Atmospheric and Oceanic Science Letters最新文献

{"title":"Impacts of the annual cycle of background SST in the tropical Pacific on the phase and amplitude of ENSO","authors":"Song Jiang ,&nbsp;Congwen Zhu ,&nbsp;Ning Jiang","doi":"10.1016/j.aosl.2024.100496","DOIUrl":"10.1016/j.aosl.2024.100496","url":null,"abstract":"<div><div>The dominant annual cycle of sea surface temperature (SST) in the tropical Pacific exhibits an antisymmetric mode, which explains 83.4% total variance, and serves as a background of El Niño–Southern Oscillation (ENSO). However, there is no consensus yet on its anomalous impacts on the phase and amplitude of ENSO. Based on data during 1982–2022, results show that anomalies of the antisymmetric mode can affect the evolution of ENSO on the interannual scale via Bjerknes feedback, in which the positive (negative) phase of the antisymmetric mode can strengthen El Niño (La Niña) in boreal winter via an earlier (delayed) seasonal cycle transition and larger (smaller) annual mean. The magnitude of the SST anomalies in the equatorial eastern Pacific can reach more than ±0.3℃, regulated by the changes in the antisymmetric mode based on random sensitivity analysis. Results reveal the spatial pattern of the annual cycle associated with the seasonal phase-locking of ENSO evolution and provide new insight into the impact of the annual cycle of background SST on ENSO, which possibly carries important implications for forecasting ENSO.</div><div>摘要</div><div>基于1982–2022年资料分析, 本文发现, 热带太平洋海温年循环的主导模态为反对称模式, 是ENSO发展的背景场. 然而, 其对ENSO相位和振幅的异常影响尚未可知. 反对称模态异常可以通过Bjerknes反馈影响ENSO的年际变化, 其正 (负) 异常可以通过更早 (更晚) 的季节循环转变时间和更大 (更小) 的年平均值增强冬季El Niño (La Niña) 的强度. 根据随机敏感性实验分析, 与反对称模态变化有关的赤道中东太平洋海温异常可达±0.3℃以上. 研究结果为背景海温年循环对ENSO的影响提供了新的见解, 这可能对ENSO的预测具有重要意义.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 1","pages":"Article 100496"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140781271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of the improved dung beetle optimizer, muti-head attention and hybrid deep learning algorithms to groundwater depth prediction in the Ningxia area, China","authors":"Jiarui Cai ,&nbsp;Bo Sun ,&nbsp;Huijun Wang ,&nbsp;Yi Zheng ,&nbsp;Siyu Zhou ,&nbsp;Huixin Li ,&nbsp;Yanyan Huang ,&nbsp;Peishu Zong","doi":"10.1016/j.aosl.2024.100497","DOIUrl":"10.1016/j.aosl.2024.100497","url":null,"abstract":"<div><div>Due to the lack of accurate data and complex parameterization, the prediction of groundwater depth is a challenge for numerical models. Machine learning can effectively solve this issue and has been proven useful in the prediction of groundwater depth in many areas. In this study, two new models are applied to the prediction of groundwater depth in the Ningxia area, China. The two models combine the improved dung beetle optimizer (DBO) algorithm with two deep learning models: The Multi-head Attention–Convolution Neural Network–Long Short Term Memory networks (MH-CNN-LSTM) and the Multi-head Attention–Convolution Neural Network–Gated Recurrent Unit (MH-CNN-GRU). The models with DBO show better prediction performance, with larger <em>R</em> (correlation coefficient), RPD (residual prediction deviation), and lower RMSE (root-mean-square error). Compared with the models with the original DBO, the <em>R</em> and RPD of models with the improved DBO increase by over 1.5%, and the RMSE decreases by over 1.8%, indicating better prediction results. In addition, compared with the multiple linear regression model, a traditional statistical model, deep learning models have better prediction performance.</div><div>摘要</div><div>本研究将两个新模型应用于位于中国西北干旱半干旱区的宁夏地区地下水深度预测. 这两个模型将改进的蜣螂优化 (DBO) 算法与两个深度学习模型相结合, 即多头注意力-卷积神经网络-长短期记忆网络和多头注意力-回旋神经网络-门控递归单元. 带有DBO的模型预测结果表现出更大的相关系数 (R) , 残差预测偏差 (RPD) 和较低的均方根误差 (RMSE) , 预测结果更好. 此外, 与DBO模型相比, 改进后的DBO模型的R和RPD增加了1.5%以上, RMSE降低了1.8%以上, 表明预测结果更好. 与传统的统计模型多元线性回归模型相比, 深度学习模型具有更好的预测性能.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 1","pages":"Article 100497"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140794268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arctic sea-ice extent: No record minimum in 2023 or recent years","authors":"Ola M. Johannessen ,&nbsp;Tor I. Olaussen","doi":"10.1016/j.aosl.2024.100499","DOIUrl":"10.1016/j.aosl.2024.100499","url":null,"abstract":"<div><div>Arctic sea-ice extent reaches its minimum each year in September. On 11 September 2023 the minimum was 4.969 million square kilometers (mill.km²). This was not a record low, which occurred in 2012, when the minimum was 4.175 mill.km², 0.794 mill.km² less than the minimum in 2023. However, the ice extent had decreased by 0.432 mill.km² compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. In general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO₂ in the atmosphere, where the increase of CO₂ in recent decades explains about 80% of the decrease in sea ice in September, while the remainder is caused by natural variability.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 1","pages":"Article 100499"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140790831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increase in the variability of terrestrial carbon uptake in response to enhanced future ENSO modulation","authors":"Younong Li ,&nbsp;Li Dan ,&nbsp;Jing Peng ,&nbsp;Qidong Yang ,&nbsp;Fuqiang Yang","doi":"10.1016/j.aosl.2024.100508","DOIUrl":"10.1016/j.aosl.2024.100508","url":null,"abstract":"<div><div>El Niño–Southern Oscillation (ENSO) is a major driver of climate change in middle and low latitudes and thus strongly influences the terrestrial carbon cycle through land–air interaction. Both the ENSO modulation and carbon flux variability are projected to increase in the future, but their connection still needs further investigation. To investigate the impact of future ENSO modulation on carbon flux variability, this study used 10 CMIP6 earth system models to analyze ENSO modulation and carbon flux variability in middle and low latitudes, and their relationship, under different scenarios simulated by CMIP6 models. The results show a high consistency in the simulations, with both ENSO modulation and carbon flux variability showing an increasing trend in the future. The higher the emissions scenario, especially SSP5-8.5 compared to SSP2-4.5, the greater the increase in variability. Carbon flux variability in the middle and low latitudes under SSP2-4.5 increases by 30.9% compared to historical levels during 1951–2000, while under SSP5-8.5 it increases by 58.2%. Further analysis suggests that ENSO influences mid- and low-latitude carbon flux variability primarily through temperature. This occurrence may potentially be attributed to the increased responsiveness of gross primary productivity towards regional temperature fluctuations, combined with the intensified influence of ENSO on land surface temperatures.</div><div>摘要</div><div>ENSO是中低纬度地区气候系统的主要驱动因素, 对陆地碳循环有重要影响. 本研究基于10个CMIP6地球系统模式, 分析了不同情景下ENSO变率与中低纬度地区总初级生产力变率的关系. 结果显示, 未来ENSO变率和总初级生产力变率在未来多数模式均显示为增加. 在未来情境下(2051-2100年), 中低纬度地区的总初级生产力变率较历史时期(1951–2000年)增加了30.9%(SSP2-4.5), 58.2%(SSP5-8.5). 进一步分析表明, ENSO主要通过温度影响中低纬度碳通量变率. 这种现象可能归因于总初级生产力对温度的响应增强, 以及ENSO对陆地表面温度的影响.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 1","pages":"Article 100508"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140776937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of the Greenland Sea ice anomaly in the late-spring drought over Northwest China","authors":"Yang Liu ,&nbsp;Huopo Chen","doi":"10.1016/j.aosl.2024.100488","DOIUrl":"10.1016/j.aosl.2024.100488","url":null,"abstract":"<div><div>Drought across Northwest China in late spring has exerted a vital effect on the local climate and agricultural production, and has been alleviated during the past decades. This study explored the influence of the preceding Arctic sea ice on the May drought in Northwest China caused by the precipitation deficit. Further analysis indicated that when the Greenland Sea ice concentration is abnormally high during February to April, the dry conditions in Northwest China tend to be alleviated. The increase of sea ice in the Greenland Sea can excite a meridional circulation, which causes sea surface temperature (SST) anomalies in the North Atlantic via the sea–air interaction, manifested as significant warm SST anomalies over the south of Greenland and the subtropical North Atlantic, but negative SST anomalies over the west of the Azores. This abnormal SST pattern maintains to May and triggers a zonal wave train from the North Atlantic through Scandinavia and Central Asia to Northwest China, leading to abnormal cyclones in Northwest China. Consequently, Northwest China experiences a more humid climate than usual.</div><div>摘要</div><div>晚春西北地区干旱的发生对西北地区气候和农业生产等具有重要的影响, 但在近几十年, 西北干旱状况呈现出缓解的趋势. 本文研究了前期北极海冰异常对5月中国西北地区 (降水短缺引起的) 干旱异常的影响. 进一步研究表明, 二至四月格陵兰海海冰偏多时, 西北地区干旱有所缓解. 偏多的格陵兰海海冰可激发出经向环流异常, 环流异常通过海–气相互作用在北大西洋产生海温异常, 主要表现为格陵兰岛以南和北大西洋副热带海温偏高, 亚速尔群岛以西海温偏低. 这种海温异常可持续到5月, 并引发从北大西洋经斯堪的纳维亚半岛和中亚至中国西北地区的纬向波列, 并在西北地区产生气旋环流异常, 从而导致该地区水汽辐合, 干旱状况有所缓解.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 1","pages":"Article 100488"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implications of 1.5 K climate warming on warm-season ozone exposure and atmospheric oxidation capacity in China","authors":"Zhihao Shi ,&nbsp;Lin Huang ,&nbsp;Xiaodong Xie ,&nbsp;Momei Qin ,&nbsp;Jingyi Li ,&nbsp;Bingye Xu ,&nbsp;Lingling Jin ,&nbsp;Jianlin Hu","doi":"10.1016/j.aosl.2024.100556","DOIUrl":"10.1016/j.aosl.2024.100556","url":null,"abstract":"<div><div>Surface ozone (O₃) poses significant threats to public health, agricultural crops, and plants in natural ecosystems. Global warming is likely to increase future O₃ mainly by altering atmospheric photochemical reactions and enhancing biogenic volatile organic compound (BVOC) emissions. To assess the impacts of the future 1.5 K climate target on O₃ concentrations and ecological O₃ exposure in China, numerical simulations were conducted using the CMAQ (Community Multiscale Air Quality) model during April–October 2018. Ecological O₃ exposure was estimated using six indices (i.e., M7, M24, N100, SUM60, W126, and AOT40f). The results show that the temperature rise increases the MDA8 O₃ (maximum daily eight-hour average O₃) concentrations by ∼3 ppb and the number of O₃ exceedance days by 10–20 days in the North China Plain (NCP), Yangtze River Delta (YRD), and Sichuan Basin (SCB) regions. All O₃ exposure indices show substantial increases. M24 and M7 in eastern and southern China will rise by 1–3 ppb and 2–4 ppb, respectively. N100 increases by more than 120 h in the surrounding regions of Beijing. SUM60 increases by greater than 9 ppm h⁻¹, W126 increases by greater than 15 ppm h⁻¹ in Shaanxi and SCB, and AOT40f increases by 6 ppm h⁻¹ in NCP and SCB. The temperature increase also promotes atmospheric oxidation capacity (AOC) levels, with the higher AOC contributed by OH radicals in southern China but by NO₃ radicals in northern China. The change in the reaction rate caused by the temperature increase has a greater influence on O₃ exposure and AOC than the change in BVOC emissions.</div><div>摘要</div><div>地表臭氧(O₃)对公众健康, 农作物以及自然生态系统构成重大威胁. 全球变暖会增强大气光化学反应以及增加生物源挥发性有机化合物(BVOC)排放, 从而导致 O₃浓度增加. 为了评估未来 1.5 K 气候目标对中国 O₃浓度以及生态 O₃暴露的影响, 在 2018 年 4 月至 10 月期间使用 CMAQ模型进行了数值模拟. 使用六个指标(即 M7, M24, N100, SUM60, W126 和 AOT40f)估算生态 O₃暴露. 结果表明, 在华北平原,长江三角洲和四川盆地地区, 温度升高使每日最大8 小时平均 O₃浓度增加约 3 ppb, O₃超标天数增加 10–20 天. 所有 O₃暴露指标均显著增加. 中国东部和南部的 M24 和 M7 将分别增加 1–3 ppb 和 2–4 ppb. 北京周边地区的 N100 增加超过 120 小时. 陕西和四川盆地的 SUM60 增加超过 9 ppm h⁻¹, W126 增加超过 15 ppm h⁻¹, 华北平原和四川盆地的 AOT40f 增加 6 ppm h⁻¹. 温度升高还提升了大气氧化能力(AOC)水平, 在中国南部较高的 AOC 由羟基自由基贡献, 而在中国北部则由硝基自由基贡献. 由温度升高引起的反应速率变化对 O₃暴露和 AOC 的影响比 BVOC 排放增加带来的贡献更大.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"17 6","pages":"Article 100556"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Significant contributions of the petroleum industry to volatile organic compounds and ozone pollution: Insights from year-long observations in the Yellow River Delta","authors":"Jinghao Tang ,&nbsp;Hengqing Shen ,&nbsp;Hong Li ,&nbsp;Yuanyuan Ji ,&nbsp;Xuelian Zhong ,&nbsp;Min Zhao ,&nbsp;Yuhong Liu ,&nbsp;Mingzhi Guo ,&nbsp;Fanyi Shang ,&nbsp;Likun Xue","doi":"10.1016/j.aosl.2024.100523","DOIUrl":"10.1016/j.aosl.2024.100523","url":null,"abstract":"<div><div>The petroleum industry is a significant source of anthropogenic volatile organic compounds (VOCs), but up to now, its exact impact on urban VOCs and ozone (O₃) remains unclear. This study conducted year-long VOC observations in Dongying, China, a petroleum industrial region. The VOCs from the petroleum industry (oil and gas volatilization and petrochemical production) were identified by employing the positive matrix factorization model, and their contribution to O₃ formation was quantitatively evaluated using an observation-based chemical box model. The observed annual average concentration of VOCs was 68.6 ± 63.5 ppbv, with a maximum daily average of 335.3 ppbv. The petroleum industry accounted for 66.5% of total VOCs, contributing 54.9% from oil and gas evaporation and 11.6% from petrochemical production. Model results indicated that VOCs from the petroleum industry contributed to 31% of net O₃ production, with 21.3% and 34.2% contributions to HO₂+NO and RO₂+NO pathways, respectively. The larger impact on the RO₂ pathway is primarily due to the fact that OH+VOCs account for 86.9% of the primary source of RO₂. This study highlights the critical role of controlling VOCs from the petroleum industry in urban O₃ pollution, especially those from previously overlooked low-reactivity alkanes.</div><div>摘要</div><div>通过在黄河三角洲典型城市东营市一年的挥发性有机物 (VOCs) 观测, 使用正交矩阵因子分解模型和化学盒子模型定量了石油工业对VOCs和臭氧污染的贡献. 研究发现石油工业VOCs对总VOCs的贡献达66.5%, 其中油气挥发贡献54.9%, 石油化工生产贡献11.6%. 石油工业VOCs对O3净生成速率的贡献达31%. 这些结果揭示了石油工业在VOCs和臭氧污染等方面对城市空气质量的重要影响.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"17 6","pages":"Article 100523"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141408167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A portable instrument for measurement of atmospheric Ox and NO2 based on cavity ring-down spectroscopy","authors":"Jinzhao Tong ,&nbsp;Renzhi Hu ,&nbsp;Changjin Hu ,&nbsp;Haotian Cai ,&nbsp;Chuan Lin ,&nbsp;Jiawei Wang ,&nbsp;Liang Chen ,&nbsp;Pinhua Xie","doi":"10.1016/j.aosl.2024.100493","DOIUrl":"10.1016/j.aosl.2024.100493","url":null,"abstract":"<div><div>Atmospheric O<em>_x</em> (nitrogen dioxide (NO₂) + ozone (O₃)) can better reflect the local and regional change characteristics of oxidants compared to O₃ alone, so obtaining O<em>_x</em> accurately and rapidly is the basis for evaluating the O₃ production rate. Furthermore, O_<em>x</em> has proved to be a more representative indicator and can serve as a reflection of pollution prevention efficacy. A portable instrument for measuring atmospheric O<em>_x</em> and NO₂ based on cavity ring-down spectroscopy (O<em>_x</em>/NO₂-CRDS) was developed in this work. The NO₂ concentration is accurately measured according to its absorption characteristic at 407.86 nm. Ambient O₃ is converted into NO₂ by chemical titration of high concentrations of nitrogen oxide (NO), and the O₃ conversion efficiencies obtained are nearly 99%. The detection limit of the O<em>_x</em>/NO₂-CRDS system for O<em>_x</em> is 0.024 ppbv (0.1 s), and the overall uncertainty of the instrument is ± 6%. Moreover, the Kalman filtering technique was applied to improve the measurement accuracy of O<em>_x</em>/NO₂-CRDS. The system was applied in a comprehensive field observation campaign at Hefei Science Island from 26 to 30 September 2022, and the time concentration series and change characteristics of O<em>_x</em> and NO₂ were obtained for five days. The measured O<em>_x</em> concentrations were compared with those of two commercial instruments, and the consistency was good (<em>R</em>² = 0.98), indicating that this system can be deployed to accurately and rapidly obtain the concentrations of atmospheric O<em>_x</em> and NO₂. It will be a useful tool for assessing the atmospheric oxidation capacity and controlling O₃ pollution.</div><div>摘要</div><div>大气O<em>_x</em> (二氧化氮(NO₂)+臭氧(O₃))相比于O₃能够更好的反应区域氧化剂的变化特征, O<em>_x</em>也是反应大气污染防治效果的一个关键指标. 本研究基于腔衰荡光谱技术研发了一套大气O<em>_x</em>和NO₂同步测量系统 (O<em>_x</em>/NO₂-CRDS). NO₂浓度是利用其在407.86 nm处的特征吸收获取, 环境大气的O₃通过高浓度的NO被转化为NO₂进行间接测量, O₃转化效率高于99%, O<em>_x</em>/NO₂-CRDS的系统探测限为0.024 ppbv (0.1 s), 系统总不确定度为± 6%. 该O<em>_x</em>/NO₂-CRDS系统成功应用于2022年9月26日–30日的合肥市科学岛综合外场观测中, 获取了连续5天的NO₂和O<em>_x</em>的时间浓度序列和变化特征, 并将O<em>_x</em>的测量结果与商业化的设备进行了对比验证, 二者具有较好的一致性 (<em>R</em>² = 0.98), 表明O<em>_x</em>/NO₂-CRDS能够被应用于大气O<em>_x</em>和NO₂的高灵敏探测. 未来该系统也将会变成评估大气氧化性以及控制臭氧污染的重要工具.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"17 6","pages":"Article 100493"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140407470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trends of surface ozone based on hourly concentrations in the Beijing–Tianjin–Hebei region during 2017–2021","authors":"Xiaoyan Wang,&nbsp;Huihui Zheng,&nbsp;Bing Liu,&nbsp;Shuyan Xie,&nbsp;Yonghai Huang,&nbsp;Shuai Wang","doi":"10.1016/j.aosl.2024.100514","DOIUrl":"10.1016/j.aosl.2024.100514","url":null,"abstract":"<div><div>As a typical secondary air pollutant, surface ozone has been monitored routinely since 2013 in China. Most studies on the spatiotemporal variation of ozone have been centered around the daily maximum 8-h average, with little attention paid to the trends of hourly ozone, especially hourly ozone exceedances. Focusing on hourly ozone exceedances and peak values, the spatiotemporal trends of hourly ozone at 77 sites in 13 cities of the Beijing–Tianjin–Hebei (BTH) region during 2017–2021 were analyzed in this study. The number of hours with exceedances (<em>N</em>_H200) in 2019 was nearly three times that of 2021. On a five-year average, the percentage of cumulative <em>N</em>_H200 in June accounted for up to 40.5 % of all hourly exceedances. Cities in central Hebei Province had the highest cumulative annual <em>N</em>_H200. June had the highest average hourly ozone exceeded multiples of 0.158. The top two cities with the highest average exceeded multiple were Tangshan (0.166) and Beijing (0.158). Tangshan and Xingtai ranked as the top two in terms of the mean of the 10 highest daily maximum ozone concentrations (MTDM), with 286.74 and 285.37 µg m⁻³, respectively. The gap between the MTDM and the daily maximum of hourly ozone averaged over all sites had narrowed to 97.88 µg m⁻³ in 2021, much lower than that in other years, which indicated that the stability and convergence of ozone pollution in BTH region had been enhanced in 2021 to some extent.</div><div>摘要</div><div>本文以京津冀地区为研究对象, 采用国际常用的评价指标, 在分析2017–2021年臭氧小时浓度变化趋势的基础上, 重点讨论了小时浓度超标情况及其峰值水平. 结果显示, 2019年臭氧小时浓度超标数约为2021年的3倍, 6月份小时浓度超标数占比高达40.5%, 河北中部城市小时浓度超标情况突出; 2017年和2019年臭氧小时浓度超标倍数在高位区间的占比相对最高, 唐山和邢台的小时浓度峰值水平相对较高. 本文可为后续进一步研究局地臭氧污染特征和异常污染事件提供基础参考.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"17 6","pages":"Article 100514"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141042929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implications of the extremely hot summer of 2022 on urban ozone control in China","authors":"Wenhao Qiao,&nbsp;Ke Li,&nbsp;Zhenjiang Yang,&nbsp;Lei Chen,&nbsp;Hong Liao","doi":"10.1016/j.aosl.2024.100470","DOIUrl":"10.1016/j.aosl.2024.100470","url":null,"abstract":"<div><div>Frequent occurrences of extreme heat are causing severe ozone pollution over China. This study examined the driving factors of urban ozone pollution in China during the extremely hot summer of 2022 and the impact of emission control strategies using surface measurements and the GEOS-Chem model. The results show that ozone pollution was extremely severe in summer 2022, with a significant rebound by 12–15 ppbv in the North China Plain (NCP), Yangtze River Delta (YRD), and Sichuan basin (SCB), compared to 2021. Especially over the NCP, the MDA8 (maximum daily 8-hourly average) ozone exceeded 160 ppbv, and the number of ozone exceedances was over 42 days. Based on an IPR (integrated process rate) analysis, the authors found that the net chemical production was the dominant factor contributing to the strong ozone increase in summer 2022. For example, in June over the NCP, the net chemical production resulted in an increase by 3.08 Gg d⁻¹ (∼270%) in ozone mass change. Sensitivity simulations showed that both NO_<em>x</em> (nitrogen oxides) and VOC (volatile organic compound) reductions were important over the NCP, and NO_<em>x</em> reductions were more important than VOCs over southern China. To keep the ozone of 2022 at the same level as 2021, a joint reduction of NO_<em>x</em> and VOCs by at least 50%–60% would have been required. This study highlights the urgency to develop effective ozone management since extreme heat will become more frequent.</div><div>摘要</div><div>本文利用地面观测和数值模式研究了2022年夏季极端高温下我国城市臭氧污染的控制策略. 研究表明, 2022年夏季臭氧污染极为严重, 相较于2021年有显著的反弹, 其中华北, 长三角和四川盆地的月均臭氧上升12–15 ppbv. 模式过程分析结果表明净化学生产是高温时造成臭氧浓度升高的主导因素. 模式多组敏感性试验表明, 华北地区需要NO<em>_x</em>和VOC协同控制, 南方城市需要侧重对NO<em>_x</em>排放管控, 并且需要对NO<em>_x</em>和VOC协同减排至少50%–60% 才会使2022年夏季臭氧污染水平与2021年一致. 在极端高温愈发频繁的形势下, 本研究强调未来亟需研究更为有效的臭氧调控策略.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"17 6","pages":"Article 100470"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139891779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}