Atmospheric Science Letters最新文献_第7页

Signal-to-noise errors in free-running atmospheric simulations and their dependence on model resolution 自由运行大气模拟的信噪比误差及其与模型分辨率的关系

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2024-01-31 DOI: 10.1002/asl.1212

Francesca M. Cottrell, James A. Screen, Adam A. Scaife

{"title":"Signal-to-noise errors in free-running atmospheric simulations and their dependence on model resolution","authors":"Francesca M. Cottrell, James A. Screen, Adam A. Scaife","doi":"10.1002/asl.1212","DOIUrl":"10.1002/asl.1212","url":null,"abstract":"Ensemble forecasts have been shown to better predict observed Atlantic climate variability than that of their own ensemble members. This phenomenon—termed the signal-to-noise paradox—is found to be widespread across models, timescales, and climate variables, and has wide implications. The signal-to-noise paradox can be interpreted as forecasts underestimating the amplitude of predictable signals on seasonal-to-decadal timescales. The cause of this remains unknown. Here, we examine sea level pressure variability from a very large multi-model ensemble of uninitialized atmosphere-only simulations, focusing on boreal winter. To assess signal-to-noise errors, the ratio of predictable components (RPC) is examined globally, as well as for regional climate indices: the North Atlantic Oscillation, Arctic Oscillation, Southern Annular Mode, and an Arctic index. Our analyses reveal significant correlations between the multi-model ensemble-mean and observations over large portions of the globe, particularly the tropics, North Atlantic, and North Pacific. However, RPC values greater than one are apparent over many extratropical regions and in all four climate indices. Higher-resolution models produce greater observation-model correlations and greater RPC values than lower-resolution models in all four climate indices. We find that signal-to-noise errors emerge more clearly at higher resolution, but the amplitudes of predictable signals do not increase with resolution, at least across the range of resolutions considered here. Our results suggest that free-running atmospheric models underestimate predictable signals in the absence of sea surface temperature biases, implying that signal-to-noise errors originate in the atmosphere or in ocean–atmosphere coupling.","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"25 6","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl.1212","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139656188","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}

引用次数: 0

Low latitude mesospheric clouds in a warmer climate 气候变暖条件下的低纬度中间层云层

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2024-01-16 DOI: 10.1002/asl.1209

Deepashree Dutta, Steven C. Sherwood, Katrin J. Meissner, Martin Jucker

{"title":"Low latitude mesospheric clouds in a warmer climate","authors":"Deepashree Dutta, Steven C. Sherwood, Katrin J. Meissner, Martin Jucker","doi":"10.1002/asl.1209","DOIUrl":"10.1002/asl.1209","url":null,"abstract":"Observations show that mesospheric clouds (MCs) have been increasing in recent decades, presumably due to increased mesospheric water vapor which is mainly caused by greater methane (CH4) oxidation in the middle atmosphere. Past warm climates such as those of the early Cretaceous and Paleogene periods are thought to have had higher CH4 concentrations than present day, and future CH4 concentrations will also likely continue to rise. Here, idealized atmosphere chemistry-climate model experiments forced with strong polar-amplified sea-surface temperatures and elevated carbon dioxide (CO2) and CH4 concentrations predict a substantial spreading of MCs to middle and low latitudes, well beyond regions where they are currently found. Sensitivity tests show that increased water vapor from CH4 oxidation and cooling from increased CO2 and CH4 concentrations create favorable conditions for cloud formation, producing MC fractions of 0.02 in the low latitudes and 0.1 in the mid-latitudes in the Northern Hemisphere when CH4 concentration is 16× higher than pre-industrial. Further increases in CH4 result in a monotonic increase in low- and mid-latitude MCs. A uniform surface ocean warming, changes in polar amplification, or the solar constant do not significantly affect our results. While the appearance of these clouds is interesting, their ice and liquid water content is not sufficient to cause a significant radiative effect. On the other hand, dehydration of the mesosphere due to these low- and mid-latitude MCs could potentially lead to a reduction in atomic hydrogen, thereby affecting mesospheric ozone concentration, although further study is required to confirm this.","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"25 6","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl.1209","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139482773","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}

引用次数: 0

Quantitative assessment of the potential of optimal estimation for aerosol retrieval from geostationary weather satellites in the frame of the iAERUS-GEO algorithm 在 iAERUS-GEO 算法框架内对从地球静止气象卫星进行气溶胶检索的优化估计潜力进行定量评估

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2024-01-16 DOI: 10.1002/asl.1199

Adèle Georgeot, Xavier Ceamanos, Jean-Luc Attié

{"title":"Quantitative assessment of the potential of optimal estimation for aerosol retrieval from geostationary weather satellites in the frame of the iAERUS-GEO algorithm","authors":"Adèle Georgeot, Xavier Ceamanos, Jean-Luc Attié","doi":"10.1002/asl.1199","DOIUrl":"10.1002/asl.1199","url":null,"abstract":"Satellite remote sensing enables the study of atmospheric aerosols at large spatial scales, with geostationary platforms making this possible at sub-daily frequencies. High-temporal-resolution aerosol observations can be made from geostationary data by using robust numerical inversion methods such as the widely-used optimal estimation (OE) theory. This is the case of the instantaneous Aerosol and surfacE Retrieval Using Satellites in GEOstationary orbit (iAERUS-GEO) algorithm, which successfully retrieves aerosol optical depth (AOD) maps from the Meteosat Second Generation weather satellite based on a simple implementation of the OE approach combined with the Levenberg–Marquardt method. However, the exact gain in inversion performances that can be obtained from the multiple and more advanced possibilities offered by OE is not well documented in the current literature. Against this background, this article presents the quantitative assessment of OE for the future improvement of the iAERUS-GEO algorithm. To this end, we use a series of comprehensive experiments based on AOD maps retrieved by iAERUS-GEO using different OE implementations, and ground-based observations used as reference data. First, we assess the varying importance in the inversion process of satellite observations and a priori information according to the content of satellite aerosol information. Second, we quantify the gain of AOD estimation in log space versus linear space in terms of accuracy, AOD distribution and number of successful retrievals. Finally, we evaluate the accuracy improvement of simultaneous AOD and surface reflectance retrieval as a function of the regions covered by the Meteosat Earth's disk.","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"25 3","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl.1199","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139475841","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}

引用次数: 0

Low cloud response to aerosol-radiation-cloud interactions: Idealized WRF numerical experiments for EUREC4A project 低云对气溶胶-辐射-云相互作用的响应：EUREC4A 项目的理想化 WRF 数值实验

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2024-01-11 DOI: 10.1002/asl.1208

Nazario Tartaglione, Fabien Desbiolles, Anna del Moral-Méndez, Agostino N. Meroni, Anna Napoli, Matteo Borgnino, Antonio Parodi, Claudia Pasquero

{"title":"Low cloud response to aerosol-radiation-cloud interactions: Idealized WRF numerical experiments for EUREC4A project","authors":"Nazario Tartaglione, Fabien Desbiolles, Anna del Moral-Méndez, Agostino N. Meroni, Anna Napoli, Matteo Borgnino, Antonio Parodi, Claudia Pasquero","doi":"10.1002/asl.1208","DOIUrl":"10.1002/asl.1208","url":null,"abstract":"Aerosols significantly affect cloud microphysics and energy budget in different ways. The contribution of the direct, semi-direct, and indirect effects of aerosols on radiation are here investigated over the North Atlantic tropical ocean under different aerosol loadings. The Weather Research and Forecasting Model is used to perform a set of numerical idealized experiments, which are forced with prescribed aerosol profiles. We evaluate the effects of aerosols on modeled shallow clouds and surface radiative budget. The results indicate that large aerosol loadings are associated with enhanced cloudiness and reduced precipitation. While the change in rainfall is mainly due to the larger number of smaller droplets, the change in cloudiness is attributed to the effects of absorbing aerosols, mainly dust particles, which are responsible for a rise of temperature that feeds back onto specific humidity. As in the boundary layer the increase of moisture dominates, the net effect is a higher relative humidity, which favors the formation of thin low non-precipitating clouds. The feedback accounts for a dynamical change in the lower troposphere: shortwave radiation absorption increases temperature at the top of the marine atmospheric boundary-layer and reduces entrainment of warm and dry air, increasing low level moisture content. Despite the overall increase in cloudiness, daytime cloud cover is reduced. The semi-direct effect of aerosols on clouds results in a warming of the surface, opposite to the indirect effect.","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"25 5","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl.1208","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139477106","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}

引用次数: 0

Case study on the formation of a torrential-rainfall-producing southwest vortex: Backward trajectory analyses and sensitivity simulations 关于形成西南暴雨漩涡的案例研究：后向轨迹分析和敏感性模拟

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2024-01-11 DOI: 10.1002/asl.1210

Kang-Quan Yang, Di-Xiang Xiao, Xing-Wen Jiang, Zi Mai, Shen-Ming Fu

{"title":"Case study on the formation of a torrential-rainfall-producing southwest vortex: Backward trajectory analyses and sensitivity simulations","authors":"Kang-Quan Yang, Di-Xiang Xiao, Xing-Wen Jiang, Zi Mai, Shen-Ming Fu","doi":"10.1002/asl.1210","DOIUrl":"10.1002/asl.1210","url":null,"abstract":"The southwest vortices (SWVs) are a unique type of mesoscale vortex that frequently induce torrential rainfall in China. In this study, we focused a long-lived quasi-stationary SWV, which was the primary system for producing an extremely heavy rainstorm within/around Sichuan (the maximum hourly precipitation was ~103.8 mm) in Mid July 2021. After reproduced the SWV's formation by using Weather Research and Forecasting model, we conducted trajectory analyses and topography sensitivity simulations to understand the effects of complicated topography on the vortex's formation. It is found that, the regions south and southwest of the SWV acted as the most important source regions for the air clusters that formed the SWV (proportion ≥ 65%), and the air clusters originated from the upper layer contributed the most (≥60%). Of these, the air clusters sourced from the upper layer southwest and south of the SWV played the most important role in the SWV's formation, as their increase in cyclonic vorticity and their contributions to trajectory number and vorticity were all much larger than those of the others. Sensitivity simulations indicated that, detailed topography features around the Sichuan Basin were crucial in determining the structure, intensity and precipitation of the SWV, whereas, the topography features were not a decisive factor for the SWV's formation. In summary, our findings are useful to enrich the current understanding of the SWVs' formation, which would be helpful to improve the related forecasts.","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"25 5","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl.1210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139475534","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}

引用次数: 0

Comparison of different global ensemble prediction systems for tropical cyclone intensity forecasting 热带气旋强度预报中不同全球集合预报系统的比较

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2024-01-10 DOI: 10.1002/asl.1207

Deyu Lu, Ruiqiang Ding, Jiangyu Mao, Quanjia Zhong, Qian Zou

引用次数: 0

The merged and superposed sub-tropical jet and polar-front jet in the southwest Pacific: A case study 西南太平洋副热带射流与极锋射流的合并与叠加：案例研究

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2024-01-08 DOI: 10.1002/asl.1203

Y. Yang, T. Carey-Smith, R. Turner

引用次数: 0

Large-eddy simulation of plume dispersion in a turbulent boundary layer flow generated by a dynamically controlled recycling method 动态控制循环法产生的湍流边界层流中羽流扩散的大涡流模拟

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2023-12-26 DOI: 10.1002/asl.1204

Hiromasa Nakayama, Tetsuya Takemi

{"title":"Large-eddy simulation of plume dispersion in a turbulent boundary layer flow generated by a dynamically controlled recycling method","authors":"Hiromasa Nakayama, Tetsuya Takemi","doi":"10.1002/asl.1204","DOIUrl":"10.1002/asl.1204","url":null,"abstract":"When conducting large-eddy simulations (LESs) of plume dispersion in the atmosphere, crucial issue is to prescribe time-dependent turbulent inflow data. Therefore, several techniques for driving LESs have been proposed. For example, in the original recycling (OR) method developed by Kataoka and Mizuno (Wind and Structures, 2002, 5, 379–392), a mean wind profile is prescribed at the inlet boundary, the only fluctuating components extracted at the downstream position are recycled to the inlet boundary. Although the basic turbulence characteristics are reproduced with a short development section, it is difficult to generate target turbulent fluctuations consistent with realistic atmospheric turbulence. In this study, we proposed a dynamically controlled recycling (DCR) method that is a simple extension of the OR procedure. In this method, the magnitude of turbulent fluctuations is dynamically controlled to match with the target turbulent boundary layer (TBL) flow using a turbulence enhancement coefficient based on the ratio of the target turbulence statistics to the computed ones. When compared to the recommended data of Engineering Science Data Unit (ESDU) 85020, the turbulence characteristics generated by our proposed method were quantitatively reproduced well. Furthermore, the spanwise and vertical plume spreads were also simulated well. It is concluded that the DCR method successfully simulates plume dispersion in neutral TBL flows.","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"25 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl.1204","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139054252","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}

引用次数: 0

Tropical Atlantic rainfall drives bias in extratropical seasonal forecasts 热带大西洋降雨导致外热带季节性预报出现偏差

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2023-12-12 DOI: 10.1002/asl.1205

T. Collier, J. Kettleborough, A. A. Scaife, L. Hermanson, P. Davis

引用次数: 0

Convectively coupled Rossby–Gravity waves in a field campaign: How they are captured in reanalysis products 实地活动中的对凸耦合罗斯比-重力波：如何在再分析产品中捕捉它们

IF 3 4区地球科学

Atmospheric Science Letters Pub Date : 2023-12-10 DOI: 10.1002/asl.1206

Xiaocong Wang, Minghua Zhang

{"title":"Convectively coupled Rossby–Gravity waves in a field campaign: How they are captured in reanalysis products","authors":"Xiaocong Wang, Minghua Zhang","doi":"10.1002/asl.1206","DOIUrl":"10.1002/asl.1206","url":null,"abstract":"Convectively coupled equatorial waves are a significant source of atmospheric variability in the tropics. Current numerical models continue to struggle in simulating the coupled diabatic heating fields that are responsible for the development and maintenance of these waves. This study investigates how the diabatic fields associated with Mixed Rossby–Gravity waves (MRGs) are represented in four reanalysis products by using a unique observational dataset from the TRMM-KWAJEX (Tropical Rainfall Measuring Mission-Kwajalein Experiment) field campaign. These reanalyses include ERA5, Japanese 55-year Reanalysis (JRA-55), Climate Forecast System Reanalysis (CFSR), and Modern-Era Retrospective Analysis for Research and Applications (MERRA). We found that all four reanalyses captured the MRG structures in winds and temperature, and to a lesser degree in the humidity field except in the boundary layer. However, only the ERA5 and MERRA reanalyses captured the gradual rise and succession of the diabatic heating from boundary layer turbulence, shallow convection, cumulus congestus, and deep convection within the waves. ERA5 is the only product that also captured the gradual rise of the subgrid-scale vertical transport of moist static energy. All reanalysis products underestimated the diabatic heating from cumulus congestus. Results provide observational basis on what aspects of MRG can be trusted and what cannot in the reanalysis products.","PeriodicalId":50734,"journal":{"name":"Atmospheric Science Letters","volume":"25 4","pages":""},"PeriodicalIF":3.0,"publicationDate":"2023-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asl.1206","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138569318","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}

引用次数: 0