Journal of Atmospheric and Solar-Terrestrial Physics最新文献

{"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}

{"title":"Spatial and temporal dynamics of solar energy resources in China and forecast of future solar radiation","authors":"Yong Zhou ,&nbsp;Xueli Sha ,&nbsp;Lingyu Wang ,&nbsp;Xiang Li ,&nbsp;Zhihao Zhang","doi":"10.1016/j.jastp.2025.106463","DOIUrl":"10.1016/j.jastp.2025.106463","url":null,"abstract":"<div><div>Solar radiation exhibits significant temporal fluctuations due to the influence of atmospheric water vapor, aerosols, haze, etc. It is crucial to analyze the temporal pattern of change and future distribution of solar energy resources for optimize their utilization and facilitate their development. Consequently, this study analyzes solar radiation data from 1994 meteorological stations, identifying complex trends and using sudden change tests to predict the annual and seasonal distributions of solar radiation in China over the next five or ten years. The results indicate a declining trend in global solar radiation across most of China, with an average annual decrease of −4.26 MJ/m²/y. The annual variation in diffuse solar radiation demonstrates an upward trajectory, with an average increase of 0.34 MJ/m²/y. For the next 5 and 10 years, global solar radiation values are estimated to range from 3020 to 6840 MJ/m² and from 2970 to 6940 MJ/m², respectively. The spatial distribution exhibits higher in the west and north, and lower in the east and south. The annual diffuse solar radiation values for the next five and ten years are estimated to range from 650 to 3060 MJ/m² and 680–3120 MJ/m², respectively, exhibiting an increasing trend from north to south.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106463"},"PeriodicalIF":1.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437085","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":"Chaotic variability of the magnetic field at Earth’s surface driven by ionospheric and space plasmas","authors":"Alexander Bershadskii","doi":"10.1016/j.jastp.2025.106456","DOIUrl":"10.1016/j.jastp.2025.106456","url":null,"abstract":"<div><div>It is shown that the universal chaotic/turbulent processes in space (solar wind and magnetosphere) and in ionospheric plasmas drive the chaotic temporal variability and determine the level of randomness of the magnetic field at Earth’s surface in the temporal range from a few hours to a few years. The results of observations provided by the spacecraft and satellite missions, and the global magnetic observatory network were used for this purpose. A good agreement has been established between the results of observations and a theoretical approach based on the Kolmogorov–Iroshnikov phenomenology in the frames of distributed chaos notion.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106456"},"PeriodicalIF":1.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403635","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":"Influence of land use land cover and topography on lightning distribution over north and north-east Indian region","authors":"Swapnil S. Potdar ,&nbsp;Devendraa Siingh ,&nbsp;Rupraj Biswasharma ,&nbsp;Alok Sagar Gautam ,&nbsp;R.P. Singh","doi":"10.1016/j.jastp.2025.106460","DOIUrl":"10.1016/j.jastp.2025.106460","url":null,"abstract":"<div><div>Spatio-temporal variation of lightning characteristics over North India (NI) and North-East India (NEI) during the period 2001–2014 is studied in connection with the land use land cover (LULC) and topography of the Himalaya ranges. Lightning flashes detected by Lightning Imaging Sensor (LIS) on board the Tropical Rainfall Measuring Mission (TRMM) satellite are analysed for different LULC classes measured by Moderate Resolution Imaging Spectroradiometer (MODIS) and elevation data from Shuttle Radar Topography Mission (SRTM). We observed that the annual lightning flashes are high in the NI region compared to the NEI region; with a peak during monsoon period in the NI region, whereas peaks in the NEI were found to be during pre-monsoon months. The thermodynamics parameters such as maximum temperature (MaxT), convective available potential energy (CAPE), latent heat flux (LHF) and bulk microphysics such as total cloud cover liquid water (TCCLW) and total cloud cover ice water (TCCIW) along with lightning flash rate density (LFRD) also analysed with respect to different LULC classes. The impact of LULC on lightning activity is evident in both the study regions. In the both the region, human-induced landscapes such as croplands, urban built-up areas consistently show the high lightning activity due to favourable thermodynamic and microphysical conditions. Natural landscapes such as forest, grasslands show moderate lightning activity while savannas and permanent wetlands shows high lightning activity showing that vegetation helps in maintaining high soil moisture which may play a significant role in lightning occurrences. Topography significantly influenced lightning occurrence, with higher flash rates in foothill areas due to surface heating and moisture convergence, and in Meghalaya due to orographic lifting. Lightning activity in both study regions is higher at lower altitudes (&lt;500m) and decreases with altitude, with a more prominent decline in case of NI region. We found the positive lightning trends in areas of expanding agriculture and urbanization highlighting the role of LULC change in the lightning distribution over both the regions.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"268 ","pages":"Article 106460"},"PeriodicalIF":1.8,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377801","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":"Different microphysics parameterizations of hydrometeor pathways in WRF simulation: A case of two high rainfall events in Nigeria","authors":"Anselem Onyejuruwa ,&nbsp;Zhenghua Hu ,&nbsp;Abu Reza Md Towfiqul Islam ,&nbsp;Eniola Olaniyan ,&nbsp;Kyaw Than Oo","doi":"10.1016/j.jastp.2025.106455","DOIUrl":"10.1016/j.jastp.2025.106455","url":null,"abstract":"<div><div>This study evaluates the role and performance of microphysical processes and parameterizations in simulating two distinct rainfall events over Nigeria. Four microphysics (MP) schemes in the Weather Research and Forecasting (WRF) model—Goddard, Morrison, Thompson, and WDM6—were utilized. The analysis focused on mean rainfall rates, hydrometeor pathways, and spatial rainfall accumulation amounts and patterns.</div><div>Results indicate that while most MP schemes underestimated the mean rainfall rate, they reasonably captured the spatial distributions in both events. Based on statistical metrics of 24-h accumulated rainfall, the Goddard scheme produced the lowest mean absolute bias (MAB) and the highest rainfall detection ability (POD and TS) for the June rainfall event. For the February event, the Morrison scheme exhibited the least absolute bias and achieved high POD and TS values. The differences in rainfall production among the MP schemes were primarily attributed to variations in the growth rates of rainwater hydrometeors within the hydrometeor pathways (HPs), while rainfall duration was influenced by consistent collision and coalescence of cloud droplets. Excessive cloud water production also contributed to delays in rainwater formation, leading to reduced simulated rainfall. Additionally, the rapid melting of large graupel mass significantly affected the performance of different schemes in simulating rainfall. Furthermore, variations in low to mid-tropospheric vertical velocity and surface parameters (such as temperature and specific humidity) were shown to significantly control microphysical processes and, consequently, impact rainfall production.</div><div>Overall, the analysis suggests that more sophisticated MP schemes do not necessarily provide better simulations of precipitable hydrometeor pathways.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"268 ","pages":"Article 106455"},"PeriodicalIF":1.8,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377800","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":"Possible ionospheric effects of two major earth quakes in Papua New Guinea","authors":"B. Felix Pereira,&nbsp;Jessy Sekere","doi":"10.1016/j.jastp.2025.106457","DOIUrl":"10.1016/j.jastp.2025.106457","url":null,"abstract":"<div><div>Pre-seismic ionospheric F2 layer instabilities have been studied which could help in predicting earthquakes. Two major earthquakes in the western province of Papua New Guinea, one in Sissano in 1998 of magnitude 7.1 and the other in Aitape in 2002 of magnitude 6.7 were analyzed. An analysis of the perturbations in the electron content up to the ionospheric F₂ layer peak and F2 layer peak height (h_mF2) variations during earthquake time has been done using published ionosonde data. A decrease in peak electron density ranging from 20 to 30% was observed within 10 days during pre-seismic as well as post-seismic periods during both earthquakes. On these days, an increase in the height of the peak electron density was also observed. This could be because during seismic periods, a large amount of radon gas is emitted during earthquake preparation time, which ionize neutral atoms and molecules and the ions raise to ionospheric heights by electric fields created and produce ionospheric fluctuations. This helps in predicting the earthquake in advance.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106457"},"PeriodicalIF":1.8,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403632","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":"Assessment of variability in chlorophyll-a and covariates in East/Japan sea: New insights from the ARIMAX model and wavelet coherence","authors":"Salman Tariq ,&nbsp;Ayesha Mariam ,&nbsp;Muhammad Khan","doi":"10.1016/j.jastp.2025.106450","DOIUrl":"10.1016/j.jastp.2025.106450","url":null,"abstract":"<div><div>The atmospheric aerosols and the concentration of Chlorophyll-a (Chl-a) in coastal and clear water is an important research field that involves the multiple aspects of environmental degradation and analyzing the health of the marine environment. Therefore, ocean color satellite remote sensing is an efficient way to observe and monitor the aquatic system and the ocean at various spatial, temporal, and spectral scales. Therefore, this study analyzes the spatiotemporal dynamic variability in various ocean color variables, i.e., Sea surface temperature (SST), Aerosol optical depth (AOD), Black carbon dry deposition (BCD), Calcite concentration (CC), Ocean Rain (O-Rain), and Sensible heat flux (SHF) over the East/Japan Sea (EJS) from 2002 to 2023. Furthermore, we used the ARIMAX model and Wavelet coherence (WTC) analysis for analyzing the variability of these oceanic parameters with Chl-a. The spatial concentration of Chl-a is observed high over the northern EJS, particularly around 141ᵒ E, 50ᵒ N, southwestern EJS, and around 141ᵒ E, 43ᵒ N (along the Japanese coast). Furthermore, the western EJS also showed the highest concentration of Chl-a than the eastern EJS. Generally, the mean concentration of Chl-a in EJS increasing at the rate of 0.4 mg m⁻³/yr showed the maximum value of 0.8 mg m⁻³ during the study period. Moreover, the ARIMAX models elucidated a direct coupling of the Chl-a with O-Rain and BCD while it showed an inverse and statistically significant association with AOD, SST, CC, and SHF. The WTC analysis indicated a strong association of above 0.8 of Chl-a with all selected variables between a scale period of 8–16. Among all selected variables, CC, SHF, and BCD show a stronger association with Chl-a over the EJS. Therefore, this study will help the policymakers in identifying the major hotspots of Chl-a in EJS to analyze the water quality and health of the marine environment.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106450"},"PeriodicalIF":1.8,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403634","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":"Study of VLF signal during partial solar eclipse of 25 October 2022","authors":"Ramesh Krishna B,&nbsp;P. Chaithra,&nbsp;Kamsali Nagaraja","doi":"10.1016/j.jastp.2025.106458","DOIUrl":"10.1016/j.jastp.2025.106458","url":null,"abstract":"<div><div>The partial solar eclipse on October 25, 2022, had an observable effect on very low frequency (VLF) signals along the transmission paths of GQD (22.10 kHz) and DHO (23.40 kHz). Signal variations were analyzed for October 22–28, 2022, with a focus on amplitude changes during the greatest eclipse (GE) phase. During the partial solar eclipse, the GQD and DHO signal paths experienced 11% and 14% obstructions, respectively. On the day of the eclipse, the amplitude of the GQD is 0.83 dB lower compared to pre-days and 0.11 dB greater than post-days, and for DHO it is increased by 0.26 dB and 0.57 dB for pre- and post-eclipse days at the time of GE. Observations revealed stronger solar flare signatures in GQD signal compared to the DHO signal, attributed to differences in ionospheric conditions along the propagation paths. A pronounced rise in amplitude before and after the GE phase was observed in the GQD signal, linked to solar flare activity. Additionally, the analysis confirmed that the PSE was the primary driver of increased VLF signal amplitude during the GE phase along the DHO path. The results emphasize the significant impact of partial solar eclipses on ionospheric dynamics and VLF signal propagation.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"269 ","pages":"Article 106458"},"PeriodicalIF":1.8,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418889","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}