Earth and Space Science最新文献

{"title":"Prospects of Predicting the Polar Motion Based on the Results of the Second Earth Orientation Parameters Prediction Comparison Campaign","authors":"Tomasz Kur,&nbsp;Justyna Śliwińska-Bronowicz,&nbsp;Malgorzata Wińska,&nbsp;Henryk Dobslaw,&nbsp;Jolanta Nastula,&nbsp;Aleksander Partyka,&nbsp;Santiago Belda,&nbsp;Christian Bizouard,&nbsp;Dale Boggs,&nbsp;Sara Bruni,&nbsp;Lue Chen,&nbsp;Mike Chin,&nbsp;Sujata Dhar,&nbsp;Robert Dill,&nbsp;PengShuo Duan,&nbsp;Jose M. Ferrandiz,&nbsp;Junyang Gou,&nbsp;Richard Gross,&nbsp;Sonia Guessoum,&nbsp;Songtao Han,&nbsp;Robert Heinkelmann,&nbsp;ChengLi Huang,&nbsp;Christopher Irrgang,&nbsp;Jacek Kudrys,&nbsp;Jia Li,&nbsp;Marcin Ligas,&nbsp;Lintao Liu,&nbsp;Weitao Lu,&nbsp;Volker Mayer,&nbsp;Wei Miao,&nbsp;Maciej Michalczak,&nbsp;Sadegh Modiri,&nbsp;Michiel Otten,&nbsp;Todd Ratcliff,&nbsp;Shrishail Raut,&nbsp;Jan Saynisch-Wagner,&nbsp;Matthias Schartner,&nbsp;Erik Schoenemann,&nbsp;Harald Schuh,&nbsp;M. Kiani Shahvandi,&nbsp;Benedikt Soja,&nbsp;Xiaoqing Su,&nbsp;Daniela Thaller,&nbsp;Maik Thomas,&nbsp;Guocheng Wang,&nbsp;Yuanwei Wu,&nbsp;CanCan Xu,&nbsp;Xueqing Xu,&nbsp;Xinyu Yang,&nbsp;Xin Zhao,&nbsp;Zhijin Zhou","doi":"10.1029/2023EA003278","DOIUrl":"https://doi.org/10.1029/2023EA003278","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Growing interest in Earth Orientation Parameters (EOP) resulted in various approaches to the EOP prediction algorithms, as well as in the exploitation of distinct input data, including the observed EOP values from various operational data centers and modeled effective angular momentum functions. Considering these developments and recently emerged new methodologies, the Second Earth Orientation Parameters Prediction Comparison Campaign (2nd EOP PCC) was pursued in 2021–2022. The campaign was led by Centrum Badań Kosmicznych Polskiej Akademii Nauk in cooperation with Deutsches GeoForschungsZentrum and under the auspices of the International Earth Rotation and Reference Systems Service. This paper provides the analysis and evaluation of the polar motion predictions submitted during the 2nd EOP PCC with the prediction horizons between 10 and 30 days. Our analysis shows that predictions are highly reliable with only a few occasional discrepancies identified in the submitted files. We demonstrate the accuracy of EOP predictions by (a) calculating the mean absolute error relative to polar motion observations from September 2021 through December 2022 and (b) assessing the stability of the predictions in time. The analysis shows unequal results for the <i>x</i> and <i>y</i> components of polar motion (PMx and PMy, respectively). Predictions of PMy are usually more accurate and have a smaller spread across all submitted files when compared to PMx. We present an analysis of similarity between the participants to indicate what methods and input data give comparable output. We also prepared the ranking of prediction methods for polar motion summarizing the achievements of the campaign.</p>\u0000 </section>\u0000 </div>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023EA003278","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142588021","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 Model of SSUSI-Derived Auroral Ionization Rates","authors":"Stefan Bender,&nbsp;Patrick J. Espy,&nbsp;Larry J. Paxton","doi":"10.1029/2024EA003578","DOIUrl":"https://doi.org/10.1029/2024EA003578","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>We present an empirical model for auroral (90–150 km) electron–ion pair production rates, ionization rates for short, derived from Special Sensor Ultraviolet Spectrographic Imager electron energy and flux data. Using the Fang et al. (2010, https://doi.org/10.1029/2010gl045406) parametrization for mono-energetic electrons, and the NRLMSISE-00 neutral atmosphere model (Picone et al., 2002, https://doi.org/10.1029/2002ja009430), the calculated ionization rate profiles are binned in 2-hr magnetic local time and 3.6°geomagnetic latitude to yield time series of ionization rates at 5-km altitude steps. We fit each of these time series to the geomagnetic indices Kp, PC, and Ap, the 81-day averaged solar <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>F</mi>\u0000 <mn>10.7</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{F}}_{10.7}$</annotation>\u0000 </semantics></math> radio flux index, and a constant term. The resulting empirical model can easily be incorporated into coupled chemistry–climate models to include particle precipitation effects.</p>\u0000 </section>\u0000 </div>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003578","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579766","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":"Low-Frequency Reconstruction for Full Waveform Inversion by Unsupervised Learning","authors":"Ningcheng Ciu,&nbsp;Tao Lei,&nbsp;Wei Zhang","doi":"10.1029/2024EA003565","DOIUrl":"https://doi.org/10.1029/2024EA003565","url":null,"abstract":"<p>Obtaining reliable low-frequency seismic data is crucial for effectively reducing cycle-skipping in full waveform inversion. However, acquiring high signal-to-noise ratio low-frequency information from field data remains a challenge. An effective solution to mitigate cycle-skipping is to utilize low-frequency information synthesized by neural networks to obtain low-wavenumber initial models. Previous attempts to reconstruct synthetic low-frequency data using supervised learning methods have shown feasibility but were limited to training with synthetic data that required labeled information. In this study, we employed an unsupervised learning method, namely cycle-consistent adversarial networks (CycleGAN), to reconstruct large-scale-feature related low-frequency information based on the high-frequency input data. Unlike supervised learning, CycleGAN allows the use of field data as input to train the network, which is more closely aligned with practical applications. Nevertheless, this approach presents challenges in terms of training complexity and potential output stability. To overcome these challenges, we reconstructed an appropriate target data set that combines high, medium, and low-frequency components and incorporated additional loss functions to enhance the network's output performance. We conducted quantitative evaluations of the method's sensitivity to the target data set and its ability to handle low-quality input data through numerical testing. The final results from field data testing confirmed the feasibility and effectiveness of the proposed method.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003565","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579767","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":"Reconstruction of Nearshore Surface Gravity Wave Heights From Distributed Acoustic Sensing Data","authors":"Samuel Meulé,&nbsp;Julián Pelaez-Quiñones,&nbsp;Frédéric Bouchette,&nbsp;Anthony Sladen,&nbsp;Aurélien Ponte,&nbsp;Annika Maier,&nbsp;Itzhak Lior,&nbsp;Paschal Coyle","doi":"10.1029/2024EA003589","DOIUrl":"https://doi.org/10.1029/2024EA003589","url":null,"abstract":"<p>Distributed Acoustic Sensing (DAS) is a photonics technology converting seafloor telecommunications and optical fiber cables into dense arrays of strain sensors, allowing to monitor various oceanic physical processes. Yet, several applications are hindered by the limited knowledge of the transfer function between geophysical variables and DAS measurements. This study investigates the quantitative relationship between surface gravity DAS-recorded wave-generated strain signals along the seafloor and the pressure at a colocated sensor. A remarkable linear correlation is found over various sea conditions allowing us to reliably determine significant wave heights from DAS data. Utilizing linear wave potential theory, we derive an analytical transfer function linking cable deformation and wave kinematic parameters. This transfer function provides a first quantification of the effects related to surface gravity waves and fiber responses. Our results validate DAS's potential for real-time reconstruction of the surface gravity wave spectrum over extended coastal areas. It also enables the estimation of waves hydraulic parameters at depth without the need from offshore deployments.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003589","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561569","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":"The Self-Calibrating Tilt Accelerometer: A Method for Observing Tilt and Correcting Drift With a Triaxial Accelerometer","authors":"E. K. Fredrickson,&nbsp;W. S. D. Wilcock,&nbsp;M. J. Harrington,&nbsp;G. Cram,&nbsp;J. Tilley,&nbsp;D. Martin,&nbsp;J. Burnett","doi":"10.1029/2024EA003909","DOIUrl":"https://doi.org/10.1029/2024EA003909","url":null,"abstract":"<p>We present observations from two field deployments of a calibrated tiltmeter that we name the Self-Calibrating Tilt Accelerometer (SCTA). The tiltmeter is based upon a triaxial quartz crystal accelerometer; the horizontal channels measure tilt and are periodically rotated into the vertical to obtain a measurement of the acceleration of gravity. Changes in the measured total acceleration are ascribed to drift in the vertical channel and used as calibrations for removing that same drift from the tilt time series observed between calibrations. Changes in the span (sensitivity) of the accelerometer channels can also be measured by calibrating them pointing up and down. A 3-year test on the seafloor at Axial Seamount show that the calibrations are consistent with a linear-exponential model of drift to a RMS residual of ∼0.5 μg (μrad). The calibrated tilt time series was impacted by platform settling for the first 2 years, but after repositioning the tiltmeter, the calibrated observations were consistent for the final year with the tilt observed on a nearby LILY tiltmeter, within an assumed level of drift for the unconstrained LILY sensor. A separate 15-month test in a stable vault at Piñon Flat Observatory was complicated by seasonal temperature variations of &gt;5°C; the calibrations are consistent with a linear-exponential model of drift to ∼2 μg RMS when temperature and temperature time-derivative dependence is included. Similarly, the calibrated tilt time series was impacted by thermal deformation of the SCTA assembly. A future test in a thermally and tectonically stable borehole will be required to assess the accuracy of the SCTA.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003909","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561605","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 Rare Tropical Cyclone Associated With Southwest Monsoon Over the Northern Part of the South China Sea—Tropical Storm Maliksi","authors":"J. Y. He,&nbsp;P. W. Chan,&nbsp;C. W. Choy,&nbsp;P. Cheung,&nbsp;C. C. Lam,&nbsp;Y. H. He,&nbsp;C. K. Pan,&nbsp;K. K. Lai,&nbsp;H. Su,&nbsp;E. Z. Zhang,&nbsp;C. J. Sun,&nbsp;C. J. Huang","doi":"10.1029/2024EA003826","DOIUrl":"https://doi.org/10.1029/2024EA003826","url":null,"abstract":"<p>This study examines the characteristics and development of Tropical Storm Maliksi, which is a special case of tropical cyclone developed in the northwestern part of the South China Sea during a southwest monsoon outbreak. Detailed analyses were conducted using observational data and forecast products. Surface observations, radar wind profilers, aircraft data, and satellite products were used to evaluate Maliksi's wind structure, revealing multiple circulation centers and gale force winds. Vertical wind profiles, warm core structure, wind waves, and the influence of sea temperatures and salinity on Maliksi's intensification were investigated. Regarding forecasting, AI-based models outperformed conventional numerical weather prediction (NWP) models in predicting Maliksi's initial development, though both struggled to capture the persistence of strong winds as the system moved inland. High-resolution NWP simulations were employed to examine terrain-induced wind variability around Hong Kong International Airport, revealing the mountain wake effect and uneven wind and turbulence distribution. These findings provide insights into the challenges of forecasting and monitoring such tropical cyclones, and highlight the need for enhanced observational platforms and forecasting tools along coastlines vulnerable to these systems.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003826","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555480","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":"Improving Interpolating Accuracy of Weighted Mean Temperature by Using a Novel Lapse Rate Model in Compact VMF1 Product","authors":"Peng Sun,&nbsp;Kefei Zhang,&nbsp;Dantong Zhu,&nbsp;Moufeng Wan,&nbsp;Ren Wang,&nbsp;Suqin Wu","doi":"10.1029/2024EA003702","DOIUrl":"https://doi.org/10.1029/2024EA003702","url":null,"abstract":"<p>In GNSS (Global Navigation Satellite Systems) meteorology, the accuracy of precipitable water vapor (PWV) retrieved from the tropospheric delay of GNSS signals is affected by the conversion factor. Compact VMF1 product (known as GGOS Atmosphere data) provides high-accuracy global grid-wise weighted mean temperature (<i>T</i>_<i>m</i>) values, which can be utilized to calculate the conversion factor. However, the <i>T</i>_<i>m</i> provided in the compact VMF1 data are solely ground surface values. To enhance the performance of compact VMF1 product, a new <i>T</i>_<i>m</i> lapse rate model for each grid point was developed for the purpose of reducing its surface <i>T</i>_<i>m</i> to the elevation of the GNSS site. Then the reduced <i>T</i>_<i>m</i> values over the neighboring grid points together with horizontal interpolation were used to obtain the interpolated <i>T</i>_<i>m</i> for the GNSS station. The sample data for the development of the new model were the <i>T</i>_<i>m</i> profiles obtained from ERA5 monthly averaged data spanning 2009–2018. To assess the model's performance, global radiosonde data at 504 radiosonde stations spanning 2019–2021 were employed. Results demonstrated that implementing the <i>T</i>_<i>m</i> lapse rate model significantly enhanced the accuracy of interpolating <i>T</i>_<i>m</i> values for GNSS stations with substantial height disparities from adjacent grid points, thereby improving PWV conversion accuracy. This indicates that employing the new <i>T</i>_<i>m</i> lapse rate model to adjust surface <i>T</i>_<i>m</i> data in the compact VMF1 product holds promise for enhancing its utility in GNSS meteorology.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003702","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555481","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 Scalable, Cloud-Based Workflow for Spectrally-Attributed ICESat-2 Bathymetry With Application to Benthic Habitat Mapping Using Deep Learning","authors":"Forrest Corcoran,&nbsp;Christopher E. Parrish,&nbsp;Lori A. Magruder,&nbsp;J. P. Swinski","doi":"10.1029/2024EA003735","DOIUrl":"https://doi.org/10.1029/2024EA003735","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Since the 2018 launch of NASA's ICESat-2 satellite, numerous studies have documented the bathymetric measurement capabilities of the space-based laser altimeter. However, a commonly identified limitation of ICESat-2 bathymetric point clouds is that they lack accompanying spectral reflectance attributes, or even intensity values, which have been found useful for benthic habitat mapping with airborne bathymetric lidar. We present a novel method for extracting bathymetry from ICESat-2 data and automatically adding spectral reflectance values from Sentinel-2 imagery to each detected bathymetric point. This method, which leverages the cloud computing systems Google Earth Engine and NASA's SlideRule Earth, is ideally suited for “big data” projects with ICESat-2 data products. To demonstrate the scalability of our workflow, we collected 3,500 ICESat-2 segments containing approximately 1.4 million spectrally-attributed bathymetric points. We then used this data set to facilitate training of a deep recurrent neural network for classifying benthic habitats at the ICESat-2 photon level. We trained two identical models, one with and one without the spectral attributes, to investigate the benefits of fusing ICESat-2 photons with Sentinel-2. The results show an improvement in model performance of 18 percentage points, based on F1 score. The procedures and source code are publicly available and will enhance the value of the new ICESat-2 bathymetry data product, ATL24, which is scheduled for release in Fall 2024. These procedures may also be applicable to data from NASA's upcoming CASALS mission.</p>\u0000 </section>\u0000 </div>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003735","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540826","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":"Illuminating the Hierarchical Segmentation of Faults Through an Unsupervised Learning Approach Applied to Clouds of Earthquake Hypocenters","authors":"E. Piegari,&nbsp;G. Camanni,&nbsp;M. Mercurio,&nbsp;W. Marzocchi","doi":"10.1029/2023EA003267","DOIUrl":"https://doi.org/10.1029/2023EA003267","url":null,"abstract":"<p>We propose a workflow for the recognition of the hierarchical segmentation of faults through earthquake hypocenter clustering without prior information. Our approach combines density-based clustering algorithms (DBSCAN and OPTICS), and principal component analysis (PCA). Given a spatial distribution of earthquake hypocenters, DBSCAN identifies first-order clusters, representing regions with the highest density of connected seismic events. Within each first-order cluster, OPTICS further identifies nested higher-order clusters, providing information on their number and size. PCA analysis is applied to first- and higher-order clusters to evaluate eigenvalues, allowing discrimination between seismicity associated with planar features and distributed seismicity that remains uncategorized. The identified planes are then geometrically characterized in terms of their location and orientation in the space, length, and height. This automated procedure operates within two spatial scales: the largest scale corresponds to the longest pattern of approximately equally dense earthquake clouds, while the smallest scale relates to earthquake location errors. By applying PCA analysis, a planar feature outputted from a first-order cluster can be interpreted as a fault surface while planes outputted after OPTICS can be interpreted as fault segments comprised within the fault surface. The evenness between the orientation of illuminated fault surfaces and fault segments, and that of the nodal planes of earthquake focal mechanisms calculated along the same faults, corroborates this interpretation. Our workflow has been successfully applied to earthquake hypocenter distributions from various seismically active areas (Italy, Taiwan, and California) associated with faults exhibiting diverse kinematics.</p>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023EA003267","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525124","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":"Planetary Wave Signature in Low Latitude Sporadic E Layer Obtained From Multi-Mission Radio Occultation Observations","authors":"S. Sobhkhiz-Miandehi,&nbsp;Y. Yamazaki,&nbsp;C. Arras,&nbsp;Y. Miyoshi,&nbsp;H. Shinagawa,&nbsp;A. P. Jadhav","doi":"10.1029/2024EA003757","DOIUrl":"https://doi.org/10.1029/2024EA003757","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>The Sporadic E layer or Es is an ionospheric phenomenon characterized by enhancements in electron density within 90–120 km above the Earth's surface. Based on the wind shear theory, the formation of Es layers is associated with vertical shears in the horizontal wind, in the presence of the Earth's magnetic field. This study explores the role of planetary waves on inducing these vertical shears and subsequently shaping Es layers. Our investigations benefit from a large amount of data facilitated by the FORMOSAT-7/COSMIC2 and Spire missions, which offer extensive global coverage. A wave analysis is applied to the Es intensity as represented by the S4 index derived from radio occultation measurements, in search of potential planetary wave signatures. Additionally, measurements from Aura/MLS are used to analyze corresponding spectra for the geopotential height, enabling a comparative examination of planetary wave signatures in the Es layer and geopotential height variations. The findings reveal westward and eastward wave components with specific wavenumbers and periods, suggesting the involvement of westward propagating quasi 6-day, quasi 4-day planetary waves, and eastward propagating Kelvin waves with a period of around 3 days in Es layer formation at low latitudes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003757","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525529","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}