{"title":"Understanding the driving mechanism for heat waves variability over South Asia during El Niño and La Niña events","authors":"Gayatri Prasad Adhikari , Geli Wang","doi":"10.1016/j.atmosres.2025.108076","DOIUrl":"10.1016/j.atmosres.2025.108076","url":null,"abstract":"<div><div>This study focuses on heat waves (HWs) variability over South Asia (SA) influenced by El Niño Southern Oscillation (ENSO) during 1950–2023. The influence factor and driving mechanism for HWs variability over SA in the El Niño and La Niña years are discussed. We observe positive composite anomalies of HWs events and frequency over the north-western region of SA in La Niña years but negative composite anomalies in El Niño years. In La Niña years, outgoing long-wave radiation (total cloud cover) over the north-western region of SA has positive (negative) anomalies. Thus, less cloud cover regions allow more solar radiation to increase the surface temperature and HWs. During La Niña years, positive composite anomalies of HWs over the north-western region of SA are mainly due to positive anomalies of outgoing long wave radiation, negative anomalies of total cloud cover, positive anomalies of soil temperature level 1, negative anomalies of relative humidity, positive anomalies of short-wave radiation and negative anomalies of long-wave radiation. However, during El Niño years, negative composite anomalies of HWs over the north-western region of SA are due to negative anomalies of outgoing long wave radiation, positive anomalies of total cloud cover, and negative anomalies of direct solar radiation. During El Niño years, vertical-latitude cross-section and vertical-longitude cross-section analysis show significant positive anomalies of air temperature, positive anomalies of vertical velocity, negative anomalies of relative humidity, and positive anomalies of geopotential height; support increases in the HWs over the southern and central -eastern region of SA. These findings give important insights into how future weather patterns may evolve during ENSO events and can contribute to early forecasting and making heat wave adaptation strategies.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"321 ","pages":"Article 108076"},"PeriodicalIF":4.5,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143715701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yue Xin , Wenting Hu , Anmin Duan , Bin Tang , Yuheng Tang
{"title":"Evaluation of the CMIP6 models for simulating the trend of the Barents-Kara Sea compound heatwaves in boreal autumn","authors":"Yue Xin , Wenting Hu , Anmin Duan , Bin Tang , Yuheng Tang","doi":"10.1016/j.atmosres.2025.108077","DOIUrl":"10.1016/j.atmosres.2025.108077","url":null,"abstract":"<div><div>Compound heatwaves (CHWs) pose more severe environmental and socio-economic risks than individual heatwave events, with their frequency increasing rapidly worldwide. In the Arctic, particularly the Barents–Kara Sea (BKS), CHWs are intensifying, accelerating ice melt, permafrost thaw, and ecosystem disruptions. Accurate climate projections require a robust assessment of climate models' ability to simulate these extreme events. This study evaluates the performance of 24 CMIP6 models in reproducing autumn CHW trends in the BKS, revealing substantial intermodel discrepancies in trend magnitudes and spatial patterns. The observed BKS regional CHW trend is 0.55 events per decade. Group A models (e.g., ACCESS-CM2, CanESM5, GFDL-CM4) exhibit smaller errors, with a mean absolute bias of −0.03 events per decade, while Group B models (e.g., FGOALS-g3, GFDL-ESM4, MIROC6) show larger discrepancies, with a mean absolute bias of −0.40 events per decade. Further analysis reveals that Group A models better simulate the enhanced moisture transport from the Atlantic to the BKS, a key driver of CHWs, with smaller deviations in latent heat flux and net longwave radiation. The results highlight the significant role of water vapor in the occurrence of CHWs and suggest that improving the representation of these processes could enhance the accuracy of future Arctic CHW projections. This study underscores the importance of model evaluation for improving climate predictions and understanding the dynamics of extreme heat events in high-latitude regions.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108077"},"PeriodicalIF":4.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"“Roller coaster”-type temperature fluctuations in China in 2024 winter and the asymmetric influence from the Polar front jet","authors":"Ting Ding, Hui Gao, Xiang Li","doi":"10.1016/j.atmosres.2025.108060","DOIUrl":"10.1016/j.atmosres.2025.108060","url":null,"abstract":"<div><div>Notable “roller coaster”-type temperature fluctuations occurred in the 2024 winter in China though the seasonal mean temperature displayed a normal value. The standard deviation of daily temperature anomalies broke the highest record since 1961. By adopting an objective definition of the “roller coaster”-type temperature fluctuation, 19 events of such occurrences are observed during 1981–2024, four of which occurred in the 2024 winter. Corresponds to the temperature fluctuations in the winter, the Siberian high exhibits a synchronous variation, with significantly greater intensities in the three cold spells and considerably weaker values in the three warm spells. In contrast, the Polar front jet displays an asymmetric influence, with significantly enhanced zonal wind speeds in warm spells, while normal intensity in cold spells. The statistical results for each of the 45-day warm and cold groups in the current winter also support this conclusion.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"321 ","pages":"Article 108060"},"PeriodicalIF":4.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guantian Wang , Zeyong Hu , Haipeng Yu , Genhou Sun , Ruijia Niu , Xin Wang
{"title":"Land-atmosphere coupling characteristics in summer based on microwave radiometer data at Nagqu site of Tibetan Plateau","authors":"Guantian Wang , Zeyong Hu , Haipeng Yu , Genhou Sun , Ruijia Niu , Xin Wang","doi":"10.1016/j.atmosres.2025.108074","DOIUrl":"10.1016/j.atmosres.2025.108074","url":null,"abstract":"<div><div>The energy transfer within the planetary boundary layer (PBL) is a crucial variable influencing weather processes both on the Tibetan Plateau (TP) and in its downstream areas. This paper assesses the accuracy of ground-based microwave radiometer (MWR) in comparison with radiosonde data in different weather conditions. The effects of surface heat flux and precipitation on the atmosphere in different weather conditions are quantified to facilitate the study of land- atmosphere coupling in the Nagqu region. The findings indicate that microwave radiometer can provide accurate measurements of air temperature within 4 km height and specific humidity below cloud cover. The variation in surface sensible heat aligns with changes in the convective boundary layer (CBL) height, whereas latent heat shows no significant correlation during the diurnal cycle. Furthermore, daily precipitation process influences the lower atmosphere in the Nagqu region, with the impact scaling with precipitation intensity. The MWR observations indicate that precipitation generated by the Tibetan Plateau vortex (TPV) has the most significant impact on the land-atmosphere energy exchange.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108074"},"PeriodicalIF":4.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yi Liu , Jialei Wang , Yang Song , Shi Liang , Min Xia , Qilin Zhang
{"title":"Lightning nowcasting based on high-density area and extrapolation utilizing long-range lightning location data","authors":"Yi Liu , Jialei Wang , Yang Song , Shi Liang , Min Xia , Qilin Zhang","doi":"10.1016/j.atmosres.2025.108070","DOIUrl":"10.1016/j.atmosres.2025.108070","url":null,"abstract":"<div><div>Lightning poses varying degrees of threat to human production, life and personal safety because of its huge destructive power. Lightning prediction with intensity estimation is an important reference for disaster warning, determining lightning protection level and real-time and dynamic lightning risk assessment. Real-time observation of total lightning can compensate for the problem of limited range or shielding of radar observation and is of great significance for thunderstorm tracking and lightning nowcasting. In this paper, the VLF Lightning Location Network (VLF-LLN) is used to obtain real-time long-range lightning location data. Through density estimation based on the Gaussian mixture model and weighted according to time proximity, the spatio-temporal range and frequency information of lightning high-density area are obtained. Then, a spatio-temporal data extrapolation model ME-RNN is proposed to predict the intensity of lightning activity and its evolution pattern in the thunderstorm region, so as to realize the nowcasting of lightning activity. Based on the PredRNN architecture, the model integrates the MotionGRU operator optimized for the characteristics of lightning data, and integrates the generative adversative network (GAN) to capture the transient changes of lightning phenomena and predict its movement trend. At 6 min, 18 min and 36 min before the thunderstorm reached the area of concentration (AOC), the prediction accuracy of the model was 94.1 %, 79.4 % and 65.8 %, respectively. Furthermore, the ME-RNN model can track the active thunderstorm cells associated with lightning activity, and realize the prediction of the separation and merging of lightning high-density area, as well as the prediction of moving trend.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"321 ","pages":"Article 108070"},"PeriodicalIF":4.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dynamic prediction of PM2.5 concertation in China using experience replay with multi-period memory buffers","authors":"Haoze Shi, Xin Yang, Hong Tang, Yuhong Tu","doi":"10.1016/j.atmosres.2025.108063","DOIUrl":"10.1016/j.atmosres.2025.108063","url":null,"abstract":"<div><div>PM<sub>2.5</sub> pollution is a significant contributor to both respiratory and cardiovascular diseases. An aging population is more sensitive to air pollution. Hence accurately predicting PM<sub>2.5</sub> concentrations is crucial for safeguarding public health in an aging society. Machine learning is one of the key research methods in the field of PM<sub>2.5</sub> concentration short-term forecasting. However, existing short-term forecasting methods often prioritize model improvements, while overlooking the fundamental patterns of PM<sub>2.5</sub> concentration data. Utilizing only the temporally closest observations cannot take full advantage of the information provided by historical datasets. Wavelet analysis of datasets in this study revealed the periodic components in PM<sub>2.5</sub> concentrations. Building on this periodic variation, we proposed an experience replay strategy that integrates both a long-term and a short-term memory buffer to enhance PM<sub>2.5</sub> concentration prediction. The long-term memory buffer stores historical events that are similar to the current pollution scenario, providing the model with a stable historical reference. Meanwhile, the short-term memory buffer captures exceptional samples that are challenging to predict, thus ensuring greater adaptability in scenarios with high variability and uncertainty. The next three-day 5 km PM<sub>2.5</sub> concentration grid-prediction experiment was carried out on four typical models in 2020 across China. The results show that the proposed experience replay strategy significantly improv es prediction accuracy on all models. By repeatedly replaying the stored experience, the model progressively strengthens its generalization ability and prediction accuracy, particularly in complex, dynamic, and pollution-prone environments. The proposed approach in this study will contribute to public health protection and environmental management.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108063"},"PeriodicalIF":4.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wen Liu , Haishen Lü , Yonghua Zhu , Xiaoyi Wang , Mingwen Liu , Yiding Ding , Jianbin Su
{"title":"The explanation of small- and medium-watershed-scale bias variability in IMERG in Chinese humid regions","authors":"Wen Liu , Haishen Lü , Yonghua Zhu , Xiaoyi Wang , Mingwen Liu , Yiding Ding , Jianbin Su","doi":"10.1016/j.atmosres.2025.108075","DOIUrl":"10.1016/j.atmosres.2025.108075","url":null,"abstract":"<div><div>The absence of in situ precipitation data in remote small and medium watersheds (SMWs) highlights the need for reliable satellite precipitation estimations (SPEs). This study evaluates and compares the updated Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG) V07 Final Run uncalibrated (V07F-Uncal) and calibrated (V07F-Cal) products against their predecessors (V06F-Uncal and V06F-Cal). The comparison is conducted across 339 SMWs in Chinese humid regions during the summers from 2015 to 2020, using rain gauge observations as benchmarks. Conditional multivariate regression is employed to examine the relationships between satellite precipitation <span><math><mi>bias</mi></math></span> values and factors such as precipitation intensity, surface temperature, and fraction of vegetation cover (FVC). Results show that V07F-Uncal outperforms V06F-Uncal in terms of <span><math><mi>CC</mi></math></span> and <span><math><mi>RMSE</mi></math></span> in most mountainous and coastal SMWs, but it consistently underestimates precipitation, particularly in the mountainous regions. <span><math><mi>Bias</mi></math></span> for both V07F-Uncal and V06F-Uncal transitions from positive to increasingly negative values with rising precipitation intensity. V07F-Uncal exhibits a tighter distribution of <span><math><mi>bias</mi></math></span> values across all intensity categories compared to V06F-Uncal, but it shows a pronounced negative <span><math><mi>bias</mi></math></span> in high-intensity categories. In terms of performance metrics and the distribution of <span><math><mi>bias</mi></math></span> values, V06F-Cal demonstrates marked improvements over V06F-Uncal. However, the enhancements observed in V07F-Cal relative to V07F-Uncal are not substantial. As for the variability of <span><math><mi>bias</mi></math></span> values associated with changes in precipitation intensity, surface temperature and FVC, the explained <span><math><mi>bias</mi></math></span> variability in V07F-Uncal is significantly higher than in V06F-Uncal, averaging approximately 43 % versus 22 %. In western mountainous SMWs, this variability is also greater than in the eastern region (52 % versus 34 %). Precipitation intensity is the primary factor explaining <span><math><mi>bias</mi></math></span> variability for both V07F-Uncal and V06F-Uncal, although in specific regions, the <span><math><mi>bias</mi></math></span> variability of V06F-Uncal may relate to the surface temperature or its interaction with precipitation intensity. FVC exerts minimal influence (<3 %) on <span><math><mi>bias</mi></math></span> variability for both products. This research is crucial for improving the accuracy of SPEs in SMWs, which are vital for flood simulation and disaster adaptation in ungauged SMWs.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108075"},"PeriodicalIF":4.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ricardo A. Gutierrez-Villarreal , Clémentine Junquas , Jhan-Carlo Espinoza , Patrice Baby , Elisa Armijos
{"title":"Influence of local topographic structures on the atmospheric mechanisms related to the Andean-Amazon rainiest zone","authors":"Ricardo A. Gutierrez-Villarreal , Clémentine Junquas , Jhan-Carlo Espinoza , Patrice Baby , Elisa Armijos","doi":"10.1016/j.atmosres.2025.108068","DOIUrl":"10.1016/j.atmosres.2025.108068","url":null,"abstract":"<div><div>The Andes-Amazon transition region features critically important ecological services on the local, regional and global scales. This region is among the rainiest zones in the world, with rainfall rates of up to 7000 mm/year. However, the physical mechanisms leading to the existence of these “precipitation hotspots” remain poorly known. Here, we attempt to disentangle the controlling atmospheric mechanisms exerted by local topographic structures that started to uplift about 5–10 million years ago in response to the Nazca Ridge subduction, in the vicinity of the Quincemil hotspot, the most intense of them. We first use the Weather Research and Forecasting model to conduct sensitivity tests to planetary boundary layer parameterizations at 5 km horizontal grid spacing during the austral summer of 2012–13. After finding the most suitable configuration in terms of the diurnal cycle of rainfall intensity and extent, we further perform topographic sensitivity tests by reducing the Fitzcarrald Arch lowlands and, on top of it, by removing the Camisea mountain. The Fitzcarrald Arch deflects moisture flux towards Quincemil, while the Camisea mountain induces local vortical circulations that increase moisture transport, convergence and rainfall over Quincemil, ultimately controlling its location and intensity by up to 40 %. When reducing the height of the Andes in half, we find that it sustains the development of precipitation hotspots, accounting for up to 60 % of rainfall, by providing a mechanical forcing to increase regional-scale moisture fluxes. Such mechanisms dominate during nighttime, when rainfall peaks in the region, and might explain the existence of the rainiest zone in the Andes-Amazon transition.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108068"},"PeriodicalIF":4.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shuo Jia , Jiefan Yang , Hengchi Lei , Hongbin Chen
{"title":"An investigation into microphysical processes of autumn frontal clouds influenced by the warm conveyor belt in Central China","authors":"Shuo Jia , Jiefan Yang , Hengchi Lei , Hongbin Chen","doi":"10.1016/j.atmosres.2025.108065","DOIUrl":"10.1016/j.atmosres.2025.108065","url":null,"abstract":"<div><div>Understanding frontal clouds and precipitation is crucial due to its increasing variability and intensity driven by global warming, which impacts agriculture, water resource management, and climate adaptation. Autumn precipitation in Central China is frequently induced by extratropical cyclones, often featuring a frontal cloud system influenced by warm conveyor belt (WCB). In this paper, the detailed microphysical processes of an autumn precipitation event were examined using reconstructed vertical profiles of polarimetric variables, supplemented with numerical simulation to better depict the microphysics evolution in different stages. Results showed that during the initial stage, a strong, inclined updraft and supersaturated layer influenced by WCB, enhanced the formation and depositional growth of ice particles above −10 °C level, then ice particles grew by riming in addition to aggregation in −5–0 °C layer while precipitation particles coalescence and collecting cloud droplets occurred in warm cloud. As the vertical extent of supersaturated layer increased, the intensified process of collecting cloud droplets and vigorous riming process contributed to the maximum surface rainfall intensity. In the weakening stage, ice-phase processes attenuated before the warm cloud processes showed reducing tendencies. This decline is attributed to weakened inclined updraft and supersaturated layer falling below 0 °C level, which impaired the conditions necessary for ice-phase processes. It is concluded that the thermodynamic structure of WCB, namely the vertical extension of inclined updraft and the presence of supersaturated layer, significantly influenced both the ice-phase and liquid-phase microphysical processes of the frontal cloud system as well as the surface precipitation.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108065"},"PeriodicalIF":4.5,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jianhao Ren , Honglei Wang , Yue Tan , Wenjie Wang , Bin Zhu , Tianliang Zhao , Wen Lin , Duanyang Liu , Lijuan Shen , Shuangshuang Shi
{"title":"Temporal variations in black carbon in the Yangtze River Delta of China: Long-term observations and trends under different pollution processes","authors":"Jianhao Ren , Honglei Wang , Yue Tan , Wenjie Wang , Bin Zhu , Tianliang Zhao , Wen Lin , Duanyang Liu , Lijuan Shen , Shuangshuang Shi","doi":"10.1016/j.atmosres.2025.108067","DOIUrl":"10.1016/j.atmosres.2025.108067","url":null,"abstract":"<div><div>As an important absorptive component of aerosols in the atmosphere, black carbon (BC) plays a key role in climatic processes. Continuous BC measurements in the atmosphere of Nanjing, China, were performed from 2015 to 2022. By combining data from PM<sub>2.5</sub>, PM<sub>10</sub>, SO<sub>2</sub>, CO, NO<sub>2</sub>, O<sub>3</sub> and meteorological variables, the temporal variations in BC during different pollution events were determined in this study. The annual mean BC concentration increased from 2015 to 2018 (0.80 ± 0.05 μg/(m<sup>3</sup> a)) and decreased from 2019 to 2022 (0.30 ± 0.001 μg/(m<sup>3</sup> a)). The daily variations in BC concentrations during different processes (haze, dust, ozone, fireworks and fog) in Nanjing showed different characteristics. The BC concentration increased the most during haze events (50 %–100 %), while it changed little during fog events, so BC can be used to distinguish between these two processes. During O<sub>3</sub> pollution events, the BC concentration increased by 6 %–44 %. During dust pollution events, BC concentration decreased owing to the high wind speed. Besides, BC wasn't a major pollutant originating from Nanjing fireworks. During haze and O<sub>3</sub> pollution events, BC concentrations tended to increase (0.45 μg/m<sup>3</sup>–1.51 μg/m<sup>3</sup>) as the pollution levels increase. It's worth noting that BC concentrations were higher in autumn (4.85 μg/m<sup>3</sup>) than other seasons during moderate haze events because of enhanced long-range BC transport. Furthermore, during O<sub>3</sub> pollution events, high BC concentrations exacerbated BC-boundary layer (BL) interactions and sustained high O<sub>3</sub> concentrations. Bimodal distribution of haze (O<sub>3</sub>) pollution at all levels, but the nocturnal BC concentration peak weakened during heavy haze events.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"320 ","pages":"Article 108067"},"PeriodicalIF":4.5,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}