Earth and Space Science最新文献_第4页

Development and Analysis of a Global Refractive Index of Water Data Layer for Spaceborne and Airborne Bathymetric Lidar

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-03-02 DOI: 10.1029/2024EA004106

James T. Dietrich, Christopher E. Parrish

{"title":"Development and Analysis of a Global Refractive Index of Water Data Layer for Spaceborne and Airborne Bathymetric Lidar","authors":"James T. Dietrich, Christopher E. Parrish","doi":"10.1029/2024EA004106","DOIUrl":"https://doi.org/10.1029/2024EA004106","url":null,"abstract":"After over a half-century of development, bathymetric lidar is a mature and widely used technology for mapping the littoral zone in support of nautical charting, benthic habitat assessment, inundation modeling and other applications. In 2018, bathymetric lidar transitioned from a purely airborne technology to also a spaceborne capability with the launch of NASA's ICESat-2 satellite. An important aspect of obtaining accurate seafloor elevations and horizontal coordinates in bathymetric lidar is refraction correction, which corrects for the change in the speed and direction of the laser at the air-water interface. Unfortunately, data on the refractive index of seawater needed for correction are largely lacking, especially over global extents, which are required for ICESat-2 bathymetry. This study developed and evaluated a new global refractive index of water data layer. A two-phased sensitivity analysis was conducted to investigate how systematic and random uncertainties in the refractive index layers impact bathymetric lidar uncertainty. We then developed the global refractive index of water layer using global marine data sets and evaluated it using a combination of Argo Float data and in situ refractometer measurements. The results provide a strong indication of the usefulness of the global refractive index layer, which is currently being implanted into the workflow for generating a new ICESat-2 bathymetric data set (ATL24). To benefit other studies, the global refractive index layer is publicly available. Future improvements are possible, leveraging crowd-sourced data collection to continually improve the spatial resolution and nearshore accuracy of the refractive index data set.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA004106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530137","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}

引用次数: 0

Ground-Based Monitoring of Stratospheric Ozone and Temperature Over Germany Since the 1960s

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-03-01 DOI: 10.1029/2024EA003821

W. Steinbrecht, V. A. Velazco, R. Dirksen, L. Doppler, P. Oelsner, R. Van Malderen, H. De Backer, E. Maillard Barras, R. Stübi, S. Godin-Beekmann, A. Hauchecorne

{"title":"Ground-Based Monitoring of Stratospheric Ozone and Temperature Over Germany Since the 1960s","authors":"W. Steinbrecht, V. A. Velazco, R. Dirksen, L. Doppler, P. Oelsner, R. Van Malderen, H. De Backer, E. Maillard Barras, R. Stübi, S. Godin-Beekmann, A. Hauchecorne","doi":"10.1029/2024EA003821","DOIUrl":"https://doi.org/10.1029/2024EA003821","url":null,"abstract":"Routine ground-based measurements of total ozone column (TOC), as well as ozone profile soundings started in the late 1960s in Germany. The resulting ozone and temperature records at Hohenpeissenberg and Berlin/Potsdam/Lindenberg show long-term changes similar to other stations in Central Europe, and to the changes seen globally. Following the increase of ozone depleting substances (ODS), stratospheric ozone has declined from the 1960s until the 1990s. Since about 2000, ozone has leveled or slightly increased, consistent with declining amounts of ODS. The stratosphere has been cooling and the troposphere has been warming, in agreement with general expectations due to increasing greenhouse gas concentrations. The clearest signs of recovering ozone are seen around 40 km altitude. Two factors contribute to this increase: the decrease of stratospheric chlorine loading and cooling of the upper stratosphere, which slows gas-phase ozone destruction cycles, and enhances the ter-molecular reaction producing ozone. Tropospheric ozone has increased substantially from the 1960s to the early 1990s. Since then, it has remained more or less constant, on a level higher compared to the 1960 and 1970s. Particularly low tropospheric ozone was observed in 2020, due to reduced precursor emissions during the COVID-19 related lockdowns. The atmospheric concentrations of greenhouse gases will likely continue to rise, while the concentrations of ozone depleting substances are expected to slowly decline. To see how the atmosphere responds, and to help understand future changes, continued monitoring will be required for many years to come, both over Germany and worldwide.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003821","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521936","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}

引用次数: 0

An Instrument Concept for High-Resolution Observations of the Solar Wind Electron Strahl Using Coded Aperture Imaging

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-02-26 DOI: 10.1029/2024EA003814

Riley A. Reid, Robert Marshall

{"title":"An Instrument Concept for High-Resolution Observations of the Solar Wind Electron Strahl Using Coded Aperture Imaging","authors":"Riley A. Reid, Robert Marshall","doi":"10.1029/2024EA003814","DOIUrl":"https://doi.org/10.1029/2024EA003814","url":null,"abstract":"In this concept study, we explore coded aperture imaging as a high-angular resolution imaging technique for suprathermal electron strahl observations in the solar wind. In particular, studying the relative contribution of pitch-angle scattering to solar wind strahl broadening near 1 AU requires very high-resolution observations of electron pitch angle. Coded aperture imaging is advantageous because it is a high-signal method that can provide high-angular resolution observations from a simple, and compact platform. In this study, we present an initial design concept to achieve a 40<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${}^{circ}$</annotation>\u0000 </semantics></math> field-of-view with 3.1<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${}^{circ}$</annotation>\u0000 </semantics></math> angular resolution from a CubeSat-sized platform. We include an “egg-crate” collimator design to mitigate the impact of the partially coded field-of-view as well as block solar photons. We also describe an estimate of the instrument data production and a possible CMOS candidate for low energy energetic particle detection. Finally, we present initial results of simulated strahl in Geant4 and the instrument response to these distributions. We find that reconstructed distributions can have accurate estimates of the strahl width. However, we find that especially for more broad strahl observations, coded aperture artifacts diminish the reconstruction quality and result in large deviations between input and output distributions. Possible options to improve accuracy include increasing integration time or reducing energy resolution.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003814","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497128","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}

引用次数: 0

Advances on the Links Between Turbulent and Submeso- to Mesoscales During EUREC4A

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-02-25 DOI: 10.1029/2024EA003865

E. Gauvrit, M.-N. Bouin, J.-M. Delouis, F. Boulanger

{"title":"Advances on the Links Between Turbulent and Submeso- to Mesoscales During EUREC4A","authors":"E. Gauvrit, M.-N. Bouin, J.-M. Delouis, F. Boulanger","doi":"10.1029/2024EA003865","DOIUrl":"https://doi.org/10.1029/2024EA003865","url":null,"abstract":"Turbulent processes in the atmospheric boundary layer (ABL) are parameterized in numerical weather prediction and climate models. Better understanding their modulation by larger-scale organized structures, some of them being represented explicitly, is thus of great interest. In this study, we test an innovative statistical tool, the Wavelet Scattering Transform (WST) on turbulent measurements of 3D velocities at different levels in the ABL during the <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mtext>EUREC</mtext>\u0000 <mn>4</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${text{EUREC}}^{4}$</annotation>\u0000 </semantics></math>A campaign near Barbados. The measurements were done in trade wind environment over the sea. They encompass two categories of ABL convection, roll vortices (RV) or convective cells (CC) whose organization depends on cold pool and density currents. Statistical tools such as Fourier transforms or moment analysis give access to levels of energy, characteristic sizes and variances in CC and RV conditions. The WST provides further information, with strong modulations of the turbulent scales by submeso- to mesoscales in CC, whereas modulating scales are smaller than the horizontal scale of rolls in RV. Penetrating dry tongues from the ABL top are revealed by modulation scales varying with height. In RV conditions, modulations differ in cross-wind and along-wind observations confirming that along-wind measurements do not provide good sampling of the ABL turbulence. WST are a valuable tool for investigating ABL turbulence and its interactions with coherent structures, and could be used on scalar variables and surface fluxes.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003865","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481368","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}

引用次数: 0

Diurnal Variations of Below-Canopy CO2 Concentration in a Subtropical Forested Valley

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-02-23 DOI: 10.1029/2024EA003864

Shizuo Fu, Yang Wang, Guofang Miao, Rong Wang, Hongda Zeng, Bai Yang, Jing M. Chen

{"title":"Diurnal Variations of Below-Canopy CO2 Concentration in a Subtropical Forested Valley","authors":"Shizuo Fu, Yang Wang, Guofang Miao, Rong Wang, Hongda Zeng, Bai Yang, Jing M. Chen","doi":"10.1029/2024EA003864","DOIUrl":"https://doi.org/10.1029/2024EA003864","url":null,"abstract":"CO2 concentration was continuously measured at four levels in the below-canopy layer of a subtropical evergreen broadleaf forest in Southeast China. The below-canopy CO2 concentration was higher during the day than at night at all levels, in contrast to many previous studies. The amplitude of the diurnal variation of the below-canopy CO2 concentration was controlled by the daily-mean air or soil temperature. In the daytime, solar radiation heated the canopy layer more than the below-canopy layer, so the below-canopy layer became stable. Large vertical gradients of CO2 concentration therefore developed near the ground surface. CO2 concentration increased with stability when the stability was weak, because the increased stability suppressed the vertical turbulent mixing. On the contrary, CO2 concentration decreased with stability when the stability was strong, because the strong stability was maintained by intense solar radiation, which enhanced photosynthesis. In the nighttime, radiative cooling of the canopy layer caused the below-canopy layer to be near-neutral or unstable. CO2 concentration was therefore generally low and exhibited rather small vertical gradients. Nighttime CO2 concentration slightly increased when the stability became stronger. It was frequently observed that CO2 concentration rapidly decreased around the sunset from the peak value to a low value. Our results suggest that the storage term is important in the daytime eddy-covariance measurements, and the CO2 concentration above the canopy should be corrected in order to represent the CO2 concentration below the canopy.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003864","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475735","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}

引用次数: 0

Modeling Reservoir-Induced Seismicity: A Dynamic Poro-Visco-Elasto-Plastic Earthquake Simulator With Spontaneous Dilatant Coseismic Rupture

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-02-20 DOI: 10.1029/2024EA004029

Regina Katsman, Zvi Ben-Avraham

{"title":"Modeling Reservoir-Induced Seismicity: A Dynamic Poro-Visco-Elasto-Plastic Earthquake Simulator With Spontaneous Dilatant Coseismic Rupture","authors":"Regina Katsman, Zvi Ben-Avraham","doi":"10.1029/2024EA004029","DOIUrl":"https://doi.org/10.1029/2024EA004029","url":null,"abstract":"Compared to other kinds of fluid-related seismicity, reservoir-induced seismicity (RIS) is usually characterized by higher magnitudes. Seismic and water level monitoring and statistical modeling, however, do not provide comprehensive understanding of the RIS mechanism and controls. This study presents a novel finite element method-based 2D poro-visco-elasto-plastic fully dynamic earthquake model, specifically applicable to RIS simulations. A dynamic coseismic rupture phase driven by wave-mediated stress transfers coupled with rate-and-state dependent friction coefficient weakening is modeled, along with interseismic deformations. Coseismic crack opening in a dilatant regime, inducing porosity and permeability hikes, is implemented. The adaptive time stepping resolves the contrasting time scales of coseismic rupturing and quasi-static interseismic deformations, without having to switch the modeling strategy, thereby enabling the modeling of a large number of seismic cycles. The model component verifications demonstrate convincing agreement with theoretical predictions. In the first stage of the simulations, Drucker-Prager plasticity is used to generate a normal fault with enhanced porosity in the Earth's upper crust, over a long time-scale of millions of years. In the second stage of the simulations, RIS is modeled under typical reservoir impoundment dynamics, producing four seismic sequences, triggered by pore pressure increase at the fault at shallow depth below the reservoir. This pressurization is released by aftershocks in every seismic cluster, accompanied by permeability hikes and associated with fault “valving” behavior. The model allows investigation of spatio-temporal RIS characteristics and their controls. It may contribute to earthquake prediction in situ and facilitate earthquake mitigation policies.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA004029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143447199","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}

引用次数: 0

A Modeling Study of the Topographic Effects on Shallow Convective Clouds

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-02-20 DOI: 10.1029/2024EA003867

Mingxin Gong, Shizuo Fu, Jane Liu, Xin Deng

{"title":"A Modeling Study of the Topographic Effects on Shallow Convective Clouds","authors":"Mingxin Gong, Shizuo Fu, Jane Liu, Xin Deng","doi":"10.1029/2024EA003867","DOIUrl":"https://doi.org/10.1029/2024EA003867","url":null,"abstract":"Shallow convective clouds (SCCs) play important roles in the Earth system. Previous studies mostly focus on SCCs over the oceans or plains. It is unclear how topography affects SCCs. In this study, the impacts of isolated ridges on the development of SCCs are investigated using large-eddy simulations, where the maximum height and the half-width of the ridge are systematically varied. In all simulations, the potential temperature over the ridge top is higher than over the plain, and the difference increases with the volume of the ridge. Upslope winds are only produced in simulations where the maximum slope angle is >0.5°. The vapor transport by upslope winds tends to increase the humidity over the ridge top. On the contrary, the dry air entrained from above the convective boundary layer tends to decrease the humidity over the ridge top. The upslope winds from the two sides of the ridge collide near the ridge top. This produces wide updrafts, and thereby facilitates the development of SCCs. As the ridge geometry varies, the variation of the depth of SCCs is collectively determined by the variations of the temperature, humidity, and updrafts. The depth of the SCCs increases with the maximum height of the ridge. It also increases as the half-width increases from 2 to 8 km, but only slightly changes as the half-width further increases to 16 km. The results of this study can potentially be used to implement the topographic effects in the parameterizations of SCCs.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003867","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455965","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}

引用次数: 0

Effects of Cloud Cover on Surface Sublimation at 4,817 m a.s.l. on the Flat-Top August-One Glacier of the Northern Tibetan Plateau

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-02-19 DOI: 10.1029/2024EA003778

Shuhai Guo, Yueping Li, Rensheng Chen, Chuntan Han

{"title":"Effects of Cloud Cover on Surface Sublimation at 4,817 m a.s.l. on the Flat-Top August-One Glacier of the Northern Tibetan Plateau","authors":"Shuhai Guo, Yueping Li, Rensheng Chen, Chuntan Han","doi":"10.1029/2024EA003778","DOIUrl":"https://doi.org/10.1029/2024EA003778","url":null,"abstract":"As a crucial role in earth's energy budget, cloud cover exerts great effects on climate change. Although existing sublimation studies across High Mountain Asia (HMA) glaciers have identified the importance of cloud cover in limiting sublimation, the primary/main factors limiting sublimation under high cloud cover conditions are unknown. Based on the 5-year meteorological observation at the top of August-one glacier in the northern Tibetan Plateau (TP), we analyzed the role of cloud cover on meteorological variables and sublimation. The cloud cover over this glacier was found to have distinct effects on the primary meteorological variables, causing the generally negative and positive temperature gradients in clear-sky and overcast conditions, respectively. Additionally, the increase in cloud cover is associated with decreased near-surface humidity gradient and wind speed, which is unfavorable for sublimation. Glacier sublimation was limited in overcast conditions, whereas the sublimation rate was about two-and-half times higher in clear-sky conditions. We noted that the specific humidity gradient and wind speed combined as a more important role in determining sublimation based on the multiple linear regression analysis. Overall, on this westerly dominated glacier, the weak sublimation in overcast conditions was primarily associated with the combined effect of significantly higher air moisture and decreased wind speed. These results contribute to a better understanding of the link between near-surface water vapor exchange between glaciers and the atmosphere.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003778","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143447145","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}

引用次数: 0

GOES-R PM2.5 Evaluation and Bias Correction: A Deep Learning Approach

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-02-19 DOI: 10.1029/2024EA004012

Alqamah Sayeed, Pawan Gupta, Barron Henderson, Shobha Kondragunta, Hai Zhang, Yang Liu

{"title":"GOES-R PM2.5 Evaluation and Bias Correction: A Deep Learning Approach","authors":"Alqamah Sayeed, Pawan Gupta, Barron Henderson, Shobha Kondragunta, Hai Zhang, Yang Liu","doi":"10.1029/2024EA004012","DOIUrl":"https://doi.org/10.1029/2024EA004012","url":null,"abstract":"Estimating surface-level fine particulate matter from satellite remote sensing can expand the spatial coverage of ground-based monitors. This approach is particularly effective in assessing rapidly changing air pollution events such as wildland fires that often start far away from centralized ground monitors. We developed Deep Neural Network (DNN) algorithm to improve hourly PM2.5 estimates informed by GOES-R; meteorology forecasts, and PM2.5 observations from AirNow. The surface-satellite-model collocated data sets for the period of 2020–2021 were used to assess the biases in GOES-GWR PM2.5 (only operationally available data set) against AirNow measurements at hourly and daily scales. Then a DNN based bias correction algorithm is used to improve the accuracies of GOES-GWR PM2.5. The DNN uses GOES-GWR PM2.5, GOES-R aerosol parameters, and HRRR meteorological fields as input and AirNow PM2.5 is used as target variable. The application of DNN reduced the PM2.5 biases as compared to GOES-GWR estimates. RMSE was also reduced to 6.55 μg/m3 from 8.72 μg/m3 in GOES-GWR estimates. The DNN model was also evaluated on two sets of independent data sets for its robustness. In the first independent data set for the first half of 2020, ∼89% of stations show an increase in correlation (r) and, ∼76% and ∼62% of stations show a reduction in bias. The IOA and r for the independent data were 0.77 and 0.61 (GWR: 0.68 and 0.53) and RMSE was 4.48 μg/m3 (GWR = 6.13 μg/m3) for the same period. The algorithm will be operationally deployed by NOAA and US-EPA to estimate surface level PM2.5 from satellite derived Aerosol optical depth.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA004012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439197","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}

引用次数: 0

PyReX: A Recursion Based Crossover Detection Algorithm in Python for Along-Track Geophysical Measurements

IF 2.9 3区地球科学

Earth and Space Science Pub Date : 2025-02-17 DOI: 10.1029/2024EA003932

K. V. N. G. Vikram, D. V. P. Krishna, K. M. Sreejith

{"title":"PyReX: A Recursion Based Crossover Detection Algorithm in Python for Along-Track Geophysical Measurements","authors":"K. V. N. G. Vikram, D. V. P. Krishna, K. M. Sreejith","doi":"10.1029/2024EA003932","DOIUrl":"https://doi.org/10.1029/2024EA003932","url":null,"abstract":"A crossover point is the location of intersection of any two ground tracks charted by multiple platforms (ships, satellite radar and laser altimeters etc.). Detection of crossovers is of prime importance to estimate the discrepancies in the geophysical measurements at the crossover points. Usual approach of crossover detection considers consecutive data points in tracks as segments and checks for intersections between all combinations of these segments. We present a Recursion based crossover detection algorithm in Python (PyReX) for rapid detection of crossovers by avoiding redundant intersection checks. We test the performance of this algorithm using along-track sea surface height measurements from satellite altimeters. We observe that the time taken for flagging a crossover between pair of tracks with N segments each varies as <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>log</mi>\u0000 <mspace></mspace>\u0000 <mi>N</mi>\u0000 </mrow>\u0000 <annotation> $log ,N$</annotation>\u0000 </semantics></math> vis-a-vis the <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>N</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${N}^{2}$</annotation>\u0000 </semantics></math> dependency associated with the traditional methods. We further demonstrate that PyReX significantly improves the computation speed for high frequency along-track measurements from satellite altimeters and ship-borne gravity data compared to existing algorithms. PyReX is a flexible, open-source code that could be easily customized for variety of applications involving large-scale track-line data sets.","PeriodicalId":54286,"journal":{"name":"Earth and Space Science","volume":"12 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024EA003932","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423615","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}

引用次数: 0