Journal of Atmospheric and Solar-Terrestrial Physics最新文献

{"title":"Evaluation of machine learning models to estimate particulate matter (2.5) in oil producing Arab countries: Kuwait as a case study","authors":"Sharaf AlKheder,&nbsp;Hajar Al-Otaibi","doi":"10.1016/j.jastp.2025.106536","DOIUrl":"10.1016/j.jastp.2025.106536","url":null,"abstract":"<div><div>Air pollution is one of the most serious environmental issues facing the State of Kuwait. The environment and the population's health depend on the state's ability to maintain air quality. Most air pollution is caused by the increasing population, increased human activities, and increased vehicle ownership. Reducing pollution and preserving the environment therefore depends on managing environmental pollutants. This research aimed to create a reliable method for assessing the concentrations of Particulate Matter 2.5 (PM_2.5; i.e., particles with a diameter less than 2.5 μm (μm)), one of the most harmful pollutants. Most of the existing studies on air quality prediction in Kuwait or similar areas face some challenges in the model accuracy, lack of datasets, and environmental variation. To address these challenges, four machine learning models: neural network models, support vector machine algorithms, generalized additive models, and random forests were used. The models were trained in four scenarios: daily or monthly data and data divided by city or aggregated. The results showed that the random forest model outperformed the others in predicting PM_2.5 concentration in all scenarios, with Coefficient of determination (<em>R</em>²) over 0.85, root mean squared error (RMSE) under 6.25 μg/m³ and mean absolute error (MAE) under 6.17 μg/m³. This study can be used as a guide for choosing the best model for estimating daily PM_2.5 concentrations in Kuwait and other places with the same climate.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"271 ","pages":"Article 106536"},"PeriodicalIF":1.8,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898804","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 meteorological variability on aerosol size distribution during the winter fog campaign over Delhi: a case study","authors":"A.K. Srivastava ,&nbsp;K. Ram ,&nbsp;D.S. Bisht ,&nbsp;M.P. Raju ,&nbsp;V. Singh ,&nbsp;V.K. Soni","doi":"10.1016/j.jastp.2025.106531","DOIUrl":"10.1016/j.jastp.2025.106531","url":null,"abstract":"<div><div>The aerosol size distribution, particularly the number and mass distributions, plays a crucial role in understanding changes in optical properties due to hygroscopic growth, which affects visibility and radiative forcing on a regional scale. The Indo-Gangetic Plain (IGP), including National Capital Region (NCR) of Delhi, experiences severe fog and haze with reduced visibility during the post-monsoon to winter months (October–February) every year. This study reports aerosol mass size distribution over Delhi during a winter fog campaign (December 15, 2015–February 15, 2016) using a ground-based optical particle counter. The fine and coarse mode aerosols were contributed to ∼85% and 15% to the total aerosol mass concentration during the campaign period. The characteristic changes in aerosol size distribution, effective radius, and the influence of meteorological factors, particularly relative humidity (RH) and temperature, under three visibility conditions: Vis-1 (&lt;600 m), Vis-2 (600–1200 m), and Vis-3 (&gt;1200 m) were investigated. Fine-mode aerosols accounted for ∼85 % of the total aerosol mass, with their concentration increasing by a factor of 3.7 during Vis-1 and 2.3 during Vis-2 compared to Vis-3, when the effective radius of aerosol was lowest (R_eff: 0.44 μm). Fine particle concentrations showed a positive correlation with RH (R = 0.35) and a negative correlation with visibility (R = −0.65), suggesting that the high RH and fine-mode aerosols contribute to fog formation and reduced visibility in Delhi-NCR.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"271 ","pages":"Article 106531"},"PeriodicalIF":1.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902276","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":"Machine learning based method for dynamic forecasting of total electron content in the equatorial ionosphere","authors":"Sumitra Iyer ,&nbsp;Yogesh Jadhav ,&nbsp;Harsh Taneja ,&nbsp;Daivik Padmanabhan","doi":"10.1016/j.jastp.2025.106533","DOIUrl":"10.1016/j.jastp.2025.106533","url":null,"abstract":"<div><div>The total electron content in the ionosphere is a vital parameter for the users of the Global Navigation Satellite System (GNSS) as it causes a delay in the satellite signal propagating through it, which in turn degrades the positional accuracy of the receiver. Thus, improving the GNSS positioning requires precise ionospheric Total Electron Content (TEC) prediction, especially in the equatorial region where complex electrodynamics and erratic space weather events introduce substantial short-term variability. Although deep learning techniques have shown promise, they frequently rely heavily on large historical datasets, are computationally demanding, and are not interpretable. In this work, we propose a Multiclass Classifier Short-Term Dynamic Prediction Model (MSTDM) that uses reliable and interpretable machine learning techniques to forecast Vertical TEC (VTEC) 30 min ahead of time. The model optimizes the training set using a threshold-based learning algorithm to identify nonrepetitive and relevant VTEC patterns from recent data. The model uses polynomial interpolation to impute missing values, and a sliding window method is used to extract temporal features, which are then further refined through statistical feature selection. The continuous VTEC values are first discretized into distinct classes, after which Support Vector Machines (SVM) and Random Forests (RF) were employed for supervised classification. Different feature selection techniques were used. Prediction accuracy for SVM and RF with Recursive Feature Elimination (RFE) demonstrated the best results during geomagnetic storm days. The results varied from 85 to 91 % and 87–92 %, respectively. The RF-RFE model outperformed other configurations with 99 % training accuracy and 96 % test accuracy. Thus, this method provided a high-performing, interpretable, and computationally efficient solution for short-term VTEC forecasting.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"271 ","pages":"Article 106533"},"PeriodicalIF":1.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143922432","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":"Conjugate hemisphere asymmetric variation in sporadic E: Role of wind shear and meteor ions","authors":"Bitap Raj Kalita ,&nbsp;P.K. Bhuyan ,&nbsp;Kehe Wang","doi":"10.1016/j.jastp.2025.106532","DOIUrl":"10.1016/j.jastp.2025.106532","url":null,"abstract":"<div><div>The long-term (7 years) ionosonde observations of sporadic E (foEs) at two magnetically conjugate stations in the 95°E longitude, and the HWM vertical wind profiles are utilized to investigate the role of meteor ion deposition rates and vertical wind shear in the seasonal variation of Es. The chosen geometry of the two stations is such that southern station (Cocos islands,12.2°S, 96°N, geo-mag lat:21°S) is geographically at the low latitude, whereas the northern station (Dibrugarh 27.5°N, 95°E, geo-mag lat: 18°N) is at the <em>low</em> mid-latitude due to the north-shifted dip equator. The statistical observations show nearly invariant seasonal characteristics of Es at the southern low-latitude station (during low solar activity)in contrast to the summer maximum at the <em>low</em> mid-latitude station. Both low and high intensity Es over Cocos were found to be anti-correlated with solar activity. However, the high-intensity Es (&gt;7 MHz) at the southern station is more frequent in the solstice. During the high solar activity period, the seasonal invariance is not maintained, and the minimum is recorded during the March equinox. The local time variation of foEs occurrence shows diurnal (semi-diurnal) oscillation at low (mid) latitude station. The HWM vertical profile of zonal winds show that wind shear depth at the low latitude station has low seasonal variation, whereas, at the <em>low</em> middle latitude station the maximum wind shear peaks during summer. Analysis of previously reported radar observations shows that the season of minimum (maximum) meteor deposition rate at equatorial/low-latitude (middle-latitude) regions are aligned with the observed season of minimum (maximum) of Es at low (middle) latitudes. Therefore, the difference of the seasonal variation of sporadic E (Es) at the two conjugate stations may be explained by a combined mechanism of wind shear variation and meteor deposition rates.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"272 ","pages":"Article 106532"},"PeriodicalIF":1.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947338","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":"Evaluating the performance of the rainfall forecast model based on GNSS ZTD and ERA5 CAPE for Hong Kong","authors":"Yang Liu ,&nbsp;Qiaoling Zhang ,&nbsp;Tenglong Wang ,&nbsp;Yibin Yao ,&nbsp;Mingxian Hu ,&nbsp;Haobo Li ,&nbsp;Bao Zhang ,&nbsp;Chaoqian Xu ,&nbsp;Qingzhi Zhao","doi":"10.1016/j.jastp.2025.106525","DOIUrl":"10.1016/j.jastp.2025.106525","url":null,"abstract":"<div><div>The Earth's troposphere delay provides valuable information for rainfall forecasting. Tropospheric delay products (e.g., Zenith Total Delay (ZTD)) derived from the Global Navigation Satellite System (GNSS) have become an indispensable approach for accessing tropospheric information. Several studies have established rainfall forecast models based on the GNSS-derived ZTD. However, the forecast predictors used in these models were all developed from the ZTD or its highly correlated parameters, resulting in high virtual forecast results. Therefore, a novel predictor, Convective Available Potential Energy (CAPE), was introduced to enhance the existing rainfall forecast model and is composed of the ZTD and CAPE rainfall (ZCR) model. The ZCR model includes six predictors: the ZTD value, ZTD variation, its derivation, CAPE value, CAPE variation, and its derivation. Hourly ZTD, CAPE, and rainfall data from three stations in Hong Kong with a time span of one year were collected to perform the experiment. The forecast accuracy of the ZCR model was evaluated using the corrected forecasted rate (CFR) and false alarm rate (FAR). The optimal thresholds of the predictors were determined using the percentile method, following the highest CFR and lowest FAR. The forecast accuracies of the ZTD and CAPE models, composed of their own three predictors, were comparable at the seasonal and monthly scales. Finally, we combined the ZTD and CAPE predictors into a ZCR model. Compared with the single ZTD or CAPE models, the combined ZCR model can significantly improve the accuracy of the FAR, with the CFR and FAR values of 93.53 % and 26.82 %, respectively. And the ZCR model also illustrates that the forecast accuracy on the monthly scale is higher than that on the seasonal scale.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"271 ","pages":"Article 106525"},"PeriodicalIF":1.8,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917914","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":"Research on PWV fusion based on ERA5 PWV and FY-4A PWV in Chinese mainland","authors":"Wei Du ,&nbsp;Yong Wang ,&nbsp;Xiao Liu ,&nbsp;Jing Huang ,&nbsp;Yanping Liu ,&nbsp;Xiangshun Meng","doi":"10.1016/j.jastp.2025.106526","DOIUrl":"10.1016/j.jastp.2025.106526","url":null,"abstract":"<div><div>High precision and high spatiotemporal resolution of precipitable water vapor (PWV) serve as fundamental support for meteorological research, severe weather forecasting and warning systems, as well as long-term climate change trend analysis. The FY-4A PWV has been widely utilized in PWV research due to its high observational accuracy and superior spatial resolution. However, there are many missing values in the FY-4A PWV due to the influence of weather and cloud cover. The ERA5 PWV has the advantages of high temporal resolution, complete data, rapid updates, and a multitude of parameters, but its spatial resolution is relatively low at 0.25° × 0.25°. Therefore, the focus of this study is to integrate the advantages of multiple datasets to obtain high-precision PWV data with superior spatiotemporal resolution and completeness. This study takes the Chinese Mainland as research area, the ERA5 PWV was interpolated to the same spatial resolution as the FY-4A PWV (4km × 4 km) using the cubic convolution interpolation, and the interpolated ERA5 PWV was used to fill in the missing values of FY-4A PWV. Based on their respective precision weights, the datasets were integrated through the fusion model to generate a complete and high-accuracy PWV product. The results show that more than 55 % of the interpolated ERA5 PWV has a correlation coefficient of more than 0.9 with the GNSS PWV, and the difference in the ERA5 PWV accuracy before and after interpolation is within 3 mm in each region. By establishing regional and seasonal data fusion model, the RMSE of the PWV after fusion can be relatively improved by 0.34 %–24.96 %,0.36 %–29.39 %,0.78 %–27.94 %,0.78 %–34.31 % for the four seasons, respectively. The fusion effect is better in spring and winter, and the fusion PWV error is basically within 4 mm. This study achieves the acquisition of high-precision PWV data with a spatial resolution of 4km × 4 km on an hourly basis in Chinese mainland. The fused PWV can provide an important database for further applications and research.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"271 ","pages":"Article 106526"},"PeriodicalIF":1.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878869","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":"Atmospheric electric field variations and its correlation with air quality index as observed from two low-latitude Indian stations","authors":"Rakhijul Alam Faruque ,&nbsp;Sujay Pal ,&nbsp;Gahul Amin ,&nbsp;Sushanta Kumar Mondal","doi":"10.1016/j.jastp.2025.106505","DOIUrl":"10.1016/j.jastp.2025.106505","url":null,"abstract":"<div><div>Atmospheric electric field (AEF) variations and their relationship with air quality indicators like the Air Quality Index (AQI) are vital in understanding both local AEF and global electric circuit (GEC) behaviors. The present study investigates the diurnal and seasonal variations of AEF at two different locations in West Bengal, India: Bagula (BGL) and Purulia (PRL). The fair weather AEF variations from these sites are compared with the global standard Carnegie curve and with other global sites. Compared to the urban site, which exhibits notable departures from the Carnegie curve, the fair-weather mean diurnal variation at the rural site displays distinct GEC signals. The AEF variations are also analyzed with respect to the AQI, and particulate matter in those two sites to evaluate the impact of local air pollution on atmospheric electricity. Moderate to strong correlations between AEF and AQI across different seasons are obtained. The seasonal AEF variation and AQI have a strong link for the winter season (r = 0.75), the post-monsoon season (r = 0.59) at BGL, and the post-monsoon season (r = 0.63) at PRL. The monsoon season experienced the lowest correlation in both sites. The AEF exhibits a strongly negative association with the AQI on a daily scale during periods of extreme pollution in both sites, suggesting the formation of a negative space charge layer that modifies AEF. Results indicate the possibility of estimating AQI values from the AEF measurements during high episodes of pollution.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"271 ","pages":"Article 106505"},"PeriodicalIF":1.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143881612","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 visualizations of solar car motion along the road","authors":"Emin Gardashov ,&nbsp;Murad Eminov ,&nbsp;Gökhan Kara ,&nbsp;Rauf Gardashov","doi":"10.1016/j.jastp.2025.106524","DOIUrl":"10.1016/j.jastp.2025.106524","url":null,"abstract":"<div><div>A mathematical model for the simulation of the motion of a solar car along the arbitrary uneven road has been developed. This model consists of two parts. The first is the “mathematical model of solar radiation falling onto the panel of the solar car” that determines the amount of solar energy falling onto the panel at any instant of time and at any point of the road. The second is the “mathematical model of the motion of the solar car” that determines the law of motion by solving the differential equation of motion while taking into account all the main forces acting on the car; namely: driving, gravity, reaction, and resistance. The model-simulated data has been used to create ArcGIS-based 3D visualization of car motion along the chosen roads.</div><div>The model developed here can be used to evaluate the performance of chosen type of solar car on uneven road and can serve for the solution of various problems such as: i) optimal choice of car motion starting time to minimize travelling time; ii) determination of the optimal speed that should be maintained along the uneven road for hybrid (PV + accumulator) cars; iii) determination of the instants of time when car will reach the mountain passes where a huge amount of solar radiation or sufficiently charged accumulators, are needed; iv) to determine the proper instants of time for triggering the accumulator and its charging, etc. At the same time, the model allows to estimate the amount of solar energy harvested by PV panel during the motion on the chosen highway. This energy depends mainly on the geographical location, the season, the weather conditions, the topography of the road (trajectory) and car speed.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"271 ","pages":"Article 106524"},"PeriodicalIF":1.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869259","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 physical parameterization for cloudy-sky downward longwave radiation: Validation for tropical and subtropical regions in Brazil","authors":"José Marcelo Lopes Júnior ,&nbsp;Juan Carlos Ceballos ,&nbsp;Simone Marilene Sievert da Costa ,&nbsp;Francisco Luiz Leitão de Mesquita ,&nbsp;Hallan Souza de Jesus ,&nbsp;André Rodrigues Gonçalves","doi":"10.1016/j.jastp.2025.106512","DOIUrl":"10.1016/j.jastp.2025.106512","url":null,"abstract":"<div><div>Downward longwave radiation is a crucial component of the surface radiation balance and is essential for a better understanding of the greenhouse effect. It is strongly influenced by atmospheric temperature, water vapor content, and cloudiness. This study proposes a new model to estimate downward longwave radiation under cloudy sky conditions, suitable for the application of remote sensing data. The Santa Barbara DISORT Atmospheric Radiative Transfer code was employed to develop parameterizations for cloud and atmospheric processes. The simulations indicated that the emissivity of a stratiform cloud when the cloud is thicker than 300 m (ε = 0.985) approaches that of a blackbody. It is shown that atmospheric emissivity and transmittance can be parameterized as functions of precipitable water content below cloud base. The model was validated using observational data from six different sites in Brazil. The parameterizations of primary model variables (atmospheric layer emissivity, atmospheric transmittance, and precipitable water below the cloud base) generally showed good agreement with radiosonde data. The parameterization of precipitable water in the sub-cloud atmosphere yielded good results, with a maximum RMSE of 0.44 g cm⁻². The developed model presents an average overestimation of only 14 W m⁻², corresponding to a percentage error of 3.5 %, and an overall average RMSE of 18.3 W m⁻² (4.6 %). It shows satisfactory performance and is suitable for application in tropical and subtropical regions, as the underlying physics of this method is consistent worldwide.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"271 ","pages":"Article 106512"},"PeriodicalIF":1.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860318","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":"Assessing temperature and water vapor in the atmospheric column over South America: a synopsis of identified trends using ERA5 reanalysis","authors":"Anna Carolina Bazzanela,&nbsp;Wanderson Luiz-Silva,&nbsp;Juan Neres,&nbsp;José Ricardo França,&nbsp;Lucas Menezes,&nbsp;Fabricio Polifke","doi":"10.1016/j.jastp.2025.106514","DOIUrl":"10.1016/j.jastp.2025.106514","url":null,"abstract":"<div><div>Climate change is already a reality globally. Several studies have quantified how these alterations affect specific energy budget components, such as radiative fluxes, heat storage, and energy transfer processes, correlating with verified modifications in several climate variables. Given the crucial role of thermodynamic processes in the hydrological cycle, this paper aims to provide a comprehensive overview of the climatology of air temperature and water vapor throughout the atmospheric column across South America. Moreover, detected trends in these variables are analyzed in the present climate using reanalysis data, focusing on the regions defined by the IPCC's Sixth Assessment Report (AR6). The results reveal an increasing air temperature trend at all levels of the atmosphere over the continent. The highest rates of air temperature rise are in the central portion of South America, while at high levels, the rate of warming is more significant in the northern part of the continent. There is an increasing trend in water vapor throughout the atmospheric column, particularly in the northern sector of South America. The identified decreasing trends of water vapor or specific humidity in the southeastern region do not exhibit a statistically significant signal. Such observed changes cause alterations in global and regional circulation patterns, mainly associated with extreme events.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"271 ","pages":"Article 106514"},"PeriodicalIF":1.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860350","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}