Consulta: subjectFacets:"High resolution"
Registros recuperados: 9
Data/hora: 10/06/2024 13:48:16

Ocean Gravity Models From Future Satellite Missions
Provedor de dados: 5
Autores: Louis, Gilles; Lequentrec-lalancette, Marie-françoise; Royer, Jean-yves; Rouxel, Didier; Géli, Louis; Maïa, Marcia; Faillot, Mathilde.
Over the past 3 decades, satellite altimetry has been a key tool for dynamic ocean studies and for accurately estimating sea surface heights. The geodetic reference surface—the “geoid”—can be approximated as the mean sea surface height of an ocean corrected for dynamic terms such as tides and currents. It is an equipotential surface of the gravity field; and variations of this field are quantified as free‐air anomalies, from which density heterogeneities of the oceanic basement can be inferred. Using such data in combination with other geophysical data, scientists have improved their knowledge of the nature of submarine relief and underlying structures. In solid Earth geophysics, major breakthroughs came from the development of high‐resolution marine...
Tipo: Text
Palavras-chave: Altimetry; High resolution; SWAT soil and water assessment tool.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00451/56260/57829.pdf

Copolarized and Cross‐Polarized SAR Measurements for High‐Resolution Description of Major Hurricane Wind Structures: Application to Irma Category 5 Hurricane
Provedor de dados: 5
Autores: Mouche, Alexis; Chapron, Bertrand; Knaff, John; Zhao, Yili; Zhang, Biao; Combot, Clement.
C‐Band high resolution radar (SAR) is the only space‐borne instrument able to probe at very high resolution and over all ocean basins the sea surface under extreme weather conditions. When co‐analyzed with Stepped Frequency Microwave Radiometer (SFMR) wind estimates, the radar backscatter signals acquired in major Hurricanes from Sentinel‐1 and Radarsat‐2 SAR, reveal high sensitivity in the cross‐polarized channel for wind speeds up to 75 m/s. The combination of the two co‐ and cross‐ polarized channels can then be used to derive high resolution surface wind estimates. The retrieval methods and impacts of intense rainfall are discussed in the context of a Hurricane Irma (2017) case study. On September 7, 2017, Sentinel‐1 measurements intercepted Hurricane...
Tipo: Text
Palavras-chave: SAR; Copolarization and cross-polarization; High resolution; Category 5 Hurricane; Hurricane Irma.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00497/60898/64236.pdf

A high-resolution study of Holocene paleoclimatic and paleoceanographic changes in the Nordic Seas
Provedor de dados: 5
Autores: Risebrobakken, B; Jansen, E; Andersson, C; Mjelde, E; Hevroy, K.
High-resolution records from IMAGES core MD95-2011 in the eastern Norwegian Sea provide evidence for relatively large- and small-scale high-latitude climate variability throughout the Holocene. During the early and mid-Holocene a situation possibly driven by consistent stronger westerlies increased the eastward influence of Arctic intermediate and near-surface waters. For the late Holocene a relaxation of the atmospheric forcing resulted in increased influence of Atlantic water. The main changes in Holocene climate show no obvious connection to changing solar irradiance, and spectral analysis reveals no consistent signature for any periodic behavior of Holocene climate at millennial or centennial timescales. There are, however, indications of consistent...
Tipo: Text
Palavras-chave: Holocene; Climate; Nordic Seas; NAO; High resolution; Variability.
Ano: 2003
URL: https://archimer.ifremer.fr/doc/00224/33500/32119.pdf

Intense deformation field at oceanic front inferred from directional sea surface roughness observations
Provedor de dados: 5
Autores: Rascle, Nicolas; Molemaker, Jeroen; Marie, Louis; Nouguier, Frederic; Chapron, Bertrand; Lund, Bjorn; Mouche, Alexis.
Fine scale current gradients at the ocean surface can be observed by sea surface roughness. More specifically, directional surface roughness anomalies are related to the different horizontal current gradient components. This paper reports results from a dedicated experiment during the LASER (LAgrangian Submesoscale ExpeRiment) drifter deployment. A very sharp front, 50 m wide, is detected simultaneously in drifter trajectories, sea surface temperature and sea surface roughness. A new observational method is applied, using sun glitter reflections during multiple airplane passes to reconstruct the multi-angle roughness anomaly. This multi-angle anomaly is consistent with wave-current interactions over a front, including both cross-front convergence and...
Tipo: Text
Palavras-chave: Sea surface roughness; Surface current; Remote sensing; Sun glitter; High resolution; Oceanic fronts.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00386/49767/50301.pdf

Phytoplankton distribution from Western to Central English Channel, revealed by automated flow cytometry during the summer-fall transition
Provedor de dados: 5
Autores: Louchart, Arnaud; Lizon, Fabrice; Lefebvre, Alain; Didry, Morgane; Schmitt, François G.; Artigas, Luis Felipe.
Automated pulse shape-recording flow cytometry was applied to address phytoplankton spatial distribution, at high frequency, in stratified and well mixed water masses in the Western and Central English Channel during the summer-fall transition. Cytometric pulse shapes derived from optical features of single cells allowed the characterization of eight phytoplankton groups. Abundance and total red fluorescence (chlorophyll a autofluorescence) per group were used to define six phytoplankton communities. Their distribution revealed high spatial heterogeneity. Abundance presented a longitudinal gradient for six over the eight groups and succession of brutal shifts along the cruise. Maximum values were often located near the Ushant front in the Western English...
Tipo: Text
Palavras-chave: English Channel; Phytoplankton distribution; High resolution; Automated flow cytometry; Fronts; Mesoscale structure.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00601/71324/69752.pdf

Editorial: New Insights into Microbial Ecology through Subtle Nucleotide Variation
Provedor de dados: 5
Autores: Eren, A. Murat; Sogin, Mitchell L.; Maignien, Lois.
Tipo: Text
Palavras-chave: Oligotyping; Minimum entropy decomposition; 16S rRNA gene; Microbial ecology; High resolution.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00601/71310/69739.pdf

Potential of High Spatial and Temporal Ocean Color Satellite Data to Study the Dynamics of Suspended Particles in a Micro-Tidal River Plume
Provedor de dados: 5
Autores: Ody, Anouck; Doxaran, David; Vanhellemont, Quinten; Nechad, Bouchra; Novoa, Stefani; Many, Gael; Bourrin, Francois; Verney, Romaric; Pairaud, Ivane; Gentili, Bernard.
Ocean color satellite sensors are powerful tools to study and monitor the dynamics of suspended particulate matter (SPM) discharged by rivers in coastal waters. In this study, we test the capabilities of Landsat-8/Operational Land Imager (OLI), AQUA&amp;TERRA/Moderate Resolution Imaging Spectroradiometer (MODIS) and MSG-3/Spinning Enhanced Visible and Infrared Imager (SEVIRI) sensors in terms of spectral, spatial and temporal resolutions to (i) estimate the seawater reflectance signal and then SPM concentrations and (ii) monitor the dynamics of SPM in the Rhone River plume characterized by moderately turbid surface waters in a micro-tidal sea. Consistent remote-sensing reflectance (Rrs) values are retrieved in the red spectral bands of these four satellite...
Tipo: Text
Palavras-chave: River plumes; Coastal waters; High resolution; Suspended particulate matter; Remote sensing.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00333/44408/44066.pdf

Wave spectrum retrieval from airborne sunglitter images
Provedor de dados: 5
Autores: Yurovskaya, Maria; Rascle, Nicolas; Kudryavtsev, Vladimir; Chapron, Bertrand; Marie, Louis; Molemaker, Jeroen.
Reconstruction and evolution of two-dimensional spectra of surface waves in the Gulf of Mexico are derived from airborne sun-glitter imagery. As the proposed method is based on a linear transfer function deduced from the shape of the sunglitter brightness, the absolute wavenumber elevation spectrum does not require any additional assumption or information about sky brightness, wind or wave energy. The detailed description of the airborne image processing method is given. As demonstrated, retrieved spectra agree well with nearby NDBC buoy data, both for spectrum shape, level and energy angular distribution. The 180-degree wave direction ambiguity, inherent to image-derived spectra, is eliminated by using cross-correlation analysis between two consecutive...
Tipo: Text
Palavras-chave: Sunglitter; Sea surface waves; Directional wave spectrum; Aerial photography; Field measurements; Remote sensing observations; High resolution; Drone.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00465/57712/60174.pdf

High resolution seismic imaging of the ocean structure using a small volume airgun source array in the Gulf of Cadiz
Provedor de dados: 5
Autores: Geli, Louis; Cosquer, Emmanuel; Hobbs, R. W.; Klaeschen, D.; Papenberg, C.; Thomas, Yannick; Menesguen, Claire; Hua, Bach-lien.
A small volume (117 cu-inch) seismic source producing signal predominantly in the 150-200 Hz frequency window was used during the GO calibration experiment in the Gulf of Cadiz (April-May 2007). The data show the small scale (&lt; 10 m in the z direction) internal structure of the ocean. High-resolution images display seismic reflectors that often appear as distinct, horizontal, short (similar to a few hundred meters to a few km long) segments, lying at different depths, while low-resolution (similar to 20 to 30 Hz) display long, horizontal reflectors (similar to a few tens of km), sometimes linked by short, apparently "dipping" segments. The present data suggest that this apparent dipping effect is due to the insufficient separation power (similar to...
Tipo: Text
Palavras-chave: High resolution; Seismics; Oceanography.
Ano: 2009
URL: https://archimer.ifremer.fr/doc/2009/publication-7297.pdf