Search results for "Circulation"
showing 10 items of 1137 documents
Influence du rapport à l’apprendre sur l’évolution des conceptions scientifiques
2016
International audience
Impact des activités de recherches sur l’acquisition des connaissances en classe de CM2 thème : respiration-circulation sanguine
2006
Mémoire professionnel - 30 pages
Températures extrêmes minimales de printemps et types de circulation atmosphérique sur l’Europe moyenne.
2019
55 pages; National audience
Variabilité climatique printanière et phénologie végétale en Auxois : exemple d'Alise-Sainte-Reine (Côte d'Or).
2018
Un suivi photographique est effectué depuis 2011 sur le site viticole d'Alise-Sainte-Reine, dans l'Auxois en Bourgogne du Nord (département de la Côte-d'Or), afin de mettre en évidence des indicateurs permettant d'expliquer la variabilité interannuelle des stades phénologiques de certaines espèces végétales par l'analyse de la variabilité climatique et de la fréquence, succession et durée des types de circulation atmosphérique et de temps. Les photos prises au début du mois de mai montrent une différence sensible entre d'une part les années 2011 et 2018, et d'autre part les années 2016 et 2017. Sur la vigne de la parcelle sélectionnée et les arbres environnants, le déploiement des feuilles …
Global equatorial variability of 850 and 200 hPa zonal winds from rawinsondes between 1963 and 1989
1995
The longitude-height-time variability of 3-month averaged zonal wind anomalies at 850 and 200 hPa over the equatorial area (5{degrees}N-5{degrees}S) is analyzed using a three-dimensional dataset constructed from rawinsonde data (1963-1989). The first mode, closely related to the Southern Oscillation Index, suggests a strong vertical coupling associated with a horizontal out-of-phase pattern between the central/western Pacific and the remainder of the equatorial belt. The vertical coupling appears to be phase-locked to the annual cycle with strongest intensities found over South America and near the maritime continent early in the calendar year and over the Pacific basin and Africa during th…
Sahel droughts and Enso dynamics
1996
Correlations between summer Sahel rainfall and Southern Oscillation Index has increased during the last thirty years. At high frequency time scale (periods lower than 8 years), an intertropical Atlantic zonal divergent circulation anomaly is forced by the difference of sea surface temperature (SST) anomalies between the eastern equatorial parts of Pacific and Atlantic. This zonal connection worked well during most of the E1 Nino/Southern Oscillation (ENSO) events occurring after 1970; positive/negative SST anomalies in the eastern Pacific/Atlantic led to rainfall deficits over the whole West Africa. At low frequency time scale (periods greater than 8 years), positive SST anomalies in the In…
Types de configurations pluviométriques sur le bassin méditerranéen, forçages atmosphériques et évènements intenses (1979-2013).
2015
Sixrecurrent and redundant daily rainfall patterns have been extracted over the Mediterranean area from 1979 to 2013: five areassociated to regionals rainfall excess (South-West Mediterranean, Mid-North Mediterranean, East Mediterranean, WestMediterranean and north-west Mediterranean) and one to generalized deficit. Each rainfall pattern is associated with atypical barometric spatial configuration leading to local wind bringing moisture to the coast leading to specific local rainfallsurplus. Rainfall patterns also explain a large part of the spatial characteristics and the probability of occurrence of intenseevents. For example, more than 20% of days of “West-Mediterranean” rainfall pattern…
Épisodes secs en hiver dans le bassin méditerranéen : variabilité et forçages atmosphériques (1957-2013).
2016
The mean number of dry days in winter increased in the Mediterranean Basin during the 1957-2013 period,mainly because of dry spells becoming longer. The shortest events (Very Short Dry Spells) were less frequentwhereas longer events (Short Dry Spells, Medium Dry Spells and Long Dry Spells) were more frequent on theMediterranean Basin. 76 very long events (Very Long Dry Spells – VLDS) occurred during the 1957-2013period. A hierarchical clustering analysis of these VLDS events allows to detect 5 mainly Mediterraneanconfigurations: North-West Mediterranean, West Mediterranean, North-East Mediterranean, South-EastMediterranean and localized events.
Étude des températures simulées avec Méso-NH : sensibilité à l’artificialisation des sols à Grenoble et Lyon.
2022
International audience; La modélisation atmosphérique à très fine échelle permet d’analyser la dynamique de l’îlot dechaleur urbain en contexte de topographie complexe. Deux simulations (Urbaine et Non-Urbaine) mettenten évidence les effets associés à l'urbanisation. La taille des agglomérations, dans le cas de Lyon etGrenoble, n'influence pas la différence de température entre les deux simulations. Les conditions destabilité influencent fortement ces différences. L'ICU peut être intensifié par l'affaiblissement du vent oul’effet de piégeage et/ou le développement d’une couche d’inversion.
High resolution rainfall variability in the vineyard: first results from a local scale network in Burgundy.
2012
4 pages; International audience; Rainfall is a major component of Vitivinicultural Terroirs. In many regions, it controls a large part of water intake byvine and it has an important role in diseases occurrence. Winegrowers often record rainfall with only one or a couple ofrain gauges. Such a sparse coverage might not be accurate enough to capture efficiently the spatial variability ofrainfall, which is a necessary prerequisite for efficient crop management (e.g. for irrigation or spraying decisions, etc.).In order to study high resolution variability of rainfall, we implemented a 40 tipping bucket rain gauges network over anarea of 28 km² in the hilly region of Beaune (France). The mesh siz…