Journal of Atmospheric and Oceanic Technology最新文献_第10页

Performance Modeling of a Diode-Laser-Based Direct Detection Doppler Lidar for Vertical Wind Profiling 基于二极管激光的直接探测多普勒激光雷达垂直风廓线性能建模

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-07-25 DOI: 10.1175/jtech-d-22-0001.1

K. Repasky, Owen Cruikshank, Luke Colberg

{"title":"Performance Modeling of a Diode-Laser-Based Direct Detection Doppler Lidar for Vertical Wind Profiling","authors":"K. Repasky, Owen Cruikshank, Luke Colberg","doi":"10.1175/jtech-d-22-0001.1","DOIUrl":"https://doi.org/10.1175/jtech-d-22-0001.1","url":null,"abstract":"\u0000Micropulse differential absorption lidar (MPD) for water vapor, temperature, and aerosol profiling have been developed, demonstrated, and are addressing the needs of the atmospheric science community for low-cost ground-based networkable instruments capable of long-term monitoring of the lower troposphere. The MPD instruments use a diode-laser-based (DLB) architecture that can easily be adapted for a wide range of applications. In this study, a DLB direct detection Doppler lidar based on the current MPD architecture is modeled to better understand the efficacy of the instrument for vertical wind velocity measurements with the long-term goal of incorporating these measurements into the current network of MPD instruments. The direct detection Doppler lidar is based on a double-edge receiver that utilizes two Fabry-Perot interferometers and a vertical velocity retrieval that requires the ancillary measurement of the backscatter ratio, which is the ratio of the total backscatter coefficient to the molecular backscatter coefficient. The modeling in this paper accounts for the major sources of error. It indicates that the vertical velocity can be retrieved with an error of less than 0.56 m s−1 below 4 km with a 150-m range resolution and an averaging time of five minutes.","PeriodicalId":15074,"journal":{"name":"Journal of Atmospheric and Oceanic Technology","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49147901","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}

引用次数: 2

The impact of non-zenith elevation angles on ground-based infrared thermodynamic retrievals. 非天顶仰角对地基红外热力学反演的影响。

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-07-25 DOI: 10.1175/jtech-d-21-0134.1

Jongjin Seo, T. Wagner, P. J. Gero, D. Turner

{"title":"The impact of non-zenith elevation angles on ground-based infrared thermodynamic retrievals.","authors":"Jongjin Seo, T. Wagner, P. J. Gero, D. Turner","doi":"10.1175/jtech-d-21-0134.1","DOIUrl":"https://doi.org/10.1175/jtech-d-21-0134.1","url":null,"abstract":"\u0000Observing thermodynamic profiles within the planetary boundary layer is essential to understanding and predicting atmospheric phenomena due to the significant exchange of sensible and latent heat between the land and atmosphere within that layer. The Atmospheric Emitted Radiance Interferometer (AERI) is a ground-based infrared spectrometer used to obtain the vertical profiles of temperature and water vapor mixing ratio. Most AERIs are only capable of zenith views, though the Marine AERI (M-AERI) has a design that allows it to view various elevation angles. In this study, we quantify the improvement in the information content and accuracy of the retrieved profiles when non-zenith angles are included, as is common with microwave radiometer profilers. The impacts of the additional scan angles are quantified through both a synthetic study and with M-AERI observations from the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) campaign. The simulation study shows low elevation angles contain more information content for temperature while high elevation angles have more information content for water vapor. Outside of very humid environments, the addition of low elevation angles also results in lower root mean square errors when compared to high angles for both temperature and water vapor mixing ratio, although this is primarily a result of averaging multiple observations together to reduce instrument noise. Real-world results from the ACAPEX data set indicate similar results as the simulation study, although not all predicted benefits are realized due to the small sample size and observation uncertainties.","PeriodicalId":15074,"journal":{"name":"Journal of Atmospheric and Oceanic Technology","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47409468","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}

引用次数: 0

Static and dynamic performance of the RBRargo3 CTD RBRargo3 CTD的静态和动态性能

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-07-21 DOI: 10.1175/jtech-d-21-0186.1

M. Dever, B. Owens, C. Richards, S. Wijffels, A. Wong, I. Shkvorets, M. Halverson, G. Johnson

引用次数: 1

A Variational Interpolation Method for Gridding Weather Radar Data 一种网格化天气雷达数据的变分插值方法

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-07-21 DOI: 10.1175/jtech-d-22-0015.1

Jordan Brook, A. Protat, J. Soderholm, R. Warren, H. McGowan

引用次数: 4

Evaluating vertical velocity retrievals from vertical vorticity equation constrained dual-Doppler analysis of real, rapid-scan radar data 从实际快速扫描雷达数据的垂直涡度方程约束双多普勒分析中评估垂直速度反演

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-07-21 DOI: 10.1175/jtech-d-21-0136.1

Joshua G. Gebauer, A. Shapiro, C. Potvin, N. Dahl, M. Biggerstaff, A. Addison Alford

{"title":"Evaluating vertical velocity retrievals from vertical vorticity equation constrained dual-Doppler analysis of real, rapid-scan radar data","authors":"Joshua G. Gebauer, A. Shapiro, C. Potvin, N. Dahl, M. Biggerstaff, A. Addison Alford","doi":"10.1175/jtech-d-21-0136.1","DOIUrl":"https://doi.org/10.1175/jtech-d-21-0136.1","url":null,"abstract":"\u0000Accurate vertical velocity retrieval from dual-Doppler analysis (DDA) is a longstanding problem of radar meteorology. Typical radar scanning strategies poorly observe the vertical component of motion, leading to large uncertainty in vertical velocity estimates. Using a vertical vorticity equation constraint in addition to a mass conservation constraint in DDA has shown promise in improving vertical velocity retrievals. However, observation system simulation experiments (OSSEs) suggest this technique requires rapid radar volume scans to realize the improvements due to the vorticity tendency term in the vertical vorticity constraint. Here, the vertical vorticity constraint DDA is tested with real, rapid-scan radar data to validate prior OSSEs results. Generally, the vertical vorticity constraint DDA produced more accurate vertical velocities from DDAs than those that did not use the constraint. When the time between volume scans was greater than 30 seconds, the vertical velocity accuracy was significantly affected by the vorticity tendency estimation method. A technique that uses advection correction on provisional DDA wind fields to shorten the discretization interval for the vorticity tendency calculation improved the vertical velocity retrievals for longer times between volume scans. The skill of these DDAs was similar to those using a shorter time between volume scans. These improvements were due to increased accuracy of the vertical vorticity tendency using the advection correction technique. The real radar data tests also revealed that the vertical vorticity constraint DDAs are more forgiving to radar data errors. These results suggest that vertical vorticity constraint DDA with rapid-scan radars should be prioritized for kinematic analyses.","PeriodicalId":15074,"journal":{"name":"Journal of Atmospheric and Oceanic Technology","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44632715","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}

引用次数: 1

Supervised Classification of Sound Speed Profiles Via Dictionary Learning 基于字典学习的声速剖面监督分类

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-07-21 DOI: 10.1175/jtech-d-21-0090.1

Jhon A. Castro-Correa, Stephanie A. Arnett, T. Neilsen, Lin Wan, M. Badiey

{"title":"Supervised Classification of Sound Speed Profiles Via Dictionary Learning","authors":"Jhon A. Castro-Correa, Stephanie A. Arnett, T. Neilsen, Lin Wan, M. Badiey","doi":"10.1175/jtech-d-21-0090.1","DOIUrl":"https://doi.org/10.1175/jtech-d-21-0090.1","url":null,"abstract":"\u0000The presence of internal waves (IWs) in the ocean alters the isotropic properties of sound speed profiles (SSPs) in the water column. Changes in the SSPs affect underwater acoustics since most of the energy is dissipated into the seabed due to the downward refraction of sound waves. In consequence, variations in the SSP must be considered when modeling acoustic propagation in the ocean. Regularly, empirical orthogonal functions (EOFs) are employed to model and represent SSPs using a linear combination of basis functions that capture the sound speed variability. A different approach is to use dictionary learning (DL) to obtain a learned dictionary (LD) that generates a non-orthogonal set of basis functions (atoms) that generate a better sparse representation. In this paper, the performance of EOFs and LDs are evaluated for sparse representation of SSPs affected by the passing of IWs. In addition, an LD-based supervised framework is presented for SSP classification and is compared with classical learning models. The algorithms presented in this work are trained and tested on data collected from the shallow water experiment 2006. Results show that LDs yield lower reconstruction error than EOFs when using the same number of basis. In addition, overcomplete LDs demonstrate to be a robust method to classify SSPs during low, medium, and high IW activity, reporting comparable and sometimes higher accuracy than standard supervised classification methods.","PeriodicalId":15074,"journal":{"name":"Journal of Atmospheric and Oceanic Technology","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46384317","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}

引用次数: 2

Improvement of the Ocean Mixed Layer Model via Large Eddy Simulation and Inverse Estimation 基于大涡模拟和反演的海洋混合层模式改进

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-07-14 DOI: 10.1175/jtech-d-21-0157.1

Yeonju Choi, Y. Noh, N. Hirose, Hajoon Song

{"title":"Improvement of the Ocean Mixed Layer Model via Large Eddy Simulation and Inverse Estimation","authors":"Yeonju Choi, Y. Noh, N. Hirose, Hajoon Song","doi":"10.1175/jtech-d-21-0157.1","DOIUrl":"https://doi.org/10.1175/jtech-d-21-0157.1","url":null,"abstract":"\u0000The ocean mixed layer model (OMLM) is improved using the large eddy simulation (LES) and the inverse estimation method. A comparison of OMLM (Noh model) and LES results reveals that underestimation of the turbulent kinetic energy (TKE) flux in the OMLM causes a negative bias of the mixed layer depth (MLD) during convection, when the wind stress is weak or the latitude is high. It is further found that the entrainment layer thickness is underestimated. The effects of alternative approaches of parameterizations in the OMLM, such as nonlocal mixing, length scales, Prandtl number, and TKE flux, are examined with an aim to reduce the bias. Simultaneous optimizations of empirical constants in the various versions of Noh model with different parameterization options are then carried out via an iterative Green’s function approach with LES data as constraining data. An improved OMLM is obtained, which reflects various new features, including the enhanced TKE flux, and the new model is found to improve the performance in all cases, namely, wind-mixing, surface heating, and surface cooling cases. The effect of the OMLM grid resolution on the optimal empirical constants is also investigated.","PeriodicalId":15074,"journal":{"name":"Journal of Atmospheric and Oceanic Technology","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44307422","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}

引用次数: 1

Assessment of retrieved GMI emissivity over land, snow, and sea ice in the GEOS system GEOS系统中陆地、冰雪和海冰上GMI发射率的反演评估

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-07-13 DOI: 10.1175/jtech-d-21-0187.1

Bryan M. Karpowicz, Yanqiu Zhu, S. Munchak, W. McCarty

{"title":"Assessment of retrieved GMI emissivity over land, snow, and sea ice in the GEOS system","authors":"Bryan M. Karpowicz, Yanqiu Zhu, S. Munchak, W. McCarty","doi":"10.1175/jtech-d-21-0187.1","DOIUrl":"https://doi.org/10.1175/jtech-d-21-0187.1","url":null,"abstract":"\u0000Directly assimilating microwave radiances over land, snow and sea ice remains a significant challenge for data assimilation systems. These data assimilation systems are critical to the success of global numerical weather prediction systems including the Global Earth Observing System-Atmospheric Data Assimilation System (GEOS-ADAS). Extending more surface sensitive microwave channels over land, snow and ice could provide a needed source of data for Numerical Weather Prediction particularly in the Planetary Boundary Layer (PBL). Unfortunately, the accuracy of emissivity models currently available within the GEOS-ADAS along with other data assimilation systems are insufficient to simulate and assimilate radiances. Recently, Munchak et al. (2020) published a 5-year climatological database for retrieved microwave emissivity from the GPM Microwave Imager (GMI) aboard the Global Precipitation Measurement (GPM) Mission. In this work the database is utilized by modifying the GEOS-ADAS to use this emissivity database in place of the default emissivity value available in the Community Radiative Transfer Model (CRTM), which is the fast radiative transfer model used by the GEOS-ADAS. As a first step, the GEOS-ADAS is run in a so-called “stand-alone” mode to simulate radiances from GMI using the default CRTM emissivity, and replacing the default CRTM emissivity models with values from Munchak et al, 2020. The simulated GMI observations using Munchak et al., 2020 agree more closely with observations from GMI. These results are presented along with a discussion of the implication for GMI observations within the GEOS-ADAS.","PeriodicalId":15074,"journal":{"name":"Journal of Atmospheric and Oceanic Technology","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47380204","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}

引用次数: 0

Bayesian Classification of Non-Meteorological Targets in Polarimetric Doppler Radar Measurements 极化多普勒雷达测量中非气象目标的贝叶斯分类

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-06-28 DOI: 10.1175/jtech-d-21-0177.1

T. Mäkinen, Jenna Ritvanen, S. Pulkkinen, Nadja Weisshaupt, J. Koistinen

{"title":"Bayesian Classification of Non-Meteorological Targets in Polarimetric Doppler Radar Measurements","authors":"T. Mäkinen, Jenna Ritvanen, S. Pulkkinen, Nadja Weisshaupt, J. Koistinen","doi":"10.1175/jtech-d-21-0177.1","DOIUrl":"https://doi.org/10.1175/jtech-d-21-0177.1","url":null,"abstract":"\u0000ABSTRACT: The latest established generation of weather radars provides polarimetric measurements of a wide variety of meteorological and non-meteorological targets. While the classification of different precipitation types based on polarimetric data has been studied extensively, non-meteorological targets have garnered relatively less attention beyond an effort to detect them for removal from meteorological products. In this paper we present a supervised learning classification system developed in the Finnish Meteorological Institute (FMI) that uses Bayesian inference with empirical probability density distributions to assign individual range gate samples into 7 meteorological and 12 non-meteorological classes, belonging to five top level categories of hydrometeors, terrain, zoogenic, anthropogenic, and immaterial. We demonstrate how the accuracy of the class probability estimates provided by a basic Naive Bayes classifier can be further improved by introducing synthetic channels created through limited neighborhood filtering, by properly managing partial moment nonresponse, and by considering spatial correlation of class membership of adjacent range gates. The choice of Bayesian classification provides well-substantiated quality estimates for all meteorological products, a feature that is being increasingly requested by users of weather radar products. The availability of comprehensive, fine-grained classification of non-meteorological targets also enables a large array of emerging applications, utilizing non-precipitation echo types and demonstrating the need to move from a single, universal quality metric of radar observations to one that depends on the application, the measured target type, and on the specificity of the customers’ requirements.","PeriodicalId":15074,"journal":{"name":"Journal of Atmospheric and Oceanic Technology","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46248177","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}

引用次数: 1

Identification and removal of aircraft clutter to improve wind velocity measurement made with Chung-Li VHF Radar 识别和去除飞机杂波以改善中利甚高频雷达的风速测量

IF 2.2 4区地球科学

Journal of Atmospheric and Oceanic Technology Pub Date : 2022-06-22 DOI: 10.1175/jtech-d-21-0115.1

Meng‐Yuan Chen, C. Su, Yuan-Hann Chang, Y. Chu

{"title":"Identification and removal of aircraft clutter to improve wind velocity measurement made with Chung-Li VHF Radar","authors":"Meng‐Yuan Chen, C. Su, Yuan-Hann Chang, Y. Chu","doi":"10.1175/jtech-d-21-0115.1","DOIUrl":"https://doi.org/10.1175/jtech-d-21-0115.1","url":null,"abstract":"\u0000In this study, a data processing based on the empirical mode decomposition (EMD) of Hilbert-Huang Transform (HHT) is developed at Chung-Li VHF radar to identify and remove the aircraft clutter for improving the atmospheric wind measurement. The EMD decomposes the echo signals into the so-called intrinsic mode functions (IMFs) in the time domain, and then the aircraft clutter that is represented by a number of specific IMFs can be identified in the radar returns and separated from the clear air echoes that are observed concurrently by the VHF radar. The identified clutter is validated by using the aircraft information collected by the Automatic Dependent Surveillance-Broadcast (ADS-B) receiver. It shows that the proposed algorithm can detect the aircraft echoes that are mixed with the clear air echoes. After implementing the algorithm on the experimental data, the atmospheric horizontal wind velocities are estimated after the aircraft clutter is removed. In order to evaluate the degree of the improvement of the horizontal wind measurement, a comparison in the horizontal wind velocities between Chung-Li VHF radar and a co-located UHF wind profiler radar is made. The results show that the use of EMD and the proposed data processing can effectively reduce the uncertainty and substantially improve the precision and reliability of the horizontal wind measurement.","PeriodicalId":15074,"journal":{"name":"Journal of Atmospheric and Oceanic Technology","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2022-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46842536","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}

引用次数: 0