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Constraining Regional Hydrological Sensitivity Over Tropical Oceans Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-25 Jie He, Yi Deng, Boniface Fosu, Yen-Heng Lin, Kezhou Lu
Regional hydrological sensitivity (i.e., precipitation change per degree local surface warming) contributes substantially to the uncertainty in future precipitation projections over tropical oceans. Here, we investigate the sensitivity of relative precipitation (P*, precipitation divided by the basin average precipitation) to local sea surface temperature (SST) change by dissecting it into three components
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Scattering Evidence for an Ancient Subducted Slab Using the Unique Raypath P*PKP Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-24 Hao Zhang, John E. Vidale, Wei Wang
We observe high-frequency scatterers consistent with the interpretation of a tabular high-velocity structure under the Indian Ocean as an ancient subducted slab. We use a previously rarely used raypath, P waves scattered in the slab into PKP waves (P∗${\mathrm{P}}^{\ast }$PKP), from 12 earthquakes and explosions in five locations recorded on the antique LASA (Large Aperture Seismic Array) located in
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Record High March 2024 Arctic Total Column Ozone Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-25 Paul A. Newman, Leslie R. Lait, Natalya A. Kramarova, Lawrence Coy, Stacey M. Frith, Luke D. Oman, Sandip S. Dhomse
Observations of March 2024 Arctic (63°N–90°N) total column ozone set a record high of 477 Dobson Units (DU) against the 1979–2023 satellite era time series. It was about 60 DU higher than average and 6 DU higher than the previous March 1979 471 DU record. Daily Arctic ozone was above average for every day in March 2024, and set record highs from 11–26 March 2024. Microwave Limb Sounder data show this
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Mars Soil Temperature and Thermal Properties From InSight HP3 Data Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-24 T. Spohn, N. Müller, J. Knollenberg, M. Grott, M. P. Golombek, A.-C. Plesa, V. T. Bickel, P. Morgan, C. Krause, D. Breuer, S. E. Smrekar, W. B. Banerdt
Diurnal and seasonal variations in soil and surface temperature measured with the HP3${\mathrm{H}\mathrm{P}}^{3}$ thermal probe and radiometer of NASA's InSight Mars mission are reported. At a representative depth of 10–20 cm, an average temperature of 217.5 K was found, varying by 5.3–6.7 K during a sol and by 13.3 K during the seasons. From the damping of the temperature variation with depth and
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Analysis of Aerosol Optical Mixing Using the EOMOS Model From Typical AERONET Sites Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-24 Gang Yan, Bingqiang Sun, Chenxu Gao, Yunqian Chen, Jianmin Chen
Satellite remote sensing predominantly employs optical properties for aerosol classification, often neglecting aerosol mixing and lacking validation accuracy. This study defines five aerosol types: marine, continental, dust, urban-industrial, and biomass-burning. Proposing the external optical mixing optimization solver (EOMOS) model based on the external mixing assumption, the model's accuracy is
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Thermochemistry of the Mantle Transition Zone Beneath the Western Pacific Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-24 Lauren Waszek, Rashni Anandawansha, Justin Sexton, Benoit Tauzin
The Earth's mantle transition zone has significant control on material flux between upper and lower mantle, thus constraining its properties is imperative to understand dynamic processes and circulation patterns. Global seismic data sets to study the transition zone typically display highly uneven spatial distribution. Therefore, complementary geometries are essential to improve knowledge of physical
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Modeling Climate and Tectonic Controls on Bias in Measured River Incision Rates Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-24 Clarke DeLisle, Brian J. Yanites
Rates of land surface processes provide insights into climatic and tectonic influences on topography. Bedrock incision rates are estimated by dating perched landforms such as strath terraces, assuming a constant bedrock incision rate from terrace abandonment to the next terrace level or present river level. These estimates express biases from the stochastic nature of sediment and water discharge in
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On the Spirality of the Asymmetric Rain Field of Tropical Cyclones Under Vertical Wind Shear Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-24 K. H. Lau, R. Toumi
The downshear-left enhancement of tropical cyclone rainfall has been demonstrated previously, but the radial dependence of this effect was not analyzed in detail. This study quantifies the progressive upwind shift of the wavenumber-1 maximum rain position with radius relative to the vertical wind shear direction. This shift is visualized as a distinctive upwind spiral of the maximum. It is shown that
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Quantifying Uncertainty in ML-Derived Atmosphere Remote Sensing: Hourly Surface NO2 Estimation With GEMS Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-20 Qin He, Kai Qin, Jason Blake Cohen, Ding Li, Jhoon Kim
Accurate estimation of nitrogen dioxide (NO2) levels at high spatio-temporal resolution is crucial for atmospheric research and public health assessments. This study introduces a novel machine learning (ML) framework enhanced with uncertainty quantification (UQ) to predict hourly NO2 concentrations over East Asia. Benefiting from tropospheric NO2 columns from the Geostationary Environment Monitoring
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How Does Plastic Litter Accumulate in Submarine Canyons? Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-21 Yuping Yang, Dawei Wang, Benjamin Kneller, Guangfa Zhong, Kaiqi Yu, Minghan Wang, Jingping Xu
Manned submersible dives in the northwest South China Sea encountered substantial amounts of plastic litter accumulated at the base of scours along the floor of a submarine canyon, which may associate with the depositional behaviors of turbidity currents. In this study, we conduct numerical simulations using field-scale bathymetry to investigate the relationship between the canyon floor morphology
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Upwind Moisture Controls on Interannual Variations of Precipitation and Vegetation in China's Drylands Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-20 Yan Li, Ru Xu, Zhao Yang, Sha Zhou, Mengqian Lu, Huiqing Lin, Shuangshuang Zi, Ruijie Su
Dryland precipitation depends on upwind and local moisture sources via moisture recycling. How upwind moisture variations affect interannual variations of downwind precipitation and vegetation in China's drylands remains unclear. We used high-resolution moisture tracking data sets and found terrestrial moisture (93%) was the dominant moisture source for China's drylands, especially from drylands themselves
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Meridional Path of ENSO Impact on Following Early-Summer North Pacific Climate Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-21 Lingfeng Tao, Xiu-Qun Yang, Linyuan Sun, Xuguang Sun, Jiabei Fang, Danping Cai, Botao Zhou, Haishan Chen
Prior research extensively investigates the delayed influence of El Niño-Southern Oscillation (ENSO) events on subsequent summer climates, with persistent sea surface temperature anomalies (SSTAs) in remote tropical oceans serving as crucial pathways. This study unveils a previously overlooked midlatitude pathway. During the developing winter, El Niño events induce basin-scale cold SSTAs in the central
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CO2 Dependence in Global Estimation of All-Sky Downwelling Longwave: Parameterization and Model Comparison Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-20 Koh Kawaguchi, Callum J. Shakespeare, Michael L. Roderick
The downwelling longwave radiation at the surface (DLR) is a key component of the Earth's surface energy budget. We present a novel set of equations that explicitly account for both clouds and the CO2$\mathrm{C}{\mathrm{O}}_{\mathrm{2}}$ effect to calculate the all-sky DLR. This paper first extends the clear-sky DLR model of Shakespeare and Roderick (2021, https://doi.org/10.1002/qj.4176) to include
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First High-Precision U–Pb CA–ID–TIMS Age of the Chuanlinggou Formation, North China Craton: Implications for Global Correlations of Black Shales and the Statherian/Calymmian Boundary Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-20 Shuan-Hong Zhang, Sandra L. Kamo, Richard E. Ernst, Guo-Hui Hu, Qi-Qi Zhang, Hafida El Bilali, Yue Zhao
The Chuanlinggou Formation in the northern North China preserves the world's earliest multicellular eukaryote microfossils. Here we present a high-precision zircon U–Pb CA–ID–TIMS age of 1,641.7 ± 1.2 Ma for a tuff layer within the black shales of the Chuanlinggou Formation. The new age is similar to those obtained for black shales from the Cuizhuang Formation in the southern North China, and the Barney
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Whistler Waves and Two-Stream Instabilities at Non-Stationary Quasi-Perpendicular Collisionless Shocks Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-21 Horia Comişel, Octav Marghitu
Upstream propagating waves are observed to correlate with the reflected ions in the foot of a high Mach number quasi-perpendicular collisionless shock. The respective wavefronts show time varying amplitude matching the variation of the reflected ions and the shock reformation cycles. We interpret this process in terms of the fast two-stream instability and investigate the results of the PIC simulation
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Refined Estimates of Global Ocean Deep and Abyssal Decadal Warming Trends Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-19 Gregory C. Johnson, Sarah G. Purkey
Deep and abyssal layer decadal temperature trends from the mid-1980s to the mid-2010s are mapped globally using Deep Argo and historical ship-based Conductivity-Temperature-Depth (CTD) instrument data. Abyssal warming trends are widespread, with the strongest warming observed around Antarctic Bottom Water (AABW) formation regions. The warming strength follows deep western boundary currents transporting
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Seismic Evidence of Basin Development in NE Tibetan Plateau in Response to Deep Crustal Dynamics From Joint Inversion of Rayleigh Wave Ellipticity and Phase Velocity Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-21 Pengfei Ren, Zhen Guo, Yiduo Liu, Bin Luo, Xiaoyang Wu
The NE Tibet experienced complex and distinct basin developments and uplifts in different areas. However, the reasons for such distinct surface deformation and their relationship to deep crustal geodynamic processes are not well understood. Here, we obtain a crust model of NE Tibet by jointly inverting Rayleigh wave ellipticity and phase velocity. Our results reveal that deep crustal strength contrasts
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Quantifying the Amplifying Effect of the Winter North Pacific Oscillation on the Subsequent ENSO Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-20 Suqiong Hu, Masahiro Watanabe, Wenjun Zhang, Tomoki Iwakiri, Feng Jiang
Atmospheric variability associated with the winter North Pacific Oscillation (NPO), preceding El Niño-Southern Oscillation (ENSO) events by about 1 year, is driven mainly by the tropical Pacific sea surface temperature (SST) anomalies but may also affect the subsequent ENSO. To isolate the latter, we conduct an idealized hindcast experiment using a climate model MIROC6, in which the NPO-related surface
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Sunward Oxygen Ion Fluxes and the Magnetic Field Topology at Mars From Hybrid Simulations Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-21 E. Dubinin, R. Modolo, F. Leblanc, M. Pätzold, N. Romanelli
It is commonly believed that because of the direct solar wind interaction with the Martian atmosphere/ionosphere, the planet could have lost a significant part of its atmosphere. Closed field lines of the crustal magnetic field can weaken a transport of the ionospheric ions to the tail. Reconnection of the interplanetary magnetic field lines draping around Mars and the crustal magnetic field can also
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Internal Variability Dominated the Extreme Cold Wave Over North America in December 2022 Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-18 Hainan Gong, Kangjie Ma, Lin Wang
In December 2022, North America experienced an unprecedented extreme cold event. However, the underlying physical mechanisms of this cold wave, and the extent to which it is driven by internal variability or external forcing, are not fully understood. Using ERA5 reanalysis data and the HadGEM3-A-N216 attribution simulations, we identified internal variability as the main cause, contributing −5.14 K
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Spatial Distribution in Surface Aerosol Light Absorption Across India Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-19 Taveen S. Kapoor, Chimurkar Navinya, Adishree Apte, Nishit J. Shetty, Pradnya Lokhande, Sujit Singh, Sadashiva Murthy B. M., Meena Deswal, Jitender S. Laura, Akila Muthalagu, Asif Qureshi, Ankur Bhardwaj, Ramya Sunder Raman, Yang Lian, G. Pandithurai, Pooja Chaudhary, Baerbel Sinha, Shahadev Rabha, Binoy K. Saikia, Tanveer Ahmad Najar, Arshid Jehangir, Sauryadeep Mukherjee, Abhijit Chatterjee, Harish
Light-absorbing carbonaceous aerosols that dominate atmospheric aerosol warming over India remain poorly characterized. Here, we delve into UV-visible-IR spectral aerosol absorption properties at nine PAN-India COALESCE network sites (Venkataraman et al., 2020, https://doi.org/10.1175/bams-d-19-0030.1). Absorption properties were estimated from aerosol-laden polytetrafluoroethylene filters using a
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Asymmetrical Solar Wind Deflection in the Martian Magnetosheath Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-19 Shibang Li, Haoyu Lu, Jinbin Cao, Xiaoshu Wu, Xiaoxin Zhang, Nihan Chen, Yihui Song, Jianxuan Wang, Yuchen Cao, Jianing Zhao
As incident solar wind encounters the martian upper atmosphere, it undergoes deflection particularly in the magnetosheath. However, the plasma flow exhibits asymmetrical distribution features within this transition region, which is investigated by employing a three-dimensional Hall magnetohydrodynamic (MHD) model from an energy transfer perspective in this study. Simulation results reveal that solar
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A Slowdown in Translation Speed of Western North Pacific Tropical Cyclones Undergoing Rapid Intensification Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-19 Jinjie Song, Philip J. Klotzbach, Yifei Dai, Yihong Duan
This study examines long-term trends in western North Pacific (WNP) tropical cyclones (TCs) experiencing rapid intensification (RI) from 1971 to 2022. Although there is only a weak slowdown for all intensifying WNP TCs, the average translation speed for RI TCs has significantly decelerated over the RI main development region (7.5°–25°N, 115°–160°E). This slowdown is primarily due to increasing RI probabilities
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A Composite Seismic Source Model for the First Major Event During the 2022 Hunga (Tonga) Volcanic Eruption Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-17 Jinyin Hu, Thanh-Son Phạm, Hrvoje Tkalčić
The violent eruption of the Hunga (Tonga) submarine volcano on 15 January 2022 caused a 58 km-heigh ash plume, catastrophic tsunami, and significant global seismic and infrasound waves. However, the physical mechanism underpinning its multiple-explosive events remains unclear, and its resolvability relies on the seismic waveform source inversion. The studies of two different point-source models, the
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Investigating Hydrated Silica in Syrtis Major, Mars: Implications for the Longevity of Water–Rock Interaction Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-18 J. R. C. Voigt, V. Z. Sun, C. E. Viviano, K. M. Stack
We use the crystallinity of hydrated silica, represented by the 1.4 μm absorption position in orbiter spectroscopic data, as a proxy for the longevity of water–rock interaction in the Syrtis Major region. Geological maps and crater size–frequency distribution analyses are employed to contextualize mineral detections and estimate surface ages. Hydrated silica is detected within two distinct geological
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Impact of Paleogeography on the Stratospheric Polar Vortex in the Geological Past Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-19 Pengkun Yang, Yan Xia, Yongyun Hu, Ming Bao, Xuejuan Ren, Chen Zhou, Yimin Zhu
The stratospheric polar vortex (SPV) significantly influences current weather and climate patterns. However, its state in the geological past remains largely unexplored. This study investigates SPV variations in the past 250 million years, using a fully coupled Earth System Model. It is found that midlatitude paleogeography primarily drove substantial SPV variations in the deep time, while changes
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Kinetic Theory of Drift-Mirror Mode Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-19 Yao Yao, Haotian Chen, Zilong Li, Jiquan Li
We present a nonlocal gyrokinetic theory for the drift-mirror mode in high-β$\beta $ anisotropic plasmas. Here, β$\beta $ represents the ratio of plasma pressure to magnetic pressure. The equilibrium distribution is established self-consistently via guiding-center Hamiltonian theory. To keep the nonuniformity and finite Larmor radius (FLR) effects on an equal footing, we derive the three-field nonlocal
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The LCROSS Impact Crater as Seen by ShadowCam and Mini-RF: Size, Context, and Excavation of Copernican Volatiles Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-17 C. I. Fassett, M. S. Robinson, G. W. Patterson, B. W. Denevi, P. Mahanti, E. Mazarico, E. G. Rivera-Valentín, F. S. Turner, M. R. Manheim, A. Colaprete
The Lunar CRater Observations and Sensing Satellite (LCROSS) impacted a Centaur rocket stage into a permanently shadowed region (PSR) in Cabeus crater, excavating water ice and other volatiles. We used the Miniature Radio Frequency (Mini-RF) instrument on the Lunar Reconnaissance Orbiter and the ShadowCam instrument on the Korean Pathfinder Lunar Orbiter to detect the probable 22-m diameter crater
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Looking for Subsurface Oceans Within the Moons of Uranus Using Librations and Gravity Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-15 D. J. Hemingway, F. Nimmo
Several of the icy moons in the Jupiter and Saturn systems appear to possess internal liquid water oceans. Our knowledge of the Uranian moons is more limited but a future tour of the system has the potential to detect subsurface oceans. Planning for this requires an understanding of how the moons' internal structures—with and without oceans—relate to observable quantities. Here, we show that the amplitude
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Humid, Warm and Treed Ecosystems Show Longer Time-Lag of Vegetation Response to Climate Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-17 Xinran Gao, Wen Zhuo, Alemu Gonsamo
Climate-vegetation interaction assessments often focus on vegetation response to concurrent climatic perturbations, seldom on the time-lag effect of climate. Here we employ global satellite observations, climate data records and CO2 flux measurements to calculate the time-lag of vegetation response to climate. We analyze the time-lags of various climate variables under distinct environmental conditions
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Permafrost Hydrogeology of Taylor Valley, Antarctica: Insights From Deep Electrical Resistivity Tomography Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-16 Valentina Romano, Federico Fischanger, Gary Wilson, Alessandra Sciarra, Adriano Mazzini, Claudio Mazzoli, Fabio Florindo, Maria Chiara Tartarello, Massimiliano Ascani, Jacob Anderson, Rachel Worthington, Richard Hardie, Bob Dagg, Livio Ruggiero
Global warming has prompted globally widespread permafrost thawing, resulting in enhanced greenhouse gas release into the atmosphere. Studies conducted in the Northern Hemisphere reveal an alarming increase in permafrost thawing. However, similar data from Antarctica are scarce. We conducted a 2-D Deep Electrical Resistivity Tomography (DERT) survey in Taylor Valley, Antarctica, to image the distribution
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Inland Summer Speedup at Zachariæ Isstrøm, Northeast Greenland, Driven by Subglacial Hydrology Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-15 Shfaqat A. Khan, Mathieu Morlighem, Shivani Ehrenfeucht, Helene Seroussi, Youngmin Choi, Eric Rignot, Angelika Humbert, Derek Pickell, Javed Hassan
The Northeast Greenland Ice Stream (NEGIS) has experienced substantial dynamic thinning in recent years. Here, we examine the evolving behavior of NEGIS, with focus on summer speedup at Zachariae Isstrøm, one of the NEGIS outlet glaciers, which has exhibited rapid retreat and acceleration, indicative of its vulnerability to changing climate conditions. Through a combination of Sentinel-1 data, in-situ
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Large-Scale Climate Features Control Fire Emissions and Transport in Africa Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-15 Amin Dezfuli, Charles M. Ichoku, Michael G. Bosilovich
Recent increase in extreme wildfire events has led to major health and environmental consequences across the globe. These adverse impacts underlined the need for better understanding of this phenomenon and to formulate mitigating actions. While previous research has focused on local weather drivers of wildfires, our knowledge about their large-scale climatic controls remains limited, especially in
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Variation of Molecular Ions in the Inner Magnetosphere Observed by the Arase Satellite Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-16 A. Nagatani, Y. Miyoshi, K. Asamura, L. M. Kistler, S. Nakamura, K. Seki, Y. Ogawa, I. Shinohara
We analyzed time-of-flight (TOF) data from the Arase satellite to investigate temporal variations of the molecular ion group (O2+, NO+, and N2+) at 19.2 keV/q in the inner magnetosphere for 6 years from the solar declining to rising phase. The molecular ions counts were estimated by subtracting the background contamination of oxygen counts. While the number of clear molecular ion events was small,
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Changes in Four Decades of Near-CONUS Tropical Cyclones in an Ensemble of 12 km Thermodynamic Global Warming Simulations Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-15 Colin M. Zarzycki, Tyrone Zhang, Andrew D. Jones, Deeksha Rastogi, Pouya Vahmani, Paul A. Ullrich
We evaluate tropical cyclones (TCs) in a set of thermodynamic global warming (TGW) simulations over the continental United States (CONUS). A 12 km simulation forced by ERA5 provides a 40-year historical (1980–2019) control. Four complimentary future scenarios are generated using thermodynamic deltas applied to lateral boundary, interior, and surface forcing. We curate a data set of 4,498 6-hourly TC
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A Model-Based Investigation of the Recent Rebound of Shelf Water Salinity in the Ross Sea Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-16 Jingwei Zhang, Xuebin Zhang, Matt A. King, Kewei Lyu
Intense atmosphere-ocean-ice interactions in the Ross Sea play a vital role in global overturning circulation by supplying saline and dense shelf waters. Since the 1960s, freshening of the Ross Sea shelf water has led to a decline in Antarctic Bottom Water formation. However, during 2012–2018, salinity of the western Ross Sea has rebounded. This study adopts a global ocean-sea ice model to investigate
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Fluid Drainage Leads to Thermal Decomposition of Wet Gouge During Experimental Seismic Slip Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-13 Thi Trinh Nguyen, Li-Wei Kuo, Qing-En Kong, Chia-Wei Kuo, Jia-Jyun Dong, Dennis Brown, Huan Wang, Szu-Ting Kuo, Haibing Li, Jialiang Si
Several borehole cores intersecting faults related to coseismic slip display high-temperature features, including thermal decomposition of fault gouge. We present evidence that these features may be related to fluid drainage of the slip zone during seismic slip. We sheared water-saturated kaolinite powders under both fluid drained and undrained conditions, expected for seismic slip at shallow crustal
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Plasma Structure Decay Rates in the Equatorial Ionosphere Are Strongly Coupled by Turbulence Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-13 M. F. Ivarsen, J.-P. St-Maurice, J. Park, J. Klenzing, Y. Jin, W. Lee
Equatorial plasma irregularities in the ionospheric F-region proliferate after sunset, causing the most apparent radio scintillation “hot-spot” in geospace. These irregularities are caused by plasma instabilities, and appear mostly in the form of under-densities that rise up from the F-region's bottomside. After an irregularity production peak at sunset, the amplitude of the resulting turbulence decays
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Delayed Summer Monsoon Onset in Response to the Cold Tongue in the South China Sea Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-13 Xiaorong Fang, Weidong Yu
The interannual variation of the South China Sea (SCS) summer monsoon onset (SMO) may bring extreme weather and climate disasters in East Asia. However, its skillful forecast still remains challenging. This study investigates the intraseasonal ocean-atmosphere interaction that affects the SCSSMO through diagnostic analysis and numerical experiments. It reveals that the cold sea surface temperature
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Using Random Forests to Compare the Sensitivity of Observed Particulate Inorganic and Particulate Organic Carbon to Environmental Conditions Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-13 Rui Jin, Anand Gnanadesikan, Christopher Holder
The balance between particulate inorganic carbon (PIC) and particulate organic carbon (POC) holds significant importance in carbon storage within the ocean. A recent investigation delved into the spatial distribution of phytoplankton and the physiological mechanisms governing their growth. Employing random forests, a machine learning technique, this study unveiled apparent relationships between POC
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Plasma Sheet Magnetic Flux Transport During Geomagnetic Storms Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-13 Savvas Raptis, Viacheslav Merkin, Shinichi Ohtani, Matina Gkioulidou, Leonardo H. Regoli
Plasma sheet convection is a key element of storm-time plasma dynamics in the magnetosphere. While decades of observations have advanced our understanding of convection in general, specifically storm-time convection remains poorly understood. Using data from ISAS/NASA's Geotail and NASA's MMS, this study characterizes plasma sheet magnetic flux transport across the magnetotail during numerous storms
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The Shortwave Cloud-SST Feedback Amplifies Multi-Decadal Pacific Sea Surface Temperature Trends: Implications for Observed Cooling Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-13 Zachary I. Espinosa, Mark D. Zelinka
Climate models struggle to produce sea surface temperature (SST) gradient trends in the tropical Pacific comparable to those seen recently in nature. Here, we find that the magnitude of the cloud-SST feedback in the subtropical Southeast Pacific is correlated across models with the magnitude of Eastern Pacific multi-decadal SST variability. A heat-budget analysis reveals coupling between cloud-radiative
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Orbital Tuning of Short Reversed Geomagnetic Polarity Intervals in the Cretaceous Normal Polarity Superchron Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-13 J. M. F. Ramos, J. F. Savian, D. R. Franco, M. F. Figueiredo, C. G. Leandro, F. Frontalini
While the Cretaceous Normal Polarity Superchron has documented instances of brief reversed polarity intervals, the absence of accurate age determinations for such abrupt shifts poses a challenge in leveraging them as reliable reference tiepoints. This study presents a cyclostratigraphic analysis of gamma-ray data from the DSDP Site 402A. The identification of Milankovitch cycles allowed us to construct
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South Pacific Water Intrusion Into the Sub-Thermocline Makassar Strait in the Winter of 2016–2017 Following a Super El Niño Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-13 Mingting Li, Dongliang Yuan, Arnold L. Gordon, Laura K. Gruenburg, Dongxiao Wang
The Makassar Strait throughflow (MST) is the major component of the Indonesian Throughflow (ITF), transferring Pacific water into the Indian Ocean. In our previous study, we identified a new zonal pathway, a. k.a. the North Equatorial Subsurface Current (NESC), which carried equatorial water into the MST sub-thermocline (>300 m) in the summer 2016 following the 2015/16 El Niño. We now show continued
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Mapping Los Angeles Basin Depth With Sp Converted Phases Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-13 Yan Yang, Robert W. Clayton
The depth of the Los Angeles (LA) basin is a critical factor for seismic hazard assessment and active tectonic studies. By analyzing S-waves generated by earthquakes below the basin that convert to P-waves at the sediment-bedrock interface, we estimate the maximum depth of the LA basin to be 9 km. This estimate depends on the velocities within and below the basin, and the depth presented here is based
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Strong Energy Conversion at Magnetotail Plasma Sheet Boundary Layer Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-12 C. X. Du, H. S. Fu, J. B. Cao, Z. Wang, Y. Yu, W. D. Fu, W. Z. Zhang
The magnetotail plasma sheet boundary layer (PSBL) is a dynamic boundary layer between the hot-denser plasma sheet and the cold-tenuous tail lobes. It plays an important role in exchanging mass and energy in the magnetotail. In previous studies, the local current carried by the electron beams has been well understood. The strong energy conversion (E ⋅ J, E is electric field and J is current density)
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First Altitude-Triggered Lightning Experiment Associated With an Elevated Wind Turbine Blade on the Ground Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-11 Jinliang He, Guohua Yang, Quanxin Li, Jianpei Zhang, Yang Zhang, Weitao Lyu, Lei Fu, Chijie Zhuang, Bo Zhang
Lightning is the severest threaten to safe operation of wind turbines. In this letter, the authors present the first altitude-triggered lightning experiment involving an elevated 12 m-long wind turbine blade placed on the ground. A total of 50 precursors with amplitude over 62.9 A were observed through measurements of channel-base current, fast electric field, and optical data. The air gap with around
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Three Atmospheric Patterns Dominate Decadal North Atlantic Overturning Variability Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-11 Dafydd Stephenson, Daniel E. Amrhein, LuAnne Thompson
Atlantic Meridional Overturning Circulation (AMOC) variability originates from a large number of interacting processes with multiple time scales, with dominant processes dependent on both the latitude and timescale of interest. Here, we isolate the optimal atmospheric modes driving climate-relevant decadal AMOC variability using a novel approach combining dynamical and statistical attribution (dynamics-weighted
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Modeling the Impact of Seasonal Water Table Fluctuations on Ambient Noise Interferometry Using Acousto-Elastic Effect Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-12 Y. Wang, J. Schmittbuhl, J. Azzola, F. Mattern, D. Zigone, O. Lengliné, V. Magnenet, J. Vergne
Ambient noise interferometry has become a common technique for monitoring slight changes in seismic velocity in a variety of contexts. However, the physical origin of the resolved small velocity fluctuations is not well established for long-term seasonal effects. Here we propose a physical forward model of scattered waves in a deformable medium that includes acousto-elastic effect, which refers to
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Separating Injection-Driven and Earthquake-Driven Induced Seismicity by Combining a Fully Coupled Poroelastic Model With Interpretable Machine Learning Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-11 R. G. Hill, D. T. Trugman, M. Weingarten
In areas of induced seismicity, earthquakes can be triggered by stress changes due to fluid injection and static deformation from fault slip. Here we present a method to distinguish between injection-driven and earthquake-driven triggering of induced seismicity by combining a calibrated, fully coupled, poroelastic stress model of wastewater injection with interpretation of a machine learning algorithm
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Mid-Latitude Auroras and Energetic Particle Precipitation Occurred Unusually in a Moderate Magnetic Storm on 1 December 2023 Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-11 Longxing Ma, Yiqun Yu, Xiaoqi Ding, Xiyu Liu, Depeng An, Chenlong Zhou, Jinbin Cao, Kazuo Shiokawa
Mid-latitude auroras are conventionally generated during intense magnetic storms. However, mid-latitude auroras were observed by naked eyes at Beijing China (39°N, 116°E) unusually during a moderate storm event on 1 December 2023 with the minimum Sym-H index only ∼${\sim} $ −120 nT. This study combines conjugative in-site and ground-based observations to analyze the auroras and underlying physical
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Contrasting Chlorine Chemistry on Volcanic and Wildfire Aerosols in the Southern Mid-Latitude Lower Stratosphere Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-11 Peidong Wang, Susan Solomon
Volcanic eruptions and wildfires can impact stratospheric chemistry. We apply tracer-tracer correlations to satellite data from Atmospheric Chemistry Experiment—Fourier Transform Spectrometer and the Halogen Occultation Experiment at 68 hPa to consistently compare the chemical impact on HCl after multiple wildfires and volcanic eruptions of different magnitudes. The 2020 Australian New Year (ANY) fire
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Unraveling the Extensive Impact of Subthermocline Eddies on the Western Pacific Undercurrent System Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-11 Fuad Azminuddin, Chan Joo Jang, Raden Dwi Susanto, Saat Mubarrok
Subthermocline eddies (SEs) influencing ocean circulation are progressively known, yet their extensive impact on the western Pacific undercurrent system remains largely unexplored and, in some regions, often underestimated. Okubo-Weiss parameter analysis reveals a distinctive meridional pattern of cyclonic and anticyclonic SE distribution in the interior western Pacific basin that aligns with zonally
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Seamounts Enhance the Local Emission of CO2 in the Northern South China Sea Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-11 Gong Zhang, Bo Han, Qinghua Yang, Xueming Zhu, Xiaojing Wang, Honge He, Hongliang Li, Xinyang Wang, Wei Xie, Dake Chen
The South China Sea is a typical marginal sea characterized by the presence of numerous seamounts. However, the effect of seamounts on the air-sea CO2 flux has not yet been well studied. In September 2021, the air-sea CO2 flux was measured directly using eddy covariance (EC), and discrete waterside sampling was conducted. The results indicate that the northern South China Sea is a source of atmospheric
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A Mid-Crustal Channel of Positive Radial Anisotropy Beneath the Eastern South China Block From F-J Multimodal Ambient Noise Tomography Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-10 Juqing Chen, Zhengbo Li, Xiaofei Chen
We investigated the crustal radial anisotropy in the eastern South China Block (ESCB) with the F-J multimodal ambient noise tomography. Well corresponding to widespread mid-crustal low-velocity zones in the VSV${V}_{SV}$ model, a pronounced mid-crustal channel of positive radial anisotropy is revealed. In the Cathaysia Block, it may origin from sub-horizontally aligned quartz induced by extension
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The Influence of Large-Scale Spatial Warming on Jet Stream Extreme Waviness on an Aquaplanet Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-10 T. J. Batelaan, C. Weijenborg, G. J. Steeneveld, C. C. van Heerwaarden, V. A. Sinclair
The effect of modified equator-to-pole temperature gradients on the jet stream by low-level polar warming and upper-level tropical warming is not fully understood. We perform aquaplanet simulations to quantify the impact of different sea surface temperature distributions on jet stream strength, large wave amplitudes and extreme waviness. The responses to warming in the waviness metrics Sinuosity Index
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Inferring the Speed of Sound and Wind in the Nighttime Martian Boundary Layer From Impact-Generated Infrasound Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-10 Marouchka Froment, Zongbo Xu, Philippe H. Lognonné, Carène Larmat, Raphael F. Garcia, Mélanie Drilleau, Brent G. Delbridge, Aymeric Spiga, Taichi Kawamura, Éric Beucler
The properties of the first kilometers of the Martian atmospheric Planetary Boundary Layer have until now been measured by only a few instruments and probes. InSight offers an opportunity to investigate this region through seismoacoustics. On six occasions, its seismometers recorded short low-frequency waveforms, with clear dispersion between 0.4 and 4 Hz. These signals are the air-to-ground coupling
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The Effect of Nitrogen on the Dihedral Angle Between Fe−Ni Melt and Ringwoodite: Implications for the Nitrogen Deficit in the Bulk Silicate Earth Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-10 Kyusei Tsuno, Damanveer S. Grewal, Virginia Xu, Logan Leinbach, Kurt Leinenweber, Axel Wittmann, Sang-Heon Shim
Nitrogen (N) is extremely depleted in the bulk silicate Earth (BSE). However, whether the silicate magma ocean was as N-poor as the present-day BSE is unknown. We performed multi-anvil experiments at 20 GPa and 1,673−2,073 K to determine the dihedral angle of Fe−Ni−N alloy melt in ringwoodite matrix to investigate whether percolation of Fe-rich alloy melt in the solid mantle can explain N depletion
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Issue Information Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-10
No abstract is available for this article.
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Deep Learning Improves Global Satellite Observations of Ocean Eddy Dynamics Geophys. Res. Lett. (IF 4.6) Pub Date : 2024-09-07 Scott A. Martin, Georgy E. Manucharyan, Patrice Klein
Ocean eddies affect large-scale circulation and induce a kinetic energy cascade through their non-linear interactions. However, since global observations of eddy dynamics come from satellite altimetry maps that smooth eddies and distort their geometry, the strength of this cascade is underestimated. Here, we use deep learning to improve observational estimates of global surface geostrophic currents