Geophysical Research Letters最新文献

{"title":"Sampling Bias From Satellite Retrieval Failures of Cloud Properties and Its Implications for Aerosol-Cloud Interactions","authors":"Goutam Choudhury,&nbsp;Tom Goren","doi":"10.1029/2025GL115429","DOIUrl":"10.1029/2025GL115429","url":null,"abstract":"<p>Satellite radiometers like MODIS use a bi-spectral retrieval algorithm to simultaneously retrieve cloud optical thickness and cloud effective radius <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mfenced>\u0000 <msub>\u0000 <mi>r</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation> $left({r}_{mathrm{e}}right)$</annotation>\u0000 </semantics></math>. However, retrievals fail for liquid clouds when the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>r</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${r}_{mathrm{e}}$</annotation>\u0000 </semantics></math> observation exceeds the maximum threshold of 30 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>μ</mi>\u0000 </mrow>\u0000 <annotation> ${upmu }$</annotation>\u0000 </semantics></math>m in MODIS's solution space, leading to a sampling bias. Here, we quantify this bias by reconstructing pixels with failed retrievals using two methods: a conservative approach assigning a fixed minimum <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>r</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${r}_{mathrm{e}}$</annotation>\u0000 </semantics></math> threshold to failed pixels, and a representative approach modeling failed <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>r</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${r}_{mathrm{e}}$</annotation>\u0000 </semantics></math> using CloudSat radar measurements. We show that MODIS overestimates cloud droplet number concentration by 8%–9% and underestimates liquid water path by 8%–11% globally. We demonstrate that this bias can introduce erroneous correlations between cloud properties that may be misinterpreted as causal processes. Accordingly, we show that accounting for this bias increases the cloud water adjustments by 24%–36%, highlighting the crucial need to expand the solution space in MODIS and similar sensors.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL115429","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144087947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly Systematic Response of Seismic Rupture Patterns to Background Loading Rate: Insights From Repeating Earthquakes","authors":"Keisuke Yoshida,&nbsp;Satoshi Ide","doi":"10.1029/2025GL115207","DOIUrl":"https://doi.org/10.1029/2025GL115207","url":null,"abstract":"<p>Although earthquakes are known to recur in approximately the same areas, their recurrence patterns and final sizes can vary considerably. To understand this variability, we analyzed a prominent sequence of repeating earthquakes from the latest catalog in Japan, activated following the 2011 earthquake (<i>M</i>_w 9.0). Waveform analysis of 53 events (2003–2023) revealed variations in magnitude from <i>M</i>_w 3.2 to 4.0. Their moment-rate functions suggest they were not mere repetitions, but rather represented a more generalized form of recurrence. Their ruptures were consistently initiated in the same patch, and most events exhibited double ruptures after the Tohoku earthquake, transitioning to single ruptures over time, in a surprisingly systematic manner. A comparison with 40 smaller events (<i>M</i>_w 2–2.5) showed no obvious relationship between initial momentum and final magnitude. Our results suggest earthquake rupture patterns respond remarkably systematically to changes in the background loading rate, reflecting in situ frictional characteristics.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL115207","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144091683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disentangling Regional Drivers of Top Antarctic Snowfall Days With a Convolutional Neural Network","authors":"Rebecca Baiman,&nbsp;Andrew C. Winters,&nbsp;Kirsten J. Mayer,&nbsp;Clairisse A. Reiher","doi":"10.1029/2025GL115254","DOIUrl":"10.1029/2025GL115254","url":null,"abstract":"<p>Snowfall is the primary contributor to Antarctic surface mass balance. Identifying regional-scale mechanisms that drive heavy snowfall provides context for changes in Antarctic surface mass balance in a warmer climate. We compare drivers of top snowfall days across five Antarctic regions using machine learning and traditional synoptic diagnostics. A convolutional neural network identifies top snow days with an accuracy of 92%–94% per region when trained on just atmospheric moisture and low-level meridional wind, highlighting the importance of atmospheric river-like structures to top Antarctic snowfall days. The network's skill depends mainly on low-level wind in East Antarctica and atmospheric moisture in West Antarctica, suggesting that dynamic processes are comparatively more important in driving East Antarctic top snowfall days. We leverage the quasi-geostrophic omega equation to identify mechanisms for ascent and snowfall production, and we find that East Antarctic top snowfall days feature stronger synoptic-scale forcing for ascent compared to West Antarctica.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL115254","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144087945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detecting Millimetric Slow Slip Events Along the North Anatolian Fault With GNSS","authors":"Alpay Özdemir,&nbsp;Jorge Jara,&nbsp;Uğur Doğan,&nbsp;Romain Jolivet,&nbsp;Ziyadin Çakir,&nbsp;Jean-Mathieu Nocquet,&nbsp;Semih Ergintav,&nbsp;Roger Bilham","doi":"10.1029/2024GL111428","DOIUrl":"10.1029/2024GL111428","url":null,"abstract":"<p>Active faults release part of the elastic strain energy stored in the crust via aseismic slip, either through slow slip events (SSEs) or steady slowly creep. However, spatial and temporal interactions between these different styles of aseismic slip have yet to be quantified especially at depth. Along the central section of the North Anatolian Fault, we apply a Multichannel Singular Spectrum Analysis (MSSA) on GNSS time series of ground motion to detect a <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>w</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${M}_{w}$</annotation>\u0000 </semantics></math> 4.8 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>±</mo>\u0000 </mrow>\u0000 <annotation> $pm $</annotation>\u0000 </semantics></math> 0.08 shallow SSE (2–5 km depth) lasting for 26 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>±</mo>\u0000 </mrow>\u0000 <annotation> $pm $</annotation>\u0000 </semantics></math> 5 days, in agreement with local creepmeter observations. Our observations confirm the recurrence of SSEs next to a steadily creeping section of the fault. Finally, we discuss how steady creep and SSEs interact spatially and temporally along the fault segment.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL111428","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144087937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of Thermospheric Circulation by Lower-Thermospheric Winter-to-Summer Circulation: The Atmosphere Gear Effect","authors":"Jack C. Wang,&nbsp;Jia Yue,&nbsp;Wenbin Wang,&nbsp;Liying Qian","doi":"10.1029/2024GL113414","DOIUrl":"10.1029/2024GL113414","url":null,"abstract":"<p>This study investigates the impact of the lower-thermospheric winter-to-summer circulation on the thermosphere's thermal structure and meridional circulation. Using NCAR TIE-GCM, we compare simulations with and without the lower-thermospheric circulation, finding that its inclusion enhances summer-to-winter thermospheric circulation by 40% in the summer hemisphere but decelerates it in the winter thermosphere. Meanwhile, vertical wind exhibits stronger upward motion poleward of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>±</mo>\u0000 <mn>30</mn>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> $pm 30{}^{circ}$</annotation>\u0000 </semantics></math> latitude above <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>6</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${10}^{-6}$</annotation>\u0000 </semantics></math> hPa (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math>174 km) when lower-thermospheric circulation is incorporated. This dynamic coupling functions as an atmospheric “gear mechanism,” accelerating momentum and energy transfer to higher altitudes. Including lower-thermospheric circulation improves agreement between the nudged run and NRLMSIS 2.1 in intra-annual variability (IAV) of mass density. This suggests lower-thermospheric circulation is a key factor in modulating IAV in the coupled thermosphere-ionosphere system. This study reveals a new coupling mechanism between the lower atmosphere, thermosphere, and ionosphere, with significant implications for understanding upper-atmospheric dynamics and improving space weather models.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113414","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144087944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Near-Term Future Sea-Level Projections Supported by Extrapolation of Tide-Gauge Observations","authors":"Jinping Wang,&nbsp;Xuebin Zhang,&nbsp;John A. Church,&nbsp;Matt King,&nbsp;Xianyao Chen","doi":"10.1029/2024GL112940","DOIUrl":"10.1029/2024GL112940","url":null,"abstract":"<p>Global, regional and local sea-level projections rely on complex process-based models of the climate-ocean-cryosphere system. While extrapolation of observational data has been examined on global and regional scales, this approach has not yet been used for the additional complexities of coastal sea-level projections. Here, we evaluate the sea-level trend and acceleration for a global network of 222 tide-gauge observations over 1970–2023, which are then extrapolated to provide local projections up to 2050 and compared with the process-based projections from the Intergovernmental Panel on Climate Change Sixth Assessment Report (AR6). For 2050 relative to 2020, the observation-based and medium-confidence AR6 projections agree within the <i>likely</i> range at 96% of tide-gauge locations. Despite larger spatial variability, the observation-based projections are usually well below the low-likelihood, high-impact AR6 projections. The observation-based projections provide complementary perspectives of near-term local sea-level changes, and this agreement provides increased confidence in the current understanding and projections of sea-level changes over coming decades.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL112940","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Importance of Learning Non-Local Dynamics for Stable Data-Driven Climate Modeling: A 1D Gravity Wave-QBO Testbed","authors":"Hamid A. Pahlavan,&nbsp;Pedram Hassanzadeh,&nbsp;M. Joan Alexander","doi":"10.1029/2024GL114136","DOIUrl":"10.1029/2024GL114136","url":null,"abstract":"<p>Model instability remains a core challenge for data-driven parameterizations, especially those developed with supervised algorithms, and rigorous methods to address it are lacking. Here, by integrating machine learning (ML) theory with climate physics, we demonstrate the importance of learning spatially <i>non-local</i> dynamics using a 1D quasi-biennial oscillation model with parameterized gravity waves (GW) as a testbed. While common offline metrics fail to identify shortcomings in learning non-local dynamics, we show that the receptive field (RF) can identify instability a-priori. We find that neural network-based parameterizations, though predicting GW forcings from wind profiles with 99% accuracy, lead to unstable simulations when RFs are too small to capture non-local dynamics. Additionally, we demonstrate that learning non-local dynamics is crucial for the stability of a data-driven spatiotemporal <i>emulator</i> of the zonal wind field. This work underscores the need to integrate ML theory with physics in designing data-driven algorithms for climate modeling.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL114136","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Downstream Hydrology Reduces Glaciers' Direct Contribution to Sea-Level Rise","authors":"David R. Rounce,&nbsp;Regine Hock,&nbsp;Alexander A. Prusevich,&nbsp;Danielle S. Grogan,&nbsp;Richard B. Lammers,&nbsp;Matthias Huss,&nbsp;Andrew Bliss,&nbsp;Botao Zan","doi":"10.1029/2025GL114866","DOIUrl":"10.1029/2025GL114866","url":null,"abstract":"<p>Glacier mass loss is a primary contributor to sea-level rise. All prior assessments assume all glacial melt water reaches the ocean, but many mountain glaciers are located far from oceans and may be affected by the downstream systems. Here we track future glacier runoff through the hydrological system and estimate ∼95% directly reaches the ocean through the river systems for all emissions scenarios, while the remaining 5% is lost (consumed) via evapotranspiration or stored on land. Endorheic basins in High Mountain Asia account for 76%–82% of the glacier runoff that does not directly reach the ocean. The remaining 18%–24% is lost or stored in exorheic basins, including those with considerable anthropogenic water use like the Indus and Ganges. While the percentage of glacier runoff reaching the ocean differs between basins, the percentages are roughly constant over time for most basins.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL114866","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of Super Atmospheric Rivers Associated With Explosive Extratropical Cyclones Over the Northern Pacific Ocean","authors":"Y.-M. Peng,&nbsp;G. Fu,&nbsp;P.-Y. Li,&nbsp;J. Ni","doi":"10.1029/2025GL114654","DOIUrl":"10.1029/2025GL114654","url":null,"abstract":"<p>Atmospheric Rivers (ARs) are elongated, narrow corridors of concentrated moisture in the atmosphere, transporting significant amounts of water vapor outside the tropics and causing heavy precipitation. ARs are often accompanied with explosive extratropical cyclones (EECs) over oceans. This paper investigates the characteristics of 118 super ARs associated with EECs over the Northern Pacific Ocean. Nearly 78.0% of ARs are associated with strong or super EECs, indicating that stronger ARs may lead to more explosive development of EECs. The composite analyses of ARs suggest that the AR is typically located in southwest of the cyclone center, in front of the cold front, with mean value of AR top pressure of approximately 693.51 hPa. In addition, water vapor from low latitudes and that evaporating from the sea surface are two important water vapor sources for ARs. Through investigating the evolution of EECs, a mechanism strengthens ARs and EECs.</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GL114654","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Where Snow and Forest Meet: A Global Atlas","authors":"C. Deschamps-Berger,&nbsp;J. I. López-Moreno,&nbsp;S. Gascoin,&nbsp;G. Mazzotti,&nbsp;A. Boone","doi":"10.1029/2024GL113684","DOIUrl":"10.1029/2024GL113684","url":null,"abstract":"<p>The complex interactions between snow cover and forests have implications for ecosystems, water resources and the Earth's climate. However, the geographic distribution of where snow and forest overlap remains poorly known. Here, we evaluate the importance of snowfall over forested environments and its spatial variability at the global scale and a 0.1° spatial resolution, leveraging an existing climatological reanalysis and a satellite tree cover map. We find that 23% of the land mass (30.5·10⁶ km²) experiences snowfall in forested areas, mostly in the boreal forest (15.8·10⁶ km²) and elsewhere in mountains (4.9·10⁶ km²). There, the solid fraction of precipitation in forest is greater than the median value of 11.1% over 15.3·10⁶ km², reaches 64% locally, and 23% when aggregated over hydrological basins larger than 10⁵ km².</p>","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"52 10","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GL113684","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}