Surface Current Observations Using High Frequency Radar and Its Assimilation Into the New York Harbor Observing and Prediction System PDF Download

Author: Ganesh Gopalakrishnan
Publisher:
ISBN:
Category : Estuarine hydrology
Languages : en
Pages : 412

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Author: Integrated Ocean Observing System (U.S.)
Publisher:
ISBN:
Category : Ocean circulation
Languages : en
Pages : 60

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"This manual is a living document that reflects the state-of-the-art QC testing procedures for HF radar surface currents observations. It is written for the experienced operator but also provides examples for those who are just entering the field"--Page 3. [doi:10.7289/V5T43R96 (https://doi.org/10.7289/V5T43R96)].

Author: Andreas Schiller
Publisher: Springer Science & Business Media
ISBN: 9400703325
Category : Science
Languages : en
Pages : 736

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Book Description
Over the past decade the significant advances in real-time ocean observing systems, ocean modelling, ocean data assimilation and super-computing has seen the development and implementation of operational ocean forecast systems of the global ocean. At the conclusion of the Global Ocean Data Assimilation Experiment (GODAE) in 2008 ocean analysis and forecasting services were being supported by 12 international centres. This book is about ocean forecasting - a maturing field which remains an active area of research, and includes such topics as ocean predictability, observing system design, high resolution ocean modelling and ocean data assimilation. It presents the introduction to ocean forecasting which provides a foundation for new opportunities in areas of coupled bio-geochemical forecasting and coupled atmosphere-wave-ocean forecasting. The book describes an updated account of research and development to improve forecast systems, determining how best to service the marine user community with forecast information as well as demonstrating impact to their applications. It also discusses operational centres that are now supporting a range of real-time ocean services including online graphical and data products for their user communities and their feedback on the quality of information. The contents of this book are aimed at early career scientists and professionals with an interest in operational oceanography and related ocean science. There are excellent opportunities for exciting careers in the emerging field of operational oceanography in order to address current and future challenges as well as provide the supporting services to a rapidly growing user community.

Author: Larry Atkinson
Publisher:
ISBN:
Category :
Languages : en
Pages : 77

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Partial contents include: (1) HF Radar Instruments, Past to Present; (2) Mapping Surface Currents in Monterey Bay with CODAR-type HF Radar; (3) The Coastal Jet: Observations of Surface Currents over the Oregon Continental Shelf from HF Radar; (4) Tidal and Wind-driven Currents from OSCR; (5) Larval Transport and Coastal Upwelling: an Application of HF Radar in Ecological Research; (6) Evolution of Bearing Determination in HF Current Mapping Radars; (7) Shipboard Deployment of a VHF OSCR System for Measuring Offshore Currents; and (8) Experience with Shipborne Measurements of Surface Current Fields by Radar.

Author: Agustin Sanchez-Arcilla
Publisher: Frontiers Media SA
ISBN: 2889761401
Category : Science
Languages : en
Pages : 458

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Author:
Publisher:
ISBN:
Category : Computer programs
Languages : en
Pages : 103

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The use of the HF radar to measure and map surface currents has proliferated along the coastlines of many countries for purposes of Search and Rescue, Oil Spill Management, Oceanographic and Fishery Science studies. In the US Navy, these surface current maps are being evaluated for operational use in real-time data assimilating coastal circulation models, and direct monitoring tools in environmentally sensitive operating areas. The SeaSonde HF radar, a DF system, was considered in this study. It uses the MUSIC algorithm to recover bearings from the Doppler backscatter spectrum of the sea surface. By varying the radial and antenna patterns, the simulated backscatter spectra were passed through the SeaSonde software suite for radial pattern recovery. This unprecedented approach directly evaluated SeaSonde's MUSIC, and the associated uncertainties were examined against the simulated inputs of (1) fixed amplitude and phase deviations from the ideal antenna pattern, (2) measured antenna patterns and (3) decreasing SNR. It was found that using the measured antenna pattern to recover radials yielded least uncertainty, but a definitive prediction of MUSIC's radial-recovery capability in relation to the pattern's complex amplitude and phase structure remained illusive. The results highlighted the need to calibrate the military's DF-systems for accurate azimuth recovery.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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The capability of phased-array HF radar systems to sample the spatial distribution of wave energy is investigated in different storm scenarios and coastal configurations. First, a formulation introduced by D.E. Barrick to extract significant wave height Hs from backscatter Doppler spectra was calibrated and subsequently tested (to assess bias and uncertainty) with data from seven different buoy/gauge stations collected during three different field experiments. Afterward, Hs observations were obtained for selected sampling locations within the radar effective domain (in all experiments), and a filtering technique based on wavelet transform characterization and decomposition was applied. The accuracy of the filtered radar-derived observations was assessed by comparing these estimates to results from independently calibrated wave propagation models. It was found that the HF radar accurately measured the energy field induced by different storm events. The filtering technique minimized the contribution of unrealistic features introduced by the presence of defective sampling, which is intrinsic to radar remote sensing at this frequency, and it proved to be central for the use of the HF radar as a tool to identify wave energy trends and potential zones of wave energy concentration in coastal areas. These findings show that the sampling capabilities of radar systems may be greatly enhanced because reliable wave energy estimates can be obtained in addition to conventional surface current measurements. This is particularly important in locations such as harbor entrances where in situ measuring devices cannot be deployed.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309252202
Category : Science
Languages : en
Pages : 190

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Book Description
According to the United Nations, three out of five people will be living in cities worldwide by the year 2030. The United States continues to experience urbanization with its vast urban corridors on the east and west coasts. Although urban weather is driven by large synoptic and meso-scale features, weather events unique to the urban environment arise from the characteristics of the typical urban setting, such as large areas covered by buildings of a variety of heights; paved streets and parking areas; means to supply electricity, natural gas, water, and raw materials; and generation of waste heat and materials. Urban Meteorology: Forecasting, Monitoring, and Meeting Users' Needs is based largely on the information provided at a Board on Atmospheric Sciences and Climate community workshop. This book describes the needs for end user communities, focusing in particular on needs that are not being met by current urban-level forecasting and monitoring. Urban Meteorology also describes current and emerging meteorological forecasting and monitoring capabilities that have had and will likely have the most impact on urban areas, some of which are not being utilized by the relevant end user communities. Urban Meteorology explains that users of urban meteorological information need high-quality information available in a wide variety of formats that foster its use and within time constraints set by users' decision processes. By advancing the science and technology related to urban meteorology with input from key end user communities, urban meteorologists can better meet the needs of diverse end users. To continue the advancement within the field of urban meteorology, there are both short-term needs-which might be addressed with small investments but promise large, quick returns-as well as future challenges that could require significant efforts and investments.

Author: Kyung C. Kim
Publisher:
ISBN: 9781423518273
Category :
Languages : en
Pages : 92

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Book Description
High Frequency (HF) radar backscatter instruments are being developed and tested in the marine science and defense science communities for their abilities to sense surface parameters remotely in the coastal ocean over large areas. In the Navy context, the systems provide real-time mapping of ocean surface currents and waves critical for characterizing and forecasting the battle space environment.

Author: Weiguang Chang
Publisher:
ISBN:
Category :
Languages : en
Pages :

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"The flow-dependent background error statistics and other uncertainties involved in Ensemble Kalman Filter (EnKF), such as model error, initial perturbations, etc., are studied by a numerical weather prediction model and a few simple idealized experiments, respectively. Following the aforementioned studies, a convective-scale EnKF system is implemented to assimilate real radar data of radial velocity provided by the McGill J. S. Marshall Radar Observatory. The performance of this system and its impact on short-term ensemble forecasts are examined in three summer cases with different precipitation structures. In order to enhance and prolong the improvement brought by radar data assimilation on weather prediction, an adaptive radar observation method is proposed based on the background error statistics in EnKF. This method takes advantage of the phased-array radar technique to adaptively place observations where the important and unobserved model variable has more chances of improvement.The idealized experiments of EnKF suggest that a better analysis requires sufficient ensemble spread in initial perturbation, accurate estimation of model and observation errors, and radar data thinning if necessary. The studies on the background error statistics showed that homogeneous isotropic background error perturbations can develop into situation-dependent features in 15 minutes, and the error structures in the regions with and without precipitation are different. Results from the high-resolution EnKF system indicate that the analysis uncertainty can be reduced after a 1-h cycling process; and that radial velocity assimilation has an impact on the precipitation field. Additionally, the improvement in ensemble forecasts is evident in observation space within a 2-hour lead-time. When the adaptive radar observation method is applied on radial velocity assimilation, the unobserved vertical velocity can be better improved in areas where background error cross-covariances is more significant. Nevertheless, the improvement on the unobserved variable is much smaller than for the observed variable." --