Journal of Atmospheric and Solar-Terrestrial Physics最新文献

{"title":"Ionospheric effects during the total solar eclipse over South-East Asia-Pacific on 9 March 2016, Part 2: Total electron content reduction and fluctuation patterns","authors":"Asnawi Husin ,&nbsp;Jiyo Harjosuwito ,&nbsp;Sefria Anggarani ,&nbsp;Varuliantor Dear ,&nbsp;Agri Faturahman ,&nbsp;Rezy Pradipta","doi":"10.1016/j.jastp.2024.106295","DOIUrl":"10.1016/j.jastp.2024.106295","url":null,"abstract":"<div><p>We report our observations and data analysis of ionospheric effects during the total solar eclipse over the South-East Asia-Pacific region on 9 March 2016. Here we present observations of spatio-temporal changes in the total electron content (TEC) distribution in the areas traversed by the eclipse. TEC reductions of 10-14 TECU were observed over the eastern part of Indonesia and over Guam. In the surveilled areas, TEC reductions due to solar extreme ultraviolet (EUV) obstruction during the eclipse were more prominent at coordinate points located further east, closer to the point of greatest eclipse duration in the middle of the Pacific. In addition, we also discuss observations of medium-scale traveling ionospheric disturbances (MSTIDs) associated with the passage of this solar eclipse. Signatures of eclipse-related TIDs were seen in the TEC perturbation (TECP) signals from several GPS receiver stations in eastern part of Indonesia and in the Doppler signals from ionosonde measurements at Guam. These MSTIDs were observed at F-region heights with a period of 30–45 min, Doppler velocity amplitude of 15 m/s, and TECP fluctuations of 0.3–0.4 TECU.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"262 ","pages":"Article 106295"},"PeriodicalIF":1.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141711933","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":"Quantifying urban air quality through multispectral satellite imagery and Google earth Engine","authors":"Faezeh Zamiri Aghdam ,&nbsp;Mahdi Hasanlou ,&nbsp;Milad Dehghanijabbarlou","doi":"10.1016/j.jastp.2024.106301","DOIUrl":"10.1016/j.jastp.2024.106301","url":null,"abstract":"<div><p>The escalating concerns surrounding urban air pollution's impact on both the environment and human health have prompted increased attention from researchers, policymakers, and citizens alike. As such, this study addresses growing concerns about urban air pollution's impact on the environment and human health, emphasizing the need for early, high-resolution PM2.5 pollutant measurements. Utilizing Google Earth Engine (GEE) machine learning algorithms, our study evaluates six models over four years in Tehran and Tabriz. Inputs include satellite imagery, meteorological data, and pollutant measurements from air quality stations. Four models—Histogram Gradient Boosting, Random Forest, Extreme Gradient Boosting, and Ada Boosted Decision Trees—outperform Support Vector Machine and Linear Regression. The selected model, a combination of decision tree algorithms and Ada Boost, achieves a notable correlation coefficient of 79.8% and an RMSE of 0.271 g/m3. This superior performance enables the generation of high-resolution (30-m) PM2.5 estimates for the two cities. The study's comprehensive approach, involving various data sources and advanced machine learning techniques, contributes a valuable method for accurate PM2.5 assessment. The findings hold significance for urban air quality management and provide a potential framework for generating detailed PM2.5 datasets based on Landsat images.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"261 ","pages":"Article 106301"},"PeriodicalIF":1.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623791","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 on long term troposphere lower stratosphere temperature (TLST) trend in tropical and subtropical northern hemisphere using ground based and COSMIC satellite data","authors":"Tsehaye Negash ,&nbsp;U. Prakash Raju","doi":"10.1016/j.jastp.2024.106306","DOIUrl":"10.1016/j.jastp.2024.106306","url":null,"abstract":"<div><p>The troposphere, the lowest and closest layer of the atmosphere, is where all meteorological events take place. The tropospheric — lower stratospheric (TLS) temperature trend is determined using linear regression and is essential to comprehending the consequences of climate change in the future. In this article, we explored the long-term temperature variabilities and trends of TLS (1–25 km) temperature and its responses by natural drivers such as El Nino southern oscillation (ENSO), solar flux (SF), quasi-biannual oscillation (QBO), Indian ocean dipole (IOD), and aerosol indexes (AI) using monthly averaged zonal mean COSMIC satellite and ground — based Radiosonde (RS) observations for the period of 2006 – 2020 over tropical station Addis (<span><math><msup><mrow><mn>9</mn></mrow><mrow><mn>0</mn></mrow></msup></math></span> N, <span><math><mrow><mn>38</mn><mo>.</mo><msup><mrow><mn>8</mn></mrow><mrow><mn>0</mn></mrow></msup></mrow></math></span> E) and subtropical station Cairo (<span><math><mrow><mn>30</mn><mo>.</mo><mn>0</mn><msup><mrow><mn>3</mn></mrow><mrow><mn>0</mn></mrow></msup></mrow></math></span> N, <span><math><mrow><mn>31</mn><mo>.</mo><mn>2</mn><msup><mrow><mn>3</mn></mrow><mrow><mn>0</mn></mrow></msup></mrow></math></span> E). The tropopause is located at the tropical station Addis at 17 km with a temperature of 190–194 K, and for the subtropical station Cairo, it is located at 15 km with a temperature of 201 K, which supports the decrement of tropopause height from the tropics to the subtropics with a slight increase in temperature. The two main oscillations in the TLS region can be seen by using the wavelet analysis technique: the semiannual oscillation (SAO) and the annual oscillation (AO), with the AO being especially strong in the lower troposphere. Furthermore, Morlet wavelet analysis on cold-point tropopause temperature CPTt displays AO and cold point tropopause height CPTh reveals a QBO-like signal. The TLS region has positive peaks at heights of 7, 21, 22, 13, and 4 km for the Addis station, and at 15, 19, 25, 15, and 16 km for the Cairo station in response to natural drivers such as ENSO, SF, QBO, IOD, and aerosol. Lag analyses demonstrate a one-month delay for all natural forcings, except for oceanic indices and SSF, up to three months below the tropopause (below 15 km). There is a noticeable 3 to 4 months lag in every oscillation above the tropopause. A warming trend in the tropospheric region and a cooling trend in the UTLS regions are revealed by MLR trend analysis. In contrast to the subtropical Cairo station, which has the highest warming rate of 0.38 K/decade at 2 km and the maximum cooling rate of −0.2 K/decade at 10 km, the tropical Addis station has the highest cooling rate of −0.38 K/decade at 12 km and the highest warming rate of 0.28 K/decade at 3 km. Our trend findings are consistent with previous research.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"261 ","pages":"Article 106306"},"PeriodicalIF":1.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141637102","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":"Structure of tropical cyclones in the southeast Iran using satellite observations","authors":"Elham Ghasemifar ,&nbsp;Somayeh Naserpour ,&nbsp;Zahra Sonboli","doi":"10.1016/j.jastp.2024.106308","DOIUrl":"10.1016/j.jastp.2024.106308","url":null,"abstract":"<div><p>The southeast Iran is exposed to flash floods from tropical cyclones originating in the North Indian Ocean. During late May–September of the period 2007–2022, 11 cyclones hit this region. Although the theoretical basis of these cyclones is well documented in the literature, their physical structure in terms of rain rate, rain type, warm rain, cloudiness, and aerosol distribution is not yet documented. In this study, the structure of 11 cyclones was investigated by the radar (Tropical Rainfall Measuring Mission (TRMM), Global Precipitation Measurement (GPM) and CloudSat), lidar (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO)), and optic (Aqua) satellite data and ERA5 reanalysis datasets. The results show that the maximum moisture transport and upward motion are located in the southeast quadrant. As a result, the maximum total rain rate, the stratiform and the convective rain rate fall in this quadrant. The distribution of the rain rate is consistent with the distribution of the storm top height. The southeast quadrant followed by the northeast receives the least warm rain. Moreover, the southeast quadrant also recorded the highest frequency of convective clouds. The maximum aerosol optical depth is located in the southern quadrants, particularly in the southwest and is consistent up to 5 km, after which the maximum shifts to the northwest. The obtained results can help decision makers within the hydrological and risk management industries.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"261 ","pages":"Article 106308"},"PeriodicalIF":1.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623792","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":"Empirical orthogonal function based modelling of ionosphere using Turkish GNSS network","authors":"Kutubuddin Ansari ,&nbsp;Janusz Walo ,&nbsp;Selcuk Sagir ,&nbsp;Kinga Wezka","doi":"10.1016/j.jastp.2024.106294","DOIUrl":"https://doi.org/10.1016/j.jastp.2024.106294","url":null,"abstract":"<div><p>The study investigates ionospheric total electron content (TEC) variation over Turkey from the five selected global navigation satellite system (GNSS) stations situated in diverse parts of Turkey. The geomagnetic indices are used and observed TEC are modeled with the technique known as Empirical orthogonal function (EOF). It is valuable to note that the correlation coefficient between observed GNSS TEC values and EOF TEC values varies from 0.8020 to 0.9394. The root means square error (RMSE) values between observed GNSS TEC values and EOF TEC lie between 3.1665 TECU to 4.4220 TECU. These results show that the EOF model performs quite well in the Turkish region and can present the model TEC variations perfectly. Finally, these GNSS observed and EOF-predicted TEC values along with geomagnetic indices are studied with the tropospheric wind speed. The results showed that both observed and modeled TEC have very low correlations with tropospheric wind speed and do not provide any significant value. Hence, we concluded that the ionospheric region is not affected by tropospheric wind speed. It happens because the tropospheric wind speed is a matter of the lower troposphere and its atmospheric pressure while the ionosphere is far from the earth and depends upon the number of free electrons.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"261 ","pages":"Article 106294"},"PeriodicalIF":1.8,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1364682624001226/pdfft?md5=35b6e91fd6cc91584c77ecd649524292&pid=1-s2.0-S1364682624001226-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141605032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the relationship between lightning discharge current and plasma spectrum","authors":"Hong Deng ,&nbsp;Facai Su ,&nbsp;Ping Yuan ,&nbsp;Baoyu Chen ,&nbsp;Tingting An ,&nbsp;Linhui Chen ,&nbsp;Yingying An ,&nbsp;Guorong Liu","doi":"10.1016/j.jastp.2024.106307","DOIUrl":"https://doi.org/10.1016/j.jastp.2024.106307","url":null,"abstract":"<div><p>Lightning return stroke discharge current is a key parameter being concerned in lightning protection design. Since the current of natural lightning is difficult to be directly measured, and the existing experimental methods cannot obtain the information of the current change along the channel, the correlation between the current intensity and the corresponding spectral characteristics makes it possible to investigate the current transmission characteristic. The high time resolution spectra of the whole channel outside the cloud for nine multi-return cloud-to-ground (CG) lightning discharges were captured by using a high time-resolved slit-less spectrograph, and the light radiation characteristics of the discharge plasma channel have been investigated. Based on plasma spectral diagnosis method, combined with the synchronous electric field change waveform caused by lightning, using the relationship between electric field variation amplitude and the corresponding discharge current, the dependence of spectral characteristics on discharge current intensity was analyzed. We found that the intensity of the ionic lines in the spectrum are positively correlated with the current intensity. Semi-empirical data fitting shown that for most of the lightning studied in this work, there is a good quadratic correlation between ionic lines intensity and peak current. The correlation between spectral characteristics and discharge current intensity depends on the radiation mechanism of spectral lines with different excitation energy. The intensity of the ionic lines in the spectrum can reflect the current intensity in more detail than the total luminous intensity.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"261 ","pages":"Article 106307"},"PeriodicalIF":1.8,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141605033","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":"First measurements of wind-turbine perturbations of fair-weather electric fields","authors":"Karl D. Stephan ,&nbsp;Richard Sonnenfeld ,&nbsp;Analies DeGroot King ,&nbsp;Nathan Cortez ,&nbsp;Roberto Toledo","doi":"10.1016/j.jastp.2024.106298","DOIUrl":"https://doi.org/10.1016/j.jastp.2024.106298","url":null,"abstract":"<div><p>Wind turbines have been shown to develop corona at blade tips due to the presence of the fair-weather electric field, but up to now there have been no published investigations of how the presence of a wind turbine perturbs the fair-weather field as measured on the ground near the turbine. Such data may be useful to evaluate the integrity of turbine lightning protection systems. We present the first such published measurements in this paper. Our model predicts measurable periodic variations, and our experimental measurements show a peak-to-peak perturbation up to about 7 V m⁻¹ in a nominal 100 V m⁻¹ fair-weather field as measured on the ground under the moving turbine's blades. Smaller perturbations are detectable at greater distances.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"261 ","pages":"Article 106298"},"PeriodicalIF":1.8,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141605031","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":"Report on the effects of the May 2024 Mother's day geomagnetic storm observed from Chile","authors":"J.A. Lazzús ,&nbsp;I. Salfate","doi":"10.1016/j.jastp.2024.106304","DOIUrl":"10.1016/j.jastp.2024.106304","url":null,"abstract":"<div><p>This study investigates the extreme geomagnetic storm of May 10–15, 2024, utilizing data from the SER ground-based station in Chile and the DSCOVR satellite. The methodology involves calculating the horizontal magnetic field (H), filtering geomagnetic data using a Butterworth filter, and conducting cross-correlation analysis between solar wind parameters and Pc5 pulsations. The storm, starting with a sudden storm commencement triggered by a coronal mass ejection around 18:00 UT on May 10, exhibited a main phase lasting about 8 h, followed by a recovery phase starting on May 11. The extreme storm exhibited abrupt fluctuations in the interplanetary magnetic field data and solar wind parameters, inducing a depression in the geomagnetic field H-component reaching ΔH ∼ −551 nT at the SER station. Throughout the storm, solar wind parameters such as density, speed, and temperature exhibited varied ranges, with significant changes observed in all storm phases. Notably, during the initial and main phases, cross-correlation analysis unveiled robust associations between Pc5 pulsations and solar wind parameters such as density and speed, with maximum R values reaching 0.98 for both phases.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"261 ","pages":"Article 106304"},"PeriodicalIF":1.8,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623789","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":"Geomagnetically induced currents (GICs) during strong geomagnetic activity (storms, substorms, and magnetic pulsations) on 23–24 April 2023","authors":"Irina Despirak ,&nbsp;Pavel Setsko ,&nbsp;Andris Lubchich ,&nbsp;Rajkumar Hajra ,&nbsp;Yaroslav Sakharov ,&nbsp;Gurbax Lakhina ,&nbsp;Vasiliy Selivanov ,&nbsp;Bruce Tsatnam Tsurutani","doi":"10.1016/j.jastp.2024.106293","DOIUrl":"https://doi.org/10.1016/j.jastp.2024.106293","url":null,"abstract":"<div><p>We analyzed intense geomagnetically induced currents (GICs) recorded during a complex space weather event observed on 23–24 April 2023. Two geomagnetic storms characterized by SYM/H intensities of −179 nT and −233 nT were caused by southward interplanetary magnetic field (IMF) Bz component of −25 nT in the sheath fields, and −33 nT in the magnetic cloud (MC) fields, respectively. GIC observations were divided into two local time sectors: nighttime (1700–2400 UT on 23 April) GICs observed during the interplanetary sheath magnetic storm, and morning sector (0200–0700 UT on 24 April) GICs observed during the MC magnetic storm. By using the direct measurements of GICs on several substations of Karelian-Kola power line (located in the north-west portion of Russia) and gas pipeline station near Mäntsälä (south of Finland), we managed to trace the meridional profile of GIC increases at different latitudes. It was shown that the night sector GIC intensifications (∼18–42 A) occurred in accordance with poleward expansion of the westward electrojet during a substorm. On the other hand, the intense morning sector GICs (∼12–46 A) were caused by Ps 6 magnetic pulsations. In addition, a strong local morning GIC (∼44 A) was associated with a local substorm-like disturbance caused by a high-density solar wind structure, possibly a coronal loop portion of an interplanetary coronal mass ejection.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"261 ","pages":"Article 106293"},"PeriodicalIF":1.8,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141605029","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":"Numerical simulations of the heavy rain event in the Democratic People's Republic of Korea during 9–10 August 2020","authors":"Yong-Min Ro,&nbsp;Kum-Ryong Jo","doi":"10.1016/j.jastp.2024.106297","DOIUrl":"10.1016/j.jastp.2024.106297","url":null,"abstract":"<div><p>Accurate forecasting of heavy rainfalls and understanding of their dynamics are important to minimize the damage caused by them in the Democratic People's Republic of Korea (DPR Korea). This study is conducted on a heavy rainfall event (452 mm) on 9–10 August 2020 over Pankyo region located on the midlands of the Korean peninsula. To verify the proper configuration of convection-permitting simulations, sensitivity experiments were performed with five microphysical schemes (Lin, Goddard, Thompson, Morrison and WDM6) of the Weather Research and Forecasting (WRF) model. The results suggested that all high-resolution simulations reflect the main characteristics of observed precipitation pattern well, but the location and intensity of maximum precipitation from scheme to scheme. Among the considered all the microphysics, the Lin scheme showed the best agreement with observed precipitation. Results also showed that the Lin scheme reproduced the vertical distribution and time variation of several hydrometeors, as well as dynamic and thermodynamic parameters associated with heavy rainfall well. These outcomes suggest that the suitable selection of microphysics schemes with WRF model is important to predict and understand heavy rainfall events over the DPR Korea.</p></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"261 ","pages":"Article 106297"},"PeriodicalIF":1.8,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141630575","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}