Atmospheric and Oceanic Science Letters最新文献

{"title":"Visible and shortwave-infrared spectral characteristics of mixed-phase clouds in typical satellite radiometer channels","authors":"Lijun Hu ,&nbsp;Bin Yao ,&nbsp;Shiwen Teng ,&nbsp;Byung-Ju Sohn ,&nbsp;Hongchun Jin ,&nbsp;Chao Liu","doi":"10.1016/j.aosl.2024.100588","DOIUrl":"10.1016/j.aosl.2024.100588","url":null,"abstract":"<div><div>Mixed-phase clouds (MPCs) involve complex microphysical and dynamical processes of cloud formation and dissipation, which are crucial for numerical weather prediction and cloud-climate feedback. However, satellite remote sensing of MPC properties is still challenging, and there is seldom MPC result inferred from passive spectral observations. This study examines the spectral characteristics of MPCs in the shortwave-infrared (SWIR) channels over the wavelength of 0.4–2.5 µm, and evaluates the potential of current operational satellite spectroradiometer channels for MPC retrievals. With optical properties of MPCs based on the assumption of uniform mixing of both ice and liquid water particles, the effects of MPC ice optical thickness fraction (IOTF) and effective radius on associated optical properties are analyzed. As expected, results indicate that the MPC optical properties show features for ice and liquid water clouds, and their spectral variations show noticeable differences from those for homogeneous cases. A radiative transfer method is employed to examine the sensitivity of SWIR channels to given MPC cloud water path (CWP) and IOTF. MPCs have unique signal characteristics in the SWIR spectrum. The 0.87-µm channel is most sensitive to CWP. Meanwhile, the 1.61- and 2.13-µm channels are more sensitive to water-dominated MPCs (IOTF approaching 0), and the 2.25-µm channel is sensitive to both water-dominated and ice-dominated MPCs (IOTF approaching 1). Such spectral differences are potentially possible to be used to infer MPC properties based on radiometer observations, which will be investigated in future studies.</div><div>摘要</div><div>混合相态云对数值天气预报和云-气候反馈研究都至关重要, 但是对其特性的卫星定量反演还存在巨大挑战。本论文利用辐射传输模拟, 研究混合相云在0.4–2.5 µm光谱范围内的光谱特征, 评估当前典型星载被动光谱辐射计观测反演混合相态云的潜力, 研究发现, 混合相态云的光学特性同时呈现出冰云和液态水云的特点, 而它们的光谱变化特征与冰云或液态水云存在一定差别。其中, 0.87-µm通道对CWP最敏感, 1.61- 和2.13-µm 通道对水云占主导的混合云更加敏感, 2.25-µm通道则对所有混合云都有一定的敏感性, 这些光谱差异可用于反演混合云的特性, 这也将是未来研究重点关注的内容.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 4","pages":"Article 100588"},"PeriodicalIF":2.3,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169741","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":"Evaluation of surface wind speed over East Asia and the adjacent ocean in three reanalyses using satellite and in-situ observations","authors":"Siyuan Li ,&nbsp;Kai Wang ,&nbsp;Hao Miao ,&nbsp;Xuedan Zhu ,&nbsp;Yanjie Liu ,&nbsp;Jinxiao Li ,&nbsp;Wei Wang ,&nbsp;Xiao Zheng ,&nbsp;Juan Feng ,&nbsp;Xiaocong Wang","doi":"10.1016/j.aosl.2024.100587","DOIUrl":"10.1016/j.aosl.2024.100587","url":null,"abstract":"<div><div>Surface wind speed (SWS) not only plays a crucial role in regulating the Earth's energy and hydrological cycle, but also is an important source of sustainable renewable energy. This study assesses the credibility of SWSs in three reanalyses (ERA5, MERRA2, and JRA-55) in East Asia using both satellite and in-situ observations. Results show all three reanalyses can capture the spatial pattern of SWS as in observations, yet there are notable differences in magnitude. On land, ERA5 and MERRA2 overestimate the SWS by about 0.6 and 1.5 m s⁻¹, respectively, whereas JRA-55 underestimates it. The biases over the oceans are opposite to those on land and are relatively small due to the assimilation of observations of oceanic surface winds. Overall, JRA-55 and ERA5 offer better estimates of seasonal means and variances of SWS than MERRA2. The observed SWS shows a negative trend of −0.08 m s⁻¹/10 yr on land and a positive trend of 0.09 m s⁻¹/10 yr in the western North Pacific. Only JRA-55 shows similar trends to observations over both land and ocean, while ERA5 and MERRA2 show varying degrees of deviation from the observations. Further investigation shows that there is a strong link between the trend of SWS and that of the large-scale circulation, and that a large part of the SWS trend can be attributed to changes in large-scale circulations.</div><div>摘要</div><div>利用卫星和地面站点观测数据, 本文对再分析产品中的地表风速 (SWS) 进行了可信度评估. 研究结果表明, 再分析产品能够较好地再现SWS的观测分布特征, 但在风速的量级上则存在显著差异. 具体而言, 在陆地区域, ERA5和MERRA2分别高估了约0.6 m s⁻¹和1.5 m s⁻¹, 而JRA-55则存在低估现象; 而在海洋区域, 偏差情况与陆地相反. 总体来看, JRA-55和ERA5在模拟SWS的气候态及其变率方面, 更加接近观测数据. 其中, JRA-55中SWS的年代际趋势与观测数据最为一致.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 5","pages":"Article 100587"},"PeriodicalIF":2.3,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696475","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 meteorological conditions on the NASM pollution data assimilation system","authors":"Shan Zhang ,&nbsp;Liqun Li ,&nbsp;Linfeng Shang ,&nbsp;Dongji Wang ,&nbsp;Guangtao Niu ,&nbsp;Xuejun Guo ,&nbsp;Xiangjun Tian","doi":"10.1016/j.aosl.2024.100586","DOIUrl":"10.1016/j.aosl.2024.100586","url":null,"abstract":"<div><div>Since meteorological conditions are the main factor driving the transport and dispersion of air pollutants, an accurate simulation of the meteorological field will directly affect the accuracy of the atmospheric chemical transport model in simulating PM_2.5. Based on the NASM joint chemical data assimilation system, the authors quantified the impacts of different meteorological fields on the pollutant simulations as well as revealed the role of meteorological conditions in the accumulation, maintenance, and dissipation of heavy haze pollution. During the two heavy pollution processes from 10 to 24 November 2018, the meteorological fields were obtained using NCEP FNL and ERA5 reanalysis data, each used to drive the WRF model, to analyze the differences in the simulated PM_2.5 concentration. The results show that the meteorological field has a strong influence on the concentration levels and spatial distribution of the pollution simulations. The ERA5 group had relatively small simulation errors, and more accurate PM_2.5 simulation results could be obtained. The RMSE was 11.86 μg m⁻³ lower than that of the FNL group before assimilation, and 5.77 μg m⁻³ lower after joint assimilation. The authors used the PM_2.5 simulation results obtained by ERA5 data to discuss the role of the wind field and circulation situation on the pollution process, to analyze the correlation between wind speed, temperature, relative humidity, and boundary layer height and pollutant concentrations, and to further clarify the key formation mechanism of this pollution process.</div><div>摘要</div><div>气象条件对于污染物的累积, 清除, 传输和扩散有关键的作用. 本文将分别使用FNL 和ERA5再分析资料作为天气模式WRF的初始场, 基于构建的联合数据同化系统, 定量评估气象场对模拟PM_2.5浓度的作用, 同时揭示不同气象要素对于污染物积累, 维持和消散的影响. 研究表明ERA5资料在各个区域的污染模拟结果更接近观测值, 分析了风速, 温度, 相对湿度以及边界层高度与污染物浓度之间的相关性, 并进一步阐明污染过程的形成机制.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 4","pages":"Article 100586"},"PeriodicalIF":2.3,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169740","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":"Characteristics and possible causes of the Meiyu over the Yangtze–Huaihe River Basin in 2023","authors":"Yao Ha ,&nbsp;Haixia Dai ,&nbsp;Shuai Song ,&nbsp;Yaming Zhao ,&nbsp;Wei Lu","doi":"10.1016/j.aosl.2024.100585","DOIUrl":"10.1016/j.aosl.2024.100585","url":null,"abstract":"<div><div>The Meiyu in the Yangtze–Huaihe River basin (YHRB) in 2023 was featured by delayed onset and retreat, a shorter duration, and below-normal Meiyu precipitation. The relatively weak cold air invading southward from the mid-to-high latitudes in late May–early June contributed to the delayed onset of Meiyu season, and the persistent rainfall caused by Typhoon “Talim” and Super Typhoon “Doksuri” led to the delayed retreat. The westward-shifted and intensified western Pacific subtropical high (WPSH), coupled with the eastward-shifted and strengthened south Asian high (SAH), as well as the Eurasian mid-to-high latitude circulation featuring “two troughs–one ridge”, resulting in the below-average Meiyu precipitation with the heaviest rainfall primally in eastern YHRB. Further analysis indicates that the 2023 Meiyu was influenced by the combined effects of the decaying La Niña, warm sea surface temperature (SST) anomalies in the North Pacific west wind drift area, and less than normal snow cover over the Tibetan Plateau. Warmer than normal SST in the western Pacific warm pool and the North Pacific westerly drift region favored the narrow meridional circulation at middle latitudes and WPSH, whereas the strengthened SAH and East Asian summer monsoon were impacted by persistently reduced snow cover over the northeastern Tibetan Plateau.</div><div>摘要</div><div>2023年中国江淮流域入梅和出梅日期均偏晚, 梅雨量整体偏少. 本文研究发现, 5月末6月初中高纬冷空气偏弱是入梅偏晚的原因, 台风“泰利”和强台风“杜苏芮”引起的持续性降水导致了出梅偏晚. 中低纬地区偏西偏强的西太平洋副热带高压和偏东偏强的南亚高压叠置, 配合欧亚中高纬 “两槽一脊”环流型, 使得江淮流域梅雨量偏少, 且降水集中在江淮流域东部. 进一步分析表明, 2023年梅雨期中国受La Niña 衰减位相的影响, 西太平洋暖池和北太平洋西风漂流区的暖海温异常导致中纬度环流经向性偏弱, 西太平洋副热带高压偏西, 偏强. 而南亚高压和东亚夏季风异常主要受到青藏高原东北部积雪持续异常偏少的影响.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 5","pages":"Article 100585"},"PeriodicalIF":2.3,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696474","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 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}