Journal of Atmospheric and Solar-Terrestrial Physics最新文献

{"title":"Mean winds and tidal variability from troposphere to the thermosphere retrieved from combined ground based and space borne measurements","authors":"A. Kalyan Teja ,&nbsp;M. Venkat Ratnam ,&nbsp;S. Vijaya Bhaskara Rao","doi":"10.1016/j.jastp.2024.106389","DOIUrl":"10.1016/j.jastp.2024.106389","url":null,"abstract":"<div><div>An attempt has been made to obtain mean winds covering the complete middle and upper atmosphere over a tropical region, Tirupati(13.5°N, 79.2°E) using a combined dataset of ERA5 reanalysis, SVU-meteor radar, and ICON/MIGHTI after comprehensive validation. Regardless of the season, thermospheric(200–300 km) and mesospheric(80–100 km) winds exhibit significant diurnal variability. Mean winds exhibit two distinct semi-annual oscillations at the stratopause and in the mesosphere. Tidal amplitudes are larger in meridional winds compared to that of zonal winds in the MLT region. This work has the potential in the field of numerical modeling of atmospheric circulation, especially to verify numerical simulations.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106389"},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758867","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":"Comparative time series analysis of SARIMA, LSTM, and GRU models for global SF6 emission management system","authors":"Ganime Tuğba Önder","doi":"10.1016/j.jastp.2024.106393","DOIUrl":"10.1016/j.jastp.2024.106393","url":null,"abstract":"<div><div>To maintain the balance of the atmosphere, the amount of change in greenhouse gas emissions must be under control. In order to create a management system and take forward-looking steps in this regard, there is no concrete data other than prediction models today. The success of prediction methods is better understood by comparing multiple methods. This research estimates the changes in the emissions of Sulfur Hexafluoride gas (SF₆) in the atmosphere using Seasonal Autoregressive Integrated Moving Average Model (SARIMA), Long-Short Term Memory Neural Network (LSTM) and Gated Recurrent Unit (GRU) forecast models and compares their accuracies. Focusing on monthly SF₆ emission values Between 1998; 2023, time series analysis was performed to predict future emission figures. The actual values and forecast results were compared and evaluated with performance criteria such as R², RMSE, NSE, MAE and MAPE%. The findings of this research highlight a continuous upward trend in SF₆ emissions and project that emission levels could approximately double from current levels by 2050. During the analysis process, all three methods performed well in estimating global SF₆ gas emissions. The LSTM model generally outperformed SARIMA and GRU models, having the lowest MAPE (0.003%), MAE (0.0003), RMSE (0.0003), and R² (1) values. It also exhibited very high predictive success with an NSE value of 0.9991. Therefore, it was determined to be the most suitable estimation method with the least error. The aim of this study is to contribute scientifically to the reduction strategies of SF₆ emissions.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106393"},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151997","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":"Efficient three-source model for Schumann resonance","authors":"A.P. Nickolaenko","doi":"10.1016/j.jastp.2024.106395","DOIUrl":"10.1016/j.jastp.2024.106395","url":null,"abstract":"<div><div>An efficient and simple model of global thunderstorm activity is described, which allows computing the diurnal and seasonal variations of the peak frequency of the first Schumann resonance (SR) mode. The model results are compared with the long-term monitoring of the diurnal - seasonal variations of the first SR frequency recorded in the vertical electric field component. The records were performed at the Hungarian Széchenyi István Geophysical Observatory or the Nagycenk Geophysical observatory (NCK; 47.6°N, 16.7°E). They cover the 16-year period ranging from Jan. 1994 to Dec. 2009. Comparison of model data with experimental observations allowed formulating the following conclusions. The model of the global thunderstorm activity is rather simple, it suggests that position of the global thunderstorm centers in Asia, Africa, and America varies from month to month, but it recurs from year to year. The only exception in spatial parameters is the effective width of the area occupied by lightning strokes, which is found from the observational data. Diurnal variations in thunderstorm intensity correspond to classical WMO data. In spite of its simplicity, the model is quite efficient; it allows accurately compute the diurnal variations of the first mode peak frequency. Deviations of the model <em>f</em>₁ values from those observed experimentally do not exceed 1% while the cross-correlation coefficient of their temporal variations is equal to 0.5–0.6. Authors hope to apply this model in future studies, as well as in interpreting observations at other field sites. Extension of comparable data will clarify the effective parameters of the global thunderstorm activity serving as the source of SR oscillations.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106395"},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151998","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":"Mechanism of a stepped leader in a negative lightning","authors":"A.V. Ivanovskiy","doi":"10.1016/j.jastp.2024.106391","DOIUrl":"10.1016/j.jastp.2024.106391","url":null,"abstract":"<div><div>The mechanism of a stepped leader not related to processes in the cloud is considered. The average leader speed is determined by the formation of a channel due to heating of one of the space stems in the electric field of the streamer corona. If the drift speed of the electrons in the formed channel is higher than the leader propagation speed, a drift wave arises which catches up with the boundary of the streamer zone. The electric field growth leads to a formation of the stepped leader. The mechanism is realized in case of a negative leader. Realism of this scenario has been checked by numerical simulations. For the negative leader the formation of the step with parameters close to those for natural leaders has been obtained. The estimated maximum speed of the electron drift at the stage of channel formation, which exceeds the negative leader propagation speed observed in the experiments, counts in favor of the above ideas.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106391"},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744320","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":"Modeling of Zenith Tropospheric Delay using ERA5 data over East African region","authors":"Geoffrey Andima ,&nbsp;Richard Cliffe Ssenyunzi ,&nbsp;Emirant Bertillas Amabayo ,&nbsp;Alessandra Mascitelli ,&nbsp;Eugenio Realini","doi":"10.1016/j.jastp.2024.106390","DOIUrl":"10.1016/j.jastp.2024.106390","url":null,"abstract":"<div><div>The Zenith Tropospheric Delay (ZTD) is a crucial parameter in meteorology and climate research, often estimated from surface meteorological parameters and Global Navigation Satellite Systems (GNSS) observations. In East Africa, the lack of reliable surface meteorological data and gaps in GNSS observations compromise the accuracy and reliability of ZTD data. To address this issue, site-specific ZTD models were developed using ERA5 data from 2013 to 2017, employing Empirical Orthogonal Function (EOF) analysis. The accuracy of the proposed EOF models was validated using the tropospheric product from the Nevada Geodetic Laboratory (NGL) as a reference and compared to the Global Pressure and Temperature 3 (GPT3) ZTD model. The results of the study show that the EOF ZTD models significantly outperformed the GPT3 model, reducing Mean bias (MnB) by 72.3% and Root Mean Square Error (RMSE) by 3.0%. EOF models performed particularly well for stations near the equator (latitudes 4°S and 4°N) and between latitudes 12° S and 4° S in terms of MnB and RMSE, respectively. Seasonally, EOF models surpassed the GPT3 model in MnB and RMSE across most seasons near the equator, except during the September–October–November (SON) period, where GPT3 showed an 85.5% better performance in MnB. For stations between latitudes 12° S and 4° S, GPT3 generally performed better in terms of RMSE, except during the March–April–May (MAM) period, where the EOF model excelled. However, the EOF model consistently showed better (reduced) MnB in this region. This study demonstrates that the EOF method is a viable alternative for estimating ZTD in areas with limited surface meteorological data and GNSS observation gaps. The site-specific ZTD models developed using the EOF method can significantly improve the accuracy and reliability of ZTD data, with broad applications in geodesy, atmospheric science, and navigation among others.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106390"},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143153072","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":"Remote sensing of air pollutants in China to study the effects of emission reduction policies on air quality","authors":"Gerrit de Leeuw ,&nbsp;Ronald van der A ,&nbsp;Jianhui Bai ,&nbsp;Mirjam den Hoed ,&nbsp;Jieying Ding ,&nbsp;Jianping Guo ,&nbsp;Zhengqiang Li ,&nbsp;Ying Zhang ,&nbsp;Cheng Fan ,&nbsp;Kai Qin ,&nbsp;Selviga Sinnathamby ,&nbsp;Sarah Safieddine ,&nbsp;Costas Varotsos ,&nbsp;Yong Xue ,&nbsp;Yan Yin ,&nbsp;Qianqian Zhang ,&nbsp;Xin Zhang ,&nbsp;XingYing Zhang ,&nbsp;Xiumei Zhang","doi":"10.1016/j.jastp.2024.106392","DOIUrl":"10.1016/j.jastp.2024.106392","url":null,"abstract":"<div><div>Air Quality (AQ) is determined by the concentrations of aerosols and trace gases. Aerosol concentration is measured by the mass concentration of particles smaller than 2.5 μm (PM2.5) or 10 μm (PM10), while trace gases include ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and carbon monoxide (CO). Ammonia (NH₃) and (biogenic) volatile organic compounds ((B)VOCs) also play an important role in atmospheric chemistry affecting the concentrations of trace gases and ultimately AQ. This study focuses on various aspects of AQ in China, utilizing remote sensing data from satellite and ground-based sensors to obtain information on PM emissions and concentrations and AQ-relevant trace gases. This research was conducted within the framework of the ESA/NRSCC MOST collaboration project Dragon 5, as part of the EMPAC (Exploitation of satellite remote sensing to enhance our comprehension of the Mechanisms and Processes influencing Air quality in China) project. It summarizes findings on four main topics: (1) Retrieval of trace gas concentrations and aerosol products from satellite data, validation using ground-based reference data, and interpretation of results in terms of AQ effects, such as the conversion of column-integrated properties to near-surface concentrations; (2) Determination of trace gases emissions relevant to AQ, using satellite data and models; (3) Analysis of time series data on trace gases and aerosols to assess the impact of emission reduction policies on AQ improvement; (4) Research contributing to a deeper understanding of mechanisms and processes affecting atmospheric composition about AQ.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106392"},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151974","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":"Preface to the special issue “Recent advances in Space Geophysics including COLAGE”","authors":"Inez S. Batista,&nbsp;Livia Alves,&nbsp;Clezio De Nardin,&nbsp;Sergio Dasso,&nbsp;Juan A. Valdivia","doi":"10.1016/j.jastp.2024.106368","DOIUrl":"10.1016/j.jastp.2024.106368","url":null,"abstract":"","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106368"},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143151975","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":"Evaluation of meteorological drought indices using remote sensing","authors":"Mojgan Ahmadi ,&nbsp;Hadi Ramezani Etedali ,&nbsp;Abbass Kaviani ,&nbsp;Alireza Tavakoli","doi":"10.1016/j.jastp.2024.106387","DOIUrl":"10.1016/j.jastp.2024.106387","url":null,"abstract":"<div><div>Drought indices are a suitable tool for management measures and dealing with drought and are widely used worldwide. One of the most important stages of assessing the drought situation in each region is determining the drought indices to analyze the intensity and duration of drought in that region. The drought index is actually a function of various environmental factors that affect the drought phenomenon. In this study, the drought indices of the standardized precipitation index (SPI), China-Z index (CZI), Z Score Index (ZSI), and modified CZI (MCZI) in different month time scales (1, 3, 6, 9, 12, 18, 24 and 48) and the present of normal index (PNI) in different monthly, seasonally and yearly time scales in Kurdistan Province (stations Saqqez, Qorveh, Bijar, Sanandaj) were evaluated. Global land data assimilation system (GLDAS), Climatic Research Unit (CRU) dataset, and Tropical Rainfall Measuring Mission (TRMM) precipitation data (2000-2020) and TRMM precipitation (2000-2019) were received, and the drought indices were calculated. Root mean square error (RMSE), maximum error (ME), Pearson, and Spearman correlation coefficients were used for evaluation. The results of the SPI index showed that there is a significant relationship between TRMM, CRU, and GLDAS at the Saqqez, Qorveh, and Sanandaj stations (at the 5% level), and there was no significant relationship for TRMM at Bijar station for the 24-month time scale. The correlation coefficient results for the Saqqez and Sanandaj stations in time scales of 1 to 9 months for the SPI, CZI, ZSI, and MCZI indices were better than those of the Bijar and Qorveh stations. In assessing the SPI and CZI drought indices, the highest RMSE was for GLDAS at Bijar station and for the 48-month time scale. In general, the results showed that the drought indices of the SPI, CZI, ZSI, MCZI, and PNI obtained from the TRMM satellite, CRU dataset, and GLDAS model have a good correlation with the drought indices of synoptic stations.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106387"},"PeriodicalIF":1.8,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758866","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":"Simulation and projection of photovoltaic energy potential over a tropical region using CMIP6 models","authors":"Olusola Samuel Ojo,&nbsp;Promise Dunsin Adesemoye","doi":"10.1016/j.jastp.2024.106384","DOIUrl":"10.1016/j.jastp.2024.106384","url":null,"abstract":"<div><div>The study examines the potential impact of climate change on photovoltaic energy (PV) in Nigeria. Solar radiation and temperature datasets from 13 regional climate models (CMIP6) for 2015–2099 were used to evaluate the photovoltaic energy under moderate (SSP245) and high (SSP585) emission scenarios for near-future (2023–2053), mid-future (2054–2084), and far-future (2084–2099) periods. The precision of the models for the simulation of PV energy was validated with MERRA-2 reference data using the compromise programming index (CPI). Models with the lowest CPI were selected for regional PV energy projections. The findings showed varying numbers of increase and decrease projected changes across the four regions under SSP245 and SSP585 scenarios for the near, mid and far future timescales. Specifically, in the SSP245 scenario, the model with lowest CPI was the CMCC-CESM2 model, it projected a decrease in PV energy in the Sahel (−2.30), an increase in the Guinea Savannah (+2.80), the Rainforest (+1.20) and the coastal region (+4.80) for the far future period (2085–2099). In the SSP585 scenario, the AWI-CM-1.1-MR model projected a decrease in the Sahel region (−4.60), while the MPI-ESM1-2-LR model projected an increase in the Guinea Savannah region (+1.80), and the ACCESS-CM2 model projected an increase in the Rainforest (+10.20) and Coastal regions (+13.20) for the far-future. All values in the parentheses are measured in watts-hour per square-meters. The projected changes in PV energy revealed the need for a regional-specific approach to the planning and implementation of energy transition mix in Nigeria.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106384"},"PeriodicalIF":1.8,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698825","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 ENSO teleconnections indices, and its impacts on moroccan agriculture","authors":"Sujatha Peethani ,&nbsp;Mahesh Pathakoti ,&nbsp;Mahalakshmi D. V ,&nbsp;Ahmed MS. Kheir ,&nbsp;Apoorva Singh ,&nbsp;Ajit Govind","doi":"10.1016/j.jastp.2024.106386","DOIUrl":"10.1016/j.jastp.2024.106386","url":null,"abstract":"<div><div>In Morocco, drought periods have become more frequent and severe due to climate change, which has had a substantial effect on freshwater supply and agricultural output. The El Niño-Southern Oscillation (ENSO) and the influence of climatic variability were the main subjects of the current study, which made use of daily precipitation, maximum and minimum temperature data collected at 50 locations around the nation from 1990 to 2022. The study analysed Palmer Drought Severity Index (PDSI) over Morocco to evaluate the impact of climate indices such as the Oceanic Niño Index (ONI) and the North Atlantic Oscillation (NAO) on drought severity. It also investigated the changes in precipitation, temperature, and extreme event-related indices. Rainfall is used as a proxy for El Nino and La Nina, supported by a negative and significant correlation between Oceanic Nino Index (ONI) and rainfall. Attempted to understand the impact of the NAO on Morocco's agricultural production, particularly during the winter months. During negative NAO phases, winter temperatures can lead to reduced wheat yields by 35–45% during the El Niño years and decreased by 4–7% during the La Niña years compared to the actual yield. Relying on the NAO plays a crucial role in modulating the precipitation patterns, which implies that crop requires adequate soil moisture with no extreme temperature during the growing season in order to produce higher yield. ENSO events can indeed lead to these extreme conditions in selected locations, potentially impacting crop yields.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"265 ","pages":"Article 106386"},"PeriodicalIF":1.8,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698826","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}