Geophysical Research Letters最新文献

{"title":"Joint Effects of Submesoscale Lateral Dispersion and Biological Reactions on Biogeochemical Flux","authors":"Lulabel R. Seitz,&nbsp;Mara A. Freilich","doi":"10.1029/2024GL114112","DOIUrl":"https://doi.org/10.1029/2024GL114112","url":null,"abstract":"<p>Submesoscale dynamics, operating at spatial scales of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>O</mi>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mrow>\u0000 <mn>1</mn>\u0000 <mo>−</mo>\u0000 <mn>10</mn>\u0000 <mrow>\u0000 <mspace></mspace>\u0000 <mtext>km</mtext>\u0000 </mrow>\u0000 </mrow>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $mathcal{O}(1-10,text{km})$</annotation>\u0000 </semantics></math> and temporal scales of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>O</mi>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mrow>\u0000 <mn>1</mn>\u0000 <mrow>\u0000 <mspace></mspace>\u0000 <mtext>day</mtext>\u0000 </mrow>\u0000 </mrow>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> $mathcal{O}(1,text{day})$</annotation>\u0000 </semantics></math>, are particularly important for marine ecosystems as they occur on similar timescales as phytoplankton growth, enabling biophysical feedbacks. Lateral stirring at the submesoscale impacts phytoplankton communities by altering nutrient fluxes, spatial heterogeneity, and biodiversity. We formulate an idealized model of phytoplankton growth and transport to understand the key factors driving these biophysical interactions and to determine how the impact of submesoscale dispersion on biogeochemical fluxes depends on flow properties versus biology. By parameterizing the effects of dispersion due to lateral stirring on flux within an eastern boundary current region, we show that enhanced dispersion yields a near-linear increase in cross-shore flux, modulated by phytoplankton growth rates and ambient nutrient availability. These findings identify a pathway for improving parameterizations of biogeochemical fluxes, while revealing a source of uncertainty in their prediction by climate models.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL114112","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid Infill of Abandoned Tidal Channels Creates Hotspots for Blue-Carbon Accumulation in Coastal Wetlands","authors":"Alice Puppin,&nbsp;Davide Tognin,&nbsp;Massimiliano Ghinassi,&nbsp;Andrea D’Alpaos,&nbsp;Eli D. Lazarus,&nbsp;Chao Gao,&nbsp;Alvise Finotello","doi":"10.1029/2024GL113705","DOIUrl":"https://doi.org/10.1029/2024GL113705","url":null,"abstract":"<p>Sinuous channel networks dissecting tidal wetlands are highly dynamic and are often abandoned as a result of channel captures and meander cutoffs. However, the effects of channel dynamics on blue carbon fluxes remain unclear. Analyses of abandoned tidal channels in the Venice Lagoon (Italy) demonstrate that they take up organic carbon at significantly faster rates than neighboring marshes. This is because, despite slightly lower sediment carbon density, abandoned tidal channels yield significantly higher rates of sediment vertical accretion owing to topographic accommodation and reduced flow velocities, which facilitate the deposition of particulate matter and debris. We estimate that abandoned tidal channels in Venice capture 17 tons of carbon annually, equivalent to 21 ha of marshes, despite covering only 3.5 ha in total. Hence we argue that abandoned tidal channels serve as hotspots for blue-carbon accumulation and should be considered to improve estimates of carbon fluxes in coastal wetlands.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113705","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What Causes the Hemispheric Difference in the Asymmetry of the Temperature Annual Cycle?","authors":"Fucheng Yang,&nbsp;John C. H. Chiang,&nbsp;Zhaohua Wu","doi":"10.1029/2024GL112611","DOIUrl":"https://doi.org/10.1029/2024GL112611","url":null,"abstract":"<p>Previous studies have noted the asymmetry in the annual cycle of zonal mean surface air temperature, defined as the difference in the lengths of warming and cooling periods. Pronounced north-south hemispheric differences in this asymmetry, by up to 40 days, were attributed to the eccentricity of Earth's orbit. However, we propose that the dominant factor comes from the difference in the land-sea fraction between hemispheres, because the asymmetry is strongly influenced by the annually varying heat capacity and land-sea interactions. The oceanic temperature annual cycle generally features a longer cooling period than warming due to the seasonal variation in ocean mixed layer depth, and exhibits the opposite situation when there is seasonal sea ice. Land-sea interactions impact the zonal mean temperature annual cycle by resulting in an earlier winter trough of the downstream oceanic temperature and delaying the summer peak in west coasts.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL112611","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Initial Opening of the Drake Passage Occurred During ca. 62-59 Ma","authors":"Liang Gao,&nbsp;Xiaoqian Guo,&nbsp;Junling Pei,&nbsp;Javier N. Gelfo,&nbsp;Xinwei Hu,&nbsp;Sha Li,&nbsp;Tian Jiang,&nbsp;Meinan Shi,&nbsp;Xuelian You,&nbsp;Fang Gu,&nbsp;Yunying Zhang,&nbsp;Zhen Sun,&nbsp;Zhiliang He,&nbsp;Ruoshuang Li,&nbsp;Yabo Tong,&nbsp;Zhenyu Yang,&nbsp;Yue Zhao","doi":"10.1029/2024GL111455","DOIUrl":"https://doi.org/10.1029/2024GL111455","url":null,"abstract":"<p>Although the Drake Passage has been considered a critical component of ocean circulation and climate, its initial opening age remains controversial due to the weak constraints on the paleoposition of the Antarctic Peninsula. Here, new zircon U-Pb geochronological studies are conducted on the Barchans Islands, providing a critical age constraint on the paleopole (Latitude = 76.9°S, Longitude = 332.1°E, <i>A</i>₉₅ = 5.9°) of the peninsula at ca. 59 Ma. Geochronological and paleomagnetic studies on Anagram Island and King George Island provide a new paleopole (Latitude = 77.4°S, Longitude = 23.5°E, <i>A</i>₉₅ = 4.4°) of the Antarctic Peninsula at ca. 55 Ma. When combined with existing evidence, the initial separation between the Antarctic Peninsula and the Patagonian Andes is restricted to be between ca. 62 and 59 Ma, caused by the clockwise rotation of the Antarctic Peninsula. The separation induced the initial opening of the Drake Passage and the formation of the shallow proto-Antarctic circumpolar current, as well as Paleocene global cooling.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL111455","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pathways to Turbulent Dissipation in a Submarine Canyon","authors":"Charlotte Bellerjeau,&nbsp;Matthew H. Alford,&nbsp;Arnaud Le Boyer,&nbsp;Giovanni Dematteis,&nbsp;Alberto Naveira Garabato,&nbsp;Gunnar Voet,&nbsp;Nicole Couto,&nbsp;Bethan L. Wynne-Cattanach","doi":"10.1029/2024GL113526","DOIUrl":"https://doi.org/10.1029/2024GL113526","url":null,"abstract":"<p>Velocity and turbulence observations are used to estimate the forward cascade of kinetic energy from the internal tide to dissipation within a steep canyon. Two methods for computing cross-frequency kinetic energy flux are compared to observed dissipation. One method, coarse graining, allows strongly nonlinear dynamics while the other assumes weak nonlinearity. Fluxes from both methods agree within a factor of 3 with dissipation estimates from a finescale parameterization which is often used in climate-scale ocean models. Coarse graining predicts 68% of energy fluxing to dissipation from frequencies lower than 8cpd, while the weakly nonlinear method predicts 34%. The weighting of energy flux toward lower frequencies supports a shorter frequency-space pathway to dissipation in the presence of topographic wave breaking than assumed by parameterizations. Enhanced near-boundary mixing and upwelling has implications for the rate and spatial distribution of the upwelling branch of the global overturning circulation.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113526","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Valence/Spin States of Iron in Peridotite Glass to Megabar Pressure Implications for Dense Iron-Rich Silicate Melt at the Bottom of the Mantle","authors":"Izumi Mashino,&nbsp;Takashi Yoshino,&nbsp;Takaya Mitsui,&nbsp;Kosuke Fujiwara,&nbsp;Sayako Inoué,&nbsp;Takeshi Sakai","doi":"10.1029/2024GL113106","DOIUrl":"https://doi.org/10.1029/2024GL113106","url":null,"abstract":"<p>We have conducted high-pressure electrical conductivity and Mössbauer spectroscopic measurements of peridotite glass as an analog of silicate melts. We observed the shoulder feature in the Mössbauer spectra above 60 GPa due to the emergence of the new Fe²⁺ component, which could be associated with the change of the iron partitioning coefficient between solid and melt observed in previous melting experiments. The change in the trend of the electrical conductivity profile has been observed at around ∼83 GPa, suggesting the increase of the relative abundance of the new component. The pressure dependence of hyperfine parameters indicates the spin transitions of both Fe²⁺ and Fe³⁺ occur above 100 GPa, which is likely related to the structural change of the glass. Our results suggest that the spin state changes of iron lead to further densification of the silicate melts at the bottom of the mantle.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143778188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Boundary Condition for the Electric Field in Earth's Core Models With Conducting Boundaries","authors":"J. Rekier,&nbsp;S. A. Triana,&nbsp;B. Buffett","doi":"10.1029/2024GL113585","DOIUrl":"https://doi.org/10.1029/2024GL113585","url":null,"abstract":"<p>The Earth's core flows are governed by magnetohydrodynamic equations, where boundary conditions determine how the electric field in the liquid core relates to that in the conducting boundaries. In the Earth's core, the no-slip condition implies continuity of the electric field, following the continuous horizontal velocity field. However, numerical models often employ a free-slip condition, permitting discontinuities in horizontal velocity at the boundary, raising concerns about assuming electric field continuity, as first principles indicate the electromotive force should be continuous. Using a simple numerical model, we assess these assumptions under the free-slip condition and compare it with the no-slip case. Our results show that electric field continuity is appropriate when core and boundary conductivities are equal, accurately capturing shear flow near the boundary. However, with a conductivity contrast, neither electric boundary condition performs well, suggesting the free-slip condition should be avoided in such cases.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113585","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143778247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decrease in the Permeability of Microcracked and Macrocracked Granite at Elevated Pressure and Temperature","authors":"L. Carbillet,&nbsp;M. J. Heap,&nbsp;P. Baud,&nbsp;J. I. Farquharson","doi":"10.1029/2024GL112970","DOIUrl":"https://doi.org/10.1029/2024GL112970","url":null,"abstract":"<p>Pressure and temperature increase with depth, modifying the microstructure of crustal rocks. The opening or closing of micro- and macrocracks resulting from variations in the <i>in-situ</i> conditions influences the permeability of crustal rocks. While confining pressure is known to close pre-existing cracks, reducing permeability, the influence of temperature has received less attention. Here, we measured the permeability of micro- and macrocracked granite at confining pressures and temperatures up to 50 MPa and 150°C, respectively. We find that the permeability of micro- and macrocracked granite decreases with confining pressure. At constant pressure, increasing temperature reduces permeability by up to an order of magnitude, interpreted as the closure of microcracks due to mineral thermal expansion. Using a simplified microstructural model, we show that microcrack aperture is reduced by up to 50% at 150°C compared to room temperature. However, temperature does not appear to influence the permeability of a tortuous macrocrack.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL112970","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143778246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Eddy Flux Transport of the Magnetohydrodynamic Quasi-Geostrophic Disturbances","authors":"Chengkang Li,&nbsp;Yaokun Li","doi":"10.1029/2025GL115063","DOIUrl":"https://doi.org/10.1029/2025GL115063","url":null,"abstract":"<p>The classic Eliassen-Palm (E-P) flux in the geophysical fluid dynamics is a vector to qualify the eddy momentum and heat flux transport by Rossby waves in the latitude-height plane. In this investigation, we derive two magnetic E-P fluxes to quantify the eddy energy transport by magnetic Rossby waves by using magnetohydrodynamic quasi-geostrophic theory. The first extends the classic E-P relation; the second arises from the magnetic and motion coupling. In wave-like dynamics, the cross-component flux vanishes, allowing the first flux to fully describe energy propagation. We further show magnetic Rossby waves can grow where Rossby waves cannot. When they develop, the increasing perturbation energy is fed by the zonal flow through Reynolds and Maxwell stresses transport. Our findings, bridging the geophysical fluid dynamics and magnetohydrodynamics, advance understanding of large-scale dynamics in magnetized environments and enhance predictions of planetary magnetic field evolution, space weather, and solar dynamics.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL115063","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143778245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precipitation Estimation With NWP Model and Generative Diffusion Model","authors":"Haolin Liu,&nbsp;Jimmy C. H. Fung,&nbsp;Alexis K. H. Lau,&nbsp;Zhenning Li","doi":"10.1029/2024GL110625","DOIUrl":"https://doi.org/10.1029/2024GL110625","url":null,"abstract":"<p>Recent advancements in state-of-the-art generative deep-learning models, particularly diffusion models, have significantly enhanced the capability to produce realistic and diverse synthetic images and videos. These advancements have had a profound impact on fields such as computer vision and natural language processing. In this study, we leverage this cutting-edge generative model to refine Numerical Weather Prediction (NWP) precipitation outputs. By conditioning the generative model with fundamental meteorological variables simulated by the Weather Research and Forecasting model, we aim to reproduce the high-resolution satellite precipitation product, specifically CMORPH. Benefiting from the superior ability of generative diffusion models to learn the distribution of target data, these models excel in providing detailed and accurate precipitation estimations over the raw NWP outputs and traditional predictive models. With this presented pipeline, we provide valuable insights and practical tools for refining precipitation forecasting while preserving its extremities and variability thus better guiding decision making regarding weather dependent activities.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 7","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL110625","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143778328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}