Atmospheric and Oceanic Science Letters最新文献

{"title":"Impact of ocean data assimilation on the seasonal forecast of the 2014/15 marine heatwave in the Northeast Pacific Ocean","authors":"Tiantian Tang,&nbsp;Jiaying He,&nbsp;Huihang Sun,&nbsp;Jingjia Luo","doi":"10.1016/j.aosl.2024.100498","DOIUrl":"10.1016/j.aosl.2024.100498","url":null,"abstract":"<div><div>A remarkable marine heatwave, known as the “Blob”, occurred in the Northeast Pacific Ocean from late 2013 to early 2016, which displayed strong warm anomalies extending from the surface to a depth of 300 m. This study employed two assimilation schemes based on the global Climate Forecast System of Nanjing University of Information Science (NUIST-CFS 1.0) to investigate the impact of ocean data assimilation on the seasonal prediction of this extreme marine heatwave. The sea surface temperature (SST) nudging scheme assimilates SST only, while the deterministic ensemble Kalman filter (EnKF) scheme assimilates observations from the surface to the deep ocean. The latter notably improves the forecasting skill for subsurface temperature anomalies, especially at the depth of 100–300 m (the lower layer), outperforming the SST nudging scheme. It excels in predicting both horizontal and vertical heat transport in the lower layer, contributing to improved forecasts of the lower-layer warming during the Blob. These improvements stem from the assimilation of subsurface observational data, which are important in predicting the upper-ocean conditions. The results suggest that assimilating ocean data with the EnKF scheme significantly enhances the accuracy in predicting subsurface temperature anomalies during the Blob and offers better understanding of its underlying mechanisms.</div><div>摘要</div><div>2013年底至2016年初, 东北太平洋上发生了历史上罕见的极端海洋热浪事件 (称为“Blob”事件) , 形成了从海表延伸至海洋深处300m的强烈且持续的海温暖异常. 本文利用南京信息工程大学全球气候预测系统1.0版本 (NUIST-CFS 1.0) , 采用两种海洋资料同化方案, 探究海洋资料同化差异对这一极端海洋热浪事件季节预测的影响. 本文采用的一种同化方案为仅同化海表面温度 (Surface sea temperature, SST) 的SST-nudging方案, 而另一种方案为在前一种方案的基础上加入确定性集合卡尔曼滤波 (Deterministic Ensemble Kalman Filter, DEnKF) , 同化更多海洋观测数据的EnKF方案. 主要结论为, 利用EnKF方案可显著提高对“Blob”期间次表层温度异常预测的准确性, 这主要源于EnKF方案在预测次表层的水平和垂直热传输方面表现出色. 该研究有助于更好地理解海洋热浪事件潜在物理机制及其季节预测水平.</div></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":"18 1","pages":"Article 100498"},"PeriodicalIF":2.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140771707","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 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":"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":"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":"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}