G. Ponce, A. Meltzer, A. Wickham-Piotrowski, S. Beck, M. Ruiz, S. Hernández, M. Segovia
Using high-resolution 3D tomography and a relocated 2010–2022 earthquake catalog, we identify a seamount at 20–25 km depth beneath the Mompiche–Cojimíes region in the coastal forearc of Ecuador. This provides a rare, well-resolved example of seamount preservation at these depths. The seamount coincides with a low interseismic-coupling corridor and shows persistent seismicity along its flanks. Rupture of the 2016 Mw 7.8 Pedernales earthquake initiated on the southern flank of the seamount. The rupture propagated south, but northward propagation was arrested near the decoupled, aseismic crest, illustrating the dual mechanical behavior of the seamount. After the megathrust earthquake, seismicity migrated downdip, particularly along the eastern margin. These results show the influence of subducted topography on coupling, seismicity, and rupture segmentation in megathrust systems.
{"title":"Dual Role of a Subducted Seamount in Megathrust Rupture Initiation and Rupture Barrier","authors":"G. Ponce, A. Meltzer, A. Wickham-Piotrowski, S. Beck, M. Ruiz, S. Hernández, M. Segovia","doi":"10.1029/2025gl119106","DOIUrl":"https://doi.org/10.1029/2025gl119106","url":null,"abstract":"Using high-resolution 3D tomography and a relocated 2010–2022 earthquake catalog, we identify a seamount at 20–25 km depth beneath the Mompiche–Cojimíes region in the coastal forearc of Ecuador. This provides a rare, well-resolved example of seamount preservation at these depths. The seamount coincides with a low interseismic-coupling corridor and shows persistent seismicity along its flanks. Rupture of the 2016 Mw 7.8 Pedernales earthquake initiated on the southern flank of the seamount. The rupture propagated south, but northward propagation was arrested near the decoupled, aseismic crest, illustrating the dual mechanical behavior of the seamount. After the megathrust earthquake, seismicity migrated downdip, particularly along the eastern margin. These results show the influence of subducted topography on coupling, seismicity, and rupture segmentation in megathrust systems.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"1 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368233","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}
Xinling Zou, Lin Su, Zhisheng Zhang, Xiaomin Lin, Mang Lin
Cosmogenic radiosulfur (35S) is produced in the atmosphere by high-energy particle interactions and serves as a sensitive tracer of stratospheric intrusions. In May 2024, an extreme solar storm provided a rare opportunity to examine atmospheric 35S responses to intense solar activity. We report daily 35SO42− measurements from surface air in subtropical China and identify two distinct enrichment events. Meteorological simulations and reanalysis data reveal that 35S enrichments on May 16 resulted from a deep stratospheric intrusion that also drove a regional ozone pollution episode. In contrast, persistently elevated 35S levels during May 9–15 occurred without stratospheric influence and coincided with strong solar energetic particle fluxes. These observations suggest that extreme solar storms may contribute to transient increases in atmospheric 35S, highlighting the importance of high-resolution cosmogenic radionuclide monitoring in modern days for interpreting past solar energetic events recorded by longer-lived cosmogenic isotopes.
{"title":"Surface Air Enrichment of Cosmogenic 35S at a Subtropical Site During the May 2024 Solar Superstorm","authors":"Xinling Zou, Lin Su, Zhisheng Zhang, Xiaomin Lin, Mang Lin","doi":"10.1029/2025gl120852","DOIUrl":"https://doi.org/10.1029/2025gl120852","url":null,"abstract":"Cosmogenic radiosulfur (<sup>35</sup>S) is produced in the atmosphere by high-energy particle interactions and serves as a sensitive tracer of stratospheric intrusions. In May 2024, an extreme solar storm provided a rare opportunity to examine atmospheric <sup>35</sup>S responses to intense solar activity. We report daily <sup>35</sup>SO<sub>4</sub><sup>2−</sup> measurements from surface air in subtropical China and identify two distinct enrichment events. Meteorological simulations and reanalysis data reveal that <sup>35</sup>S enrichments on May 16 resulted from a deep stratospheric intrusion that also drove a regional ozone pollution episode. In contrast, persistently elevated <sup>35</sup>S levels during May 9–15 occurred without stratospheric influence and coincided with strong solar energetic particle fluxes. These observations suggest that extreme solar storms may contribute to transient increases in atmospheric <sup>35</sup>S, highlighting the importance of high-resolution cosmogenic radionuclide monitoring in modern days for interpreting past solar energetic events recorded by longer-lived cosmogenic isotopes.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"56 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368516","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}
Marc Federer, Sacha Le May, Michael Sprenger, Lukas Papritz
The atmospheric circulation in the midlatitudes is maintained against dissipation by converting available potential energy (APE) into kinetic energy (KE). During boreal winter this energy reservoir occasionally collapses, releasing up to 10% of hemispheric APE within days. Using the ERA5 reanalysis and a locally defined APE framework, we identify 83 such collapse events and show that most of them arise from intense conversion within a single storm track. These events are driven by the export of Arctic APE into the storm tracks along two main pathways and are accompanied by explosive cyclones, extreme surface winds, and continental cold-air outbreaks. The amplification of synoptic- and planetary-scale KE, accompanied by a weakening of the zonal mean KE, reveals a reorganization of the midlatitude circulation during APE collapses. These results show that sudden Arctic energy exports can cascade through the midlatitudes, fueling extreme storms, surface wind events and large-scale variability.
{"title":"Collapses of Hemispheric Available Potential Energy","authors":"Marc Federer, Sacha Le May, Michael Sprenger, Lukas Papritz","doi":"10.1029/2025gl119424","DOIUrl":"https://doi.org/10.1029/2025gl119424","url":null,"abstract":"The atmospheric circulation in the midlatitudes is maintained against dissipation by converting available potential energy (APE) into kinetic energy (KE). During boreal winter this energy reservoir occasionally collapses, releasing up to 10% of hemispheric APE within days. Using the ERA5 reanalysis and a locally defined APE framework, we identify 83 such collapse events and show that most of them arise from intense conversion within a single storm track. These events are driven by the export of Arctic APE into the storm tracks along two main pathways and are accompanied by explosive cyclones, extreme surface winds, and continental cold-air outbreaks. The amplification of synoptic- and planetary-scale KE, accompanied by a weakening of the zonal mean KE, reveals a reorganization of the midlatitude circulation during APE collapses. These results show that sudden Arctic energy exports can cascade through the midlatitudes, fueling extreme storms, surface wind events and large-scale variability.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"23 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368023","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}
Recent record-hot years have caused discussion over whether global warming has accelerated. Previous analysis found acceleration (i.e., increase in warming rate) has not yet reached a 95% confidence level, given natural temperature variability. We remove the estimated influence of three main natural variability factors: El Niño, volcanism, and solar variation. The resulting adjusted and thus less “noisy” data show that there has been acceleration with over 98% confidence, with faster warming over the last 10+ years than during any previous decade.
{"title":"Global Warming Has Accelerated Significantly","authors":"G. Foster, S. Rahmstorf","doi":"10.1029/2025gl118804","DOIUrl":"https://doi.org/10.1029/2025gl118804","url":null,"abstract":"Recent record-hot years have caused discussion over whether global warming has accelerated. Previous analysis found acceleration (i.e., increase in warming rate) has not yet reached a 95% confidence level, given natural temperature variability. We remove the estimated influence of three main natural variability factors: El Niño, volcanism, and solar variation. The resulting adjusted and thus less “noisy” data show that there has been acceleration with over 98% confidence, with faster warming over the last 10+ years than during any previous decade.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"56 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147368024","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}
云滴数浓度（Nd） $left({N}_{mathrm{d}}right)$对气溶胶（β） $(beta )$的敏感性在卫星观测中仍然具有挑战性。这一困难来自于表示云凝结核的局限性，这取决于气溶胶的大小和组成。为了解决这个问题，我们将云气溶胶激光雷达和红外探路者卫星观测的气溶胶类型特定的干消光系数和数量浓度检索与CloudSat和中分辨率成像光谱仪的共定位Nd ${N}_{mathrm{d}}$相结合。我们发现与矿物粉尘相关的β $beta $在所有气溶胶- nd ${N}_{mathrm{d}}$组合中始终接近于零。此外，β $beta $随着粉尘分数的增加呈非线性下降，只有当粉尘超过约70时才会出现明显的下降%. Accordingly, excluding dust from the analysis increases the globally aggregated β$beta $ from 0.24–0.26 to 0.30–0.37. These findings highlight the importance of considering aerosol composition when constraining aerosol–cloud interactions and their associated radiative forcing in satellite observations.
{"title":"Satellite Observations Show Negligible Impact of Mineral Dust on Cloud Droplet Number","authors":"Goutam Choudhury, Tom Goren, Matthias Tesche","doi":"10.1029/2025gl120234","DOIUrl":"https://doi.org/10.1029/2025gl120234","url":null,"abstract":"The susceptibility of cloud droplet number concentration <span data-altimg=\"/cms/asset/b9330f5d-de02-4e60-851b-2f8b80f4250a/grl72198-math-0001.png\"></span><mjx-container ctxtmenu_counter=\"196\" ctxtmenu_oldtabindex=\"1\" jax=\"CHTML\" role=\"application\" sre-explorer- style=\"font-size: 103%; position: relative;\" tabindex=\"0\"><mjx-math aria-hidden=\"true\" location=\"graphic/grl72198-math-0001.png\"><mjx-semantics><mjx-mrow><mjx-mrow data-semantic-children=\"2\" data-semantic-content=\"3,4\" data-semantic- data-semantic-role=\"leftright\" data-semantic-speech=\"left parenthesis upper N Subscript normal d Baseline right parenthesis\" data-semantic-type=\"fenced\"><mjx-mo data-semantic-added=\"true\" data-semantic- data-semantic-operator=\"fenced\" data-semantic-parent=\"5\" data-semantic-role=\"open\" data-semantic-type=\"fence\" style=\"margin-left: 0.056em; margin-right: 0.056em;\"><mjx-c></mjx-c></mjx-mo><mjx-msub data-semantic-children=\"0,1\" data-semantic- data-semantic-parent=\"5\" data-semantic-role=\"latinletter\" data-semantic-type=\"subscript\"><mjx-mi data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\"><mjx-c></mjx-c></mjx-mi><mjx-script style=\"vertical-align: -0.15em; margin-left: -0.085em;\"><mjx-mi data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"normal\" data-semantic- data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\" size=\"s\"><mjx-c></mjx-c></mjx-mi></mjx-script></mjx-msub><mjx-mo data-semantic-added=\"true\" data-semantic- data-semantic-operator=\"fenced\" data-semantic-parent=\"5\" data-semantic-role=\"close\" data-semantic-type=\"fence\" style=\"margin-left: 0.056em; margin-right: 0.056em;\"><mjx-c></mjx-c></mjx-mo></mjx-mrow></mjx-mrow></mjx-semantics></mjx-math><mjx-assistive-mml display=\"inline\" unselectable=\"on\"><math altimg=\"urn:x-wiley:00948276:media:grl72198:grl72198-math-0001\" display=\"inline\" location=\"graphic/grl72198-math-0001.png\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><semantics><mrow><mrow data-semantic-=\"\" data-semantic-children=\"2\" data-semantic-content=\"3,4\" data-semantic-role=\"leftright\" data-semantic-speech=\"left parenthesis upper N Subscript normal d Baseline right parenthesis\" data-semantic-type=\"fenced\"><mo data-semantic-=\"\" data-semantic-added=\"true\" data-semantic-operator=\"fenced\" data-semantic-parent=\"5\" data-semantic-role=\"open\" data-semantic-type=\"fence\">(</mo><msub data-semantic-=\"\" data-semantic-children=\"0,1\" data-semantic-parent=\"5\" data-semantic-role=\"latinletter\" data-semantic-type=\"subscript\"><mi data-semantic-=\"\" data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"italic\" data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\">N</mi><mi data-semantic-=\"\" data-semantic-annotation=\"clearspeak:simple\" data-semantic-font=\"normal\" data-semantic-parent=\"2\" data-semantic-role=\"latinletter\" data-semantic-type=\"identifier\" math","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"15 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147360969","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}
Jixin Guo, Tao Yu, Lifang Du, Jin Wang, Xiangxiang Yan, Yan Yu, Wenyu Hao, Yifan Qi, Haoran Zheng, Guotao Yang
We report the first LiDAR observations of continuous quasi-periodic (QP) metal density structures in mid-latitude E-region meteoric Ca+ layers using an all-solid-state LiDAR system in Beijing (40.4°N, 116.0°E). These QP Ca+ structures, with periods of 2–30 min and vertical wavelengths of ∼2–15 km, were primarily observed above 100 km. They were spatiotemporally correlated with spread sporadic E (Es) echoes and enhanced plasma density gradients detected by ionosondes. Two primary morphological types of QP Ca+ structures were observed: quasi-sinusoidal forms and striated structures. The characteristics of QP Ca+ structures, coupled with concurrent Es observations, suggest a possible association between these QP features and radar QP echoes associated with E-region field-aligned irregularities. This study demonstrates the potential of metal ion layers as high-sensitivity tracers for investigating E-region plasma irregularities and suggests a possible association between radar QP echoes and the underlying plasma structures.
{"title":"First LiDAR Observation of Quasi-Periodic Structures in Mid-Latitude E-Region Meteoric Ca+ Layers","authors":"Jixin Guo, Tao Yu, Lifang Du, Jin Wang, Xiangxiang Yan, Yan Yu, Wenyu Hao, Yifan Qi, Haoran Zheng, Guotao Yang","doi":"10.1029/2025gl119718","DOIUrl":"https://doi.org/10.1029/2025gl119718","url":null,"abstract":"We report the first LiDAR observations of continuous quasi-periodic (QP) metal density structures in mid-latitude E-region meteoric Ca<sup>+</sup> layers using an all-solid-state LiDAR system in Beijing (40.4°N, 116.0°E). These QP Ca<sup>+</sup> structures, with periods of 2–30 min and vertical wavelengths of ∼2–15 km, were primarily observed above 100 km. They were spatiotemporally correlated with spread sporadic E (Es) echoes and enhanced plasma density gradients detected by ionosondes. Two primary morphological types of QP Ca<sup>+</sup> structures were observed: quasi-sinusoidal forms and striated structures. The characteristics of QP Ca<sup>+</sup> structures, coupled with concurrent Es observations, suggest a possible association between these QP features and radar QP echoes associated with E-region field-aligned irregularities. This study demonstrates the potential of metal ion layers as high-sensitivity tracers for investigating E-region plasma irregularities and suggests a possible association between radar QP echoes and the underlying plasma structures.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"60 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147361116","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}
Sungho Lee, Chang Soo Cho, YoungHee Kim, Youngsang Kwon, Eunseo Choi
Most earthquakes occur at plate boundaries, but some also strike within stable continental interiors. Although dominant causes of such intraplate earthquakes remain elusive, a prevailing hypothesis attributes intraplate stress and seismicity to variations in lithospheric thickness. Here, we test this hypothesis using the Korean Peninsula as a natural laboratory by constructing three-dimensional numerical models that extend from the surface to a depth of 650 km, incorporating realistic plate boundary configurations and deep thermal and compositional heterogeneities. Our results show that lithospheric thickness variations alone cannot account for the observed seismicity distribution and stress orientations. Instead, models that include weak subduction interfaces, slabs extending into the transition zone, and mantle buoyancy—while excluding shallow lithospheric density contrasts—explain the observed seismicity and stress distribution. In particular, the subducted Pacific slab in the mantle transition zone acts as a gravitational sinker, enhancing crustal compression along the eastern margin of the peninsula.
{"title":"Upper Mantle Heterogeneity and Weak Subduction Boundaries Control Crustal Stress in the Korean Peninsula","authors":"Sungho Lee, Chang Soo Cho, YoungHee Kim, Youngsang Kwon, Eunseo Choi","doi":"10.1029/2025gl119915","DOIUrl":"https://doi.org/10.1029/2025gl119915","url":null,"abstract":"Most earthquakes occur at plate boundaries, but some also strike within stable continental interiors. Although dominant causes of such intraplate earthquakes remain elusive, a prevailing hypothesis attributes intraplate stress and seismicity to variations in lithospheric thickness. Here, we test this hypothesis using the Korean Peninsula as a natural laboratory by constructing three-dimensional numerical models that extend from the surface to a depth of 650 km, incorporating realistic plate boundary configurations and deep thermal and compositional heterogeneities. Our results show that lithospheric thickness variations alone cannot account for the observed seismicity distribution and stress orientations. Instead, models that include weak subduction interfaces, slabs extending into the transition zone, and mantle buoyancy—while excluding shallow lithospheric density contrasts—explain the observed seismicity and stress distribution. In particular, the subducted Pacific slab in the mantle transition zone acts as a gravitational sinker, enhancing crustal compression along the eastern margin of the peninsula.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"5 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147361106","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}
Yuke Liu, Xiaomei Wang, Minghao Wu, Jin Su, Chengshuai Yuan, Xuening Qi, Shuichang Zhang
The early Late Cretaceous hothouse was featured by intense storms and a prevailing monsoon climate, yet direct evidence for regional extreme precipitation events is rare. Here, we reconstruct local weathering and hydrological processes using magnesium and strontium isotopes (δ26Mg and 87Sr/86Sr) from lacustrine dolostones in the Upper Cretaceous Qingshankou Formation, Songliao Basin, Northeast China. The δ26Mg and 87Sr/86Sr records exhibit coherent bimodal variations. Surficial Mg cycling reveals two hydroclimatic regimes: during 91.9 ∼ 91.2 Ma, high precipitation intensified weathering, especially a 500-kyr pluvial interval with rainfall exceeding 2,000 mm/yr (millimeters per year), which triggered lake flooding and organic carbon burial; during 91.2 ∼ 90.7 Ma, declined weathering and precipitation indicated monsoon retreat. The Hadley circulation shrinkage, orbital-paced aquifer-eustasy, and coastal mountains induced by Okhotomorsk-East Asia collision, were triple amplifiers in elevating the Songliao Basin into a unique mid-latitude humidity hotspot with carbon burial, while contemporaneous inland and low-latitude areas experienced aridification or exhumation.
{"title":"A 500-kyr Pluvial Interval Triggered Lacustrine Carbon Burial in Late Cretaceous East Asia","authors":"Yuke Liu, Xiaomei Wang, Minghao Wu, Jin Su, Chengshuai Yuan, Xuening Qi, Shuichang Zhang","doi":"10.1029/2025gl119676","DOIUrl":"https://doi.org/10.1029/2025gl119676","url":null,"abstract":"The early Late Cretaceous hothouse was featured by intense storms and a prevailing monsoon climate, yet direct evidence for regional extreme precipitation events is rare. Here, we reconstruct local weathering and hydrological processes using magnesium and strontium isotopes (<i>δ</i><sup>26</sup>Mg and <sup>87</sup>Sr/<sup>86</sup>Sr) from lacustrine dolostones in the Upper Cretaceous Qingshankou Formation, Songliao Basin, Northeast China. The <i>δ</i><sup>26</sup>Mg and <sup>87</sup>Sr/<sup>86</sup>Sr records exhibit coherent bimodal variations. Surficial Mg cycling reveals two hydroclimatic regimes: during 91.9 ∼ 91.2 Ma, high precipitation intensified weathering, especially a 500-kyr pluvial interval with rainfall exceeding 2,000 mm/yr (millimeters per year), which triggered lake flooding and organic carbon burial; during 91.2 ∼ 90.7 Ma, declined weathering and precipitation indicated monsoon retreat. The Hadley circulation shrinkage, orbital-paced aquifer-eustasy, and coastal mountains induced by Okhotomorsk-East Asia collision, were triple amplifiers in elevating the Songliao Basin into a unique mid-latitude humidity hotspot with carbon burial, while contemporaneous inland and low-latitude areas experienced aridification or exhumation.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"72 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147361105","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}
Hua Zheng, Lisuo Hu, Yue Yu, Ruibin Ding, Xinyang Wang, Hanshi Wang, Kun Zhang, Deng Zhang, Binjie Wu, Ying Jin, Tao Zhang
Prolonged low salinity was observed in the eastern Arabian Sea (EAS) from autumn 2020 to autumn 2023, closely associated with the 2020–2023 triple-dip La Niña. Oceanic planetary wave bridge was a key driver of the extremely low salinity during winter, whereas freshwater flux remained an important contributor in other seasons. Anomalous autumn equatorial westerlies associated with the triple-dip La Niña triggered equatorial Kelvin waves in the eastern Indian Ocean, which further propagated toward Sri Lanka through reflected Rossby waves and coastal Kelvin waves. These waves ultimately traveled northward along India's western coast as downwelling coastal Kelvin waves, strengthening the horizontal advection of low-salinity waters into the EAS in winter. These findings highlight the remote influence of the El Niño-Southern Oscillation on salinity variability in the Arabian Sea and contribute to a deeper understanding of the coupling between climate modes, oceanic planetary waves, and marine environments.
{"title":"Prolonged Low-Salinity in the Eastern Arabian Sea Associated With the 2020–2023 Triple-Dip La Niña","authors":"Hua Zheng, Lisuo Hu, Yue Yu, Ruibin Ding, Xinyang Wang, Hanshi Wang, Kun Zhang, Deng Zhang, Binjie Wu, Ying Jin, Tao Zhang","doi":"10.1029/2025gl115963","DOIUrl":"https://doi.org/10.1029/2025gl115963","url":null,"abstract":"Prolonged low salinity was observed in the eastern Arabian Sea (EAS) from autumn 2020 to autumn 2023, closely associated with the 2020–2023 triple-dip La Niña. Oceanic planetary wave bridge was a key driver of the extremely low salinity during winter, whereas freshwater flux remained an important contributor in other seasons. Anomalous autumn equatorial westerlies associated with the triple-dip La Niña triggered equatorial Kelvin waves in the eastern Indian Ocean, which further propagated toward Sri Lanka through reflected Rossby waves and coastal Kelvin waves. These waves ultimately traveled northward along India's western coast as downwelling coastal Kelvin waves, strengthening the horizontal advection of low-salinity waters into the EAS in winter. These findings highlight the remote influence of the El Niño-Southern Oscillation on salinity variability in the Arabian Sea and contribute to a deeper understanding of the coupling between climate modes, oceanic planetary waves, and marine environments.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"8 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147361104","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}
Plasma sheet electron precipitation into Earth's atmosphere plays a key role in magnetosphere–ionosphere coupling at auroral latitudes. Such precipitation can be driven by four primary mechanisms that scatter equatorial electrons into the loss cone: resonant interactions with whistler-mode waves, electron cyclotron harmonics (ECH), broadband electrostatic turbulence, and field-line curvature scattering. Although each has been extensively examined, their relative occurrence rates and contributions remain poorly quantified. Using an extensive statistical data set from THEMIS (probe A) plasma and wave measurements, we compare the prevalence and characteristics of these four mechanisms. We show that broadband electrostatic turbulence and ECH are likely the dominant drivers of precipitation from the hot plasma sheet, whereas field-line curvature scattering predominates in the pre-substorm cold plasma sheet. We further examine the spatial scales of the associated precipitation patterns and characterize the representative electron spectra associated with different scattering mechanisms.
{"title":"Comparative Analysis of the Primary Drivers of Plasma Sheet Electron Precipitation","authors":"Xiao-Jia Zhang, Anton Artemyev","doi":"10.1029/2025gl120891","DOIUrl":"https://doi.org/10.1029/2025gl120891","url":null,"abstract":"Plasma sheet electron precipitation into Earth's atmosphere plays a key role in magnetosphere–ionosphere coupling at auroral latitudes. Such precipitation can be driven by four primary mechanisms that scatter equatorial electrons into the loss cone: resonant interactions with whistler-mode waves, electron cyclotron harmonics (ECH), broadband electrostatic turbulence, and field-line curvature scattering. Although each has been extensively examined, their relative occurrence rates and contributions remain poorly quantified. Using an extensive statistical data set from THEMIS (probe A) plasma and wave measurements, we compare the prevalence and characteristics of these four mechanisms. We show that broadband electrostatic turbulence and ECH are likely the dominant drivers of precipitation from the hot plasma sheet, whereas field-line curvature scattering predominates in the pre-substorm cold plasma sheet. We further examine the spatial scales of the associated precipitation patterns and characterize the representative electron spectra associated with different scattering mechanisms.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"241 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147360001","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}
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