Pub Date : 2026-01-14DOI: 10.1016/j.jastp.2026.106734
Rafath Samrin , Pundru Chandra Shaker Reddy , K. Arun Kumar , Natha Deepthi , C. Mithra , S Bhargavi Latha , Sucharitha Yadala , Gopal Kumar Thakur
India is the dominant player in the cultivation of rice around the world. Rice yield prediction can be considered as a problem that needs to be solved. Accurate and timely prediction of rice yield can provide meaningful benefits to crop yield. Time series models are widely used for rice yield prediction, but their accuracy remains inadequate. Despite their prominence, they often fail to deliver the required precision. This study considers one of the most practical machine learning (ML) methods for predicting rice yield, allowing forecasts for the next five years. The research carried out shows the rice yield prediction done using the hybrid framework which integrates multiple linear regression (MLR) with long-short-term memory (LSTM) and its performance is compared with state-of-the-art models. The yield is forecasted from the current year through the next five years, up to 2029. The data used for the prediction model will be 1998 to 2023 from four districts of West Bengal and Uttar Pradesh. An important finding of the study was that it is possible to predict rice harvest five years in advance of actual harvest, providing useful information for agricultural decision making and planning. Researchers, policy makers and farmers can all benefit from better food security planning and resource management thanks to the study's findings, which shed light on the possibilities of combining remote sensing with biophysical parameters using ML models. Measures used to assess the suggested model include R2, RMSE, MAE, MSE, accuracy (Acc), F1 score (F1), recall (Re) and precision (Pe), among others. The suggested approach yields improved accuracy, R2, RMSE, MAE, and MSE values of 0.9823, 0.956, 0.1436, 0.021, and 0.198, respectively.
{"title":"A hybrid deep learning based framework for prediction of rice yield through integration of biophysical parameters and optical remote sensing data in India","authors":"Rafath Samrin , Pundru Chandra Shaker Reddy , K. Arun Kumar , Natha Deepthi , C. Mithra , S Bhargavi Latha , Sucharitha Yadala , Gopal Kumar Thakur","doi":"10.1016/j.jastp.2026.106734","DOIUrl":"10.1016/j.jastp.2026.106734","url":null,"abstract":"<div><div>India is the dominant player in the cultivation of rice around the world. Rice yield prediction can be considered as a problem that needs to be solved. Accurate and timely prediction of rice yield can provide meaningful benefits to crop yield. Time series models are widely used for rice yield prediction, but their accuracy remains inadequate. Despite their prominence, they often fail to deliver the required precision. This study considers one of the most practical machine learning (ML) methods for predicting rice yield, allowing forecasts for the next five years. The research carried out shows the rice yield prediction done using the hybrid framework which integrates multiple linear regression (MLR) with long-short-term memory (LSTM) and its performance is compared with state-of-the-art models. The yield is forecasted from the current year through the next five years, up to 2029. The data used for the prediction model will be 1998 to 2023 from four districts of West Bengal and Uttar Pradesh. An important finding of the study was that it is possible to predict rice harvest five years in advance of actual harvest, providing useful information for agricultural decision making and planning. Researchers, policy makers and farmers can all benefit from better food security planning and resource management thanks to the study's findings, which shed light on the possibilities of combining remote sensing with biophysical parameters using ML models. Measures used to assess the suggested model include R<sup>2</sup>, RMSE, MAE, MSE, accuracy (Acc), F1 score (F1), recall (Re) and precision (Pe), among others. The suggested approach yields improved accuracy, R<sup>2</sup>, RMSE, MAE, and MSE values of 0.9823, 0.956, 0.1436, 0.021, and 0.198, respectively.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106734"},"PeriodicalIF":1.9,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979917","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}
Pub Date : 2026-01-13DOI: 10.1016/j.jastp.2026.106736
Chengyu Song , Jing Wang , Yanju Liu
Based on the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data and the Global Precipitation Climatology Project (GPCP) data, this research examines the atmospheric anomalies associated with the interannual variability of the South China Sea (SCS) summer monsoon (SCSSM) onset, focusing particularly on its connection with positional changes of the subtropical westerly jet (SWJ) and thermal conditions over the eastern Tibetan Plateau (TP). The analysis reveals distinct difference of the circulation patterns between early and late monsoon onset years, marked by pronounced cyclonic anomalies with intensified rainfall during early onsets, contrasted by anticyclonic patterns and reduced precipitation during delayed onsets. A key finding demonstrates that early SCSSM onset years coincide with a southward displacement of the upper-level SWJ north of the SCS. This positional shift generates upper-level ageostrophic southerly winds over the SCS, establishing a dipole pattern of vertical motion. Upper-level divergence and low-level convergence happen over the SCS (south of the jet core), and upper-level convergence with low-level divergence occur over the Yangtze River basin (north of the jet). Such configuration amplifies the meridional circulation anomaly, enhancing ascending motions in low-latitude East Asia while strengthening subsidence in mid-latitude regions. The study also further shows that thermal anomalies over the eastern TP significantly affect SWJ positioning and subsequent monsoon onset timing. Positive heating anomalies initiate an upper-tropospheric anticyclone, triggering eastward-propagating Rossby waves and downstream cyclonic circulation. This prompts a southward migration of the SWJ east of the TP, altering East Asian circulation patterns to facilitate an earlier SCSSM establishment. These results shed new light on the TP's role in regional climate modulation via upper-level jet dynamics, offering potential predictive value for monsoon onset forecasting.
{"title":"How the East Asian subtropical westerly jet shapes the interannual variability of the South China Sea summer monsoon onset and the associated thermal forcing effect from the Tibetan plateau","authors":"Chengyu Song , Jing Wang , Yanju Liu","doi":"10.1016/j.jastp.2026.106736","DOIUrl":"10.1016/j.jastp.2026.106736","url":null,"abstract":"<div><div>Based on the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data and the Global Precipitation Climatology Project (GPCP) data, this research examines the atmospheric anomalies associated with the interannual variability of the South China Sea (SCS) summer monsoon (SCSSM) onset, focusing particularly on its connection with positional changes of the subtropical westerly jet (SWJ) and thermal conditions over the eastern Tibetan Plateau (TP). The analysis reveals distinct difference of the circulation patterns between early and late monsoon onset years, marked by pronounced cyclonic anomalies with intensified rainfall during early onsets, contrasted by anticyclonic patterns and reduced precipitation during delayed onsets. A key finding demonstrates that early SCSSM onset years coincide with a southward displacement of the upper-level SWJ north of the SCS. This positional shift generates upper-level ageostrophic southerly winds over the SCS, establishing a dipole pattern of vertical motion. Upper-level divergence and low-level convergence happen over the SCS (south of the jet core), and upper-level convergence with low-level divergence occur over the Yangtze River basin (north of the jet). Such configuration amplifies the meridional circulation anomaly, enhancing ascending motions in low-latitude East Asia while strengthening subsidence in mid-latitude regions. The study also further shows that thermal anomalies over the eastern TP significantly affect SWJ positioning and subsequent monsoon onset timing. Positive heating anomalies initiate an upper-tropospheric anticyclone, triggering eastward-propagating Rossby waves and downstream cyclonic circulation. This prompts a southward migration of the SWJ east of the TP, altering East Asian circulation patterns to facilitate an earlier SCSSM establishment. These results shed new light on the TP's role in regional climate modulation via upper-level jet dynamics, offering potential predictive value for monsoon onset forecasting.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106736"},"PeriodicalIF":1.9,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979918","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}
Pub Date : 2026-01-11DOI: 10.1016/j.jastp.2026.106731
Na Guo, Hongyu Zheng, Qihuan Zhou, Xinjian Yin
The accurate prediction of short-term wind power is of great significance for wind power grid integration and grid stability. Short-term wind power is not only related to historical wind power, but also influenced by meteorological factors. This paper proposes a novel combination forecasting model for short-term wind power. The max-relevance min-redundancy feature selection algorithm is used to select meteorological feature data with high correlation and low redundancy. In response to the intermittent and non-stationary characteristics of short-term wind power, variational mode decomposition algorithm is used to decompose short-term wind power, and the generated components reduce the noise and redundancy of the original data. The components obtained by variational mode decomposition are combined with the main features of the extracted meteorological data as inputs to the long short-term memory network, and the outputs of each corresponding long short-term memory network are added to obtain the final prediction result. An improved sparrow search algorithm with better optimization performance is proposed and applied to hyper-parameters optimization of long short-term memory network. Two short-term wind power datasets from different regions and sampling intervals are selected as the research objects. The proposed combination forecasting model showed 28.99 %–89.31 % decrease in RMSE, 30.81 %–86.37 % decrease in MAPE, and 11.07 %–85.38 % decrease in MAE compared with other models on the first dataset. On the second dataset, three indicators decreased by 12.21 %–80.91 %, 50.18 %–87.54 %, and 9.99 %–83.01 %. The comparison results confirmed that the proposed combination forecasting model has high prediction accuracy for short-term wind power while ensuring small system deviations, and its real-time performance can also meet the needs of practical applications.
{"title":"A novel combination forecasting model for short-term wind power","authors":"Na Guo, Hongyu Zheng, Qihuan Zhou, Xinjian Yin","doi":"10.1016/j.jastp.2026.106731","DOIUrl":"10.1016/j.jastp.2026.106731","url":null,"abstract":"<div><div>The accurate prediction of short-term wind power is of great significance for wind power grid integration and grid stability. Short-term wind power is not only related to historical wind power, but also influenced by meteorological factors. This paper proposes a novel combination forecasting model for short-term wind power. The max-relevance min-redundancy feature selection algorithm is used to select meteorological feature data with high correlation and low redundancy. In response to the intermittent and non-stationary characteristics of short-term wind power, variational mode decomposition algorithm is used to decompose short-term wind power, and the generated components reduce the noise and redundancy of the original data. The components obtained by variational mode decomposition are combined with the main features of the extracted meteorological data as inputs to the long short-term memory network, and the outputs of each corresponding long short-term memory network are added to obtain the final prediction result. An improved sparrow search algorithm with better optimization performance is proposed and applied to hyper-parameters optimization of long short-term memory network. Two short-term wind power datasets from different regions and sampling intervals are selected as the research objects. The proposed combination forecasting model showed 28.99 %–89.31 % decrease in RMSE, 30.81 %–86.37 % decrease in MAPE, and 11.07 %–85.38 % decrease in MAE compared with other models on the first dataset. On the second dataset, three indicators decreased by 12.21 %–80.91 %, 50.18 %–87.54 %, and 9.99 %–83.01 %. The comparison results confirmed that the proposed combination forecasting model has high prediction accuracy for short-term wind power while ensuring small system deviations, and its real-time performance can also meet the needs of practical applications.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106731"},"PeriodicalIF":1.9,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979915","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}
Deterioration of air quality due to increasing anthropogenic activities adversely affect human health and the environment. This study presents the space-time variability of primary pollutants, namely columnar concentrations of atmospheric Carbon monoxide (XCO), Nitrogen dioxide (XNO2), and Sulphur dioxide (XSO2), across four major Indian cities, Hyderabad, New Delhi, Chandigarh, and Guwahati during 2019–2023 using the Sentinel-5P/TROPOMI open datasets from Google Earth Engine platform. Across the study sites, atmospheric CO indicates less variability, ranging from ±5.78 ppb to ±7.7 ppb, whereas atmospheric NO2 and SO2 observed moderate to high variability of distribution ranging from ±0.04 ppb to ±0.12 ppb, and ±0.99 ppb to ±1.52 ppb, respectively. The Suomi-NPP VIIRS night-time light product used in this study signifies the extent and intensity of urbanization. Alarming trends in spatially and temporally increased pollutant concentrations are observed in Guwahati due to rapid urban expansion and unregulated biomass burning. TROPOMI and MOPITT sensors demonstrated strong agreement in CO retrievals, with a relative biases ranging from −0.40 % to 5.16 %. TROPOMI derived XCO and XNO2 retrievals show good agreement with Central Pollution Control Board measurements data. Thus, comprehensive analysis of these pollutants over these cites revealed a general increase in pollutant concentrations driven by urban development and seasonal wind patterns. The findings demonstrate the robustness of multi-sensor remote sensing datasets and urbanization indicators for monitoring air quality over rapidly developing Indian cities. The study provides valuable baseline information for developing and strengthening city-specific action plans to achieve clean air under the National Clean Air Programme (NCAP).
{"title":"Nighttime light data as a proxy for assessing air pollution in urban landscapes of India: A remote sensing perspective","authors":"Anisha Jalathota , Mahesh Pathakoti , Jaya Saxena , Kanchana Lakshmi Asuri , Mahalakshmi Venkata Dangeti , Ramesh H. Gowda , Sampath Kumar , Srinivasa Rao Goru , Prakash Chauhan","doi":"10.1016/j.jastp.2026.106732","DOIUrl":"10.1016/j.jastp.2026.106732","url":null,"abstract":"<div><div>Deterioration of air quality due to increasing anthropogenic activities adversely affect human health and the environment. This study presents the space-time variability of primary pollutants, namely columnar concentrations of atmospheric Carbon monoxide (<em>X</em>CO), Nitrogen dioxide (<em>X</em>NO<sub>2</sub>), and Sulphur dioxide (<em>X</em>SO<sub>2</sub>), across four major Indian cities, Hyderabad, New Delhi, Chandigarh, and Guwahati during 2019–2023 using the Sentinel-5P/TROPOMI open datasets from Google Earth Engine platform. Across the study sites, atmospheric CO indicates less variability, ranging from ±5.78 ppb to ±7.7 ppb, whereas atmospheric NO<sub>2</sub> and SO<sub>2</sub> observed moderate to high variability of distribution ranging from ±0.04 ppb to ±0.12 ppb, and ±0.99 ppb to ±1.52 ppb, respectively. The Suomi-NPP VIIRS night-time light product used in this study signifies the extent and intensity of urbanization. Alarming trends in spatially and temporally increased pollutant concentrations are observed in Guwahati due to rapid urban expansion and unregulated biomass burning. TROPOMI and MOPITT sensors demonstrated strong agreement in CO retrievals, with a relative biases ranging from −0.40 % to 5.16 %. TROPOMI derived <em>X</em>CO and <em>X</em>NO<sub>2</sub> retrievals show good agreement with Central Pollution Control Board measurements data. Thus, comprehensive analysis of these pollutants over these cites revealed a general increase in pollutant concentrations driven by urban development and seasonal wind patterns. The findings demonstrate the robustness of multi-sensor remote sensing datasets and urbanization indicators for monitoring air quality over rapidly developing Indian cities. The study provides valuable baseline information for developing and strengthening city-specific action plans to achieve clean air under the National Clean Air Programme (NCAP).</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106732"},"PeriodicalIF":1.9,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979916","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}
Pub Date : 2026-01-07DOI: 10.1016/j.jastp.2026.106730
Abhimanyu Kumar Gond, Aarif Jamal, Tarun Verma
This study employs a hybrid Temporal Convolutional Network (TCN) and Transformer model to forecast air quality trends in Korba, Chhattisgarh, a critically polluted industrial hub dominated by extensive coal mining (including Gevra, Dipka, and Kusmunda mines), multiple thermal power plants, aluminium smelters, and cement production, from 2025 to 2047. Utilizing 44 years of satellite-derived data (1980–2024), the model integrates meteorological variables, vegetation indices (NDVI and NDBI), and coal mining metrics. Under a moderate policy change scenario, it predicts gradually rising pollutant levels: PM10 (32–84 μg/m3), PM2.5 (10–33 μg/m3), SO2 (7.25–12 μg/m3), NO2 (5.25–9 μg/m3), and AQI (45–110, Moderate per CPCB Delhi standards), with seasonal patterns showing reduced concentrations during monsoon due to rainfall washout and elevated levels in summer and winter owing to limited atmospheric dispersion. The model demonstrated strong performance (R2 = 0.75–0.91; RMSE = 1.09–11.91), effectively capturing both short- and long-term trends driven by industrial emissions and environmental factors. A sensitivity analysis further revealed the model's robust response to ±10–20 % variations in key drivers, with the most decisive influence from coal production increases, which could be elevated by 20–30 % and add 10–15 AQI points, while reduced rainfall, higher temperatures, and lower NDVI amplified dust resuspension and secondary pollutant formation. Uncertainty analysis identified high-risk periods, including elevated PM2.5 variability in 2025–2026 and AQI in 2033–2038. Validation against ground-truth data from Urja Nagar, Rampur stations, and MODIS Satellite-derived AQI (From January–September 2025; R2: 0.72, 0.61, and 0.58) confirmed forecasted AQI (30–164, mostly Moderate), posing potential respiratory risks to vulnerable groups upon prolonged exposure. These projections highlight escalating public health threats, particularly respiratory and cardiovascular diseases, underscoring the need for urgent interventions, such as stricter emission controls, a transition to renewable energy sources, the adoption of an air quality health index, and enhanced reforestation for dust mitigation. This work offers a robust, data-driven baseline and scalable framework for sustainable air quality management in industrial regions, aligning with India's vision for balanced development by 2047.
{"title":"Long-term air quality forecasting in Korba, India (2025–2047): A hybrid model using 44-year satellite data","authors":"Abhimanyu Kumar Gond, Aarif Jamal, Tarun Verma","doi":"10.1016/j.jastp.2026.106730","DOIUrl":"10.1016/j.jastp.2026.106730","url":null,"abstract":"<div><div>This study employs a hybrid Temporal Convolutional Network (TCN) and Transformer model to forecast air quality trends in Korba, Chhattisgarh, a critically polluted industrial hub dominated by extensive coal mining (including Gevra, Dipka, and Kusmunda mines), multiple thermal power plants, aluminium smelters, and cement production, from 2025 to 2047. Utilizing 44 years of satellite-derived data (1980–2024), the model integrates meteorological variables, vegetation indices (NDVI and NDBI), and coal mining metrics. Under a moderate policy change scenario, it predicts gradually rising pollutant levels: PM<sub>10</sub> (32–84 μg/m<sup>3</sup>), PM<sub>2</sub>.<sub>5</sub> (10–33 μg/m<sup>3</sup>), SO<sub>2</sub> (7.25–12 μg/m<sup>3</sup>), NO<sub>2</sub> (5.25–9 μg/m<sup>3</sup>), and AQI (45–110, Moderate per CPCB Delhi standards), with seasonal patterns showing reduced concentrations during monsoon due to rainfall washout and elevated levels in summer and winter owing to limited atmospheric dispersion. The model demonstrated strong performance (R<sup>2</sup> = 0.75–0.91; RMSE = 1.09–11.91), effectively capturing both short- and long-term trends driven by industrial emissions and environmental factors. A sensitivity analysis further revealed the model's robust response to ±10–20 % variations in key drivers, with the most decisive influence from coal production increases, which could be elevated by 20–30 % and add 10–15 AQI points, while reduced rainfall, higher temperatures, and lower NDVI amplified dust resuspension and secondary pollutant formation. Uncertainty analysis identified high-risk periods, including elevated PM<sub>2</sub>.<sub>5</sub> variability in 2025–2026 and AQI in 2033–2038. Validation against ground-truth data from Urja Nagar, Rampur stations, and MODIS Satellite-derived AQI (From January–September 2025; R<sup>2</sup>: 0.72, 0.61, and 0.58) confirmed forecasted AQI (30–164, mostly Moderate), posing potential respiratory risks to vulnerable groups upon prolonged exposure. These projections highlight escalating public health threats, particularly respiratory and cardiovascular diseases, underscoring the need for urgent interventions, such as stricter emission controls, a transition to renewable energy sources, the adoption of an air quality health index, and enhanced reforestation for dust mitigation. This work offers a robust, data-driven baseline and scalable framework for sustainable air quality management in industrial regions, aligning with India's vision for balanced development by 2047.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106730"},"PeriodicalIF":1.9,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979506","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}
Estimating agricultural drought is hindered by limited data availability. Conversely, assessing meteorological drought is very easy as it requires only meteorological data that are easy to obtain. Thus, the study aimed to find meteorological drought indices suitable for assessing agricultural drought in a tropical river basin using remote sensing satellite data. Seven meteorological drought indices, i.e., Standardised Precipitation Index (SPI), Deciles Index (DI), Percent of Normal Index (PNI), Rainfall Anomaly Index (RAI), China-Z Index (CZI), Modified China-Z Index (MCZI), and Z-score Index (ZSI) were compared with an efficient agricultural drought index, viz., Standardised Precipitation Evapotranspiration Index (SPEI) for the Subarnarekha River basin using the NASA POWER satellite data. It was noticed that the CZI had the highest correlation with the 3-month SPEI (R2 = 0.88–0.94, followed by the RAI (R2 = 0.85–0.90). The meteorological drought indices were divided into three groups based on the ability to replicate SPEI: ‘excellent’ for SPI, CZI, and MCZI; ‘good’ for ZSI and RAI; and ‘poor’ for PNI and DI. Relying solely on correlation coefficients to evaluate drought indices provided erroneous results. However, integrating correlation, RMSE, and statistical distribution enhanced the robustness of the assessment. This approach reclassified MCZI and SPI from “good” to “excellent”. SPI and CZI showed better alignment with SPEI distributions throughout both dry and wet periods, establishing them as the most reliable alternatives for evaluating agricultural drought. The findings emphasize the importance of comprehensive evaluation criteria that incorporate several statistical metrics for reliable drought assessment in tropical and data-scarce regions.
{"title":"Assessing meteorological drought indices for monitoring agricultural drought using SPEI: a remote sensing approach","authors":"Kanhu Charan Panda , Pradosh Kumar Paramaguru , Ram Mandir Singh , Sudhir Kumar Singh","doi":"10.1016/j.jastp.2026.106726","DOIUrl":"10.1016/j.jastp.2026.106726","url":null,"abstract":"<div><div>Estimating agricultural drought is hindered by limited data availability. Conversely, assessing meteorological drought is very easy as it requires only meteorological data that are easy to obtain. Thus, the study aimed to find meteorological drought indices suitable for assessing agricultural drought in a tropical river basin using remote sensing satellite data. Seven meteorological drought indices, i.e., Standardised Precipitation Index (SPI), Deciles Index (DI), Percent of Normal Index (PNI), Rainfall Anomaly Index (RAI), China-Z Index (CZI), Modified China-Z Index (MCZI), and Z-score Index (ZSI) were compared with an efficient agricultural drought index, viz., Standardised Precipitation Evapotranspiration Index (SPEI) for the Subarnarekha River basin using the NASA POWER satellite data. It was noticed that the CZI had the highest correlation with the 3-month SPEI (R<sup>2</sup> = 0.88–0.94, followed by the RAI (R<sup>2</sup> = 0.85–0.90). The meteorological drought indices were divided into three groups based on the ability to replicate SPEI: ‘excellent’ for SPI, CZI, and MCZI; ‘good’ for ZSI and RAI; and ‘poor’ for PNI and DI. Relying solely on correlation coefficients to evaluate drought indices provided erroneous results. However, integrating correlation, RMSE, and statistical distribution enhanced the robustness of the assessment. This approach reclassified MCZI and SPI from “good” to “excellent”. SPI and CZI showed better alignment with SPEI distributions throughout both dry and wet periods, establishing them as the most reliable alternatives for evaluating agricultural drought. The findings emphasize the importance of comprehensive evaluation criteria that incorporate several statistical metrics for reliable drought assessment in tropical and data-scarce regions.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106726"},"PeriodicalIF":1.9,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940740","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}
Accurate forecasting of tropospheric surface ozone (O3) concentrations is increasingly vital due to rapid urbanization and industrial growth, which have intensified photochemical smog episodes and associated health and environmental risks. Traditional deterministic models often struggle to capture the complex nonlinear relationships among meteorological and precursor variables influencing O3 formation. Addressing this limitation, the present study introduces a Radial Basis Function Network (RBFN) model for seasonal forecasting of surface O3 concentrations using real-time ground monitoring data (2014–2017) from an urban air-quality station in Hyderabad, India (TIFR–NBF: Tata Institute of Fundamental Research–National Balloon Facility). The novelty of this work lies in applying RBFNs to capture seasonal and diurnal O3 variations with high precision, using input parameters including NO, NO2, NOx, CO, VOCs, and NMHCs. The RBFN model was trained with 80 % of the dataset and validated using 20 %, and its performance was assessed through Mean Square Error (MSE), Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and the Willmott's index(WI)Comparative analysis with the nonlinear regression-based Response Surface Methodology (RSM) revealed that the RBFN achieved superior predictive accuracy with lower RMSE (0.0038 vs. 0.0185), MSE (0.000014 vs. 0.000342), MAE (0.0021 vs. 0.0094), and (WI = 0.9999 vs. 0.9812), The model effectively captured seasonal and diurnal O3 peaks, particularly during summer and pre-monsoon periods. Overall, this study demonstrates the robustness, adaptability, and real-time forecasting potential of RBFNs, underscoring their application in early-warning systems, air-quality management, and policy-driven pollution mitigation strategies for rapidly urbanizing regions.
由于快速的城市化和工业增长加剧了光化学烟雾事件和相关的健康和环境风险,对流层表面臭氧(O3)浓度的准确预报变得越来越重要。传统的确定性模型往往难以捕捉影响臭氧形成的气象和前兆变量之间复杂的非线性关系。为了解决这一限制,本研究引入了径向基函数网络(RBFN)模型,利用印度海德拉巴城市空气质量站(TIFR-NBF:塔塔基础研究所-国家气球设施)的实时地面监测数据(2014-2017年)对地表O3浓度进行季节性预测。这项工作的新颖之处在于,利用输入参数,包括NO、NO2、NOx、CO、VOCs和NMHCs,应用rbfn以高精度捕获季节和日O3变化。RBFN模型使用80%的数据集进行训练,20%的数据集进行验证,并通过均方误差(MSE)、平均绝对误差(MAE)、均方根误差(RMSE)和Willmott指数(WI)对其性能进行评估。与基于非线性回归的响应面方法(RSM)的对比分析表明,RBFN模型在RMSE (0.0038 vs. 0.0185)、MSE (0.000014 vs. 0.000342)、MAE (0.0021 vs. 0.0094)、RBFN模型预测精度较低的情况下取得了较好的预测精度。和(WI = 0.9999 vs. 0.9812),该模式有效捕获了季节和日O3峰值,特别是在夏季和季风前期。总体而言,本研究证明了rbfn的鲁棒性、适应性和实时预测潜力,强调了其在快速城市化地区的预警系统、空气质量管理和政策驱动的污染缓解战略中的应用。
{"title":"Forecasting seasonal surface ozone trends using radial basis function networks and ground level monitoring data","authors":"Sharanya Suraboyina , Gangagni Rao Anupoju , Anand Polumati","doi":"10.1016/j.jastp.2026.106725","DOIUrl":"10.1016/j.jastp.2026.106725","url":null,"abstract":"<div><div>Accurate forecasting of tropospheric surface ozone (O<sub>3</sub>) concentrations is increasingly vital due to rapid urbanization and industrial growth, which have intensified photochemical smog episodes and associated health and environmental risks. Traditional deterministic models often struggle to capture the complex nonlinear relationships among meteorological and precursor variables influencing O<sub>3</sub> formation. Addressing this limitation, the present study introduces a Radial Basis Function Network (RBFN) model for seasonal forecasting of surface O<sub>3</sub> concentrations using real-time ground monitoring data (2014–2017) from an urban air-quality station in Hyderabad, India (TIFR–NBF: Tata Institute of Fundamental Research–National Balloon Facility). The novelty of this work lies in applying RBFNs to capture seasonal and diurnal O<sub>3</sub> variations with high precision, using input parameters including NO, NO<sub>2</sub>, NO<sub>x</sub>, CO, VOCs, and NMHCs. The RBFN model was trained with 80 % of the dataset and validated using 20 %, and its performance was assessed through Mean Square Error (MSE), Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and the Willmott's index(WI)Comparative analysis with the nonlinear regression-based Response Surface Methodology (RSM) revealed that the RBFN achieved superior predictive accuracy with lower RMSE (0.0038 vs. 0.0185), MSE (0.000014 vs. 0.000342), MAE (0.0021 vs. 0.0094), and (WI = 0.9999 vs. 0.9812), The model effectively captured seasonal and diurnal O<sub>3</sub> peaks, particularly during summer and pre-monsoon periods. Overall, this study demonstrates the robustness, adaptability, and real-time forecasting potential of RBFNs, underscoring their application in early-warning systems, air-quality management, and policy-driven pollution mitigation strategies for rapidly urbanizing regions.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106725"},"PeriodicalIF":1.9,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979914","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}
Pub Date : 2026-01-05DOI: 10.1016/j.jastp.2026.106727
Mohammad Darand , Ramtin Tashan
Soil moisture, as an important hydrological component, plays a crucial role in land–atmosphere interactions. Understanding variations in soil moisture content is highly valuable for effective water resource management, agricultural activities, and climate adaptation. The objective of this study is to analyze the spatiotemporal variations of surface soil moisture (0–7 cm) across Iran during the period 1979–2024. To achieve this, daily gridded data with a spatial resolution of 0.1° from the ERA5-Land dataset provided by ECMWF were used. The results showed that the spatial distribution pattern of soil moisture content follows the spatial patterns of precipitation, rainy days, and temperature across Iran. The modified Mann–Kendall test and Sen's slope estimator were applied to detect trends and their magnitudes at a 95 % confidence level. The findings indicated that soil moisture content across Iran has shown a decreasing trend, with an average reduction of 0.0032 m3 m−3 per decade. Temporally, the greatest reduction in soil moisture occurred during the cold and rainy seasons. Spatially, the decrease in soil moisture volume during winter was significantly higher in the northeastern part of the country compared to other regions. In some areas of the Alborz and Zagros highlands, however, soil moisture content exhibited an increasing trend. The findings of this study suggest that changes in soil moisture can be a potential predictor of climate change and can be applied to the fields of water resource management, agriculture, flood management, and hydrology.
{"title":"Long-term spatiotemporal analysis of variation in soil moisture over Iran","authors":"Mohammad Darand , Ramtin Tashan","doi":"10.1016/j.jastp.2026.106727","DOIUrl":"10.1016/j.jastp.2026.106727","url":null,"abstract":"<div><div>Soil moisture, as an important hydrological component, plays a crucial role in land–atmosphere interactions. Understanding variations in soil moisture content is highly valuable for effective water resource management, agricultural activities, and climate adaptation. The objective of this study is to analyze the spatiotemporal variations of surface soil moisture (0–7 cm) across Iran during the period 1979–2024. To achieve this, daily gridded data with a spatial resolution of 0.1° from the ERA5-Land dataset provided by ECMWF were used. The results showed that the spatial distribution pattern of soil moisture content follows the spatial patterns of precipitation, rainy days, and temperature across Iran. The modified Mann–Kendall test and Sen's slope estimator were applied to detect trends and their magnitudes at a 95 % confidence level. The findings indicated that soil moisture content across Iran has shown a decreasing trend, with an average reduction of 0.0032 m<sup>3</sup> m<sup>−3</sup> per decade. Temporally, the greatest reduction in soil moisture occurred during the cold and rainy seasons. Spatially, the decrease in soil moisture volume during winter was significantly higher in the northeastern part of the country compared to other regions. In some areas of the Alborz and Zagros highlands, however, soil moisture content exhibited an increasing trend. The findings of this study suggest that changes in soil moisture can be a potential predictor of climate change and can be applied to the fields of water resource management, agriculture, flood management, and hydrology.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106727"},"PeriodicalIF":1.9,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940742","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}
Pub Date : 2026-01-05DOI: 10.1016/j.jastp.2026.106724
Baris Baykant Alagoz , Cemal Keles , Burhan Baran
Global warming is a near-future major problem that has serious consequences on life on Earth. Accumulation of CO2 emission in the atmosphere becomes a dominating factor in the global warming process. This study introduces a global temperature uptrend model that considers effects of atmospheric CO2 buildup because of combustion of natural gas, oil and coal fuels. The model is based on earth's energy balance modeling and estimates impacts of fossil fuel-based CO2 emission on the average global temperature. To evaluate effects of fossil fuel reduction policies, this model is used to study yearly 3 %, 5 % and 7 % fossil fuel reduction scenarios on 2013–2022 global fuel consumption data. This backward projection indicated that the cumulative carbon dioxide emission of 10-year global fuel consumption has potential of about +0.023 °C/y global temperature rise between 2013 and 2022 years. Moreover, this model is also used for forward projections to discuss the effects of these 10-year-long fossil fuel reduction programs on future trends of global temperature anomaly.
{"title":"A note on effects of fossil fuel reduction policies on atmospheric carbon dioxide buildup and global warming","authors":"Baris Baykant Alagoz , Cemal Keles , Burhan Baran","doi":"10.1016/j.jastp.2026.106724","DOIUrl":"10.1016/j.jastp.2026.106724","url":null,"abstract":"<div><div>Global warming is a near-future major problem that has serious consequences on life on Earth. Accumulation of CO<sub>2</sub> emission in the atmosphere becomes a dominating factor in the global warming process. This study introduces a global temperature uptrend model that considers effects of atmospheric CO<sub>2</sub> buildup because of combustion of natural gas, oil and coal fuels. The model is based on earth's energy balance modeling and estimates impacts of fossil fuel-based CO<sub>2</sub> emission on the average global temperature. To evaluate effects of fossil fuel reduction policies, this model is used to study yearly 3 %, 5 % and 7 % fossil fuel reduction scenarios on 2013–2022 global fuel consumption data. This backward projection indicated that the cumulative carbon dioxide emission of 10-year global fuel consumption has potential of about +0.023 °C/y global temperature rise between 2013 and 2022 years. Moreover, this model is also used for forward projections to discuss the effects of these 10-year-long fossil fuel reduction programs on future trends of global temperature anomaly.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106724"},"PeriodicalIF":1.9,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940744","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}
Pub Date : 2026-01-05DOI: 10.1016/j.jastp.2025.106713
A.O. Adelakun
This study applies a unified nonlinear framework–combining multifractal detrended fluctuation analysis (MF–DFA), recurrence quantification analysis (RQA), and transfer entropy (TE)–to investigate the dynamical coupling between proton density (PD), temperature (PT), and speed (PS) in the solar wind. The results reveal a consistent hierarchy across all diagnostics: temperature-speed coupling dominates (), governing the principal pathway of energy redistribution. The PT–PS pair exhibits the broadest joint singularity spectrum and the strongest multifractal asymmetry, while recurrence metrics show sustained synchronization and structured determinism. Transfer–entropy analysis confirms a thermal–compressive kinetic directionality, with PD and PT acting as information sources (, ) and PS acting as the receiver (). These findings depict the solar wind as a self-organized, multiscale system in which intermittent synchronization between thermal and kinetic processes regulates flow variability. The integrated multifractal–recurrence–entropy framework provides a new diagnostic tool for identifying regime transitions and improving space-weather predictability.
{"title":"Multifractal, recurrence, and information–Theoretic characterization of coupled proton dynamics in the solar wind","authors":"A.O. Adelakun","doi":"10.1016/j.jastp.2025.106713","DOIUrl":"10.1016/j.jastp.2025.106713","url":null,"abstract":"<div><div>This study applies a unified nonlinear framework–combining multifractal detrended fluctuation analysis (MF–DFA), recurrence quantification analysis (RQA), and transfer entropy (TE)–to investigate the dynamical coupling between proton density (PD), temperature (PT), and speed (PS) in the solar wind. The results reveal a consistent hierarchy across all diagnostics: temperature-speed coupling dominates (<span><math><mrow><mi>PT − PS</mi><mo>></mo><mi>PD − PS</mi><mo>></mo><mi>PD − PT</mi></mrow></math></span>), governing the principal pathway of energy redistribution. The PT–PS pair exhibits the broadest joint singularity spectrum and the strongest multifractal asymmetry, while recurrence metrics show sustained synchronization and structured determinism. Transfer–entropy analysis confirms a thermal–compressive <span><math><mo>→</mo></math></span> kinetic directionality, with PD and PT acting as information sources (<span><math><mrow><mi>PD</mi><mo>=</mo><mo>+</mo><mn>0</mn><mo>.</mo><mn>869</mn></mrow></math></span>, <span><math><mrow><mi>PT</mi><mo>=</mo><mo>+</mo><mn>0</mn><mo>.</mo><mn>457</mn></mrow></math></span>) and PS acting as the receiver (<span><math><mrow><mi>PS</mi><mo>=</mo><mo>−</mo><mn>1</mn><mo>.</mo><mn>326</mn></mrow></math></span>). These findings depict the solar wind as a self-organized, multiscale system in which intermittent synchronization between thermal and kinetic processes regulates flow variability. The integrated multifractal–recurrence–entropy framework provides a new diagnostic tool for identifying regime transitions and improving space-weather predictability.</div></div>","PeriodicalId":15096,"journal":{"name":"Journal of Atmospheric and Solar-Terrestrial Physics","volume":"279 ","pages":"Article 106713"},"PeriodicalIF":1.9,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897868","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}