Journal of Atmospheric and Solar-Terrestrial Physics最新文献

{"title":"Nighttime and seasonal variation of lower ionospheric parameters using tweek analysis during minimum solar activity period over low latitude","authors":"Kshama Tiwari,&nbsp;S.B. Singh,&nbsp;A.K. Singh","doi":"10.1016/j.jastp.2025.106476","DOIUrl":"10.1016/j.jastp.2025.106476","url":null,"abstract":"<div><div>VLF signals are continuously recorded, monitored, and observed by an Automatic Whistler Detector (AWD) installed at our low latitude Indian station, Banaras Hindu University, Varanasi (geom. lat. 14° 55^’ N, geom. long. 154° E and geog. lat. 25°15′ 20″ N, long. 82° 59’ 21” E). In the present study, the nighttime and seasonal variation of lower ionospheric parameters mainly D-region during a low solar minimum period from 2018 to 2019 has been analyzed at a low latitude station in Varanasi. Since large numbers of tweeks have been observed at Varanasi, we have randomly chosen three days in a month during the summer (June), winter (November), and equinox (September/October) seasons in the years, 2018 and 2019, where good-quality, continuous nighttime data were available. A total of 35,000 tweeks recorded up to <em><strong>n = 1–10</strong></em> harmonics in different seasons: summer, winter, and equinox showed percentage occurrences of approximately 37%, 32%, and 31% in 2018 and 38%, 31%, and 31% in 2019 respectively during the solar minimum period of solar cycle 24. The analysis of tweeks with harmonics up to tenth modes in different seasons showed higher occurrence in summer, reflecting at less diverse altitudes than winter and equinox seasons, with propagation paths ranging from 500 to 8500 km in 2018 and 800–8000 km in 2019. Nighttime lower ionospheric daily average electron density <strong>(</strong><em><strong>n</strong></em>_{<em><strong>e</strong></em>}<strong>)</strong> values varied from 23 to 26 cm⁻³ at altitudes of 80–94 km during 2018 and 2019. The D-region is less uniform at higher altitudes during summer. The effect of reflection height on frequency, attenuation factor, time delay, and the usefulness of tweek method for estimating electron density in the nighttime D region ionosphere for different harmonics are also discussed in this study. The electron density <strong><em>(n</em></strong>_{<strong><em>e</em></strong>}<strong><em>)</em></strong> values obtained by the tweek method during various seasons are compared to IRI-2016, radar data, and rocket data, all of which fall within a similar range of variations specifically between 80 and 90 km showing a better estimation by the tweek method. Further, we have also evaluated the attenuation coefficient of the nighttime tweek propagation. We have also simulated the frequency-time spectrum of different modes of tweeks at various heights and propagation paths.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106476"},"PeriodicalIF":1.8,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479409","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":"Multifractal and monofractal characteristics of ULF magnetic fields in Kachchh region, Gujarat, India: Prospects for earthquake precursor detection","authors":"Sushanta Kumar Sahoo,&nbsp;Madhusudhanarao Katlamudi,&nbsp;Chandra Sekhar Pedapudi","doi":"10.1016/j.jastp.2025.106478","DOIUrl":"10.1016/j.jastp.2025.106478","url":null,"abstract":"<div><div>Understanding electromagnetic emissions linked to earthquakes is critical for advancing precursor studies, yet research remains limited in seismically active regions like Kachchh, Gujarat, India. This study investigates Ultra-Low Frequency (ULF) magnetic field variations recorded over eight months (January 1–August 13, 2012) at the Multi-parametric Geophysical Observatory (MPGO) in Desalpar (23.742°N, 70.686°E). The analysis focuses on their connection to a magnitude 5.1 earthquake near the observatory on June 20, 2012. Data from a Digital Fluxgate Magnetometer (DFM) were analyzed using Detrended Fluctuation Analysis (DFA) and Multifractal Detrended Fluctuation Analysis (MFDFA) to explore scaling properties in the 0.001–0.1 Hz frequency range. Periodogram analysis identified diurnal and semi-diurnal periodicities, removed using Empirical Mode Decomposition (EMD) to isolate aperiodic signals. DFA results showed non-uniform fluctuation functions with scaling exponent variations prior to the earthquake on June 20, 2012. Notably, the instability index (β) increased in the H-component six days before the event (June 14, 2012), in the D-component on June 17–18, 2012, and in the Z-component one day before (June 19, 2012). MFDFA revealed long-range power-law correlations, with differences in multifractal spectra between observed and shuffled time series, indicating long-range correlations drive multifractality. Surrogate analyses confirmed these correlations while reducing Gaussian characteristics. The multifractal spectrum of H, D, and Z components widened during seismically active phases compared to quiet phases, emphasizing the utility of multifractal analysis in detecting ULF magnetic field instabilities. Abnormal time dynamics in the multifractal characteristics of the H- and Z-components were observed shortly before the earthquake on June 20, 2012. This research highlights the potential of such methods for earthquake monitoring and early-warning systems in active seismic regions.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106478"},"PeriodicalIF":1.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465136","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":"Spatio-temporal variation of particulate matter (PM10) concerning the COVID-19 pandemic in the major cities of Uttarakhand, India","authors":"Amar Deep ,&nbsp;Tushar Kandari ,&nbsp;Hemwati Nandan ,&nbsp;Mahima","doi":"10.1016/j.jastp.2025.106464","DOIUrl":"10.1016/j.jastp.2025.106464","url":null,"abstract":"<div><div>The present investigation focuses on one of the principal air quality parameters, Particulate Matter (PM₁₀), in some of the major cities of Uttarakhand, viz. Haridwar, Dehradun, Rishikesh, Kashipur, Rudrapur, and Haldwani during 2011–2020. In the year 2020 (from 22nd March to September), the lockdown was implemented worldwide due to the COVID-19 pandemic, which resulted in a considerable decrease in air pollutants globally and nationally. Understanding the ambient air quality of Uttarakhand requires analyzing PM₁₀ variability in these cities, which are among the most populated and industrialized in the state. Hence, a decadal study explains the change in air quality with every changing year. The observed PM₁₀ concentration was 2–3 times higher than the prescribed limits (60 μgm⁻³) fixed by the Central Pollution Control Board (CPCB) in New Delhi, India. The highest (251.8 μgm⁻³) PM₁₀ concentration was observed in the winter season (2011) as compared to other seasons in Dehradun city. The PM₁₀ concentration was observed to be high during this decadal period except in 2020 due to the COVID-19 lockdown. A negative correlation coefficient was observed when correlated with rainfall and humidity, while a positive correlation was observed when correlated with temperature for all the sampling sites. The calculated p-values for PM10 and meteorological parameters for Haridwar, Dehradun, Rishikesh, Kashipur, and Rudrapur are 0.01, 0.05, 0.01, 0.05, 0.01, and 0.01, respectively.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106464"},"PeriodicalIF":1.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562531","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":"Statistical study of low-latitude E-region irregularity occurrence rate based on Qujing VHF radar observations","authors":"Yunzhou Zhu ,&nbsp;Qiong Tang ,&nbsp;Zhongxin Deng ,&nbsp;Chen Zhou ,&nbsp;Tong Xu ,&nbsp;Yi Liu ,&nbsp;Zhengyu Zhao ,&nbsp;Fengsi Wei","doi":"10.1016/j.jastp.2025.106479","DOIUrl":"10.1016/j.jastp.2025.106479","url":null,"abstract":"<div><div>Based on the Quing VHF radar (25.6°N, 103.7°E, magnetic latitude 16.1°N, magnetic longitude 177.0°E) measurements from 2016 to 2020, the morphological characteristic of low-latitude E-region field-aligned irregularities (FAIs) was reported in this work. Statistical results show that the occurrence of Qujing E-region irregularities highly depends on both season and local time. The occurrence rate of E-region FAIs peaks in the summer, with the lowest occurrence rates in autumn and winter, and primarily occurs at night. The Doppler spectrum suggests that the Qujing E-region FAI echoes are mainly characterized by type II echoes. Quantitative analysis of both the activity of the Es layer and E-region FAI structures was also conducted. It is found that the occurrence of low-latitude E-region FAIs is closely correlated with the enhanced electron density structures inherent in the local Es layers. Given the weak electric field at low and mid-latitudes, neutral winds controlling ion drift likely trigger gradient drift instability above the Es layer, leading to small-scale irregularities in Qujing. Further investigation is required to understand the influence of the medium-scale traveling ionospheric disturbance on the occurrence rate of ionosphere E-region FAIs in low latitudes.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106479"},"PeriodicalIF":1.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465205","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":"Long-term drought characterization: A spatiotemporal analysis in Rayalaseema, southern peninsular India","authors":"Kandula Bharghavi ,&nbsp;Hemalatha Kapa ,&nbsp;Thotli Lokeswara Reddy ,&nbsp;Penti Rajesh ,&nbsp;Krishnareddigari Krishna Reddy","doi":"10.1016/j.jastp.2025.106467","DOIUrl":"10.1016/j.jastp.2025.106467","url":null,"abstract":"<div><div>The unique combination of features in Andhra Pradesh's Rayalaseema region makes it an ideal location for drought studies. These features include hilly terrain, a semi-arid climate with the lowest rainfall in India, and the influence of both the Southwest and Northeast monsoons. Rainfall is a fundamental metric for water availability, while temperature plays a pivotal role in regulating evapotranspiration rates. Understanding their trends is crucial since both factors are integral in delineating drought conditions. This study delves into the drought dynamics of the Rayalaseema region from 1961 to 2021, employing meteorological drought indices: the standardized precipitation evapotranspiration index (SPEI) and the standardized precipitation index (SPI). In order to achieve this, rainfall data was retrieved from the archives of the India Meteorological Department (IMD), while temperature data was sourced from ERA-5 (the fifth-generation European Centre for Medium-Range Weather Forecasts reanalysis). In order to assess the significance of drought characteristic trends across various temporal and spatial scales, the Mann-Kendall trend test and Sen's slope estimator techniques were applied. Rainfall patterns varied significantly, with Kurnool receiving the highest and Anantapur the lowest, while temperatures steadily increased, peaking in the sixth decade, especially in Kadapa, Kurnool, and Chittoor, with June being the warmest month. Rainfall trends shifted from negative to positive, with Kurnool and Chittoor experiencing significant increases, while Kadapa and Anantapur continued to face negative trends. Drought conditions, as measured by SPI and SPEI, were frequent, particularly in the first three decades, with a shift towards wetter conditions in later decades. The SPEI trends revealed rising drought severity, exacerbated by increasing temperatures, particularly in Kurnool and Kadapa. Nonetheless, both indices effectively capture significant drought events, with SPEI detecting more severe drought occurrences than SPI.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106467"},"PeriodicalIF":1.8,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465206","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":"Short-time forecast of ionospheric irregularities using long short-term memory networks over equatorial and low-latitudes regions","authors":"Olakunle L. Ojo ,&nbsp;Oladipo Emmanuel Abe ,&nbsp;Olaide Sakiru Hammed ,&nbsp;Olugbenga Olumodimu","doi":"10.1016/j.jastp.2025.106466","DOIUrl":"10.1016/j.jastp.2025.106466","url":null,"abstract":"<div><div>Predicting ionospheric conditions is becoming increasingly important towards the operational efficiency of both ground-based and space-borne radio communication systems with a view to compensate for the effects of space weather. This study focuses on predicting ionospheric irregularities in the complex and variable equatorial ionosphere which is deemed critical for optimal space-based application. We utilized the Long-Short-Term-Memory (LSTM) deep learning algorithm to develop a predictive model for forecasting disturbances in the equatorial ionization anomaly (EIA) region using Global Navigation Satellite Systems (GNSS) data. We utilized fifteen-year worth of data (2005–2020) to train, validate and test the performance of the model and assessed the results against a baseline model relying on daily and hourly Rate of Change of TEC Index (ROTI) values and utilized evaluation metrics such as correlation (R), determination coefficient (<span><math><mrow><msup><mi>R</mi><mn>2</mn></msup></mrow></math></span>), and mean squared error (MSE). Remarkably, the LSTM Predictive Model consistently outperformed the Baseline Model across various stations, demonstrating higher R and R² values and significantly lower MSE. These results indicate the LSTM model's superior accuracy in forecasting ionospheric disturbances, essential for space-based applications. The distribution analysis of residual errors highlighted the LSTM model's ability to better capture underlying patterns and variability in the target variable. This study contributes to enhancing ionospheric forecasting models for space applications, ensuring the dependability of space-based systems.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106466"},"PeriodicalIF":1.8,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512306","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":"Sudden pollution incidents around Beijing on a crisp October day: Insights from capturing pollution conveyor belts","authors":"Deying Wang ,&nbsp;Jizhi Wang ,&nbsp;Yuanqin Yang ,&nbsp;Wenxing Jia ,&nbsp;Junting Zhong ,&nbsp;Xiaofei Jiang ,&nbsp;Liangke Liu ,&nbsp;Yaqiang Wang ,&nbsp;Xiaoye Zhang","doi":"10.1016/j.jastp.2025.106461","DOIUrl":"10.1016/j.jastp.2025.106461","url":null,"abstract":"<div><div>North China Plain, an area is usually sunny and cloudless in autumn, rare heavy pollution suddenly occurred around Beijing. This is a new focus of public attention and research. Since late October 2023, it has caused sudden haze pollution. This study focuses on capturing the mechanisms behind sudden pollution in clear skies, tracking the establishment and transmission of adverse weather conditions, focusing on targeted key stations affected by adverse weather. Revealing the correlation between implicit multiple types of precursor meteorological signals: atmospheric boundary layer, condensation rate threshold, in the atmosphere. Obtain the coupling point of the interaction and matching between micro-scale disturbances and weather-scale fluctuations, and reveal its driving mechanism behind sudden pollution in clear skies. The novelty of this study lies in targeting regions that have achieved certain success in emission reduction. Provide insights into the \"feedback\" effects that adverse weather conditions can cause. It particularly provides a further understanding of the interactions between clouds, aerosols in the “pollution conveyor belt” and provides quantitative indicators for early warning. Provide quantitative technical support for developing accurate response measures in air quality research.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106461"},"PeriodicalIF":1.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454341","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":"Schumann resonance as a remote sensor of lower ionosphere and global thunderstorms as based on the long-term observations at Antarctic and Arctic stations","authors":"A.P. Nickolaenko ,&nbsp;M. Hayakawa ,&nbsp;O. Koloskov","doi":"10.1016/j.jastp.2025.106465","DOIUrl":"10.1016/j.jastp.2025.106465","url":null,"abstract":"<div><div>We evaluate the impact of solar activity on the global ionosphere and the position of world thunderstorms by analyzing the peak frequency of the first Schumann resonance (SR) mode in the simultaneous records of the horizontal magnetic field components at the high-latitude observatories in the Southern and Northern hemispheres. The long-term monitoring was conducted at the Ukrainian Antarctic Station (UAS) “Akademik Vernadsky” (geographic coordinates: 65.25° S and 64.25° W) and the SOUSY Arctic Svalbard observatory (78.15° N and 16.05° E). A specialized technique was applied to process observational data that exploits the half-sum and semi-difference of the peak frequencies measured simultaneously at these observatories. This approach enables the separation and quantification of the impact of solar activity on the effective height of the lower ionosphere and the distance to the global thunderstorms. The following findings are demonstrated: (i) Alterations in the position of global thunderstorms can be separated from modifications of the lower ionosphere height; (ii) The employment of pivoted vertical profile of the middle atmosphere conductivity indicates that an increase occurs of the upper characteristic height <em>h</em>_<em>L</em> of the lower ionosphere during the decline in the solar activity. (iii) Kilometer-scale changes in the ionospheric height are linked to variations in the solar activity, and this effect is accompanied by minute (approximately 1° of latitude) displacements of global thunderstorms.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106465"},"PeriodicalIF":1.8,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437084","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":"Observed thermodynamical-cloud-rain characteristics during pre-monsoon precipitating events over a high-altitude site in Western Ghats, India","authors":"P.P. Leena ,&nbsp;E.A. Resmi ,&nbsp;Dhwanit.J. Mise ,&nbsp;V. Anilkumar ,&nbsp;V.S. Arun ,&nbsp;Rohit P.Patil ,&nbsp;G. Pandithurai ,&nbsp;Lekshmi Anilkumar","doi":"10.1016/j.jastp.2025.106459","DOIUrl":"10.1016/j.jastp.2025.106459","url":null,"abstract":"<div><div>The present study detailed the atmospheric stability and cloud-rain properties during pre-monsoon precipitating events using co-located ground-based observation of a high-altitude site, in Western Ghats, India. The meteorological - moisture parameters and stability indices showed strong diurnal and seasonal variation over the study region. Higher values in the stability indices and moisture parameters were noted throughout the day (during afternoon hours) of monsoon (pre- and post-monsoon) suggesting the possibility of convective activity over the study region. Features of layered clouds mostly, with low bases were noticed during monsoon, followed by pre- and post-monsoon.</div><div>A detailed analysis of meteorological-moisture parameters, stability indices, and cloud properties during pre-monsoon, highlighted an apparent change in these parameters from non-precipitating to precipitating events. Strong precipitating event were characterized by higher low-level moisture,sharp changes in the meteorological parameters and few stability indices. Higher values of radar reflectivity (&gt;40 dBz) indicated strong precipitating event as a convective storm. Higher liquid and lower values of brightness temperature confirmed the presence of deep clouds during the strong event. Quantitative analysis showed higher values in temperature (T), equivalent potential temperature (EPT), total total index (TTI), K-index (KI), humidity index (HI), and lifted index (LI) ∼2 h before the strong event suggesting an unstable atmosphere and conducive for thunderstorm development. Single-layer clouds of ∼8% (20%) and the double layer of ∼42% (26%) were observed before (after) the strong event. An apparent difference in the CFAD of radar reflectivity was noticed between strong and weak cases with high reflectivity values in the lower altitudes for strong cases as compared to weak ones. We believe that this information is very useful for the nowcasting of thunderstorms.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106459"},"PeriodicalIF":1.8,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465137","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":"Dst index estimation from cosmic ray and solar wind data during solar cycle 24 using artificial neural networks","authors":"Hadeer F. Sabeha ,&nbsp;Alshaimaa Hassanin ,&nbsp;F.N. Minta ,&nbsp;Mohamed Elnawawy ,&nbsp;Ayman Mahrous","doi":"10.1016/j.jastp.2025.106462","DOIUrl":"10.1016/j.jastp.2025.106462","url":null,"abstract":"<div><div>This research employs artificial neural networks (ANNs) to estimate the disturbance storm time (Dst) index using cosmic ray (CR) and solar wind (SW) data from solar cycle 24. A dataset of 1361 events (2008–2019) was compiled and divided into training and testing subsets. Validation was performed using a dataset of 116 events from the year 2005. The flexibility and robustness of the model was further verified with three geomagnetic storms (GSs) representing different conditions during solar cycle 23. The CR parameters, SW parameters, and geomagnetic indices were sourced from the Forbush Effects and Interplanetary Disturbance (FEID) Catalogue and NASA's OMNI database. The ANN model utilized a feedforward neural network with Levenberg-Marquardt backpropagation, achieving optimal performance with a single hidden layer of six neurons, which minimized the root mean square error (RMSE). The model's overall correlation coefficient was 87%, indicating strong predictive capability. The results demonstrate the ANN model's efficacy in capturing complex interactions between solar and cosmic-ray phenomena and their impacts on geomagnetic activity, providing a robust tool for space weather studies. Additionally, the strong correlation observed between the Dst index and cosmic ray data suggests that incorporating these data in future studies could be highly valuable.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106462"},"PeriodicalIF":1.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479355","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}