Earth and Space Science最新文献

{"title":"Assimilation of All-Sky TROPICS Constellation Radiance Data in the NASA Goddard Earth Observing System (GEOS)","authors":"Min-Jeong Kim,&nbsp;Scott A. Braun,&nbsp;William J. Blackwell,&nbsp;R. Vince Leslie,&nbsp;Nikki Privé","doi":"10.1029/2026EA005051","DOIUrl":"https://doi.org/10.1029/2026EA005051","url":null,"abstract":"<p>This study examines the impact of assimilating all-sky microwave radiances from the Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission within the NASA Global Earth Observing System (GEOS) data assimilation and forecasting framework based on the Gridpoint Statistical Interpolation (GSI) system. Observing system experiments and Forecast Sensitivity to Observation Impact (FSOI) diagnostics were conducted, covering July through September 2023 for the experiments and August 2023 for the FSOI analysis. Results show that TROPICS radiances improve the representation of tropical moisture, temperature, and wind structures and reduce forecast error across multiple atmospheric fields. The strongest improvements occur in the lower and middle troposphere and persist through forecast day five. The constellation architecture plays a key role, with the four-satellite configuration producing larger and more spatially coherent benefits than any individual platform in idealized experiments, with smaller but consistent positive impacts in the full GEOS-FP system. Even within a radiance-rich observing system, TROPICS provides complementary information on moist convective processes. Consistency between deterministic forecast verification and FSOI diagnostics supports the robustness of these findings. Overall, small-satellite constellations with high revisit rates can add value to global numerical weather prediction by improving the depiction of tropical convection in modern data assimilation systems.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EA005051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148754030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Spatial Dependence of High-Frequency Ground Motion Along the Chilean Subduction Zone From Aftershock Sequences of the Mw 8.8 Maule and Mw 8.2 Iquique Earthquakes","authors":"Asiye Aziz Zanjani,&nbsp;Robert B. Herrmann","doi":"10.1029/2026EA005142","DOIUrl":"https://doi.org/10.1029/2026EA005142","url":null,"abstract":"&lt;p&gt;The Chilean subduction zone is a highly active seismic region, producing megathrust earthquakes approximately every decade. We apply a stochastic approach to assess spatial variations in seismic wave characteristics along the Chilean trench using weak motion data. We analyze &gt;10,000 weak motion records from 1,984 aftershocks (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mi&gt;l&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${M}_{l}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 2.5–6.3, with maximum depth and distance of 40 and 500 km, respectively) of the 2010 &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mi&gt;w&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${M}_{w}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 8.8 Maule earthquake in central Chile (CCH) and the 2014 &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mi&gt;w&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${M}_{w}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 8.2 Iquique earthquake in northern Chile (NCH). Source-attenuation models for the Iquique, Valparaíso, and Maule sub-regions were developed using Random Vibration Theory and regressions on filtered ground velocities and Fourier spectral amplitudes (0.25–20 Hz). The results reveal that geometrical spreading and frequency-dependent attenuation vary spatially. The source spectra differ mostly at intermediate frequencies using a two-corner-frequency source model. Differences in distance scaling and attenuation of seismic amplitude indicate faster energy loss along CCH paths, providing independent validation for the existing Chilean non-ergodic ground motion model. Seismic energy propagates efficiently through the colder, drier crust of NCH, while the weaker and warmer crust of CCH attenuates it faster. The frequency dependence of attenuation &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;η&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $(eta )$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; ranges from 0.30 to 0.35, but high–frequency decay &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;κ&lt;/mi&gt;\u0000 &lt;mi&gt;o&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({kappa }_{o}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EA005142","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148754152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Classification of Precipitable Water Vapor Regimes Revealed by Clustering of GNSS Radio Occultation and ERA5 Data","authors":"P. Alexander,&nbsp;A. de la Torre","doi":"10.1029/2026EA005107","DOIUrl":"https://doi.org/10.1029/2026EA005107","url":null,"abstract":"<p>Precipitable water vapor (PWV) is an essential parameter for the study of weather and climate behavior. This work presents a novel regional classification of PWV regimes based on clustering techniques applied to Global Navigation Satellite System radio occultation-derived and ERA5 reanalysis data with and without seasonal removal. Spatially and temporally averaged data sets were constructed using <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>15</mn>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> $15{}^{circ}$</annotation>\u0000 </semantics></math> × <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>15</mn>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> $15{}^{circ}$</annotation>\u0000 </semantics></math> latitude, longitude bins and monthly temporal intervals over the period June 2006 to September 2024. Multiple clustering approaches with Euclidean and dissimilarity metrics, including hierarchical (Linkage) and non-hierarchical (<i>k</i>-means, <i>k</i>-medoids) algorithms were applied. Features such as mean and standard deviation of every full time series as well as wavelet-derived characteristics of deseasonalized anomalies were used in Euclidean methods whereas the dynamic time warping procedure was applied to quantify dissimilarity. Results across data sets and methods are compared and they reveal similar regional structures which provide insights into global atmospheric moisture behavior. PWV across all algorithms and data shows strong and consistent latitudinal clustering patterns but with some differences over large land and ocean areas. In anomalies, the amount of groupings that the clustering methods are able to determine are much less and dissimilarity metrics shows more coherent meridional structure than Euclidean options. We also check the previous outcomes against ERA5 high resolution data results.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EA005107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"A GRACE/-FO-Based Framework for Improved Reproduction of Water-Balance-Constrained Evapotranspiration Across Hydroclimatic Regimes","authors":"Xiaolong Li,&nbsp;Jürgen Kusche,&nbsp;Taoyong Jin,&nbsp;Yulong Zhong,&nbsp;Benjamin Daniel Gutknecht","doi":"10.1029/2026EA005082","DOIUrl":"https://doi.org/10.1029/2026EA005082","url":null,"abstract":"<p>Diagnosing monthly evapotranspiration (ET) under water-balance constraints is essential for understanding land-atmosphere interactions and managing water resources under changing climate conditions. Since 2002, the Gravity Recovery and Climate Experiment (GRACE) and its successor GRACE Follow-On (GRACE/-FO) missions have provided precise observations of terrestrial water storage, enabling improved constraints on large-scale water balance. Building on these advances, we develop a GRACE/-FO-constrained diagnostic to framework to reproduce monthly ET derived from water-balance (ET_Budget). The framework that applies the one-parameter Budyko formulation during dry (water-limited) months and the two-parameter power-law formulation during wet (energy-limited) months, with the aridity index distinguishing between them. The framework is evaluated across 297 major river basins using ET_Budget as a reference and compared with conventional Budyko-only approaches. Results show that, relative to the Budyko-only approaches, the proposed framework substantially reduces deviations from ET_Budget, especially in 189 humid basins, while maintaining robust performance in 15 arid and 93 semi-arid regions. The proposed framework yields mean annual ET and P-ET of 612.5 and 191.4 mm yr⁻¹ over major river basins, respectively, showing no significant long-term trends but distinct spatial patterns and contrasting responses to the El Niño-Southern Oscillation phases. These findings highlight the value of the proposed framework as a diagnostic tool for improving the representation of monthly water-balance ET across diverse hydroclimatic conditions.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EA005082","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Assessing Cloud and Precipitation Properties on Temporal Scales Using LASSO Simulations Over the ARM Eastern North Atlantic (ENA) Site","authors":"Jiakun Liang,&nbsp;Daniel T. McCoy,&nbsp;William I. Gustafson Jr.,&nbsp;Scott E. Giangrande,&nbsp;Satoshi Endo,&nbsp;John Rausch,&nbsp;Jennifer D. Small Griswold","doi":"10.1029/2025EA004719","DOIUrl":"https://doi.org/10.1029/2025EA004719","url":null,"abstract":"<p>The representation of low clouds and precipitation remains a major source of uncertainty in Earth System Models (ESMs), particularly due to challenges in representing their sub-grid variability and scale-dependent sampling. This study evaluates the performance of preliminary simulations from the Large-Eddy Simulation (LES) Atmospheric Radiation Measurement Symbiotic Simulation and Observation (LASSO) project over the Eastern North Atlantic (ENA), focusing on liquid water path (LWP), ice water path (IWP), cloud fraction (CF), and surface precipitation rate across closed-cell, open-cell, and transitional cloud regimes. Using LES (100 m horizontal grid spacing) driven by ERA5 and MERRA-2 reanalyses, we assess the representativeness of ground-based point observations by analyzing their correspondence to model-resolved temporal means. Results suggest that observational sampling of at least 6 hr is required to achieve consistency with domain-scale averages, in particular for observations that exhibit pronounced sub-grid heterogeneity, such as precipitation. Differences between ERA5- and MERRA-2-driven simulations are detectable but secondary relative to regime and temporal-scale effects, and diminish with extended averaging. These findings highlight the importance of regime-aware model evaluation strategies and potentially demonstrate how LES can inform observation-model comparison practices and the development of cloud and precipitation parameterizations in ESMs.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004719","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Utilizing NASA's Operation IceBridge Airborne SWE and Precipitation Products to Assess Surface Snow Over Alaskan Glaciers","authors":"Yang Song,&nbsp;Ali Behrangi","doi":"10.1029/2025EA004891","DOIUrl":"https://doi.org/10.1029/2025EA004891","url":null,"abstract":"<p>Accurately estimating Snow Water Equivalent (SWE) in glacierized regions is critical for glacier modeling and mass balance analysis yet remains challenging due to sparse observations and uncertainties in precipitation products. The objectives are twofold: (a) assess how well three widely used precipitation datasets—Stage IV (a radar–gauge composite product), Integrated Multi-satellite Retrievals for GPM version 07 (IMERG V07, a satellite-based global product), and ERA5 (a global atmospheric reanalysis)—represent end-of-season SWE over seven Alaskan glaciers across two winter seasons, using airborne radar SWE retrievals (ARBN) from NASA's Operation IceBridge campaign as the reference, and (b) determine whether combining precipitation with auxiliary variables via machine learning (here XGBoost) modeling can reliably predict SWE beyond airborne coverage. Results reveal systematic biases: Stage IV generally overestimates SWE, IMERG V07 underestimates it, and ERA5 aligns most closely with ARBN. Model performance depends strongly on training data representativeness, with significant discrepancies arising when training and testing SWE distributions diverge. The most effective framework integrates IMERG V07, ERA5 and key auxiliary variables–snowfall fraction, total precipitable water and 2-m air temperature–with IMERG V07 and ERA5 found to be the dominant predictors. Nevertheless, accuracy is constrained by sparse in situ measurements and the paucity of high-resolution data in complex terrain. These findings underscore the need for high-quality targeted observations and integrated strategies that leverage diverse precipitation data and representative training data sets to advance SWE estimation and assessment in cryospheric environments.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004891","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Robust Regional Contrast but Penetration-Sensitive Snow Thickness Over Sea Ice From Multi-Winter Antarctic CRYO2ICE Observations","authors":"Xinlong Liu,&nbsp;Alexander D. Fraser,&nbsp;Rachel L. Tilling,&nbsp;Petra Heil,&nbsp;Stuart P. Corney","doi":"10.1029/2026EA005247","DOIUrl":"https://doi.org/10.1029/2026EA005247","url":null,"abstract":"<p>Snow on Antarctic sea ice modulates albedo, thermodynamic growth, and snow–ice formation, yet remains a leading uncertainty in altimetry-derived sea-ice thickness. Here we use the post-2022 CRYO2ICE configuration to derive along-track winter snow thickness from ICESat-2 laser and CryoSat-2 Ku-band radar freeboards over the Weddell and Ross sectors. We analyze 82,341 winter matchups (August 2022–September 2025) using a 5 km, 4 hr collocation criterion and propagate freeboard and snow-density uncertainties. Retrieved snow thickness is consistently larger in the Weddell Sea (mean 0.255 m, median 0.188 m) than the Ross Sea (0.217 m, 0.156 m), consistent with the older, thicker western Weddell ice. The contrast persists across sampled months and years and under common snow-density and penetration-factor assumptions. Formal per-matchup precision (0.039–0.040 m) is dominated by CryoSat-2 radar-freeboard uncertainty, whereas the absolute magnitude is set by the unresolved Ku-band scattering horizon. Comparison with AMSR2 passive-microwave snow depth shows weak point-to-point agreement (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>r</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 <mo>=</mo>\u0000 <mn>0.062</mn>\u0000 </mrow>\u0000 <annotation> ${r}^{2}=0.062$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>&lt;</mo>\u0000 <mn>0.001</mn>\u0000 </mrow>\u0000 <annotation> ${&lt; } 0.001$</annotation>\u0000 </semantics></math> in the Weddell and Ross sectors), reflecting differing measurement physics and spatial support. Nevertheless, both independently reproduce thicker Weddell than Ross snow. Under a common penetration factor, absolute sector-mean snow thickness varies by approximately a factor of two across the tested range, whereas the sector ordering is preserved under any uniform choice of penetration factor. CRYO2ICE therefore resolves a repeatable regional freeboard-difference signal, but conversion of that signal to absolute snow thickness remains conditional on the poorly constrained, ice-regime-dependent Ku-band scattering horizon.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EA005247","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Statistical Model of Subsurface Scattering Bias in ICESat-2's ATL06 Product","authors":"Thilini Bamunu Arachchige,&nbsp;Kelly E. Gleason,&nbsp;Jonathan C. Ryan,&nbsp;Markus Allgaier","doi":"10.1029/2026EA005083","DOIUrl":"https://doi.org/10.1029/2026EA005083","url":null,"abstract":"<p>ICESat-2 uses visible laser pulses and photon-counting detectors to range the Earth's surface, providing precision altimetry for measuring ice sheet elevation change. However, since water ice is transparent to visible light, the photon returns recorded by ICESat-2's ATLAS instrument may originate from subsurface scattering inside the snow or glacier ice volume, making the surface appear lower than it is. Here, we develop a Monte Carlo Radiative Transfer model to characterize the potential bias caused by subsurface scattering in snow and ice. Our model allows us to study the subsurface scattering bias in relation to photon number, scattering coefficient, and slope angle. We find centimeter-scale bias caused by subsurface scattering that is statistically significant for strong returns on firn and weak returns on bare glacier ice at low slope angles, and for strong returns on glacier ice at moderate slope angles. We find that the bias is amplified by slope angle, but can be accounted for with the existing correction employed in the ATL06 product. Most of the Greenland Ice Sheet is affected, but the bias is not expected to manifest in elevation change products and derived mass balance, as it would cancel out. We conclude that the modeled subsurface scattering signature in the ICESat-2 data offers future opportunities for investigating scattering coefficients of glacier ice.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EA005083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Empirical Assessment of Storm-Time Thermospheric Density Inversion Methods From LEO POD Data","authors":"Charles Constant,&nbsp;Indigo Brownhall,&nbsp;Anasuya Aruliah,&nbsp;Marek Ziebart,&nbsp;Santosh Bhattarai","doi":"10.1029/2025EA004914","DOIUrl":"https://doi.org/10.1029/2025EA004914","url":null,"abstract":"&lt;p&gt;Thermospheric mass density is one of the largest sources of operational uncertainty for spacecraft in low Earth orbit, particularly during geomagnetic storms. The growing population of Global Navigation Satellite System-equipped satellites presents a data set of opportunity: precise orbit determination (POD) data streams can be used to estimate thermospheric density along their paths. We present a multi-timescale benchmark of the two main cooperative density inversion methods, the Energy Dissipation Rate method and POD-accelerometry, against accelerometer-derived effective densities from the CHAMP and GRACE-FO-A satellites over 49 geomagnetic storms. At orbit-effective cadence, both methods achieve &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;r&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mo&gt;≥&lt;/mo&gt;\u0000 &lt;mn&gt;0.97&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${r}^{2}ge 0.97$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and a log-normal scatter &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;SD%&lt;/mtext&gt;\u0000 &lt;mo&gt;≤&lt;/mo&gt;\u0000 &lt;mn&gt;22&lt;/mn&gt;\u0000 &lt;mi&gt;%&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $text{SD%}le 22%$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and are statistically indistinguishable in typical-orbit scatter. However, the Energy Dissipation Rate method tracks storm-time variations more faithfully and produces fewer large-error orbits (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;r&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${r}^{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 0.992 vs. 0.985; RMS error 12.0% vs. 13.5%), at roughly &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;6&lt;/mn&gt;\u0000 &lt;mo&gt;×&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $6times $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; lower computational cost. Increasing the fit-span to three orbits reduces &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;SD%&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $text{SD%}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; to 13%–14% for both methods against matched-interval accelerometer effective densities, but &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;r&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${r}^{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; against unaveraged ","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025EA004914","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"A Physics-Based Frequency-Temperature Seismic Anelastic Attenuation Model for Planetary Ice Shells","authors":"L. Delaroque,&nbsp;A. Lucas,&nbsp;T. Kawamura,&nbsp;S. Rodriguez","doi":"10.1029/2026EA005178","DOIUrl":"https://doi.org/10.1029/2026EA005178","url":null,"abstract":"<p>Intrinsic attenuation in planetary ices remains poorly constrained at seismic frequencies and low temperatures, limiting quantitative predictions of wave propagation in icy moons. Existing models typically rely on constant-Q, or power-law formulations that lack microphysical grounding and fail to capture the strong temperature sensitivity of ice Ih. Here, we develop a physics-based attenuation model that combines dislocation relaxation, grain-boundary sliding, and proton reorientation mechanisms within a unified Cole-SAS-Maxwell framework, providing a consistent transition between seismic and tidal frequency regimes. The model is calibrated against laboratory and semi-empirical constraints over a broad range of homologous temperatures (0.34–1  <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>T</mi>\u0000 <mi>m</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${T}_{m}$</annotation>\u0000 </semantics></math> for ice Ih; 94 K–273 K in absolute temperature) and pressures up to 100 MPa. The proposed framework predicts order-of-magnitude variations in intrinsic shear attenuation across icy-shell thermal profiles and provides a quantitative framework for assessing wave dispersion, energy loss, and seismic detectability in the shells of Titan-like satellites.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"13 8","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EA005178","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}