Consulta: creatorFacets:"Johannessen, Johnny"
Registros recuperados: 5
Data/hora: 09/06/2024 05:26:08

On radar imaging of current features: 1. Model and comparison with observations - art. no. C07016
Provedor de dados: 5
Autores: Kudryavtsev, V; Akimov, D; Johannessen, Johnny; Chapron, Bertrand.
[1] A new radar imaging model of ocean current features is proposed. The simulated normalized radar cross section ( NRCS) takes into account scattering from "regular'' surfaces ( by means of resonant Bragg scattering and specular reflections) and scattering from breaking waves. The description of background wind waves and their transformation in nonuniform medium is based on solution of the wave action conservation equation. Wave breaking plays a key role in the radar imaging model. Breaking waves scatter radio waves ( thus directly contributing to the NRCS), provide energy dissipation in wind waves ( thus defining the wave spectrum of intermediate scale waves), and generate short surface waves ( thus affecting Bragg scattering). Surface current,...
Tipo: Text
Palavras-chave: Breaking waves; Scattering; Radar imaging model; Ocean surface current.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-762.pdf

Observing Sea States
Provedor de dados: 5
Autores: Ardhuin, Fabrice; Stopa, Justin; Chapron, Bertrand; Collard, Fabrice; Husson, Romain; Jensen, Robert E.; Johannessen, Johnny; Mouche, Alexis; Passaro, Marcello; Quartly, Graham D.; Swail, Val; Young, Ian.
Sea state information is needed for many applications, ranging from safety at sea and on the coast, for which real time data are essential, to planning and design needs for infrastructure that require long time series. The definition of the wave climate and its possible evolution requires high resolution data, and knowledge on possible drift in the observing system. Sea state is also an important climate variable that enters in air-sea fluxes parameterizations. Finally, sea state patterns can reveal the intensity of storms and associated climate patterns at large scales, and the intensity of currents at small scales. A synthesis of user requirements leads to requests for spatial resolution at kilometer scales, and estimations of trends of a few centimeters...
Tipo: Text
Palavras-chave: Sea state; Waves; Altimeter; SAR; Swell; Remote sensing; Buoy; Microseisms.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00489/60090/63432.pdf

The roadmap for a GMES operational oceanography mission
Provedor de dados: 5
Autores: Drinkwater, Mark; Rebhan, Helge; Le Traon, Pierre-yves; Phalippou, Laurent; Cotton, David; Johannessen, Johnny; Ruffini, Giulio; Bahurel, Pierre; Bell, Mike; Chapron, Bertrand; Pinardi, Nadia; Robinson, Ian; Santoleri, Lia; Stammer, Detlef.
Oceans cover approximately 70% of the Earth's surface and, with about 60% of the World's population living within 200 km of the coast, they have an untold impact on all of us. Not surprisingly, for people living close to the coast or those who depend on the ocean for their livelihood, regular forecasts of ocean conditions are just as important as traditional weather forecasts. Therefore, development of the infrastructure needed to support and sustain independent, European operational ocean forecasting, and the associated coastal and marine information services, are key priorities of the joint Global Monitoring for Environment and Security (GMES) initiative by the European Commission and ESA.
Tipo: Text
Palavras-chave: Meteorology; Infrastructure; Maturation; World's oceans.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-903.pdf

Measuring currents, ice drift, and waves from space: the Sea surface KInematics Multiscale monitoring (SKIM) concept
Provedor de dados: 5
Autores: Ardhuin, Fabrice; Aksenov, Yevgueny; Benetazzo, Alvise; Bertino, Laurent; Brandt, Peter; Caubet, Eric; Chapron, Bertrand; Collard, Fabrice; Cravatte, Sophie; Delouis, Jean Marc; Dias, Frederic; Dibarboure, Gerald; Gaultier, Lucile; Johannessen, Johnny; Korosov, Anton; Manucharyan, Georgy; Menemenlis, Dimitris; Menendez, Melisa; Monnier, Goulven; Mouche, Alexis; Nouguier, Frederic; Nurser, George; Rampal, Pierre; Reniers, Ad; Rodriguez, Ernesto; Stopa, Justin; Tison, Celine; Ubelmann, Clement; Van Sebille, Erik; Xie, Jiping.
We propose a satellite mission that uses a near-nadir Ka-band Doppler radar to measure surface currents, ice drift and ocean waves at spatial scales of 40 km and more, with snapshots at least every day for latitudes 75 to 82 degrees, and every few days for other latitudes. The use of incidence angles of 6 and 12 degrees allows for measurement of the directional wave spectrum, which yields accurate corrections of the wave-induced bias in the current measurements. The instrument's design, an algorithm for current vector retrieval and the expected mission performance are presented here. The instrument proposed can reveal features of tropical ocean and marginal ice zone (MIZ) dynamics that are inaccessible to other measurement systems, and providing global...
Tipo: Text
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00442/55318/56843.pdf

Evaluation of GlobCurrent surface ocean current products: A case study in Australia
Provedor de dados: 5
Autores: Cancet, Mathilde; Griffin, David; Cahill, Madeleine; Chapron, Bertrand; Johannessen, Johnny; Donlon, Craig.
Australia's marginal seas include a wide range of ocean current regimes ranging from tide-dominated in the North-West where the continental shelf is wide, to boundary current- and eddy-dominated in the South-East, where the shelf is narrow. Here, we take the opportunity to test the GlobCurrent surface ocean current products against in-situ observations in these two contrasting regimes. Observations by Acoustic Doppler Current Profiler (ADCP) instruments of Australia's Integrated Marine Observing System (IMOS) and drifting buoys of the Global Drifting Programme (GDP) are used. The monthly-timescale variability of the GlobCurrent alongshore current component is in moderately good agreement with the observations on the continental shelf in the South-East but...
Tipo: Text
Palavras-chave: Surface ocean currents; GlobCurrent assessment; East Australian Current; Tidal currents; In situ measurements.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00464/57607/60173.pdf