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| Registros recuperados: 69 | |
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| Blain,Gabriel Constantino; Kayano,Mary Toshie; Sentelhas,Paulo Cesar; Lulu,Jorge. |
| Considering the importance of the ratio between the actual and potential evapotranspiration (AE/PE) for agricultural purposes, the present study estimated the 10-day based AE/PE, aiming to evaluate possible influences of the Pacific Decadal Oscillation (PDO), on temporal variability series, in the region of Campinas, São Paulo State, Brazil. The shapes of the beta probability density function of the AE/PE series for four periods (two in the cold PDO phase and two in the warm PDO phase) do not show differences between the PDO phases. In this sense, the use of "average periods" to obtain a standard climatology for agrometeorological purposes (such as the climate normal of the 1961-1990 period, which encompasses sixteen years of the cold PDO phase and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Climate normal; Sea surface temperature. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052009000300029 |
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| De Boyer Montegut, Clement; Vialard, Jerome; Shenoi, S. S. C.; Shankar, D.; Durand, Fabien; Ethe, Christian; Madec, Gurvan. |
| A global ocean general circulation model (OGCM) is used to investigate the mixed layer heat budget of the northern Indian Ocean (NIO). The model is validated against observations and shows fairly good agreement with mixed layer depth data in the NIO. The NIO has been separated into three subbasins: the western Arabian Sea (AS), the eastern AS, and the Bay of Bengal (BoB). This study reveals strong differences between the western and eastern AS heat budget, while the latter basin has similarities with the BoB. Interesting new results on seasonal time scales are shown. The penetration of solar heat flux needs to be taken into account for two reasons. First, an average of 28 W m(-2) is lost beneath the mixed layer over the year. Second, the penetration of... |
| Tipo: Text |
Palavras-chave: Sea surface temperature; General circulation model; Southeastern arabian sea; Thermal structure; Summer monsoon; Solar radiation; Pacific ocean; Barrier layer; Bengal; Bay. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00185/29639/27985.pdf |
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| Vianello, Patrick; Ternon, Jean-francois; Demarcq, Herve; Herbette, Steven; Roberts, Michael J.. |
| This work is part of the MADRidge Project special issue which aims to describe pelagic ecosystems in the vicinity of three prominent shallow seamounts in the South West Indian Ocean: one here named MAD-Ridge (240 m below the surface) plus Walters Shoal (18 m) on the Madagascar Ridge, and La Pérouse (60 m) on the abyssal plain east of Madagascar. The three span latitudes 20°S and 33°S, some 1500 km. The study provides the background oceanography for the once-off, multidisciplinary snapshot cruise studies around the seamounts. As life on seamounts is determined by factors such as summit depth, proximity to the light layers of the ocean, and the ambient circulation, a first description of regional spatial-field climatologies (16–22 years) and monthly... |
| Tipo: Text |
Palavras-chave: South West Indian Ocean; Madagascar Ridge; Seamounts; Walters shoal; Sea surface temperature; Eddy kinetic energy; Mixed layer depth; Chlorophyll-a; Geostrophic currents. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74581/74476.pdf |
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| He, Juan; Zhao, Meixun; Li, Li; Wang, Pinxian; Ge, Huangmin. |
| This paper reports high-resolution biomarker records of the last 260 ka for core MD05- 2904 from the northern South China Sea (SCS). The sea surface temperature (SST) record using the U-37(k') index reveals a minimum of 21.5 degrees C (MIS 2) and a maximum of 28.3 degrees C (MIS 5.5), for a temperature difference of almost 7 degrees C, and provides the longest high-resolution U-37(k') SST record in northern SCS. The content of odd-number long chain n-alkanes and several n-alkanes indexes such as the CPI, ACL and the C-31/C-27 ratio, all reveal generally higher values during the glacials and lower values during the interglacials. Terrestrial input as indicated by n-alkane content was mostly controlled by sea-level changes: During the glacials, lower... |
| Tipo: Text |
Palavras-chave: Northern South China Sea; Sea surface temperature; Terrestrial input; Source region vegetation. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00207/31844/30259.pdf |
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| Yu, Hua; Liu, Zhenxia; Berne, Serge; Jia, Guodong; Xiong, Yingqian; Dickens, Gerald R.; Wei, Gangjian; Shi, Xuefa; Liu, J. Paul; Chen, Fajin. |
| East China Sea (ECS) is an important climate modulator of East Asia. In the last glacial period, the global sea level, the path and strength of the Kuroshio Current experienced great changes; combined with the variable volume of fresh run-off input, they made the hydrographic situation in the ECS quite different from nowadays. Based on high-resolution alkenone-sea surface temperature (SST) and oxygen isotope composition of planktonic foraminifera Globigerinoides sacculifer we reconstructed paleo-sea surface salinity (SSS) of a long piston core DGKS9604 retrieved from the middle Okinawa Trough of the eastern ECS. The delta O-18 and SST records display significant variations with global ice volume. Synchrony of the millennial-scale climate events like YD and... |
| Tipo: Text |
Palavras-chave: Sea surface salinity; Sea surface temperature; East Asian monsoon; Kuroshio Current; Okinawa Trough; East China Sea. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7398.pdf |
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| González-haro, Cristina; Ponte, Aurelien; Autret, Emmanuelle. |
| The expected amplitude of fixed-point sea surface temperature (SST) fluctuations induced by barotropic and baroclinic tidal flows is estimated from tidal current atlases and SST observations. The fluctuations considered are the result of the advection of pre-existing SST fronts by tidal currents. They are thus confined to front locations and exhibit fine-scale spatial structures. The amplitude of these tidally induced SST fluctuations is proportional to the scalar product of SST frontal gradients and tidal currents. Regional and global estimations of these expected amplitudes are presented. We predict barotropic tidal motions produce SST fluctuations that may reach amplitudes of 0.3 K. Baroclinic (internal) tides produce SST fluctuations that may reach... |
| Tipo: Text |
Palavras-chave: Sea surface temperature; Satellite observations; Tidal currents; Internal tides. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00589/70075/68048.pdf |
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| Picart, Stephane Saux; Tandeo, Pierre; Autret, Emmanuelle; Gausset, Blandine. |
| Machine learning techniques are attractive tools to establish statistical models with a high degree of non linearity. They require a large amount of data to be trained and are therefore particularly suited to analysing remote sensing data. This work is an attempt at using advanced statistical methods of machine learning to predict the bias between Sea Surface Temperature (SST) derived from infrared remote sensing and ground “truth” from drifting buoy measurements. A large dataset of collocation between satellite SST and in situ SST is explored. Four regression models are used: Simple multi-linear regression, Least Square Shrinkage and Selection Operator (LASSO), Generalised Additive Model (GAM) and random forest. In the case of geostationary satellites for... |
| Tipo: Text |
Palavras-chave: Machine learning; Systematic error; Sea surface temperature; Random forest. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00426/53797/54721.pdf |
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| Schmitt, A.; Elliot, M.; Thirumalai, K.; La, C.; Bassinot, F.; Petersen, J.; Movellan, A.; Jorry, Stephan; Borgomano, J.. |
| The ratio of magnesium to calcium (Mg/Ca) in foraminiferal shells is commonly used as a proxy for past ocean temperature. Recent advances in elemental analyses now enable single-specimen measurements of planktic foraminifera and thus, can provide information on past seasonal and interannual variability, owing to the near-monthly lifespan of foraminifera. In this study, we explore the temperature variance recorded by Mg/Ca in tests of foraminifera Globigerinoides ruber, a planktic species that occurs throughout the year in tropical waters. Using LA-ICP-MS, we characterize Mg/Ca variability in single specimens of two morphotypes of G. ruber picked from a sediment core retrieved offshore New Caledonia. We provide an estimate of the range of calcification... |
| Tipo: Text |
Palavras-chave: Globigerinoides ruber; Mg/Ca ratio; Sea surface temperature; LA-ICPMS; Seasonality; Quaternary. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00472/58336/60890.pdf |
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| Nogueira Neto, A., V; Giordani, H.; Caniaux, G.; Araujo, M.. |
| Oceanic and atmospheric processes were investigated in order to explore the causes of seasonal and interannual variability of sea surface temperatures (SST) in the western tropical Atlantic (WTA; 20 degrees S-20 degrees N, 15 degrees W-60 degrees W). A mixed-layer (ML) heat budget was performed by using Argo profiles and supplementary data sets based on satellite and atmospheric products during the period 2007-2012. The WTA is divided into four boxes which represent the main temporal and spatial heterogeneities of this region. An analysis of error of each term pointed out that the mean net surface heat fluxes are systematically underestimated by 20 W m(-2). A correction of this term provides realistic estimates of the vertical mixing which was obtained as... |
| Tipo: Text |
Palavras-chave: Tropical Atlantic; Mixed-layer heat budget; Sea surface temperature; Argo floats. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00623/73551/73798.pdf |
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| Isern-fontanet, J.; Hascoet, Erwan. |
| The noise present in infrared satellite measurements of sea surface temperature (SST) hampers the use of surface quasi-geostrophic (SQG) equations to diagnose ocean dynamics at high resolutions. Here we propose a methodology to reduce the contribution of noise when diagnosing surface vorticity, divergence, and vertical velocity from SST able to retain the dynamics at scales of a few kilometers. It is based on the use of denoising techniques with curvelets as basis functions and the application of a selective low-pass filters to improve the reconstruction of surface upwelling/downwelling patterns. First, it is tested using direct numerical simulations of SQG turbulence and then applied to diagnose low-frequency vertical velocity patterns from real MODIS... |
| Tipo: Text |
Palavras-chave: Sea surface temperature; Surface quasi-geostrophy; Remote sensing; Vertical velocity; Ocean submesoscales; Image denoising. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00170/28162/26391.pdf |
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| Isern-fontanet, Jordi; Chapron, Bertrand; Lapeyre, Guillaume; Klein, Patrice. |
| In this paper, we examine the emerging potential offered by satellite microwave radiometer SST measurements to complement altimeter data to quantitatively derive surface ocean currents. The proposed methodology does not follow standard sequential temporal analysis but follows the application of the Surface Quasi-Geostrophic (SQG) theory. Accordingly, under favourable environmental conditions, the implementation for this methodology is simple and robust, and most importantly, solely requires a single SST image. For the present demonstration, altimetric measurements are used to infer a necessary adjustment to match the kinetic energy level for length scales smaller than 300 km. This helps to derive a regional effective Brunt-Vaisala frequency to produce SQG... |
| Tipo: Text |
Palavras-chave: Microwave radiometers; Sea surface temperature; Surface quasi geostrophy. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2177.pdf |
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| Lambaerts, J.; Lapeyre, Guillaume; Plougonven, R.; Klein, Patrice. |
| Recent studies have revealed that strong sea surface temperature (SST) fronts, on the scale of a Western Boundary Current, significantly affect not just the Marine Boundary Layer but the entire troposphere. This has aroused renewed interest in air-sea interactions. The present study investigates the atmospheric response to fixed SST anomalies associated with mesoscale oceanic eddies and submesoscale filaments, using idealized simulations. Our main result is that in weak wind conditions, the vertical velocity in the planetary boundary layer (PBL) is linearly proportional to the SST Laplacian. This is established by a quantitative analysis in the spatial space as well as in the spectral space. Comparing the responses to two different SST fields shows that... |
| Tipo: Text |
Palavras-chave: Air-sea interactions; Boundary layer; Sea surface temperature. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00169/28047/26247.pdf |
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| Registros recuperados: 69 | |
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