Journal of Atmospheric and Solar-Terrestrial Physics最新文献

{"title":"Mapping of flood inundated areas using earth observation data and cloud computing platform","authors":"Mohit Arora ,&nbsp;Raj Setia ,&nbsp;Randhir Singh ,&nbsp;Sudhir Kumar Singh ,&nbsp;Sumit Kumar ,&nbsp;Brijendra Pateriya","doi":"10.1016/j.jastp.2025.106567","DOIUrl":"10.1016/j.jastp.2025.106567","url":null,"abstract":"<div><div>Floods pose a significant threat, not only impacting human lives and property, but also causing extensive damage to critical infrastructure. Rapid flood impact assessment methods require comprehensive, updated and accurate flood maps to deliver the dependable information for effective disaster risk management. In this study, the flood-inundated areas were mapped and monitored in Punjab (India) using dual-polarized (VH and VV) Sentinel-1 (A and B) images of July–August 2023 and the impact of flood on cropped area was assessed using Geographic Information System (GIS). The satellite images were processed in Google Earth Engine (GEE) platform to extract the spatial extent of flood-inundated areas. The flooded areas were validated with limited ground truth. The district wise zonal statistics was derived to find the flood inundated areas. Results showed that the backscattering coefficient (σ0) of the flooded area ranged from −4 to −20 dB for VH polarization and from −4 to −30 dB for VV polarization. These threshold limits were used to extract the flood pixels followed by masking of permanent water bodies. The water extent reached its peak from 11 to July 17, 2023 (first flood period) and again from 14 to August 17, 2023 (Second flood period) in Punjab with 5.52 % of the area inundated during first flood period and 2.65 % of the cropped area inundated during the second flood period. The overall accuracy was 91.7 % with Kappa Coefficient of 0.83 in VV polarization and 86.2 % with Kappa Coefficient of 0.73 in VH polarization. Paddy was mostly inundated by flooding in the areas with lower elevation, high runoff and along the river breeches. These results suggest that spatio-temporal mapping of flood inundation is important for policy makers towards flood risk preparedness, raising awareness, designing the mitigation strategies and implementation of flood management planning to protect nature and human life.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"274 ","pages":"Article 106567"},"PeriodicalIF":1.8,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144297708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Pc5 pulsations and their correlation with solar wind parameters during intense geomagnetic storms","authors":"Sarup Khadka Saurav ,&nbsp;Ashok Silwal ,&nbsp;Sujan Prasad Gautam ,&nbsp;Binod Adhikari ,&nbsp;Monika Karki ,&nbsp;Luciano Aparecido Magrini ,&nbsp;Ezequiel Echer ,&nbsp;Odim Mendes ,&nbsp;Margarete Oliveira Domingues","doi":"10.1016/j.jastp.2025.106534","DOIUrl":"10.1016/j.jastp.2025.106534","url":null,"abstract":"<div><div>This study examines Pc5 ultra-low frequency (ULF) waves and their relationship with solar wind parameters and geomagnetic indices during two extended periods of intense ULF activity on 19 February 2014 and 22–23 June 2015. We analyze observations from ground-based magnetometers and the Operating Missions as Nodes on the Internet (OMNI) dataset, employing continuous wavelet transform (CWT) and cross-correlation as primary statistical tools. Our results reveal that: (1) interplanetary parameters and geomagnetic indices exhibit strong correlations with Pc5 pulsations; (2) the majority of significant Pc5 power is concentrated within the 6–9 min period band. This suggests that low-latitude geomagnetic fluctuations are not locally generated but rather reflect global geomagnetic field variations originating in the magnetosphere and high-latitude ionosphere, consistent with previous findings. While the southward component of the Interplanetary Magnetic Field (IMF) <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>z</mi></mrow></msub></math></span> is often considered the primary driver of geomagnetic storms, we find its influence on Pc5 pulsations to be minimal. Instead, our analysis shows that ground-based Pc5 power scales with solar wind speed, corroborating the role of solar wind dynamics in modulating Pc5 wave activity. These findings enhance our understanding of Pc5 wave excitation mechanisms and their dependence on solar wind conditions during geomagnetic storms.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"274 ","pages":"Article 106534"},"PeriodicalIF":1.8,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing seismic activity classification in augmented soil gas radon time series data through computational intelligence techniques","authors":"Nadeem Bashir ,&nbsp;Adil Aslam Mir ,&nbsp;Muhammad Osama ,&nbsp;Saba Maqsood Abbasi ,&nbsp;Dimitrios Nikolopoulos ,&nbsp;Shahzad Ahmad Qureshi ,&nbsp;Muhammad Rafique","doi":"10.1016/j.jastp.2025.106560","DOIUrl":"10.1016/j.jastp.2025.106560","url":null,"abstract":"<div><div>The classification of seismic activities with anomalous radon time series (ARTS) is promising but hindered by unbalanced data. Rare events like earthquakes make standard classification methods less effective. For such types of problems supervised classification algorithms do not work effectively since they are designed to learn on balanced datasets. Specifically, different techniques viz. Synthetic Minority Over-sampling Technique (SMOTE), Density-Based Synthetic Minority Over-sampling Technique (DBSMOTE), and Adaptive Synthetic Sampling (ADASYN) have been used to address the class imbalance problem inherited within the original soil gas radon time series. Numerous machine and deep learning methods are considered to be the prominent classifiers, including logistic regression, support vector machines (SVM), XGBoost, long-short-term memory (LSTM), and convolutional neural networks (CNN). The investigation has been focused on optimizing the classification of imbalanced datasets through the selection of oversampling methods and learning algorithms. This study indicates that window size and overlapping parameters greatly affect model performance, particularly in discerning seismic events, with larger windows presenting challenges. SVM stands out as a relatively accurate classifier, consistently achieving competitive AUC values without overfitting. Data augmentation techniques show mixed effects, underscoring the need for careful selection based on dataset characteristics. This study suggests that SVM with oversampling methods offers an effective approach for seismic anomaly classification in earthquake prediction using soil radon gas time series data. The dataset for this study comprises soil radon and thoron gas concentration time series along with meteorological parameters spanning 14 months. Four seismic events were recorded during the data collection period. during the whole study period.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"274 ","pages":"Article 106560"},"PeriodicalIF":1.8,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to ‘Assessing temperature and water vapour in the atmospheric column over South America: a synopsis of identified trends using ERA5 reanalysis’ [J. Atmos. Sol. Terr. Phys. Vol. 271 (2025) 106514]","authors":"Anna Carolina Bazzanela,&nbsp;Wanderson Luiz-Silva,&nbsp;Juan Neres de Souza,&nbsp;José Ricardo de Almeida França,&nbsp;Lucas Menezes,&nbsp;Fabricio Polifke da Silva","doi":"10.1016/j.jastp.2025.106529","DOIUrl":"10.1016/j.jastp.2025.106529","url":null,"abstract":"","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"272 ","pages":"Article 106529"},"PeriodicalIF":1.8,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atmospheric infrasound disturbances during the large 2013 May 22 solar energetic particle event","authors":"O. Ivantyshyn ,&nbsp;L. Chernogor ,&nbsp;D. Ivantyshyn ,&nbsp;B. Rusyn ,&nbsp;A. Lozynskyy ,&nbsp;M. Melnyk","doi":"10.1016/j.jastp.2025.106547","DOIUrl":"10.1016/j.jastp.2025.106547","url":null,"abstract":"<div><div>The paper presents research on atmospheric infrasound disturbances during large solar energetic particle event on 2013 May 22. This event is remarkable for its interacting coronal mass ejections, which caused a high level of particle intensity, that reached the value of 2740 <span><math><mrow><mi>c</mi><msup><mrow><mi>m</mi></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup><msup><mrow><mi>s</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mi>s</mi><msup><mrow><mi>r</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span> in the <span><math><mo>&gt;</mo></math></span>1 MeV GOES energy channel respectively according to NOAA GOES data. The maximum energetic particle flux occurred at 08:20 UT on 05/23/2013 and about three hours after that, we registered the beginning of the daily cycle disturbance of natural atmospheric infrasound with a duration of up to 2 days and an increase in the magnitude of infrasound by <span><math><mrow><mo>∼</mo><mn>3</mn><mo>÷</mo></mrow></math></span>4 times. A probable mechanism of infrasound generation is proposed. The observed value of the time delay of infrasound arrival in relation to the moment of generation of energetic protons consists mainly of the infrasound propagation time from high latitudes to the observatory and is counted from the moment the peak flux of lower-energy protons arrives. It is found that before the disturbance, the spectrum of the atmospheric infrasound signal was dominated by oscillations with a period of <span><math><mrow><mi>T</mi><mo>≈</mo><mn>300</mn></mrow></math></span> s, while after the disturbance, the width of the infrasound frequency spectrum increased and oscillations with periods of <span><math><mrow><mi>T</mi><mo>≈</mo><mn>100</mn><mo>÷</mo><mn>230</mn></mrow></math></span> s became dominant. The correlation of the proton flux density and the infrasound amplitude with the electric field strength in the surface atmosphere is revealed and explained.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"274 ","pages":"Article 106547"},"PeriodicalIF":1.8,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Impact of Orographic and Non-Orographic Gravity Waves on Arctic Stratospheric Polar Vortex Dynamics and Springtime Ozone Loss","authors":"Anish Kumar,&nbsp;Khalil Karami,&nbsp;Christoph Jacobi,&nbsp;Sina Mehrdad","doi":"10.1016/j.jastp.2025.106538","DOIUrl":"10.1016/j.jastp.2025.106538","url":null,"abstract":"<div><div>The Arctic stratospheric polar vortex (SPV) exhibits strong interannual variability due to the large landmass in the Northern Hemisphere (NH), which also enhances the generation of orographic and non-orographic gravity waves (GWs). In this study, two idealized experiments with the ICOsahedral Nonhydrostatic (ICON) model over a 30-year period were analyzed. One experiment involved turning off orographic waves (NO_SSO), while the other one involved turned off non-orographic waves (NO_NON).</div><div>The NO_NON experiment exhibits a significantly smaller vortex area than the control simulation (ICON-CTL) and is also smaller than in the NO_SSO experiment at the same levels. In both experiments, the SPV is located more poleward compared to ICON-CTL, with the vortex center in NO_SSO being closest to the pole. The NO_SSO experiment demonstrates stronger and more stable vortices during late winter and early spring, while the NO_NON experiment shows a smaller vortex area and a shorter lifespan. The NO_NON experiment shows the highest variability in SPV breakup days.</div><div>The Polar Stratospheric Cloud (PSC) volumes in the ICON-CTL run are mainly consistent with ERA5, although they are slightly overestimated. The sensitivity experiments reveal higher PSC volumes compared to ICON-CTL, with NO_SSO maintaining significantly larger volumes during late winter and early spring. The ICON-CTL run included two exceptionally strong vortex (ESV) events over the 30-year period, while NO_NON recorded none; and NO_SSO showed an unprecedented frequency of 13 ESV events during the same period.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"273 ","pages":"Article 106538"},"PeriodicalIF":1.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial and temporal prediction of ozone concentration in the Pearl River Delta region based on a dynamic graph convolutional network","authors":"Tongshu Yang,&nbsp;Sheng Li,&nbsp;Baoqin Chen","doi":"10.1016/j.jastp.2025.106559","DOIUrl":"10.1016/j.jastp.2025.106559","url":null,"abstract":"<div><div>The variation of ozone (O₃) concentration is closely related to other meteorological factors such as temperature and wind speed, and there is significant dynamic uncertainty, making related research very complex and difficult. This paper will establish a time-space ozone prediction model based on dynamic graph convolution network to study the O₃ pollution in the Pearl River Delta (PRD) region of China. Firstly, use an isolated forest (iForest) for anomaly detection in data preprocessing. Secondly, based on data such as wind direction, wind speed, and station geographic location, establish the diffusion distance of the wind field and construct a dynamic graph sequence accordingly. Finally, a spatio-temporal dynamic graph convolutional network (STD-GCN) based on dynamic graph sequences was established for predicting O₃ concentration. The experimental results showed that STD-GCN outperformed long short-term memory (LSTM) and graph convolutional embedded LSTM (GC-LSTM). Specifically, by integrating wind field factors, STD-GCN exhibits better spatial interpretability.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"273 ","pages":"Article 106559"},"PeriodicalIF":1.8,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variability of lower atmospheric gravity waves observed over Haringhata (22.93° N, 88.50° E) during winter and monsoon seasons through CU-ST Radar","authors":"Javed Akhter ,&nbsp;Rohan Mondal ,&nbsp;Rohit Mondal ,&nbsp;Subrata Kumar Midya ,&nbsp;Ashik Paul","doi":"10.1016/j.jastp.2025.106557","DOIUrl":"10.1016/j.jastp.2025.106557","url":null,"abstract":"<div><div>Gravity waves (GWs), influenced by buoyancy and gravity, play a vital role in energy and momentum transport within the atmosphere. The present study examined the presence of GWs in the upper troposphere and lower stratosphere using data from the Calcutta University Stratosphere-Troposphere (CU ST) Radar located at the Ionosphere Field Station near Haringhata, West Bengal, India. GW characteristics were studied from radar observations during the winter (January 26 and February 8) and monsoon (rainy August 1 and non-rainy August 10) seasons of 2023. Fluctuations from zonal, meridional, and vertical velocities were utilized for GW characterization. GW parameters were estimated through hodograph analysis. The Lomb-Scargle periodogram was used to identify dominant periods of GW. Predominant westerly and southerly winds were noticed in winter, with notable wind shear associated with the subtropical westerly jet extending up to about 24 km altitude. The wind shear-driven GWs with comparatively lower dominant periods and shorter horizontal wavelengths was observed during this season. In monsoon, wind patterns were dominated by the tropical easterly jet, featuring considerable wind reversals, strong easterly winds, and noticeable periodic updrafts and downdrafts in vertical velocities. Wind shear associated with the tropical easterly jet and convective activities resulted in strong GW activity over this region. During this season, GWs with comparatively higher dominant periods and longer horizontal wavelengths were noticed, particularly on the rainy day.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"273 ","pages":"Article 106557"},"PeriodicalIF":1.8,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144203306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergent constraints for uncertainty reduction in climate projections","authors":"C. Varotsos ,&nbsp;M. Efstathiou ,&nbsp;N. Sarlis","doi":"10.1016/j.jastp.2025.106556","DOIUrl":"10.1016/j.jastp.2025.106556","url":null,"abstract":"<div><div>Studying longwave radiation and surface air temperature is essential for understanding Earth's energy budget and climate dynamics. These factors are fundamental for spotting trends, forecasting future situations, and evaluating how human actions affect global warming, making their accurate values very important. In this study, we analyze the uncertainties in surface downward longwave radiation, average monthly values of absorbed longwave radiation, and average monthly surface air temperature obtained from advanced models. The combination of the emergent constraint approach and natural time analysis was used for the first time to study the variability of these climate parameters and explore ways to reduce uncertainty. The data analysis reveals significant findings that enhance the reliability of future climate simulations, especially regarding the forecast of the atmospheric greenhouse effect components for the next two years.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"274 ","pages":"Article 106556"},"PeriodicalIF":1.8,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The relationship between cloud-to-ground lightning spatial distribution and topography in Guangzhou","authors":"Li Cai,&nbsp;Mengyuan Chen,&nbsp;Tianxi Han,&nbsp;Mi Zhou,&nbsp;Jinxin Cao,&nbsp;Jianguo Wang,&nbsp;Yadong Fan","doi":"10.1016/j.jastp.2025.106554","DOIUrl":"10.1016/j.jastp.2025.106554","url":null,"abstract":"<div><div>According to the Guangdong lightning location system (GDLLS), the data of cloud-to-ground (CG) lightning in Guangzhou from March to October of 2016–2018 are summarized and analyzed combined with digital elevation model (DEM) from ASTER GDEM V2. Frequency and intensity of three years CG lightning decrease gradually. CG lightning in Guangzhou is mainly negative. Negative return stroke percentage of most areas exceeds 80 % except for center part of Guangzhou. Most areas terrain of Guangzhou is plain, and mountainous areas are mainly distributed in five north districts. By dividing CG lightning data located in five north districts into groups according to elevation, return stroke density curve shows an irregular U shape with elevation rise while negative mean peak current and negative stroke percent curves rise on the whole. Comparing terrain and CG lightning data of 7 selected regions, CG lightning activity of mountainous areas is more frequent with higher negative stroke percent compared to flat ground without much terrain relief. Topographic regions with a central low elevation flanked by higher elevations on both sides are termed U-shaped areas. This structural configuration may suggest that atmospheric convection is enhanced within these regions, resulting in higher lightning strike density. Through thunderstorms traversing paths analysis, it is found thunderstorms usually occur in areas with great relief at the junction of mountains and flat ground. And thunderstorms generally move in the direction of the mountains extending. If the thunderstorms are strong enough, they may climb through the mountains. When thunderstorms encounter a U-shaped area, they tend to traverse to it.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"273 ","pages":"Article 106554"},"PeriodicalIF":1.8,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}