Journal of Atmospheric and Solar-Terrestrial Physics最新文献

{"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":"A new perspective on the genesis of the 2019/2020 Australian bushfire and its atmospheric radiative impacts","authors":"S. Prasanth ,&nbsp;N. Anand ,&nbsp;M.R. Manoj ,&nbsp;K. Arun ,&nbsp;S. Jose ,&nbsp;S.K. Satheesh ,&nbsp;K.K. Moorthy","doi":"10.1016/j.jastp.2025.106558","DOIUrl":"10.1016/j.jastp.2025.106558","url":null,"abstract":"<div><div>Extensive investigations of the genesis and atmospheric radiative impacts of the Australian bushfires of August 2019 to January 2020 (also known as the black summer event) have been carried out using in-situ, multi-satellite, and reanalysis data. We present the observational evidence for the role of total water storage in the initiation of this event. A strong correlation was found between the depletion of the total water storage (sum of surface and sub-surface water storage) caused by the hydrological drought and the burnt area in southeast Australia. Notably, a decadal low of Liquid Water Equivalent Thickness (LWET) going below −5 cm in December 2019 strongly suggests the crucial role of hydrological drought in the genesis of the black summer event.</div><div>The hydrological drought provided favorable conditions for intense fire activity during the black summer event and increased the aerosol loading across Australia. The assimilated Aerosol Optical Depth revealed that the impact of the black summer event on the aerosol loading is higher than previously reported. The amplified aerosol backscattering, coupled with the increased surface albedo due to the prevailing drought, led to a significant surge in outgoing shortwave flux and contributed to regional cooling. Along with the increased aerosol loading, it has also been observed that the co-emitted carbon monoxide enhanced the ozone production at 850 hPa, further degrading the air quality. These findings will offer crucial insights for predicting extreme bushfire events and their mitigation policies.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"274 ","pages":"Article 106558"},"PeriodicalIF":1.8,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314239","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}

{"title":"Study of ionospheric response to an intense geomagnetic storm of 26 August 2018 over low latitudes and polar regions","authors":"Uma Pandey ,&nbsp;Sanjay Kumar ,&nbsp;Javed N. Malik ,&nbsp;A.K. Singh","doi":"10.1016/j.jastp.2025.106528","DOIUrl":"10.1016/j.jastp.2025.106528","url":null,"abstract":"<div><div>During, the minimum phase of Solar Cycle 24, an intense geomagnetic storm occurred on August 26, 2018. This storm is significant not only because of its extremely high magnetic activity but also due to its great impact on the geo-magnetosphere. The aim of this paper is to distinguish the response of the equatorial/low latitude ionosphere to geomagnetic storms from those observed in the polar ionosphere. The ionospheric response to this storm has been investigated using 14 GPS receivers at the low latitudes and polar regions in the Asian and Antarctic sectors. Analysis of GPS-TEC data during the geomagnetic storm found both positive and negative storm effects over low and polar latitudes. The enhancement in VTEC data before the commencement of the geomagnetic storm is observed over all the stations at low latitude and polar regions, which is attributed to the pre-storm solar-induced events like CMEs, and proton events. Observed geomagnetic storm effects at different longitude sectors, whether it is positive or negative, are discussed using prompt penetration of electric field, disturbance dynamo electric field, neutral wind composition changes, and storm-induced wind lifting effects. During the recovery phase on 27–28, August the positive storm effect is noticed in daytime hours at equatorial/low latitude stations, whereas the negative storm effect as in the polar region.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"273 ","pages":"Article 106528"},"PeriodicalIF":1.8,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144124936","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":"Further evidence on the predictability of long-term solar activity: Tests using new data reconstructions","authors":"Gordon Reikard","doi":"10.1016/j.jastp.2025.106541","DOIUrl":"10.1016/j.jastp.2025.106541","url":null,"abstract":"<div><div>It has been understood for some time that radionuclides can be used to reconstruct long-term solar activity. Recently, new reconstructions have become available, spanning the interval from 6755 BC to the late nineteenth century. This can be spliced together with actual sunspot data to create a continuous series for sunspots at a decadal resolution. While the timing of minima and maxima are comparable to prior estimates, the new reconstruction implies higher overall solar activity and less trending. Forecasting experiments are run over horizons of 10–80 years using regressions, combinations of regressions and neural networks, and support vector machines. Despite the differences between the new and prior reconstructions, the findings are essentially the same as in earlier studies. Long-term solar variations do not exhibit regular periodicities. While cycles can be identified using spectral analysis, these are not confirmed in the time domain. The autocorrelation function and regressions on lags show no evidence of cycles at lower frequencies. In the experiments run here, the models generally predict well up to 30 years. At 40 years, forecast accuracy begins to deteriorate. At horizons of 50–80 years, the models either converge to the mean of the data or replicate recent fluctuations with a lag. Based on the results, solar activity is essentially stochastic and cannot be predicted by time series or artificial intelligence models beyond horizons of a few decades.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"273 ","pages":"Article 106541"},"PeriodicalIF":1.8,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144115336","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":"Analysis of temporal and spatial distribution of CG lightning activity and its relationship with terrain features around Jiuxianshan mountain","authors":"Biao Zhu ,&nbsp;Binbin Lin ,&nbsp;Bing Liu ,&nbsp;Hengyi Liu","doi":"10.1016/j.jastp.2025.106546","DOIUrl":"10.1016/j.jastp.2025.106546","url":null,"abstract":"<div><div>The study analyzes the Cloud-to-Ground (CG) lightning location data of the Lightning Monitoring System in Fujian Province from 2015 to 2021. It focuses on examining the temporal and spatial distribution of CG lightning activity within a 20 km radius surrounding the Jiuxianshan meteorological station in a mountainous area. Additionally, it investigates the influence of altitude, slope, and slope aspect on the distribution of CG flash, as well as the characteristics of the current intensity distribution of return stroke. The results indicate a notable difference in the distribution of ±CG flashes. Negative CG lightning activity in the surrounding areas of the meteorological station predominantly concentrates on the northwest and southeast directions of the station, and is most concentrated during the period from 13:00 to 20:00. The distribution of return stroke current intensity exhibits an unimodal pattern, with the intensity mostly distributed within the range of 10–40 kA, accounting for 76.5 %. Among them, the proportion of cases distributed between 10 and 20 kA is the highest, reaching 35.9 %. The analysis considering terrain information reveals a generally positive correlation between the distribution density of negative CG flashes and the slope. The negative CG density is higher on east-facing and southeast-facing slopes.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"273 ","pages":"Article 106546"},"PeriodicalIF":1.8,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144106387","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}