地球科学最新文献

{"title":"Response of Oceanic Meridional Overturning Circulation to Vegetation Removal on Different Continents","authors":"Jiaqi Guo,&nbsp;Yonggang Liu,&nbsp;Shuai Yuan,&nbsp;Xiang Li,&nbsp;Yue Liu,&nbsp;Yongyun Hu","doi":"10.1029/2025JC022978","DOIUrl":"https://doi.org/10.1029/2025JC022978","url":null,"abstract":"<p>Vegetation on different continents is often subject to substantial changes due to climate change, anthropogenic activities, or vegetation evolution, but how it affects the oceanic meridional overturning circulation (MOC) is unclear. This study explores both the transient evolution and equilibrium response of MOCs to vegetation removal on each continent except Antarctica using an atmosphere-ocean general circulation model, CESM1.2.2, under preindustrial climate conditions. The results indicate that at equilibrium, removing Eurasian vegetation slightly weakens the Atlantic MOC (AMOC) (−2.5 Sv, −16.5%) but enhances the Pacific MOC (PMOC) (+6.0 Sv, +58.3%). Conversely, removing North American vegetation strengthens the AMOC (+2.7 Sv, +17.6%) while weakening the PMOC (−1.8 Sv, −17.7%). Vegetation removal over low-latitude regions produces minimal impact on either AMOC or PMOC. Global vegetation removal causes a substantial weakening of AMOC (−5.7 Sv, −36.9%) and a pronounced strengthening of PMOC (+4.8 Sv, +47.3%), different from the linear sum of individual effects described above. The transient evolution of both AMOC and PMOC is complex, exhibiting distinct (even opposite) responses in the multidecadal timescale and centennial or millennial timescale. Abrupt changes in both AMOC (by ∼10 Sv) and PMOC (by ∼2 Sv) occur around 2700 years after the global vegetation removal. This highlights the long timescale of surface-climate responses to external forcings, which is easily overlooked in shorter simulations. Process diagnostics show that salinity anomalies—modulated by net precipitation and sea ice melt—govern the AMOC response, whereas surface temperature anomalies dominate the PMOC response.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 9","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145012299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wetland Hydrologic Synchrony and Functional Redundancy Across Contrasting Wetlandscapes","authors":"Joshua M. Epstein,&nbsp;Matthew J. Cohen","doi":"10.1002/hyp.70244","DOIUrl":"https://doi.org/10.1002/hyp.70244","url":null,"abstract":"<div>\u0000 \u0000 <p>Variation in the timing, duration, and synchrony of wetland inundation and hydrologic connectivity influences aggregate hydrologic, biogeochemical, and habitat functions of wetlandscapes (i.e., complexes of distinct wetlands embedded in uplands). To quantify and predict the redundancy of hydrological functions amongst wetlands, we measured hydrologic synchrony in three Florida wetlandscapes with contrasting morphology and connectivity patterns. Combining high frequency stage from multiple wetlands (<i>n</i> = 14–15) in each wetlandscape with LiDAR-derived topography, we measured synchrony based on wetland stage correlation and daily alignment of inundation (i.e., wet vs. dry) and surface connectivity (i.e., connected vs. disconnected) patterns. We evaluated how flowpath membership or position, wetland size, depth, and distance impacted synchrony patterns. We further evaluated whether assuming a spatially uniform planar water table across the wetlandscapes, implying perfect water level synchrony, accurately represented observed patterns. Observed synchrony was nearly perfect in the least topographically heterogeneous wetlandscape, where surface connectivity was frequent and prolonged, supporting the assumption of a spatially uniform water table. Wetland size, distance, and depth predicted synchrony, and variation in wetland hydrological function was negligible and fully attributed to topographic heterogeneity. In contrast, hydrological synchrony was lower where wetlandscape topographic heterogeneity was highest, and surface water connectivity was rare and brief. Here, flowpath membership was a significant predictor of synchrony. Hydrological redundancy of wetlands varies markedly across wetlandscapes, with aggregate landscape function degraded in proportion to wetland area loss when synchrony is high, but degraded more rapidly than the loss of area where hydrologic synchrony, and therefore redundancy, is low. With ongoing wetland losses nationally and globally, synchrony assessments inform efforts to evaluate and predict wetlandscape resilience to loss of wetland function and prioritise conservation of non-redundant wetlands to ensure the full continuum of wetlandscape structure is maintained.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145012518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insight into the spiral growth of disordered kaolinite nanocrystals","authors":"Yongjie Yang ,&nbsp;Long Chen ,&nbsp;Jiale Pu ,&nbsp;Qiang Luo ,&nbsp;Maguy Jaber ,&nbsp;Christelle Souprayen ,&nbsp;Ning Wang ,&nbsp;Qinfu Liu","doi":"10.1016/j.clay.2025.107981","DOIUrl":"10.1016/j.clay.2025.107981","url":null,"abstract":"<div><div>Structural disorder in kaolinite critically shapes its reactivity and performance across environmental and industrial contexts. Insights into spiral growth offer a mechanistic framework to decode the structural disorder of kaolinite and advance our understanding of its formation and properties. We identified a distinct expansion of the (001) interlayer spacing, from ∼7.16 Å in well-ordered kaolinite to ∼7.21 Å in disordered samples, along with selective enhancement of the (020) reflection in disordered nanocrystals. This structural disorder is closely linked to Al(4)-for-Si(4) substitution, with a high Al(4)/Al total ratio (∼2.83 %). The ionic radius ratio of <span><math><msub><mi>R</mi><mrow><msup><mi>Al</mi><mi>III</mi></msup><mfenced><mn>4</mn></mfenced></mrow></msub></math></span>_:<span><math><msub><mi>R</mi><msup><mi>O</mi><mrow><mn>2</mn><mo>−</mo></mrow></msup></msub></math></span>=0.438 substantially exceeds that of ideal tetrahedral packing, compared to <span><math><msub><mi>R</mi><mrow><msup><mi>Si</mi><mi>IV</mi></msup><mfenced><mn>4</mn></mfenced></mrow></msub></math></span>_:<span><math><msub><mi>R</mi><msup><mi>O</mi><mrow><mn>2</mn><mo>−</mo></mrow></msup></msub></math></span>=0.331, generating internal stress that exceeds the structural tolerance of triclinic kaolinite. When this stress exceeds a critical threshold, it likely promotes the formation of screw dislocations, which initiate spiral growth and generating stacking faults and in-plane lattice rotations (∼5°), as evidenced by Moiré fringe patterns and SAED. Spiral growth thus acts as a stress-adaptive mechanism, enabling the crystal to accommodate structural instability while maintaining long-range order and anisotropic deformation. These findings recast disorder as a stress-regulated growth strategy and offer a mechanistic blueprint for tuning structure in low-dimensional layered materials.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"277 ","pages":"Article 107981"},"PeriodicalIF":5.8,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145003772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Broad‐scale climate patterns combined with local flow and turbidity disturbances structure the seasonality of gross primary production in an aridland river","authors":"Betsy M. Summers, Robert O. Hall, Justin K. Reale, Eric Joseph, Mark C. Stone, David J. Van Horn","doi":"10.1002/lno.70173","DOIUrl":"https://doi.org/10.1002/lno.70173","url":null,"abstract":"Both local and global climate phenomena shape the hydrologic regimes of watersheds. For aridland rivers in the southwestern United States, peak flows occur during two distinct periods: spring snowmelt and summer monsoons. Although discharge (<jats:italic>Q</jats:italic>) is a primary driver of variation in the production and consumption of instream organic matter, or stream metabolism, few connection have been made regarding how climate impacts ecosystem processes through changes in flow and related disturbances. We considered how variation in disturbance variables, specifically <jats:italic>Q</jats:italic> and associated changes in turbidity, affected gross primary production during spring snowmelt and summer monsoons in the Rio Grande. Nine years of continuous environmental data (<jats:italic>Q</jats:italic>, turbidity, light) and climate indices (i.e., El Niño‐Southern Oscillation and Monsoon Index) were used to explain the variation in gross primary production estimates. We found that relationships were sensitive to the timescale of disturbance: at the seasonal scale, high snowmelt <jats:italic>Q</jats:italic> decreased spring mean gross primary production, while at the daily scale, high turbidity, and to a lesser extent <jats:italic>Q</jats:italic>, reduced gross primary production during summer. Also, mean <jats:italic>Q</jats:italic> and turbidity disturbances were uncoupled in spring and inversely related in summer. We conclude that long‐term datasets are essential to uncover emergent relationships between broad‐scale climate patterns and ecosystem processes and are necessary to better understand how hydroclimatic variability drives ecosystem processes at varying time scales in rivers across Earth.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"16 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145003178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observations of Persistent Downstream Magnetic Oscillations at the Earth Bow Shock","authors":"M. Golan,&nbsp;M. Gedalin","doi":"10.1029/2025JA034321","DOIUrl":"https://doi.org/10.1029/2025JA034321","url":null,"abstract":"<p>The redistribution of the directed flow energy in a collisionless shock is the central problem of shock physics. The incident ion energy is transferred to ion and electron heating, acceleration of a small fraction of particles, and enhancement of the magnetic field. The mean magnetic field enhancement is determined by the standard boundary conditions. Recently, shocks were observed in which the amplitude of the persisting downstream magnetic fluctuations exceeded the mean downstream field. The question of the ubiquity of the phenomenon is of utmost importance since it would require re-consideration of the boundary conditions. It may also mean that the effective magnetic field in supernova remnant shocks may be currently grossly underestimated. Using the Magnetospheric Multiscale observations of the Earth bow shock, we analyze the dependence of the relative amplitude of the downstream magnetic fluctuations on the main shock parameters. It is found that large fluctuations are typical for quasi-parallel shocks and higher Mach numbers.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JA034321","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Remaking the smart city through the COVID-19 pandemic: Seoul, Singapore, Taipei","authors":"Orlando Woods ,&nbsp;I-Chun Catherine Chang ,&nbsp;HaeRan Shin","doi":"10.1016/j.apgeog.2025.103773","DOIUrl":"10.1016/j.apgeog.2025.103773","url":null,"abstract":"<div><div>The COVID-19 pandemic has proven to be a catalysing force for urban innovation in general, and for smart city agendas specifically, throughout the world. From the development of contact tracing technologies and the enforcement of quarantine and safe distancing measures, to the dissemination of public health information and advancement of telehealth rollouts, the promises of “smart” technologies to reveal and govern patterns of socio-spatial contact and mobility can be found at the core of effective city management during the pandemic. Arguably nowhere is this truer than in the cities of Seoul, Singapore and Taipei, where the Asian developmental state was granted a hitherto unprecedented degree of legitimacy to expand its functions. Drawing on a three-year comparative research project exploring smart city development in Seoul, Singapore, and Taipei and beyond, we explore how the COVID-19 pandemic catalysed urban innovation and reified the importance of smart city projects for effective urban management during public health crises. At the same time, we argue that the catalysing effects of the pandemic led to the creation and extension of “hyper-smartness” throughout the micro-geographies of everyday life, overreach by the state in response to the opportunities for unchecked urban innovation, and the forging of new society-state relations in response. Evidence suggests that recognition of the successes of, and backlash against, technology-enabled urban management has since contributed to the remaking of the smart city in/and the Asian developmental state in the post-pandemic era.</div></div>","PeriodicalId":48396,"journal":{"name":"Applied Geography","volume":"184 ","pages":"Article 103773"},"PeriodicalIF":5.4,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sampling Regime Effects on Detecting Spatial Stability of Water Quality","authors":"Dan Dai, Nicolas Fernandez, Matthew J. Cohen, James W. Jawitz","doi":"10.1029/2024wr038844","DOIUrl":"https://doi.org/10.1029/2024wr038844","url":null,"abstract":"Protecting surface water quality can be complicated by high spatiotemporal variability. Pollutant sources and transport pathways may be identified through sufficiently high‐density monitoring sites and high‐frequency sampling, but practical considerations necessitate tradeoffs between spatial and temporal resolution in water quality monitoring network design. We examined how tradeoffs in sampling density and frequency affect measures of spatiotemporal variability in water quality, emphasizing pattern stability over time. We quantified the spatial stability of stream water quality across &gt;250 monitoring sites in the intensively monitored watershed draining to Lake Okeechobee, FL using Spearman's rank correlations between instantaneous observations and site long‐term means for each parameter. We found that water quality spatial patterns for geogenic, biogenic, and anthropogenic parameters were generally stable on decadal timescales for all solutes, and that sampling densely in space yields more information than sampling frequently in time. Variations in spatial stability decreased with increased sampling density but not with greater sampling frequency, attesting to the dominance of spatial variability over temporal variability. For nutrients, the spatial coefficient of variation (CV) was approximately double the temporal CV. Spatial stability of most solutes was similar across flow conditions, but high‐flow monitoring allows for more sites that effectively capture the long‐term spatial patterns of nutrient sources. Water quality monitoring regimes can be optimized for efficiency in capturing water quality patterns and should be adjusted to focus more on spatial variation. We discuss potential improvements for water quality monitoring, particularly in watersheds where scarce resources necessitate tradeoffs between sampling density and frequency.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"40 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145002945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Northwest Africa 16788: The Largest Known Individual Martian Meteorite—A New Olivine Microgabbroic Shergottite and Its Implications for Martian Magmatism","authors":"Xhonatan Shehaj,&nbsp;Giovanni Pratesi,&nbsp;Cristian Carli,&nbsp;Riccardo Avanzinelli,&nbsp;Alice Stephant,&nbsp;Annarita Franza,&nbsp;Eleonora Ammannito","doi":"10.1029/2024JE008885","DOIUrl":"https://doi.org/10.1029/2024JE008885","url":null,"abstract":"<p>We present a comprehensive study of a new Martian meteorite, Northwest Africa (NWA) 16788, found in the Sahara Desert in July 2023. This specimen constitutes the largest known individual meteorite of Martian origin, with a total weight of ⁓25 kg. A detailed mineralogical and geochemical investigation identifies NWA 16788 as an enriched olivine microgabbroic shergottite. Petrographic analysis reveals a millimeter-sized cumulate texture, which is intermediate between poikilitic and gabbroic shergottites, primarily composed of pyroxene (⁓61 vol.%), maskelynite (shocked plagioclase, ⁓21 vol.%), and olivine (⁓15 vol.%). Pyroxene grains exhibit a distinctive zoning pattern, placing NWA 16788 within a small group of Martian meteorites and lunar samples that record unique cooling histories, suggesting that similar samples may be more prevalent within the Martian igneous rocks than previously recognized. High-precision analyses of bulk ¹⁴³Nd/¹⁴⁴Nd and ⁸⁷Sr/⁸⁶Sr isotopic composition, combined with trace element abundance, indicate that NWA 16788 originated from the partial melting of an enriched Martian mantle source. Electron backscatter diffraction analysis reveals a unimodal distribution of olivine grain misorientation, averaging ⁓4.6°, consistent with a high-energy single-impact event. Moreover, visible and near-infrared spectroscopy data acquired on NWA 16788 could aid in identifying potential locations of analogous igneous rocks on the Martian surface. Finally, this study proposes refinements to the current classification scheme of Martian meteorites, aiming to reduce taxonomic ambiguity and improve the alignment between Martian meteorites and Martian igneous rocks, based on data from Mars rovers.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 9","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JE008885","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005600","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":"Analysis of CCCma Radiative Transfer Calculations for Low-Level Overcast Liquid Clouds Over ARM SGP and ENA Sites","authors":"Jordann Brendecke,&nbsp;Xiquan Dong,&nbsp;Baike Xi,&nbsp;Xiang Zhong,&nbsp;Howard W. Barker,&nbsp;Jiangnan Li,&nbsp;Peter Pilewskie","doi":"10.1029/2025JD044121","DOIUrl":"https://doi.org/10.1029/2025JD044121","url":null,"abstract":"<p>This study uses the Canadian Centre for Climate Modeling and Analysis (CCCma) radiative transfer model to estimate shortwave flux for low-level overcast liquid clouds. Calculations are evaluated against measurements at the Atmospheric Radiation Measurement Southern Great Plains (SGP, land) and Eastern North Atlantic (ENA, ocean) sites, as well as top of atmosphere (TOA) fluxes inferred from Clouds and Earth's Radiant Energy System (CERES) from 2014 to 2023. Mean observed surface (TOA) SW fluxes for the selected cases are 235.7 W m⁻² (473.8 W m⁻²) at SGP and 348.7 W m⁻² (356.4 W m⁻²) at ENA. Cloud microphysical properties retrieved from CERES MODIS are input into the CCCma using three assumed profiles: (a) cloud droplet effective radius (<i>r</i>_<i>e</i>) and liquid water content (LWC) constant with height, (b) LWC and <i>r</i>_<i>e</i> increasing linearly with height, and (c) LWC and <i>r</i>_<i>e</i> increasing linearly from cloud base to ¾ height and then decreasing linearly up to cloud top. Overall, Method 3 produces the least error variance at both sites. At SGP, mean bias and root mean square error (RMSE) are −5.0 and 44.6 W m⁻² at the surface and −4.6 and 25.4 W m⁻² at TOA. At ENA, errors are +0.2 and 121.3 W m⁻² at the surface and −8.0 and 26.1 W m⁻² at TOA. Further screening cases with good agreement between satellite- and surface-based cloud properties, RMSEs for surface fluxes decrease to 24.3 and 25.8 W m⁻² at SGP and ENA. Comparisons with CERES Fu-Liou calculations showed overall better performance by the CCCma, especially at ENA.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":"130 17","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Occurrence Morphology of Higher Band ECH Waves in the Magnetosphere Derived From MMS Observations","authors":"Aojun Ren,&nbsp;Jiang Yu,&nbsp;Xiaoman Liu,&nbsp;Jing Wang,&nbsp;Zuzheng Chen,&nbsp;Jiawen Chen,&nbsp;Dong Wei,&nbsp;Liuyuan Li,&nbsp;Jun Cui,&nbsp;Jinbin Cao","doi":"10.1029/2025JA034029","DOIUrl":"https://doi.org/10.1029/2025JA034029","url":null,"abstract":"<p>Electron cyclotron harmonic (ECH) waves, which are electrostatic emissions outside the plasmasphere, are of great interest because of their essential role in producing diffuse auroras. Since they are commonly observed in the first band, the global distributions of those waves in higher bands remain unknown in the magnetosphere. Using Magnetospheric Multiscale satellite data, we present the global occurrence morphology of higher band ECH waves in the magnetosphere. Higher band ECH waves are widespread in the pre-midnight to post-noon magnetosphere with occurrence rates slightly lower and spatial distribution narrower than the first band. They predominantly occur near the magnetic equator at <i>L</i> = 4–9 on the nightside but are more prevalent and extend to the duskside at high latitudes at <i>L</i> = 9–12 on the dayside. As the geomagnetic activity intensifies, their occurrence rates show an increasing tendency and their spatial coverage expands radially and azimuthally. Our results potentially contribute to understanding the magnetospheric electron dynamics driven by ECH waves.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}