves on both the atmospheric chemistry and dynamics.","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023AV001096","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141286935","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}

引用次数: 0

Discounting Water for Optimal Carbon Gain as a Basis of Stomatal Closure 折算水分以获得最佳碳收益是气孔关闭的基础

AGU Advances Pub Date : 2024-06-05 DOI: 10.1029/2024AV001287

Mazen Nakad

{"title":"Discounting Water for Optimal Carbon Gain as a Basis of Stomatal Closure","authors":"Mazen Nakad","doi":"10.1029/2024AV001287","DOIUrl":"https://doi.org/10.1029/2024AV001287","url":null,"abstract":"The exchange of carbon dioxide and water vapor between terrestrial ecosystems and the atmosphere is regulated by stomata (small pores in the leaves of plants). Unsurprisingly, environmental factors controlling the opening and closure of stomata has been sought as early as 1800. One approach, popularized in the early 1970s, is a stomatal optimization framework. This framework is based on the hypothesis that plants optimize carbon gain subject to water loss or water availability constraints. This constraint optimization problem was solved in various forms assuming instantaneous adjustments of stomatal aperture to maximize a reward function with no future foresight or legacy effects. Holtzman et al. (2024, https://doi.org/10.1029/2023av001113) offers a novel approach that can diagnose the effective timescale over which the reward function maximization must be time-integrated. The developed method thus optimizes an integrated carbon gain function but adjusted by a discount factor subject to water availability in the root zone. The discount factor considers how the plant values carbon gain to save water and its timescale can be inferred from observations because the model is analytically tractable. The results suggest that the most important climate factor that determines this discount timescale is multi-annual mean of the longest dry period during the growing season. The findings highlight how local climate traits influence the spatial variation in ecosystem-level water use strategies. This sets the stage for expanding such a framework to cases where multiple constraints act in concert while operating at distinct time scales.","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"5 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001287","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141251483","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}

引用次数: 0

AGU Publications Updates Authorship Policy to Foster Greater Equity and Transparency in Global Research Collaborations AGU 出版物更新作者身份政策，促进全球研究合作的公平性和透明度

AGU Advances Pub Date : 2024-05-28 DOI: 10.1029/2024AV001298

Marguerite A. Xenopoulos, Ben Bond-Lamberty, Ankur R. Desai, Deborah Huntzinger, Paula R. Buchanan, Amy E. East, Arvind Singh, Paige Wooden, Kevin Jewett, Mia Ricci

引用次数: 0