Benefits of Meteosat in description of ocean-atmosphere exchanges in the Northeast Subtropical Atlantic Ocean ; Les échanges océan-atmosphère dans l'Atlantique subtropical nord-est : apports de Météosat
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| Title: | Benefits of Meteosat in description of ocean-atmosphere exchanges in the Northeast Subtropical Atlantic Ocean ; Les échanges océan-atmosphère dans l'Atlantique subtropical nord-est : apports de Météosat |
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| Authors: | Bauer, Olivier |
| Contributors: | Centre Énergétique et Procédés (CEP), Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL), Université de Nice Sophia-Antipolis, Lucien Wald(lucien.wald@mines-paristech.fr) |
| Source: | https://pastel.hal.science/pastel-00956592 ; Océan, Atmosphère. Université de Nice Sophia-Antipolis, 1996. Français. ⟨NNT : ⟩. |
| Publisher Information: | CCSD |
| Publication Year: | 1996 |
| Collection: | MINES ParisTech: Archive ouverte / Open Archive (HAL) |
| Subject Terms: | Climate change, ocean-atmosphere interface, radiative fluxes, turbulent fluxes, cloudiness, modelling, remote sensing, Changements climatiques, Interface océan-atmosphère, Flux radiatifs, Flux turbulents, Ennuagement, Modélisation, Télédétection, Météosat, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere |
| Description: | The present work deals with exchanges in energy and matter and especially heat budget at the ocean surface in the Northeast Subtropical Atlantic Ocean. The shortwave downwelling flux is a prominent term in the budget and may be assessed by the method Heliosat applied to low resolution images acquired by the Meteosat satellite. At meso-scale, we show the great variability of the shortwave flux on hourly basis. Satisfactory results are obtained when comparing our estimates to in situ measurements. Eight semi-empirical formulae are compared to measurements or climatological averages of net longwave flux. A method has been developed exploiting Meteosat data. It reveals less accurate than the best semi-empirical formulae. Types of skies are defined as a function of the total cloud cover. The impact of the cloud cover of radiative fluxes is analyzed. Climatological averages of surface fluxes are computed in order to compute the net heat flux and its zonal variation during the months of September and October. The last part deals with three specific meteorological conditions. Using in situ measurements, we assess the impact of the variability in space and time on the computation of the budget. Noticeable changes in estimated fluxes are evidenced as a function of time scales and as a function of the spatial undersampling used in the construction of the low resolution images. ; Le travail présenté porte sur l'étude des échanges d'énergie et de matière, au travers du bilan thermique net à la surface océanique, dans une région de l'océan Atlantique nord. Le flux ondes courtes, terme prépondérant de ce bilan, est déterminé grâce à la méthode Heliosat adaptée aux données de basse résolution spatiale du satellite METEOSAT-4. A méso-échelle, sur une base horaire, nous mettons en relief la grande variabilité du flux solaire à la surface. Les résultats de comparaison avec des mesures in situ sur notre zone d'étude sont satisfaisants. Nous estimons les performances de huit formulations semi-empiriques usuelles sur la restitution ... |
| Document Type: | doctoral or postdoctoral thesis |
| Language: | French |
| Availability: | https://pastel.hal.science/pastel-00956592 https://pastel.hal.science/pastel-00956592v1/document https://pastel.hal.science/pastel-00956592v1/file/BAUER_Olivier.pdf |
| Rights: | info:eu-repo/semantics/OpenAccess |
| Accession Number: | edsbas.228F1CFC |
| Database: | BASE |
Nájsť tento článok vo Web of Science | Abstract: | The present work deals with exchanges in energy and matter and especially heat budget at the ocean surface in the Northeast Subtropical Atlantic Ocean. The shortwave downwelling flux is a prominent term in the budget and may be assessed by the method Heliosat applied to low resolution images acquired by the Meteosat satellite. At meso-scale, we show the great variability of the shortwave flux on hourly basis. Satisfactory results are obtained when comparing our estimates to in situ measurements. Eight semi-empirical formulae are compared to measurements or climatological averages of net longwave flux. A method has been developed exploiting Meteosat data. It reveals less accurate than the best semi-empirical formulae. Types of skies are defined as a function of the total cloud cover. The impact of the cloud cover of radiative fluxes is analyzed. Climatological averages of surface fluxes are computed in order to compute the net heat flux and its zonal variation during the months of September and October. The last part deals with three specific meteorological conditions. Using in situ measurements, we assess the impact of the variability in space and time on the computation of the budget. Noticeable changes in estimated fluxes are evidenced as a function of time scales and as a function of the spatial undersampling used in the construction of the low resolution images. ; Le travail présenté porte sur l'étude des échanges d'énergie et de matière, au travers du bilan thermique net à la surface océanique, dans une région de l'océan Atlantique nord. Le flux ondes courtes, terme prépondérant de ce bilan, est déterminé grâce à la méthode Heliosat adaptée aux données de basse résolution spatiale du satellite METEOSAT-4. A méso-échelle, sur une base horaire, nous mettons en relief la grande variabilité du flux solaire à la surface. Les résultats de comparaison avec des mesures in situ sur notre zone d'étude sont satisfaisants. Nous estimons les performances de huit formulations semi-empiriques usuelles sur la restitution ... |
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