Atmospheric and Oceanic Science Letters最新文献

{"title":"Impact of deforestation on precipitation extremes in China based on land use model intercomparison project models","authors":"Tianliang Gao ,&nbsp;Yue Sui ,&nbsp;Bo Liu ,&nbsp;Yuxuan Peng ,&nbsp;Wenxuan Qiao","doi":"10.1016/j.aosl.2024.100584","DOIUrl":"10.1016/j.aosl.2024.100584","url":null,"abstract":"<div><div>Deforestation has a significant influence on the hydrological cycle. Understanding the impact of deforestation on precipitation extremes is crucial for addressing global environmental challenges. This study investigates the impact of deforestation on precipitation extremes (R95p index, which represents the total amount of precipitation exceeding the 95th percentile of the reference period) in China, using outputs from three earth system models (CanESM5, IPSL-CM6A-LR, and MIROC-ES2L). All models, along with their multimodel mean, indicate a general decrease in R95p in Northeast China and southern China, and changes in Northwest China and the Tibetan Plateau are minimal. In contrast, the responses are model-dependent in the Huanghuai and Jianghuai regions. The overall nationwide multimodel mean suggests an annual R95p decrease of 10.7 mm, with individual model variations ranging from −28.0 to 2.0 mm. Further analysis using precipitation extremes scaling reveals a high spatial correlation with direct precipitation extremes changes on both annual and seasonal scales, albeit with slightly smaller magnitudes. Decomposing the response into dynamic and thermodynamic scaling, the authors find that dynamic contributions predominantly drive the changes in precipitation extremes on both annual and seasonal scales. The authors findings highlight the substantial role of dynamic processes in modulating the response of precipitation extremes to deforestation in China.</div><div>摘要</div><div>森林砍伐对水循环影响显著, 理解森林砍伐对极端降水的影响对于应对全球环境挑战至关重要.基 于CanESM5, IPSL-CM6A-LR和MIROC-ES2L三个地球系统模式, 本文探讨了森林砍伐对中国极端降水 (R95p指数, 即超过参考期第95百分位降水量总和) 的影响. 所有模式及其集合平均表明, 森林砍伐后我国东北和南方R95p普遍减少; 西北和青藏高原的变化较小; 而黄淮和江淮地区的响应则依赖于模式. 进一步, 在年和季节尺度上, 极端降水物理尺度诊断方法得到的极端降水响应与上述响应具有高空间相似性, 且动力作用主导了森林砍伐对极端降水的影响.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 5","pages":"Article 100584"},"PeriodicalIF":2.3,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of observation-based cloud droplet size distributions on the simulation of warm stratiform precipitation using a double-moment microphysics scheme","authors":"Ryohei Misumi ,&nbsp;Akihiro Hashimoto","doi":"10.1016/j.aosl.2024.100572","DOIUrl":"10.1016/j.aosl.2024.100572","url":null,"abstract":"<div><div>A double-moment cloud microphysics scheme requires an assumption for cloud droplet size distributions (DSDs). However, since observations of cloud DSDs are limited, default values for shape parameters and cloud condensation nuclei activation parameters are often used in numerical simulations. In this study, the effects of cloud DSDs on numerical simulations of warm stratiform precipitation around Tokyo are investigated using the Japan Meteorological Agency's non-hydrostatic model, which incorporates a double-moment cloud microphysics scheme. Simulations using the default cloud DSD showed higher cloud droplet number concentrations and lower radar reflectivity than observed data, suggesting that the default cloud DSD is too narrow. Simulations with a cloud DSD based on in situ cloud observations corrected these errors. In addition, observation-based cloud DSDs affected rainfall amounts through the autoconversion rate of cloud water and improved the threat scores. These results suggest that realistic cloud DSDs should be provided for double-moment cloud microphysics schemes in scientific studies.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 5","pages":"Article 100572"},"PeriodicalIF":2.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of the Changbai Mountains’ topography on spring fog over the Bohai Sea","authors":"Meng Tian ,&nbsp;Ying Wen ,&nbsp;Lihong Meng ,&nbsp;Ye Zhang ,&nbsp;Shu Liu ,&nbsp;Yang Guo","doi":"10.1016/j.aosl.2024.100571","DOIUrl":"10.1016/j.aosl.2024.100571","url":null,"abstract":"<div><div>Fog is a highly complex weather phenomenon influenced by numerous factors. This study investigated the impact of the Changbai Mountains’ topography on the formation and development of spring fog in the Bohai Sea. From 12 to 14 May 2021, the Bohai region experienced a sea fog event. Utilizing Himawari-8 satellite data, ERA5 reanalysis dataset, land and sea station observations, the WRF model, a topography sensitivity experiment, and backward trajectory tracking, the influence of the Changbai Mountains’ topography on the evolution of this sea fog event was assessed. Results indicated that the Changbai Mountains’ topography significantly impacted the propagation and concentration of the sea fog through dual effects—namely, the Venturi Effect and Foehn Clearance Effect. Comparative simulations incorporating and excluding the Changbai Mountains revealed that its topography favored weak convergence (Venturi Effect) of low-level airflow over the Bohai Sea induced by a high-pressure system, promoting westward fog expansion. Additionally, the backward trajectory analysis further indicated that the Foehn Clearance Effect of the Changbai Mountains extended its influence far beyond the immediate lee side, contributing to significant changes in atmospheric conditions such as reductions in relative humidity and increases in potential temperature. The dry, warm foehn contributed to a reduction in the liquid water content, ultimately leading to the weakening or even dissipation of the sea fog in the region close to the Changbai Mountains. This study emphasizes the crucial role of the Changbai Mountains’ topography in the development and evolution of fog, providing valuable insights for forecasting fog in regions with complex terrain.</div><div>摘要</div><div>利用Himawari-8卫星数据, ERA5再分析数据, 陆地与海上站点观测, WRF模式, 地形敏感性试验以及后向轨迹分析, 研究了长白山地形对渤海春季海雾生消演变的影响. 结果表明, 长白山地形通过狭管效应和焚风清除效应对海雾的传播和浓度有显著影响. 模拟结果显示, 长白山地形有利于渤海上空低层气流的弱汇合, 促进海雾向西传播. 此外, 后向轨迹分析显示, 长白山的焚风清除效应远超其背风坡区域, 导致相对湿度降低和位温升高等大气条件的显著变化. 干暖焚风降低了雾区的液态水含量, 导致靠近长白山的海雾减弱甚至消散. 本研究强调了长白山地形对渤海海雾发展演变的重要作用, 为复杂海域的雾预报提供参考.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 4","pages":"Article 100571"},"PeriodicalIF":2.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"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}

{"title":"Impacts of global biogenic isoprene emissions on surface ozone during 2000–2019","authors":"Yang Cao ,&nbsp;Xu Yue","doi":"10.1016/j.aosl.2024.100490","DOIUrl":"10.1016/j.aosl.2024.100490","url":null,"abstract":"<div><div>Biogenic isoprene is an important precursor of tropospheric ozone (O₃). Here, a coupled chemistry–vegetation model was used to quantify the contributions of isoprene emissions to surface O₃ pollution on the global scale during 2000–2019. The biogenic isoprene emissions showed high values in mid–low latitudes and seasonal peaks in the summer hemispheres. They promote global surface O₃ concentrations by 1.75 ppbv annually with regional hotspots of 4.39 ppbv (8.8%) in China and 5.36 ppbv (11.1%) in the U.S. in boreal summer. In the past two decades, isoprene emissions increased by 1.32 TgC yr⁻¹ (0.67% yr⁻¹) in the Northern Hemisphere but decreased by 0.71 TgC yr⁻¹ (0.44% yr⁻¹) in the Southern Hemisphere. Such changes of isoprene made opposite contributions to the surface O₃ trend, with 0.26 ppbv yr⁻¹ in eastern China but −0.32 ppbv yr⁻¹ in the southeastern U.S. due to the changes in the background regime of chemical reactions. The impact of anthropogenic changes on the O₃ trend is consistent with that of biogenic isoprene, but two to four times stronger in magnitude. This study revealed that the effective control of anthropogenic NO_<em>x</em> emissions could mitigate regional O₃ pollution even with the increased isoprene emissions under global warming.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"17 6","pages":"Article 100490"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140398368","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":"Enhanced nitrous acid (HONO) formation via NO2 uptake and its potential contribution to heavy haze formation during wintertime","authors":"Zirui Liu ,&nbsp;Rong Yang ,&nbsp;Jingyun Liu ,&nbsp;Keding Lu ,&nbsp;Guiqian Tang ,&nbsp;Yuepeng Pan ,&nbsp;Dongsheng Ji ,&nbsp;Yuesi Wang ,&nbsp;Bo Hu","doi":"10.1016/j.aosl.2024.100491","DOIUrl":"10.1016/j.aosl.2024.100491","url":null,"abstract":"<div><div>A full understanding of the sources of atmospheric nitrous acid (HONO) in the polluted urban atmosphere remains a challenge. In this study, ambient HONO and relevant species were measured during January 2019 at an urban site in Beijing, China, and a budget analysis of HONO was conducted using a box model combined with field observations. Large nighttime “missing sources” of HONO were identified on heavily polluted days based on traditional sources, which had a significant correlation with the relative humidity, ammonia (NH₃), and aerosol surface area, and the promotional effect of NH₃ for nitrogen dioxide (NO₂) uptake on the wet aerosol surface was discussed. Then, an updated parameterization scheme for quantifying the enhanced heterogeneous reactions of NO₂ on aerosol surfaces is proposed, and the missing nighttime sources of HONO could be substantially compensated after the new scheme was incorporated. Further evaluation on the contributions of HONO to hydroxyl radicals was conducted, and the authors found that the photolysis of HONO played a dominant role in the primary OH production on the polluted days (78%–90%). The study reveals great potential of an NH₃-enhanced uptake coefficient of NO₂ on the aerosol surface in the nocturnal HONO budget, and highlights the significance of HONO in the strong atmospheric oxidation capability during episodes with a heavily polluted atmosphere.</div><div>摘要</div><div>本文研究了重污染过程中气态亚硝酸 (HONO) 的关键来源并基于化学箱模型对其源汇过程进行了闭合分析. 结果显示, 现有的HONO 源汇机制并不能解释观测期间出现的高HONO事件, 尤其是重污染过程夜间存在大量的HONO \"未知源\". 本文提出了一套新的HONO 源汇参数化方案, 可以较好的模拟观测期间HONO日间和夜间来源, 并进一步评估了HONO 对羟基自由基 (OH) 的贡献, 发现 HONO 光解主导了重污染天OH生成 (78%–90%). 研究结果揭示了华北城市富氨大气环境促进 NO₂在气溶胶表面的摄取和非均相反应进而主导了夜间HONO生成, 凸显了HONO化学对于重污染过程维持大气氧化能力的重要作用.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"17 6","pages":"Article 100491"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140401827","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}