Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
Sea surface measurements are mainly gathered using satellite altimeter, buoy, and platform measurements. Satellite measurements typically have a coarse spatial resolution and need recalibration in coastal regions, whereas point measurements of buoys only represent limited areas around the measurement point because of the complex coastal bathymetry. Wave models (WAM) are used to expand the sparse observations in space and time. As a part of the project WIndPArk far-field (WIPAFF), which focused on wakes behind offshore wind farms, extensive airborne light detection and ranging (LiDAR) measurements of ocean waves in the German Bight were performed for more than 90 h. The LiDAR data processed for significant wave height can be used to validate and improve WAM models for complex areas and fill the observation gap between satellite altimeter and point measurements. This creates a detailed picture of the sea surface for coastal engineering and environmental applications. After introducing the measurement techniques and the data situation, intercomparisons between the available airborne measurements, buoy data, and WAM model output are presented to provide an insight into the potential of airborne LiDAR measurements for wave characterization and wave model validation.
Sea surface measurements are mainly gathered using satellite altimeter, buoy, and platform measurements. Satellite measurements typically have a coarse spatial resolution and need recalibration in coastal regions, whereas point measurements of buoys only represent limited areas around the measurement point because of the complex coastal bathymetry. Wave models (WAM) are used to expand the sparse observations in space and time. As a part of the project WIndPArk far-field (WIPAFF), which focused on wakes behind offshore wind farms, extensive airborne light detection and ranging (LiDAR) measurements of ocean waves in the German Bight were performed for more than 90 h. The LiDAR data processed for significant wave height can be used to validate and improve WAM models for complex areas and fill the observation gap between satellite altimeter and point measurements. This creates a detailed picture of the sea surface for coastal engineering and environmental applications. After introducing the measurement techniques and the data situation, intercomparisons between the available airborne measurements, buoy data, and WAM model output are presented to provide an insight into the potential of airborne LiDAR measurements for wave characterization and wave model validation.
Operational oceanography is now established in many countries, focusing on global, regional, or coastal areas, and targeting different aspects of the « blue », « white » or « green » ocean processes in order to provide reliable information to users. There are nowadays a large variety of interests and users, with different disciplines and levels of expertise. Validation and verification of operational products and systems are evolving in order to anticipate user's needs, and better quantify the level of confidence on all these variety of ocean products. Operational oceanography evaluation development is in front of key issues: Ocean models are reaching the submesoscale description, which is currently not adequately observed; many products are available now for a given ocean variable, and often discrepancies are larger than similarities; real time forecasting systems are also challenged by reanalyses or reprocessed time series; operational systems are getting more complex, with coupled modelling, where errors from the different compartment need to be carefully addressed in order to measure their performance and provide further improvements. In parallel, the global ocean observing system is continuously completed with additional satellites in the constellation, with innovative sensors on new satellite missions, with efforts to better integrate the global, regional and coastal in-situ observing capabilities, and the design of new instrument, like the BGC-Argo that should bring an enhanced description of the ocean biogeochemical variability. This book chapter provides an overview of the existing, mature, validation and verification science in operational oceanography; discusses the ongoing efforts and new strategies; presents some of the structured groups and outcomes; and lists a series of challenges on the field.
The provision of high-resolution in situ oceanographic data is key for the ongoing verification, validation and assessment of operational products, such as those provided by the Copernicus Marine Core Service (CMEMS). Here we analyze the ability of ARMOR3D-a multivariate global ocean state estimate that is available from CMEMS-to reconstruct a mesoscale anticyclonic intrathermocline eddy that was previously sampled with high-resolution independent in situ observations. ARMOR3D is constructed by merging remote sensing observations with in situ vertical profiles of temperature and salinity obtained primarily from the Argo network. In situ data from CTDs and an Acoustic Doppler Current Profiler were obtained during an oceanographic cruise near the Canary Islands (Atlantic ocean). The analysis of the ARMOR3D product using the in situ data is done over (i) a high-resolution meridional transect crossing the eddy center and (ii) a three-dimensional grid centered on the eddy center. An evaluation of the hydrographic eddy signature and derived dynamical variables, namely geostrophic velocity, vertical vorticity and quasi-geostrophic (QG) vertical velocity, demonstrates that the ARMOR3D product is able to reproduce the vertical hydrographic structure of the independently sampled eddy below the seasonal pycnocline, with the caveat that the flow is surface intensified and the seasonal pycnocline remains flat. Maps of ARMOR3D density show the signature of the eddy, and agreement with the elliptical eddy shape seen in the in situ data. The major eddy axes are oriented NW-SE in both data sets. The estimated radius for the in situ eddy is ∼46 km; the ARMOR3D radius is significantly larger at ∼ 92 km and is considered an overestimation that is inherited from an across-track altimetry sampling issue. The ARMOR3D geostrophic flow is underestimated by a factor of 2, with maxima of 0.11 (−0.19) m s −1 at the surface, which implies an underestimation of the local Rossby number by a factor of 3. Both the in situ and ARMOR3D eddies have decelerating flows at their northern edges. The ARMOR3D QG vertical velocity distribution has upwelling/downwelling cells located along the eddy periphery and similar magnitudes to the in situ-derived QG vertical velocity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.