Atmospheric Research最新文献_第10页

Influence of clouds on planetary boundary layer height: A comparative study and factors analysis 云对行星边界层高度的影响：比较研究和因素分析

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-15 DOI: 10.1016/j.atmosres.2024.107784

Hui Li , Boming Liu , Wei Gong , Yingying Ma , Shikuan Jin , Weiyan Wang , Ruonan Fan , Shuailong Jiang

Clouds are one of the key factors influencing the evolution of the planetary boundary layer (PBL). Understanding the complex interactions between clouds and PBL height (PBLH) is essential for accurately simulating and predicting PBL processes. This study investigates the impact of clouds on PBLH evolution based on the lidar, radiosonde, ceilometer, and meteorological parameters observations at the Southern Great Plains site during the period January 2013 to December 2020. The findings indicates that the presence of clouds has an impact on the evolution of the PBLH. During the daytime, PBLH is lower under cloudy conditions than clear conditions, whereas during nighttime, PBLH is higher under cloudy conditions. This phenomenon arises because the intense solar radiation on clear days and strong turbulent mixing on cloudy nights contribute to the formation and maintenance of PBLH. Furthermore, during the daytime, clouds scatter and absorb solar radiation, leading to lower net radiation (NetR), sensible heat flux (SHF), surface temperature (TEM), and soil temperature (SoilT). These conditions, coupled with weaker turbulence intensity and high relative humidity (RH), leading to lower PBLH under cloudy conditions. Although TEM and SoilT are relatively high during clear nights, rapid surface radiative cooling and strong atmospheric stability inhibit the development of the PBLH. Consequently, during cloudy nights, clouds absorb and reflect longwave radiation from the surface, reducing surface radiative cooling rates, enhancing atmospheric instability and turbulence intensity. Furthermore, higher NetR and SHF, along with decreased RH, result in slightly deeper PBLH compared to clear conditions. Overall, this study systematically elucidates the influence of clouds on PBLH evolution and contributes to the understanding of the modulation of cloud on PBL structure.

云是影响行星边界层（PBL）演变的关键因素之一。了解云层与行星边界层高度（PBLH）之间复杂的相互作用对于准确模拟和预测行星边界层过程至关重要。本研究基于 2013 年 1 月至 2020 年 12 月期间在南部大平原站点观测到的激光雷达、辐射计、气压计和气象参数，研究了云对 PBLH 演变的影响。研究结果表明，云的存在对 PBLH 的演变有影响。白天，多云条件下的 PBLH 低于晴朗条件下的 PBLH，而夜间，多云条件下的 PBLH 高于晴朗条件下的 PBLH。出现这种现象的原因是，晴天的强烈太阳辐射和多云夜晚的强烈湍流混合作用促成了 PBLH 的形成和维持。此外，在白天，云会散射和吸收太阳辐射，导致净辐射（NetR）、显热通量（SHF）、地表温度（TEM）和土壤温度（SoilT）降低。这些条件加上较弱的湍流强度和较高的相对湿度（RH），导致多云条件下的 PBLH 较低。虽然晴朗夜晚的 TEM 和 SoilT 相对较高，但快速的地表辐射冷却和强大的大气稳定性抑制了 PBLH 的发展。因此，在多云的夜晚，云会吸收和反射地表的长波辐射，降低地表辐射冷却率，增强大气的不稳定性和湍流强度。此外，与晴朗条件相比，较高的 NetR 和 SHF 以及较低的相对湿度会导致 PBLH 稍微加深。总之，这项研究系统地阐明了云对 PBLH 演变的影响，有助于理解云对 PBL 结构的调节作用。

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引用次数: 0

Assimilation of high-resolution GNSS tropospheric delays and its effects on a severe convective event nowcasting 高分辨率全球导航卫星系统对流层延迟的同化及其对严重对流事件预报的影响

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-15 DOI: 10.1016/j.atmosres.2024.107785

Yuxin Zheng , Cuixian Lu , Zhilu Wu , Zhenyu Guan , Jiafeng Li , Zhuo Wang , Chengbo Liu

A crucial factor limiting convective weather nowcasting is the lack of timely updated and accurate atmospheric water vapor observations. The Global Navigation Satellite System (GNSS) can accurately sense water vapor with high temporal resolutions, which is adequate to observe many meso- and small-scale variations associated with convective weather. In this contribution, an hourly cycling data assimilation system is established to investigate the influence of assimilating GNSS zenith total delays (ZTD) on severe convective weather nowcasting. The contributions of assimilating ZTD with different temporal resolutions are discussed in detail by validating with the radiosonde observations. The results demonstrate that the assimilation of ZTD significantly improves the moisture distribution of the middle and lower troposphere. Furthermore, model simulations become wetter or drier as the frequency of ZTD assimilation increases. Verification of the precipitation forecasts is performed by comparing them with the radar-estimated precipitation. The results indicate that assimilation of GNSS ZTD improves the accuracy of precipitation forecast in the nowcasting range of 0–6 h. Compared to the control experiment, the hourly ZTD assimilation experiment reveals the highest precipitation forecast skill scores, followed by the experiments of assimilating ZTD every three and six hours, indicating that the rapid update of water vapor information could contribute to improving the precipitation nowcasting in a rapidly developing convective system.

限制对流天气预报的一个关键因素是缺乏及时更新和准确的大气水汽观测。全球导航卫星系统（GNSS）能够以较高的时间分辨率精确感知水汽，足以观测到与对流天气相关的许多中尺度和小尺度变化。本文建立了一个每小时循环数据同化系统，以研究同化全球导航卫星系统天顶总延迟（ZTD）对强对流天气预报的影响。通过与无线电探空仪观测数据进行验证，详细讨论了不同时间分辨率的天顶总延迟同化的贡献。结果表明，ZTD 同化显著改善了对流层中下层的湿度分布。此外，随着 ZTD 同化频率的增加，模式模拟会变得更湿润或更干燥。通过与雷达估算的降水量进行比较，对降水预报进行了验证。结果表明，GNSS ZTD 同化提高了 0-6 小时降水预报的准确性。与对照实验相比，每小时 ZTD 同化实验的降水预报技能得分最高，其次是每 3 小时和每 6 小时同化 ZTD 的实验，表明水汽信息的快速更新有助于改善快速发展的对流系统中的降水预报。

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引用次数: 0

Investigating secondary ice production in a deep convective cloud with a 3D bin microphysics model: Part II - Effects on the cloud formation and development 利用 3D bin 微物理模型研究深对流云中的二次产冰：第二部分 - 对云的形成和发展的影响

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-15 DOI: 10.1016/j.atmosres.2024.107797

Pierre Grzegorczyk , Wolfram Wobrock , Antoine Canzi , Laurence Niquet , Frédéric Tridon , Céline Planche

Secondary ice production (SIP) leads to the formation of new ice particles from preexisting ones. Besides generating ice crystals, SIP can also influence cloud characteristics, including convection, precipitation, and even radiative properties. This study examines the effect of ice crystal formation by Hallett-Mossop, fragmentation of freezing drops, and fragmentation due to ice–ice collision processes in an idealized deep convective cloud observed during the HAIC/HIWC campaign, using the 3D bin microphysics scheme DESCAM. Our results indicate that heterogeneous ice nucleation and fragmentation of freezing drops play a role during the early formation of the cloud while after that, Hallett-Mossop and ice-ice breakup processes dominate, representing 17.6 % and 81.5 % of the ice crystal production, for temperatures warmer than −30°C. For temperatures colder than −30°C, homogeneous and heterogeneous ice nucleation processes are the main contributors to ice crystal formation. The impact of each SIP process on particle size distributions is analyzed by tracking air parcel trajectories. This study also shows the effect of SIP processes on cloud development. Implementing SIP results in a decrease in cloud top altitude by around 1.5 km. Our analysis shows that this effect is caused by increased latent heat released below 11 km, resulting from a stronger vapor deposition on more numerous ice crystals. This enhances convection at lower levels but inhibits it above. Furthermore, incorporating SIP leads to 15 % decrease in total precipitation amount and 25 % reduction of intense rainfall (accumulated precipitation over 40 mm). Hence, our study emphasizes the importance of SIP mechanisms in cloud development and precipitation.

二次产冰（SIP）是指在原有冰粒的基础上形成新的冰粒。除了生成冰晶，二次产冰还会影响云的特性，包括对流、降水甚至辐射特性。本研究利用三维 bin 微物理方案 DESCAM，研究了 HAIC/HIWC 活动期间观测到的理想化深对流云中 Hallett-Mossop 形成冰晶、冰冻水滴破碎以及冰-冰碰撞过程导致的破碎的影响。我们的研究结果表明，在云的早期形成过程中，冰滴的异质成核和碎裂起了作用，而在此之后，Hallett-Mossop 和冰-冰破裂过程占主导地位，在温度高于 -30°C 的情况下，这两个过程分别占冰晶生成的 17.6% 和 81.5%。在温度低于-30°C 时，均质和异质冰核形成过程是冰晶形成的主要因素。通过跟踪空气包裹轨迹，分析了每个 SIP 过程对粒度分布的影响。这项研究还显示了 SIP 过程对云层发展的影响。实施 SIP 会导致云顶高度降低约 1.5 千米。我们的分析表明，造成这种影响的原因是 11 千米以下释放的潜热增加，这是因为更多冰晶上的水汽沉积更强。这增强了低空的对流，但抑制了高空的对流。此外，加入 SIP 后，降水总量减少了 15%，强降水（累计降水量超过 40 毫米）减少了 25%。因此，我们的研究强调了 SIP 机制在云的发展和降水中的重要性。

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引用次数: 0

Impacts of land surface processes on summer extreme precipitation in Eastern China: Insights from CWRF simulations 陆面过程对中国东部夏季极端降水的影响：CWRF模拟的启示

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-15 DOI: 10.1016/j.atmosres.2024.107783

Chenyi Zhang , Qingquan Li , Xin-Zhong Liang , Lili Dong , Bing Xie , Weiping Li , Chao Sun

Understanding the impacts of land surface processes on summer extreme precipitation is crucial for accurate climate predictions. This study investigated these impacts across three subregions of eastern China (North China, Central China, and South China) using the regional Climate–Weather Research and Forecasting model with two land surface parameterization schemes: the Conjunctive Surface–Subsurface Process (CSSP) scheme and the NOAH Land Surface Model (NOAH). When compared with observational and reanalysis data, both schemes were found to successfully reproduce the spatial distribution of extreme precipitation, with the CSSP scheme showing distinct advantages in simulating evapotranspiration. The influence of land surface processes on summer extreme precipitation varies among the three subregions, largely depending on soil moisture conditions. In North China, a transitional zone between arid and humid regions, soil moisture primarily influences extreme precipitation, with biases arising from difference between the lifting condensation level and the planetary boundary layer height. In Central China, where soil moisture is moderate, soil moisture and net radiation jointly influence extreme precipitation, with biases linked to the planetary boundary layer height. In South China, where soil moisture is mostly saturated during summer, net radiation dominates the variability of land surface variables, with latent heat bias leading to extreme precipitation bias. Overall, soil moisture affects extreme precipitation by altering the energy and stability of the planetary boundary layer and the lifting condensation level. These findings could inform the assessment and future improvement of models, and support the monitoring and predicting of extreme precipitation events.

了解陆面过程对夏季极端降水的影响对于准确预测气候至关重要。本研究利用区域气候-天气研究和预报模式，采用两种陆面参数化方案：结合地表-副表面过程（CSSP）方案和 NOAH 陆面模式（NOAH），研究了华东三个分区（华北、华中和华南）的陆面过程对极端降水的影响。与观测数据和再分析数据相比，两种方案都成功地再现了极端降水的空间分布，其中 CSSP 方案在模拟蒸散方面具有明显优势。陆面过程对夏季极端降水的影响在三个分区之间存在差异，主要取决于土壤水分条件。华北地区是干旱与湿润的过渡地带，土壤水分对极端降水的影响主要来自抬升凝结水平与行星边界层高度之间的差异。在土壤湿度适中的华中地区，土壤湿度和净辐射共同影响极端降水，偏差与行星边界层高度有关。在华南地区，夏季土壤水分大部分处于饱和状态，净辐射主导着陆面变量的变化，潜热偏差导致极端降水偏差。总体而言，土壤水分通过改变行星边界层的能量和稳定性以及抬升凝结水平来影响极端降水。这些发现可为评估和未来改进模式提供信息，并为极端降水事件的监测和预测提供支持。

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引用次数: 0

Climate change effects on the localized heavy rainfall event in northern Japan in 2022: Uncertainties in a pseudo-global warming approach 气候变化对 2022 年日本北部局部暴雨事件的影响：伪全球变暖方法的不确定性

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-14 DOI: 10.1016/j.atmosres.2024.107780

Ryotaro Tahara, Yusuke Hiraga, So Kazama

This study used the pseudo-global warming (PGW) method in the Weather Research and Forecasting (WRF) model to examine the effects of climate change on localized heavy rainfall events in the Tohoku and Hokuriku regions in August 2022. This heavy rainfall event is one of the representative cases of heavy rainfall in the region, in which water vapor transport from the Sea of Japan is a key factor, and its frequency and magnitude are projected to increase with climate change. Our modeling results showed that the simulated 48-h precipitation under the projected 2090s warming conditions increased by 34.6 % compared to precipitation without consideration of future warming effects. In general, the amount of water vapor in the atmosphere and convection instability over the ocean increased with future warming. While the rate of increase in water vapor is generally consistent with Clausius-Clapeyron scaling (7 %/K) based on surface temperature rise, the 48-h cumulative precipitation notably exceeds this scaling rate, even larger than triple Clausius-Clapeyron scaling. This increase in precipitation is driven by a combination of thermodynamic effects—such as enhanced water vapor content with rising temperatures—and dynamic effects, including strengthened updrafts. We showed that the model domain location can significantly affect the simulated precipitation and its changes in PGW simulations. For instance, a 29.2 % change in 48-h precipitation was observed solely due to the geospatial shift of the innermost domain. This finding indicates the importance of the model domain location as a source of uncertainty in the PGW method.

本研究利用天气研究和预报（WRF）模型中的伪全球变暖（PGW）方法，研究了气候变化对 2022 年 8 月东北和北陆地区局部暴雨事件的影响。该暴雨事件是该地区具有代表性的暴雨事件之一，其中来自日本海的水汽输送是一个关键因素，预计其频率和强度将随着气候变化而增加。我们的模拟结果表明，在预计的 2090 年代气候变暖条件下，48 小时的模拟降水量比未考虑未来气候变暖影响的降水量增加了 34.6%。一般来说，大气中的水汽量和海洋上空的对流不稳定性会随着未来气候变暖而增加。虽然水汽的增加速度与基于地表温度上升的克劳修斯-克拉皮隆缩放比例（7%/K）基本一致，但 48 小时累积降水量明显超过了这一缩放比例，甚至大于三倍克劳修斯-克拉皮隆缩放比例。降水量的增加是由热力学效应（如水汽含量随温度上升而增加）和动力学效应（包括上升气流增强）共同驱动的。我们的研究表明，在 PGW 模拟中，模式域位置会显著影响模拟降水量及其变化。例如，仅由于最内层模式域的地理空间移动，就观测到了 48 小时降水量 29.2% 的变化。这一发现表明了模式域位置作为 PGW 方法不确定性来源的重要性。

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引用次数: 0

Accelerating onset of heatwaves after the Meiyu termination in the middle-lower Yangtze River basin 梅雨终止后长江中下游流域热浪的加速出现

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-14 DOI: 10.1016/j.atmosres.2024.107782

Wei Jiang , Ting Ding , Hui Gao

This study employs station observation and Meiyu monitoring data in the middle-lower Yangtze River (MLYR) basin to investigate a distinctive heatwave phenomenon, characterized by an accelerated onset following the Meiyu termination in 2001–2022. In the basin, the proportion of rapid heatwaves (transition duration less than two days) is 30 % in the period 1981–2000, while it increased markedly to 77 % in the period 2001–2022. Furthermore, the accelerating onset of heatwaves in the basin is not limited to the surface. The results of the statistical analysis demonstrate the significant influence of circulations in the middle-low troposphere. In comparison to the circulations observed during the period between 1981 and 2000, the geopotential height (GPH) over the basin displays a considerable increase between 300 and 700 hPa following the termination of Meiyu in the later period. Additionally, there is a notable acceleration in the warming of the lower troposphere. The abrupt evolution of the circulation patterns resulted in the formation of a rapid heat-dome effect over the entire basin. This effect persists even when the warming trend of air temperatures and the enhancing trend of GPHs are removed. The heat-dome effect is closely associated with the rapid shift of the western Pacific subtropical high (WPSH), particularly its western boundary. The rapid westward extension of the WPSH after the Meiyu event and its subsequent control of the MYLR basin form an “Ω”-shape circulation structure, which block the cold air invasion from high latitudes and enhance the geopotential heights by downward shortwave radiation, to induce the heat dome over the basin. This, in turn, will accelerate the onset and persistence of heatwaves.

本研究利用长江中下游流域（MLYR）的站点观测和梅雨监测资料，研究了一种独特的热浪现象，其特征是在 2001-2022 年梅雨终止后加速出现。在该流域，1981-2000 年期间，快速热浪（过渡持续时间小于两天）的比例为 30%，而在 2001-2022 年期间，这一比例明显上升至 77%。此外，盆地热浪的加速出现并不局限于地表。统计分析结果表明，对流层中低层的环流对热浪产生了重大影响。与 1981 年至 2000 年期间观测到的环流相比，后期梅雨结束后，盆地上空 300 至 700 hPa 的位势高度（GPH）出现了大幅上升。此外，对流层下部明显加速变暖。环流模式的突然演变导致整个盆地迅速形成热穹效应。即使去除气温的变暖趋势和 GPHs 的增强趋势，这种效应仍然存在。热穹效应与西太平洋副热带高压（WPSH）的快速移动密切相关，尤其是其西部边界。梅雨事件后，西太平洋副热带高压迅速西伸，随后控制了MYLR盆地，形成了 "Ω "形环流结构，阻挡了高纬度冷空气的入侵，并通过向下的短波辐射提升了位势高度，诱发了盆地上空的热穹效应。这反过来又会加速热浪的出现和持续。

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引用次数: 0

Improving long-term prediction of terrestrial water storage through integration with CMIP6 decadal prediction 通过与 CMIP6 十年期预测相结合改进陆地蓄水的长期预测

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-13 DOI: 10.1016/j.atmosres.2024.107776

Enda Zhu , Yaqiang Wang , Yan Zhao , Xing Yuan

Accurate climate prediction is crucial for terrestrial water storage (TWS) decadal prediction, which contributes to the sustainable development of hydrological infrastructure. Although the initial memories from atmosphere, ocean and land surface are important sources of climate predictability, their impacts on the decadal hydrological prediction still remain unknown. Here, climate predictions with different initialization strategies from the sixth Coupled Model Intercomparison Project (CMIP6) are incorporated into the hydrological predictions over global major river basins through the elasticity framework. Integrations of the climate initialization and external forcings can improve the TWS prediction skill (Nash-Sutcliffe efficiency) by 0.14–0.24 over 69 % basins against a reference forecast without any climate prediction information, especially over high-latitudes at long lead time. Specifically, climate initialization results in a higher skill for TWS prediction over 62.5 % of basins, while considering the Atlantic or Pacific sea surface temperature information is benefit to the hydrological prediction over 38 %–90 % of basins at different lead times. Our findings imply that reliable hydrological decadal prediction can be achieved if skillful climate prediction that originates from initial conditions, external forcings and specific climate variability has been utilized appropriately.

准确的气候预测对陆地蓄水（TWS）十年期预测至关重要，有助于水文基础设施的可持续发展。尽管来自大气、海洋和陆地表面的初始记忆是气候可预测性的重要来源，但它们对十年水文预测的影响仍然未知。在此，通过弹性框架将第六次耦合模式相互比较项目（CMIP6）中不同初始化策略的气候预测纳入全球主要流域的水文预测中。与没有任何气候预测信息的参考预报相比，整合气候初始化和外部作用力可将 69% 流域的 TWS 预测技能（纳什-萨特克利夫效率）提高 0.14-0.24% ，尤其是在高纬度地区的长前导时间内。具体而言，气候初始化可提高 62.5% 流域的 TWS 预测技能，而考虑大西洋或太平洋海面温度信息则有利于 38%-90% 流域在不同提前期的水文预测。我们的研究结果表明，如果能够适当利用源于初始条件、外部作用力和特定气候变异性的高水平气候预测，就可以实现可靠的十年期水文预测。

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引用次数: 0

Quality control of eddy covariance fluxes of two ecosystem types with local flux-variance similarity functions in West Africa 利用西非当地通量-方差相似函数对两种生态系统类型的涡度协方差通量进行质量控制

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-10 DOI: 10.1016/j.atmosres.2024.107775

Ossénatou Mamadou , Miriam Hounsinou , Djidjoho Renaud Roméo Koukoui , Jean-Martial Cohard , Simon Afouda , Romain Biron , Jean Kempf , Théodore Ouani , Basile Kounouhewa

Ecosystem capacity studies for carbon sequestration and water extraction are largely conditioned by Eddy Covariance (EC) measurement availability and quality. Our study aims at evaluating several procedures of EC data qualification. Indeed, quality control of EC data is generally ensured by stationarity and well-developed turbulence tests. The latter is based on integral turbulence characteristic (ITC) models. In this study, we revisited the quality control procedure using locally established ITC models for wind speed components and atmospheric scalars (temperature, humidity and carbon dioxide molar densities) in unstable and stable conditions. We also considered the interdependence of flux qualities because of the corrections applied to fluxes during their preprocessing. The analyses were carried out using one year of data collected above a woodland forest and mixed crop sites, both situated in Northern Benin, West Africa. From these analyzes we note that the quality flags vary depending on the use of local or existing ITC models. Also, the test of turbulence development on atmospheric scalars, previously neglected, is of great importance in the quality control of data. Thus, taking into account the ITC models associated with the atmospheric scalars established locally in the well-developed turbulence test as well as taking into account the interdependence of the flux quality have considerably improved the standard quality control procedure used in effectively filtering unrealistic flux data while keeping a considerable percentage of good and medium quality data.

固碳和取水的生态系统能力研究在很大程度上取决于涡度协方差（EC）测量的可用性和质量。我们的研究旨在评估几种涡度协方差数据鉴定程序。事实上，EC 数据的质量控制一般由静止性和完善的湍流测试来保证。后者以整体湍流特性（ITC）模型为基础。在本研究中，我们利用当地建立的不稳定和稳定条件下的风速分量和大气标量（温度、湿度和二氧化碳摩尔密度）ITC 模型，重新审视了质量控制程序。我们还考虑了通量质量之间的相互依存关系，因为在通量预处理期间对其进行了修正。分析使用了在林地森林和混合作物地点收集的一年数据，这两个地点都位于西非贝宁北部。从这些分析中我们注意到，质量标志因使用当地或现有的 ITC 模型而异。此外，以前被忽视的大气标量湍流发展测试在数据质量控制方面也非常重要。因此，在完善的湍流测试中考虑到与当地建立的大气标量相关的 ITC 模型，并考虑到通量质量的相互依存性，大大改进了标准质量控制程序，有效过滤了不切实际的通量数据，同时保留了相当比例的优质和中等质量数据。

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引用次数: 0

Can we mitigate tropical cyclone formation using aerosols? A review of cyclogenesis and aerosol effects as a theoretical basis 我们能否利用气溶胶缓解热带气旋的形成？作为理论基础的气旋生成和气溶胶效应综述

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-09 DOI: 10.1016/j.atmosres.2024.107779

Thao Linh Tran , Roslyn Prinsley , Daniel Rosenfeld , Helen Cleugh , Jiwen Fan

Tropical cyclogenesis is a complex phenomenon, involving processes across multiple scales, with various theories proposed to explain its mechanisms. This paper provides an up-to-date summary of the established physical mechanisms and controlling factors of cyclogenesis. Understanding the nature of tropical cyclone formation is necessary to improve tropical cyclone forecasts and inform tropical cyclone mitigation strategies targeting early-stage intervention. Despite the disparities among theories, the critical role of persistent, intensified convection in tropical cyclone initiation is universally acknowledged. Therefore, our hypothesis is that interrupting convective development using aerosol injection is a potential strategy for mitigating tropical cyclone formation. Targetted injection of coarse and fine aerosols at the formation stage are two proposed potential approaches for mitigating tropical cyclones. These methods have completely different microphysical effects but each may ultimately interfere with the formation of the nascent cyclone. These potential interventions open new areas of further research, which are important and necessary to establish a solid scientific foundation for cyclogenesis mitigation.

热带气旋生成是一种复杂的现象，涉及多个尺度的过程，并提出了各种理论来解释其机制。本文对气旋生成的既定物理机制和控制因素进行了最新总结。了解热带气旋形成的本质对于改善热带气旋预报和制定针对早期干预的热带气旋减灾战略非常必要。尽管各种理论之间存在差异，但持续、增强的对流在热带气旋形成过程中的关键作用已得到普遍认可。因此，我们的假设是，利用气溶胶注入来中断对流的发展，是减缓热带气旋形成的一种潜在策略。在气旋形成阶段有针对性地注入粗气溶胶和细气溶胶是两种拟议的缓解热带气旋的潜在方法。这些方法具有完全不同的微物理效应，但最终都可能干扰新生气旋的形成。这些潜在的干预措施开辟了进一步研究的新领域，对于为减缓气旋的形成奠定坚实的科学基础十分重要和必要。

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引用次数: 0

Recent impact of reduced arctic sea-ice on the winter North Atlantic jet stream and its quantitative contributions compared to pre-industrial level 北极海冰减少对冬季北大西洋喷流的近期影响及其与工业化前水平相比的定量贡献

IF 4.5 2区地球科学 Q1 METEOROLOGY & ATMOSPHERIC SCIENCES

Atmospheric Research

Pub Date : 2024-11-09 DOI: 10.1016/j.atmosres.2024.107778

Jie Jiang , Shengping He , Ke Fan

It has been a challenge to identify the impact of Arctic sea-ice loss on the intensity and position of the winter North Atlantic jet stream (NAJS) and the related mechanisms due to the uncertain effects of atmospheric internal variability. This study investigates the response of the winter NAJS to Arctic sea-ice loss and roughly estimates the contribution of internal variability in Arctic sea ice (ArcSIC) after the pre-industrial period, based on reanalysis dataset (referred to as observation here), the Coupled Model Inter-comparison Project phase 6 (CMIP6) and the Polar Amplification Model Inter-comparison Project (PAMIP). The results indicate that the majority of PAMIP models display robust but weak equatorward shift of the NAJS response to Arctic sea-ice loss, as well as robust NAJS-related circulation anomalies. Further analysis shows that the ability of models to reproduce observed NAJS response is primarily associated with tropospheric baroclinic wave activity and the troposphere–stratosphere coupling. Based on 20th-Century reanalysis data and CMIP6 historical simulations, we further estimate the relative contributions of external forcing and internal variability (including reduced ArcSIC) to NAJS latitude and speed variability. Compared to the pre-industrial period, the recent winter NAJS at 850 hPa has accelerated and shifted poleward. By calculating the ratio of the difference in NAJS speed (latitude) between the present-day and pre-industrial in CMIP6 multi-model ensemble mean to the difference in observation, this study approximately estimates that the external forcing contributes about 40 % of NAJS acceleration with minimal influence on its shift. The remaining acceleration and poleward shift are mainly attributed to internal variability. The difference between the present-day and pre-industrial PAMIP ensemble mean is considered as the “pure” forcing of Arctic sea-ice loss. Most models indicate that reduced ArcSIC tends to slow down the acceleration and poleward shift of winter NAJS, but show quantitively a wide range of uncertainty.

由于大气内部变率的不确定影响，确定北极海冰消失对冬季北大西洋喷流强度和位置的影响以及相关机制一直是一项挑战。本研究基于再分析数据集（此处称为观测数据）、耦合模式相互比较项目第六阶段（CMIP6）和极地放大模式相互比较项目（PAMIP），研究了冬季北大西洋喷流对北极海冰损失的响应，并粗略估计了前工业化时期之后北极海冰内部变率（ArcSIC）的贡献。结果表明，大多数 PAMIP 模式对北极海冰损失的 NAJS 反应显示出强劲但微弱的赤道偏移，以及与 NAJS 有关的强劲环流异常。进一步的分析表明，模式再现观测到的北大西洋气旋响应的能力主要与对流层的气压波活动和对流层-平流层耦合有关。根据 20 世纪再分析数据和 CMIP6 历史模拟，我们进一步估算了外部强迫和内部变率（包括 ArcSIC 的减少）对 NAJS 纬度和速度变率的相对贡献。与工业化前时期相比，850 hPa 的近期冬季 NAJS 已经加速并向极地移动。通过计算 CMIP6 多模式集合平均值中目前与工业化前 NAJS 速度（纬度）之差与观测值之差的比率，本研究近似估计，外部强迫对 NAJS 加速的贡献约为 40%，而对其移动的影响微乎其微。其余的加速和极移主要归因于内部变率。现在的 PAMIP 集合平均值与工业化前的 PAMIP 集合平均值之间的差异被视为北极海冰损失的 "纯 "强迫。大多数模式表明，ArcSIC 的减少往往会减缓冬季北冰洋海冰加速和向极地移动的速度，但在数量上显示出很大的不确定性。

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