AGU Advances最新文献

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A Soil Scientist Goes to Washington: Navigating the Path to National Science Leadership 一位土壤科学家前往华盛顿:走向国家科学领导之路
IF 8.3
AGU Advances Pub Date : 2025-05-09 DOI: 10.1029/2025AV001757
Asmeret Asefaw Berhe
{"title":"A Soil Scientist Goes to Washington: Navigating the Path to National Science Leadership","authors":"Asmeret Asefaw Berhe","doi":"10.1029/2025AV001757","DOIUrl":"https://doi.org/10.1029/2025AV001757","url":null,"abstract":"<p>In 2021, shortly after President Joe Biden and Vice-President Kamala Harris took office, I was invited to join the administration as the Director of the Department of Energy's (DOE) Office of Science (SC)—to oversee the office responsible for advancing scientific research that shapes our understanding of nature and is pivotal for advancing the energy, economic, and national security of the United States. This executive position, known internally as SC-1, requires a Presidential nomination and US Senate confirmation.</p><p>After a 15-month-long process of interviews, vetting, and lots of paperwork, my nomination was approved by the US Senate in May 2022, and I embarked on a unique role in national science leadership. As the first earth scientist and person of color to hold this important scientific leadership position in the United States, I knew I would bring a unique perspective to the role. By embracing this opportunity, I not only made history but also contributed to the advancement of scientific knowledge for the benefit of society.</p><p>My journey to scientific leadership started far from the corridors of the US federal government, halfway across the world in Eritrea. I entered and “grew up” in the world of DOE while pursuing graduate education in earth sciences, at the University of California, Berkeley, where I was fortunate to be co-advised by Dr. Margaret S. Torn, a renowned scientist at the Lawrence Berkeley National Laboratory (LBNL). At LBNL, I gained valuable insights into the national laboratories, user facilities, and the broader DOE scientific ecosystem. Since then, I have been a user of multiple user facilities, secured funding from the DOE, collaborated with scientists from several national laboratories, and mentored scientists who have since secured professional appointments in DOE national laboratories.</p><p>At the time of my appointment to the DOE role, I held the positions of Professor of Soil Biogeochemistry; Ted and Jan Falasco Chair in Earth Sciences and Geology; and Associate Dean for Graduate Education at the University of California, Merced. I am a trained biogeochemist and political ecologist. A central theme of my work has been understanding the critical role that soil plays in regulating the Earth's climate. Over the years, I worked on advancing our understanding of organic matter dynamics in the soil system, response of key soil processes to environmental change, and human-soil relationships. In addition, I actively participated in on numerous national and international scholarly activities and committees, including those convened by the National Academies of Sciences, Engineering, and Medicine, State of California, and the United Nations. Further, I championed efforts to broaden participation in STEM, recognizing its essential role in fostering a more innovative and just scientific enterprise. My experiences as a scientist, educator, academic leader, and science policy contributor were instrumental in prepari","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 3","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025AV001757","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930434","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
Microclimate Refugia Are Transient in Stable Old Forests, Pacific Northwest, USA 美国太平洋西北部稳定的老森林中的小气候避难所是短暂的
IF 8.3
AGU Advances Pub Date : 2025-04-30 DOI: 10.1029/2024AV001492
Julia A. Jones, Christopher Daly, Mark Schulze, Christopher J. Stlll
{"title":"Microclimate Refugia Are Transient in Stable Old Forests, Pacific Northwest, USA","authors":"Julia A. Jones,&nbsp;Christopher Daly,&nbsp;Mark Schulze,&nbsp;Christopher J. Stlll","doi":"10.1029/2024AV001492","DOIUrl":"https://doi.org/10.1029/2024AV001492","url":null,"abstract":"<p>An issue of global concern is how climate change forcing is transmitted to ecosystems. Forest ecosystems in mountain landscapes may demonstrate buffering and perhaps decoupling of long-term rates of temperature change, because vegetation, topography, and local winds (e.g., cold air pooling) influence temperature and potentially create microclimate refugia (areas which are relatively protected from climate change). We tested these ideas by comparing 45-year regional rates of air temperature change to unique temporal and spatial air temperature records in the understory of regionally representative stable old forest at the H.J. Andrews Experimental Forest, Oregon, USA. The 45-year seasonal patterns and rates of warming were similar throughout the forested landscape and matched regional rates observed at 88 standard meteorological stations in Oregon and Washington, indicating buffering, but not decoupling of long-term climate change rates. Consideration of the energy balance explains these results: while shading and airflows produce spatial patterns of temperature, these processes do not counteract global increases in air temperature driven by increased downward, longwave radiation forced by increased anthropogenic greenhouse gases in the atmosphere. In some months, the 45-year warming in the forest understory equaled or exceeded spatial differences of air temperature between the understory and the canopy or canopy openings and was comparable to temperature change over 1,000 m elevation, while in other months there has been little change. These findings have global implications because they indicate that microclimate refugia are transient, even in this forested mountain landscape.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 3","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001492","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892855","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
A Lagrangian Perspective on the Growth of Midlatitude Storms 中纬度风暴发展的拉格朗日观点
IF 8.3
AGU Advances Pub Date : 2025-04-29 DOI: 10.1029/2024AV001555
Or Hadas, Yohai Kaspi
{"title":"A Lagrangian Perspective on the Growth of Midlatitude Storms","authors":"Or Hadas,&nbsp;Yohai Kaspi","doi":"10.1029/2024AV001555","DOIUrl":"https://doi.org/10.1029/2024AV001555","url":null,"abstract":"<p>Extratropical storms dominate midlatitude climate and weather and are known to grow baroclinically and decay barotropically. Traditionally, quantitative climatic measures of storm activity have been mostly based on Eulerian measures, taking into account the mean state of the atmosphere and how those affect Eulerian eddy activity, but they do not consider the Lagrangian growth of the storms themselves. Here, using ERA-5 reanalysis data and tracking all extratropical storms (cyclones and anticyclones) from 83 years of data, we examine the actual growth of the storms and compare it to the Eulerian characteristics of the background state as the storms develop. In the limit of weak baroclinicity, we find that baroclinicity provides a good measure for storm maximum intensity. However, this monotonic relationship breaks for high baroclinicity levels. We show that although the actual growth rate of individual storms monotonically increases with baroclinicity, the reduction in maximum intensity at high baroclinicity is caused by a decrease in storm growth time. Based on the Lagrangian analysis, we suggest a nonlinear correction to the traditional linear connection between baroclinicity and storms' activity. Then, we show that a simplified model of storm growth, incorporating the baroclinicity effect on the vertical tilt of anomalies, reproduces the observed nonlinear relationship. Expanding the analysis to include the mean flow's barotropic properties highlights their marginal effect on storm growth rate, but the crucial impact on growth time. Our results emphasize the potential of Lagrangianly studying storm dynamics to advance understanding of the midlatitude climate.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 3","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001555","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889027","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
Recent Forest Loss in the Brazilian Amazon Causes Substantial Reductions in Dry Season Precipitation 最近巴西亚马逊地区的森林减少导致旱季降水大幅减少
IF 8.3
AGU Advances Pub Date : 2025-04-25 DOI: 10.1029/2025AV001670
Yu Liu, Dominick V. Spracklen, Douglas J. Parker, Joseph Holden, Jun Ge, Weidong Guo
{"title":"Recent Forest Loss in the Brazilian Amazon Causes Substantial Reductions in Dry Season Precipitation","authors":"Yu Liu,&nbsp;Dominick V. Spracklen,&nbsp;Douglas J. Parker,&nbsp;Joseph Holden,&nbsp;Jun Ge,&nbsp;Weidong Guo","doi":"10.1029/2025AV001670","DOIUrl":"https://doi.org/10.1029/2025AV001670","url":null,"abstract":"<p>The Amazon has experienced extensive deforestation in recent decades, causing substantial impacts on local and regional climate. However, the precipitation response to this recent forest cover change remains unclear. Here, we examined biophysical effects of forest cover change in the Brazilian Amazon on dry season precipitation using a regional coupled climate model with embedded water vapor tracers. We find that the 3.2% mean reduction in forest cover that occurred in Rondônia and Mato Grosso during 2002–2015 caused a 3.5 ± 0.8% reduction in evapotranspiration and a 5.4 ± 4.4% reduction in precipitation. The reduction in evapotranspiration warmed and dried the lower atmosphere reducing convection and precipitation. Reductions in incoming moisture, dominated by reduced moisture inflow in the mid-troposphere, accounted for 25% of the total reduction in moisture and amplified the precipitation response to forest loss. The reduction in precipitation efficiency explains 84.5% of the reduction in precipitation with the remainder due to reductions in precipitable water. The reduced precipitation sourced from water vapor inflow accounts for 76.9% of the simulated precipitation reduction, with the remaining 23.1% due to reduced local evapotranspiration. Our study demonstrates substantial reductions in dry season precipitation due to recent forest cover change in the Amazon, highlighting the importance of atmospheric responses to land cover change in this region.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 2","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025AV001670","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871859","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 Known Unknowns of Petrogenic Organic Carbon in Soils 土壤中岩石成因有机碳的已知未知
IF 8.3
AGU Advances Pub Date : 2025-04-25 DOI: 10.1029/2024AV001625
Daniel L. Evans, Sebastian Doetterl, Nora Gallarotti, Eleanor Georgiadis, Sami Nabhan, Stephan H. Wartenweiler, Timo M. Y. Rhyner, Benedict V. A. Mittelbach, Timothy I. Eglinton, Jordon Hemingway, Thomas M. Blattmann
{"title":"The Known Unknowns of Petrogenic Organic Carbon in Soils","authors":"Daniel L. Evans,&nbsp;Sebastian Doetterl,&nbsp;Nora Gallarotti,&nbsp;Eleanor Georgiadis,&nbsp;Sami Nabhan,&nbsp;Stephan H. Wartenweiler,&nbsp;Timo M. Y. Rhyner,&nbsp;Benedict V. A. Mittelbach,&nbsp;Timothy I. Eglinton,&nbsp;Jordon Hemingway,&nbsp;Thomas M. Blattmann","doi":"10.1029/2024AV001625","DOIUrl":"https://doi.org/10.1029/2024AV001625","url":null,"abstract":"<p>Intensifying effects of global climate change have spurred efforts to enhance carbon sequestration and the long-term storage of soil organic carbon (OC). Current soil carbon models predominantly assume that inputs of OC are biospheric, that is, primarily derived from plant decomposition. However, these overlook the contribution of OC from soil parent material, including petrogenic organic carbon (OC<sub>petro</sub>) from OC-bearing (meta-)sedimentary bedrock. To our knowledge, no soil carbon model accounts for the inputs of OC<sub>petro</sub> to soils, resulting in significant gaps in our understanding about the roles OC<sub>petro</sub> plays in soils. Here, we call for cross-disciplinary research to investigate the transport and stability of OC<sub>petro</sub> across the bedrock–soil continuum. We pose four key questions as motivation for this effort. Ignoring the inputs of OC<sub>petro</sub> to soils has significant implications, including overestimating biospheric carbon stocks and turnover times. Furthermore, we lack information on the role that OC<sub>petro</sub> may play in priming microbial communities, as well as the impacts of land management on OC<sub>petro</sub> stocks.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 2","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001625","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871860","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
Remote Sensing Improves Multi-Hazard Flooding and Extreme Heat Detection by Fivefold Over Current Estimates 遥感技术将多灾害洪水和极端高温探测技术提高了5倍
IF 8.3
AGU Advances Pub Date : 2025-04-24 DOI: 10.1029/2025AV001667
Matthew Preisser, Paola Passalacqua
{"title":"Remote Sensing Improves Multi-Hazard Flooding and Extreme Heat Detection by Fivefold Over Current Estimates","authors":"Matthew Preisser,&nbsp;Paola Passalacqua","doi":"10.1029/2025AV001667","DOIUrl":"https://doi.org/10.1029/2025AV001667","url":null,"abstract":"<p>The co-occurrence of multiple hazards is of growing concern globally as the frequency and magnitude of extreme climate events increases. Despite studies examining the spatial distribution of such events, there has been little work in examining if all relevant life threatening and damaging hazards are captured in existing hazard databases and by common hazard metrics. For example, local/regional flash flooding events are seldom captured by optical satellite instruments and are subsequently excluded from global hazard databases. Similarly, the heat hazard definitions most frequently used in multi-hazard studies inherently fail to capture events that are life-threatening but climatologically within an expected range. Our goal is to determine the potential for increasing multi-hazard event detection capabilities by inferring additional hazard footprints from widely accessible satellite data. We use daily precipitation and temperature satellite data to develop an open-source framework that infers additional hazard footprints that are not included in traditional methods. With the state of Texas as our study area, we detected 2.5 times as many flood hazards, equivalent to $320 million in property and crop damages. Furthermore, our expanded heat hazard definition increases the impacted area by 56.6%, equivalent to 91.5 million <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mtext>km</mtext>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${text{km}}^{2}$</annotation>\u0000 </semantics></math> over an 18 year period. Increasing hazard detection capabilities and expanding existing definitions of hazards using daily satellite data increases the temporal and spatial resolutions at which multi-hazard events are detected. Having more complete data sets of all relevant hazard extents improves our ability to track global trends and more accurately determine the magnitude of hazard exposure inequities.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 2","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025AV001667","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865671","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
Disentangling the Effects of Global and Regional Drivers on Diverse Long-Term pH Trends in Coastal Waters 全球和区域驱动因素对沿海水域pH值长期变化趋势的影响
IF 8.3
AGU Advances Pub Date : 2025-04-22 DOI: 10.1029/2024AV001350
Ming Li, Renjian Li, Yijun Guo, Jeremy M. Testa, Wei-Jun Cai, Chunqi Shen, Yuren Chen, Sujay S. Kaushal
{"title":"Disentangling the Effects of Global and Regional Drivers on Diverse Long-Term pH Trends in Coastal Waters","authors":"Ming Li,&nbsp;Renjian Li,&nbsp;Yijun Guo,&nbsp;Jeremy M. Testa,&nbsp;Wei-Jun Cai,&nbsp;Chunqi Shen,&nbsp;Yuren Chen,&nbsp;Sujay S. Kaushal","doi":"10.1029/2024AV001350","DOIUrl":"https://doi.org/10.1029/2024AV001350","url":null,"abstract":"<p>Unlike declines of pH in the open ocean on the total scale (pH<sub>T</sub>), coastal systems have shown complex long-term trends in pH<sub>T</sub> due to a multitude of global and regional drivers. These drivers include changes in nutrient loading, human-accelerated chemical weathering of watersheds, acid-rain and land-use changes, and ocean acidification due to atmospheric CO<sub>2</sub> increase. We lack understanding of how these co-occurring processes have influenced long-term pH<sub>T</sub> changes in coastal waters. To address this knowledge gap, a coupled hydrodynamic-biogeochemical-carbonate chemistry model was used to conduct a hindcast simulation and scenario analyses of carbonate chemistry in the Chesapeake Bay between 1951 and 2010. Trend analysis reveals increasing pH<sub>T</sub> in the upper Bay due to river alkalinization but decreasing pH<sub>T</sub> in the bottom waters of the mid-and lower Bay due to ocean acidification. No trend is detected in the surface waters of the mid- and lower Bay due to competition between the two drivers. The effect of river alkalinization on the acidic volume in the estuary is twice that of ocean acidification. Our findings show that river alkalinization provides an important buffer against acidification while eutrophication plays a secondary role. Our results also suggest ocean alkalinity enhancement could be effective in mitigating acidification in coastal waters.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 2","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001350","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143861692","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
Supplementing Enhanced Weathering With Organic Amendments Accelerates the Net Climate Benefit of Soil Amendments in Rangeland Soils 用有机改进剂补充增强的风化作用加速了牧场土壤改进剂的净气候效益
IF 8.3
AGU Advances Pub Date : 2025-04-18 DOI: 10.1029/2024AV001480
Tyler L. Anthony, Andrew R. Jones, Whendee L. Silver
{"title":"Supplementing Enhanced Weathering With Organic Amendments Accelerates the Net Climate Benefit of Soil Amendments in Rangeland Soils","authors":"Tyler L. Anthony,&nbsp;Andrew R. Jones,&nbsp;Whendee L. Silver","doi":"10.1029/2024AV001480","DOIUrl":"https://doi.org/10.1029/2024AV001480","url":null,"abstract":"<p>Carbon dioxide (CO<sub>2</sub>) removal (carbon dioxide removal (CDR)) that combines decreased greenhouse gas emissions with atmospheric CO<sub>2</sub> reduction is needed to limit climate change. Enhanced rock weathering (ERW) of ground silicate minerals is an emerging CDR technology with the potential to decrease atmospheric CO<sub>2</sub>. However, there are few multi-year field studies and considerable uncertainty in field-rates of ERW. We explored combining finely ground metabasaltic rock with other soil CDR technologies (compost and biochar amendments) to stimulate carbon (C) sequestration. The combined ground rock (GR), compost, and biochar amendment had the greatest increases in soil C stocks over 3 years (15.3 ± 4.8 Mg C ha<sup>−1</sup>). All other treatments slowed or reversed background C losses, with GR-only treatments reducing rates of soil C loss relative to the control but still losing soil C over time. Ground rock amendments lowered nitrous oxide (N<sub>2</sub>O) emissions by 11.0 ± 0.6 kg CO<sub>2</sub>e ha<sup>−1 </sup>yr<sup>−1</sup> and increased methane (CH<sub>4</sub>) consumption by 9.5 ± 3.5 to 18.4 ± 4.4 kg CO<sub>2</sub>e ha<sup>−1 </sup>yr<sup>−1</sup>; while noteworthy, emissions reductions were an order of magnitude smaller than organic C sequestration with compost amendments. The combined amendment yielded the greatest estimated net ecosystem benefit (3 year relative changes in soil C, estimated ERW rates, and greenhouse gas emissions) of −86.0 ± 24.7 Mg CO<sub>2</sub>e ha<sup>−1</sup>. Benefits were dominated by soil organic C gains, directly from organic amendments and indirectly from increased plant growth. Weathering rates were &lt;10% of the theoretical potential. Combined ERW and organic amendments increased estimated weathering rates and stimulated soil organic C sequestration.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 2","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001480","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143846144","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
Sources, Pathways, and Drivers of Sub-Antarctic Mode Water Formation 亚南极模态水形成的来源、途径和驱动因素
IF 8.3
AGU Advances Pub Date : 2025-04-18 DOI: 10.1029/2024AV001449
Bieito Fernández Castro, Alberto C. Naveira Garabato, Matthew Mazloff, Richard G. Williams
{"title":"Sources, Pathways, and Drivers of Sub-Antarctic Mode Water Formation","authors":"Bieito Fernández Castro,&nbsp;Alberto C. Naveira Garabato,&nbsp;Matthew Mazloff,&nbsp;Richard G. Williams","doi":"10.1029/2024AV001449","DOIUrl":"https://doi.org/10.1029/2024AV001449","url":null,"abstract":"<p>Sub-Antarctic Mode Waters (SAMWs) form to the north of the Antarctic Circumpolar Current in the Indo-Pacific Ocean, whence they ventilate the ocean's lower pycnocline and play an important role in the climate system. With a backward Lagrangian particle-tracking experiment in a data-assimilative model of the Southern Ocean (B-SOSE), we address the long-standing question of the extent to which SAMWs originate from densification of southward-flowing subtropical waters versus lightening of northward-flowing Antarctic waters sourced by Circumpolar Deep Water (CDW) upwelling. Our analysis evidences the co-occurrence of both sources in all SAMW formation areas, and strong inter-basin contrasts in their relative contributions. Subtropical waters are the main precursor of Indian Ocean SAMWs (70%–75% of particles) but contribute a smaller amount (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>&lt;</mo>\u0000 </mrow>\u0000 <annotation> ${&lt; } $</annotation>\u0000 </semantics></math>40% of particles) to Pacific SAMWs, which are mainly sourced from the upwelled CDW. By tracking property changes along particle trajectories, we show that SAMW formation from northern and southern sources involves contrasting drivers: subtropical source waters are cooled and densified by surface heat fluxes, and freshened by ocean mixing. Southern source waters are warmed and lightened by surface heat and freshwater fluxes, and they are made either saltier by mixing in the case of Indian SAMWs, or fresher by surface fluxes in the case of Pacific SAMWs. Our results underscore the distinct climatic impact of Indian and Pacific SAMWs formation, involving net release of atmospheric heat and uptake of atmospheric freshwater, respectively; a role that is conferred by the relative contributions of subtropical and Antarctic sources to their formation.</p>","PeriodicalId":100067,"journal":{"name":"AGU Advances","volume":"6 2","pages":""},"PeriodicalIF":8.3,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024AV001449","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143846145","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 Hidden Internal Flow Dynamics of Shear-Thinning Magma in Dikes 岩脉中剪切减薄岩浆的隐藏内部流动动力学
IF 8.3
AGU Advances Pub Date : 2025-04-18 DOI: 10.1029/2024AV001495
Janine L. Kavanagh, Caitlin M. Chalk, Thomas J. Jones, David J. C. Dennis
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