Consulta: creatorFacets:"Vialard, Jerome"
Registros recuperados: 25
Data/hora: 17/06/2024 18:05:44

Ocean Climate Observing Requirements in Support of Climate Research and Climate Information
Provedor de dados: 5
Autores: Stammer, Detlef; Bracco, Annalisa; Achutarao, Krishna; Beal, Lisa; Bindoff, Nathaniel L.; Braconnot, Pascale; Cai, Wenju; Chen, Dake; Collins, Matthew; Danabasoglu, Gokhan; Dewitte, Boris; Farneti, Riccardo; Fox-kemper, Baylor; Fyfe, John; Griffies, Stephen M.; Jayne, Steven R.; Lazar, Alban; Lengaigne, Matthieu; Lin, Xiaopei; Marsland, Simon; Minobe, Shoshiro; Monteiro, Pedro M. S.; Robinson, Walter; Roxy, Mathew Koll; Rykaczewski, Ryan R.; Speich, Sabrina; Smith, Inga J.; Solomon, Amy; Storto, Andrea; Takahashi, Ken; Toniazzo, Thomas; Vialard, Jerome.
Natural variability and change of the Earth's climate have significant global societal impacts. With its large heat and carbon capacity and relatively slow dynamics, the ocean plays an integral role in climate, and provides an important source of predictability at seasonal and longer timescales. In addition, the ocean provides the slowly evolving lower boundary to the atmosphere, driving, and modifying atmospheric weather. Understanding and monitoring ocean climate variability and change, to constrain and initialize models as well as identify model biases for improved climate hindcasting and prediction, requires a scale-sensitive, and long-term observing system. A climate observing system has requirements that significantly differ from, and sometimes are...
Tipo: Text
Palavras-chave: Ocean observing system; Ocean climate; Earth observations; In situ measurements; Satellite observations; Ocean modeling; Climate information.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00675/78724/80996.pdf

Assessment of seasonal and year-to-year surface salinity signals retrieved from SMOS and Aquarius missions in the Bay of Bengal
Provedor de dados: 5
Autores: Akhil, V. P.; Lengaigne, Matthieu; Durand, Fabien; Vialard, Jerome; Chaitanya, A. V. S.; Keerthi, M. G.; Gopalakrishna, V. V.; Boutin, Jacqueline; De Boyer Montegut, Clement.
The Bay of Bengal (BoB) exhibits a wide range of sea surface salinity (SSS), with very fresh water induced by heavy monsoonal precipitation and river run-offs to the north, and saltier water to the south. This is a particularly challenging region for the application of satellite-derived SSS measurements because of the potential pollution of the SSS signal by radio frequency interference (RFI) and land-induced contamination in this semi-enclosed basin. The present study validates recent level-3 monthly gridded (1° × 1°) SSS products from Soil Moisture and Ocean Salinity (SMOS) and Aquarius missions to an exhaustive in situ SSS product for the BoB. Current SMOS SSS retrievals do not perform better than existing climatologies. This is in stark contrast to...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00319/42986/45003.pdf

Seasonal and intraseasonal biogeochemical variability in the thermocline ridge of the southern tropical Indian Ocean
Provedor de dados: 5
Autores: Resplandy, L.; Vialard, Jerome; Levy, M.; Aumont, Olivier; Dandonneau, Y.
The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) time series shows high variability of surface chlorophyll at seasonal and intraseasonal time scales in the oligotrophic southern tropical Indian Ocean thermocline ridge called the Seychelles-Chagos thermocline ridge (SCTR). The SCTR is characterized by an open ocean upwelling due to local Ekman pumping, which annually maintains the mixed layer (ML) shallow and is responsive to atmospheric forcing and in particular to the Madden-Julian Oscillation (MJO) at an intraseasonal time scale. Here we present an overview of SCTR biogeochemistry and investigate the physical processes driving the response observed at seasonal and intraseasonal time scales. Using satellite observations and biophysical ocean...
Tipo: Text
Palavras-chave: Madden julian oscillation; Arabian sea; Rossby waves; Interannual variability; Circulation model; Monsoon; Temperature; Perturbations; Nutrients; Dynamics.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00185/29630/27994.pdf

Simulated seasonal and interannual variability of the mixed layer heat budget in the northern Indian Ocean
Provedor de dados: 5
Autores: 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

RAMA The Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction
Provedor de dados: 5
Autores: Mcphaden, M. J.; Meyers, G.; Ando, K.; Masumoto, Y.; Murty, V. S. N.; Ravichandran, M.; Syamsudin, F.; Vialard, Jerome; Yu, L.; Yu, W.
The Indian Ocean is unique among the three tropical ocean basins in that it is blocked at 25 degrees N by the Asian landmass. Seasonal heating and cooling of the land sets the stage for dramatic monsoon wind reversals, strong ocean atmosphere interactions, and intense seasonal rains over the Indian subcontinent, Southeast Asia, East Africa, and Australia. Recurrence of these monsoon rains is critical to agricultural production that supports a third of the world's population. The Indian Ocean also remotely influences the evolution of El Nino-Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), North American weather, and hurricane activity. Despite its importance in the regional and global climate system though, the Indian Ocean is the most...
Tipo: Text
Palavras-chave: Madden julian oscillation; Tropical indian ocean; Sea heat fluxes; Intraseasonal variability; Equatorial currents; Summer monsoon; Interannual variability; Arabian sea; El nino; Rainfall variability.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00185/29632/27992.pdf

Global impact of tropical cyclones on primary production
Provedor de dados: 5
Autores: Menkes, Christophe E.; Lengaigne, Matthieu; Levy, Marina; Ethe, Christian; Bopp, Laurent; Aumont, Olivier; Vincent, Emmanuel; Vialard, Jerome; Jullien, Swen.
In this paper, we explore the global responses of surface temperature, chlorophyll and primary production to tropical cyclones (TCs). Those ocean responses are first characterized from the statistical analysis of satellite data under ~1000 TCs over the 1998-2007 period. Besides the cold wake, the vast majority of TCs induce a weak chlorophyll response, with only ~10% of induced blooms exceeding 0.1 mg.m-3. The largest chlorophyll responses mostly occur within coastal regions, in contrast to the strongest cold wakes that generally occur farther offshore. To understand this decoupling, we analyze a coupled dynamical-biogeochemical oceanic simulation forced by realistic wind vortices applied along observed TC tracks. The simulation displays a realistic...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00333/44449/44121.pdf

Low and high frequency Madden-Julian oscillations in austral summer: interannual variations
Provedor de dados: 5
Autores: Izumo, Takeshi; Masson, Sebastien; Vialard, Jerome; De Boyer Montegut, Clement; Behera, Swadhin K.; Madec, Gurvan; Takahashi, Keiko; Yamagata, Toshio.
The Madden-Julian oscillation (MJO) is the main component of intraseasonal variability of the tropical convection, with clear climatic impacts at an almost-global scale. Based on satellite observations, it is shown that there are two types of austral-summer MJO events (broadly defined as 30-120 days convective variability with eastward propagation of about 5 m/s). Equatorial MJO events have a period of 30-50 days and tend to be symmetric about the equator, whereas MJO events centered near 8A degrees S tend to have a longer period of 55-100 days. The lower-frequency variability is associated with a strong upper-ocean response, having a clear signature in both sea surface temperature and its diurnal cycle. These two MJO types have different interannual...
Tipo: Text
Palavras-chave: Intraseasonal Madden-Julian oscillation (MJO); Seychelles-Chagos thermocline ridge/thermocline dome of the Indian Ocean; Indian Ocean dipole (IOD); El Nino southern oscillation (ENSO); Diurnal cycle; Oceanic diurnal warm layers; Air-sea interactions; Ocean-atmosphere coupling; Interannual variations; Mixed layer; Australian weather.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00013/12416/9221.pdf

Impact of temperature inversions on SST evolution in the South-Eastern Arabian Sea during the pre-summer monsoon season
Provedor de dados: 5
Autores: Durand, F; Shetye, Sr; Vialard, Jerome; Shankar, D; Shenoi, Ssc; Ethe, C; Madec, G.
Temperature inversions are known to occur in the near-surface ocean regime where salinity stratification is large enough to influence the density field. However, they have not been known as features that alter near-surface processes significantly to influence the sea surface temperature (SST). From the analysis of new observed datasets as well as of state-of-the-art numerical model outputs, this paper shows that heat trapped within a temperature inversion makes significant contribution to warming of the SST in the South-Eastern Arabian Sea during the pre-southwest monsoon season.
Tipo: Text
Palavras-chave: Mixed layer; Toga decade; Ocean; Variability; Salinity; Physics; Model; Onset; OGCM; Pool.
Ano: 2004
URL: https://archimer.ifremer.fr/doc/00203/31424/29815.pdf

Interannual variability of the Tropical Indian Ocean mixed layer depth
Provedor de dados: 5
Autores: Keerthi, M. G.; Lengaigne, M.; Vialard, Jerome; De Boyer Montegut, Clement; Muraleedharan, P. M.
In the present study, interannual fluctuations of the mixed layer depth (MLD) in the tropical Indian Ocean are investigated from a long-term (1960-2007) eddy permitting numerical simulation and a new observational dataset built from hydrographic in situ data including Argo data (1969-2008). Both datasets show similar interannual variability patterns in relation with known climate modes and reasonable phase agreement in key regions. Due to the scarcity of the observational dataset, we then largely rely on the model to describe the interannual MLD variations in more detail. MLD interannual variability is two to four times smaller than the seasonal cycle. A large fraction of MLD interannual variations is linked to large-scale climate modes, with the exception...
Tipo: Text
Palavras-chave: Mixed layer; Interannual variability; Indian Ocean; Indian Ocean Dipole; El Nino/Southern Oscillation; Monsoon.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00124/23564/22771.pdf

A modeling study of the processes of surface salinity seasonal cycle in the Bay of Bengal
Provedor de dados: 5
Autores: Akhil, V. P.; Durand, Fabien; Lengaigne, Matthieu; Vialard, Jerome; Keerthi, M. G.; Gopalakrishna, V. V.; Deltel, Charles; Papa, Fabrice; De Boyer Montegut, Clement.
In response to the Indian Monsoon freshwater forcing, the Bay of Bengal exhibits a very strong seasonal cycle in sea surface salinity (SSS), especially near the mouths of the Ganges-Brahmaputra and along the east coast of India. In this paper, we use an eddy-permitting (∼25 km resolution) regional ocean general circulation model simulation to quantify the processes responsible for this SSS seasonal cycle. Despite the absence of relaxation toward observations, the model reproduces the main features of the observed SSS seasonal cycle, with freshest water in the northeastern Bay, particularly during and after the monsoon. The model also displays an intense and shallow freshening signal in a narrow (∼100 km wide) strip that hugs the east coast of India, from...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00197/30819/29189.pdf

CIRENE Air-Sea Interactions in the Seychelles-Chagos Thermocline Ridge Region
Provedor de dados: 5
Autores: Vialard, Jerome; Duvel, J. P.; Mcphaden, M. J.; Bouruet-aubertot, P.; Ward, Ben; Key, E.; Bourras, D.; Weller, Robert; Minnett, P.; Weill, A.; Cassou, C.; Eymard, L.; Fristedt, T.; Basdevant, C.; Dandonneau, Y.; Duteil, O.; Izumo, T.; De Boyer Montegut, Clement; Masson, S.; Marsac, F.; Menkes, C.; Kennan, S.
A field experiment in the southwestern Indian Ocean provides new insights into ocean-atmosphere interactions in a key climatic region.
Tipo: Text
Palavras-chave: Madden julian oscillation; Southwest indian ocean; Surface temperature; Mixed layer; Intraseasonal variability; Rainfall variability; Tropical cyclones; Western pacific; Dipole mode; El nino.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00185/29634/27990.pdf

Impact of barrier layer on winter-spring variability of the southeastern Arabian Sea
Provedor de dados: 5
Autores: Masson, S; Luo, Jj; Madec, G; Vialard, Jerome; Durand, F; Gualdi, S; Guilyardi, E; Behera, S; Delecluse, P; Navarra, A; Yamagata, T.
In the present study, we use a coupled model to evaluate the effect of shallow salinity stratification on the sea surface temperature (SST) and on the monsoon onset in the southeastern Arabian Sea (SEAS). A 100-year control experiment shows that the coupled model reproduces the main climatic features in this region in terms of SST, precipitation and barrier layer (BL). A 100-year sensitivity experiment (where BL effects have been suppressed in the SEAS) shows that BL enhances the spring SST warming by 0.5 degrees C, and leads to a statistically significant increase of precipitation in May (3 mm/day) linked to an early (10 to 15 days) monsoon onset. This suggests that the BL extent may be a useful predictor of the summer monsoon onset in the area with a...
Tipo: Text
Palavras-chave: Summer monsoon season; Surface temperature; Indian ocean; Mixed layer; Northeast monsoon; Southwest monsoon; Onset vortex; Coupled GCM; Mechanisms; Evolution.
Ano: 2005
URL: https://archimer.ifremer.fr/doc/00203/31422/29819.pdf

Influence of the state of the Indian Ocean Dipole on the following year's El Nino
Provedor de dados: 5
Autores: Izumo, Takeshi; Vialard, Jerome; Lengaigne, Matthieu; De Boyer Montegut, Clement; Behera, Swadhin K.; Luo, Jing-jia; Cravatte, Sophie; Masson, Sebastien; Yamagata, Toshio.
El Nino-Southern Oscillation (ENSO) consists of irregular episodes of warm El Nino and cold La Nina conditions in the tropical Pacific Ocean(1), with significant global socio-economic and environmental impacts(1). Nevertheless, forecasting ENSO at lead times longer than a few months remains a challenge(2,3). Like the Pacific Ocean, the Indian Ocean also shows interannual climate fluctuations, which are known as the Indian Ocean Dipole(4,5). Positive phases of the Indian Ocean Dipole tend to co-occur with El Nino, and negative phases with La Nina(6-9). Here we show using a simple forecast model that in addition to this link, a negative phase of the Indian Ocean Dipole anomaly is an efficient predictor of El Nino 14 months before its peak, and similarly, a...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00002/11304/7831.pdf

Seasonal Mixed Layer Heat Balance of the Southwestern Tropical Indian Ocean
Provedor de dados: 5
Autores: Foltz, Gregory R.; Vialard, Jerome; Kumar, B. Praveen; Mcphaden, Michael J.
Sea surface temperature (SST) in the southwestern tropical Indian Ocean exerts a significant influence on global climate through its influence on the Indian summer monsoon and Northern Hemisphere atmospheric circulation. In this study, measurements from a long-term moored buoy are used in conjunction with satellite, in situ, and atmospheric reanalysis datasets to analyze the seasonal mixed layer heat balance in the thermocline ridge region of the southwestern tropical Indian Ocean. This region is characterized by a shallow mean thermocline (90 m, as measured by the 20 degrees C isotherm) and pronounced seasonal cycles of Ekman pumping and SST (seasonal ranges of -0.1 to 0.6 m day(-1) and 26 degrees-29.5 degrees C, respectively). It is found that surface...
Tipo: Text
Palavras-chave: Sea surface temperature; Pacific ocean; Equatorial pacific; Interannual variability; Bulk parameterization; Rainfall variability; Atlantic ocean; North pacific; El nino.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00185/29629/27996.pdf

Indian Ocean Dipole and El Nino/Southern Oscillation impacts on regional chlorophyll anomalies in the Indian Ocean
Provedor de dados: 5
Autores: Currie, J. C.; Lengaigne, M.; Vialard, Jerome; Kaplan, David; Aumont, Olivier; Naqvi, S. W. A.; Maury, Olivier.
The Indian Ocean Dipole (IOD) and the El Nino/Southern Oscillation (ENSO) are independent climate modes, which frequently co-occur, driving significant interannual changes within the Indian Ocean. We use a four-decade hindcast from a coupled biophysical ocean general circulation model, to disentangle patterns of chlorophyll anomalies driven by these two climate modes. Comparisons with remotely sensed records show that the simulation competently reproduces the chlorophyll seasonal cycle, as well as open-ocean anomalies during the 1997/1998 ENSO and IOD event. Results suggest that anomalous surface and euphotic-layer chlorophyll blooms in the eastern equatorial Indian Ocean in fall, and southern Bay of Bengal in winter, are primarily related to IOD forcing....
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00166/27749/25945.pdf

Salinity adjustments in the presence of temperature data assimilation
Provedor de dados: 5
Autores: Troccoli, Alberto; Balmaseda, Magdalena A.; Segschneider, Joachim; Vialard, Jerome; Anderson, David L. T.; Haines, Keith; Stockdale, Tim; Vitart, Frédéric; Fox, Alan D.
This paper is an evaluation of the role of salinity in the framework of temperature data assimilation in a global ocean model that is used to initialize seasonal climate forecasts. It is shown that the univariate assimilation of temperature profiles, without attempting to correct salinity, can induce first-order errors in the subsurface temperature and salinity fields. A recently developed scheme by A. Troccoli and K. Haines is used to improve the salinity field. In this scheme, salinity increments are derived from the observed temperature, by using the model temperature and salinity profiles, assuming that the temperature-salinity relationship in the model profiles is preserved. In addition, the temperature and salinity fields are matched below the...
Tipo: Text
Ano: 2002
URL: https://archimer.ifremer.fr/doc/00251/36272/34839.pdf

Strong Indian Ocean sea surface temperature signals associated with the Madden-Julian Oscillation in late 2007 and early 2008
Provedor de dados: 5
Autores: Vialard, Jerome; Foltz, G. R.; Mcphaden, M. J.; Duvel, J. P.; De Boyer Montegut, Clement.
A moored buoy was recently deployed at 8 degrees S, 67 degrees E in the shallow thermocline region of the Indian Ocean known as "Seychelles-Chagos Thermocline Ridge'' (SCTR), where the Madden Julian Oscillation (MJO) is associated with strong sea surface temperature (SST) variability. We use observations from this mooring to describe the oceanic signature of two MJOs between November 2007 and February 2008. The four-month average upper ocean heat balance was largely between heating by atmospheric forcing (2.0 +/- 0.3 degrees C/month) and a significant cooling by subsurface processes (-2.2 +/- 0.8 degrees C/month), consistent with climatological Ekman pumping in the region. The two MJO events resulted in strong intraseasonal SST variations (1.5 to 2 degrees...
Tipo: Text
Palavras-chave: Layer heat balance; Paific; Perturbations; Prediction; Fluxes.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00185/29636/27988.pdf

Ocean- Atmosphere Interactions During Cyclone Nargis
Provedor de dados: 5
Autores: Mcphaden, Mj; Foltz, Jr; Lee, T.; Murty, V. S. N.; Ravichandran, Muthalagu; Vecchi, Ga; Vialard, Jerome; Wiggert, J.d.; Yu, L.
Cyclone Nargis (Figure 1a) made landfall in Myanmar (formerly Burma) on 2 May 2008 with sustained winds of approximately 210 kilometers per hour, equivalent to a category 3–4 hurricane. In addition, Nargis brought approximately 600 millimeters of rain and a storm surge of 3–4 meters to the low-lying and densely populated Irrawaddy River delta. In its wake, the storm left an estimated 130,000 dead or missing and more than $10 billion in economic losses. It was the worst natural disaster to strike the Indian Ocean region since the 26 December 2004 tsunami and the worst recorded natural disaster ever to affect Myanmar.
Tipo: Text
Palavras-chave: IndOOS; Bay of Bengal; Cyclone Nargis.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00185/29643/28009.pdf

Intraseasonal variability of equatorial Indian Ocean zonal currents
Provedor de dados: 5
Autores: Sengupta, Debasis; Senan, Retish; Goswami, B. N.; Vialard, Jerome.
New satellite and in situ observations show large intraseasonal (10-60 day) variability of surface winds and upper- ocean current in the equatorial Indian Ocean, particularly in the east. An ocean model forced by the Quick Scatterometer (QuikSCAT) wind stress is used to study the dynamics of the intraseasonal zonal current. The model has realistic upper- ocean currents and thermocline depth variabilities on intraseasonal to interannual scales. The quality of the simulation is directly attributed to the accuracy of the wind forcing. At the equator, moderate westerly winds are punctuated by strong 10-40-day westerly wind bursts. The wind bursts force swift, intraseasonal (20-50 day) eastward equatorial jets in spring, summer, and fall. The zonal momentum...
Tipo: Text
Palavras-chave: Sea surface temperature; Interannual variability; Dynamics; Circulation; Pacific; Model; Winds; Thermodynamics; Oscillation; Transports.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00203/31421/29820.pdf

Intraseasonal response of the northern Indian Ocean coastal waveguide to the Madden-Julian Oscillation
Provedor de dados: 5
Autores: Vialard, Jerome; Shenoi, S. S. C.; Mccreary, J. P.; Shankar, D.; Durand, F.; Fernando, V.; Shetye, S. R.
A new observational record of upper-ocean currents at 15 degrees N on the western coast of India is dominated by intraseasonal (55 - 110 day) variations of alongshore currents, whereas sea level at the same location has a clear seasonal signal. These observations can be interpreted within the framework of linear wave theory. At 15 degrees N, the minimum period for planetary waves is similar to 90 day, meaning that intraseasonal energy is largely trapped at the coast in the form of poleward-propagating Kelvin waves, while lower-frequency signals associated with the annual cycle can radiate offshore as planetary waves. This dynamical difference results in a steeper offshore slope of sea level at intraseasonal timescale, and thus stronger geostrophic...
Tipo: Text
Palavras-chave: Variability; Dynamics; Circulation; Currents.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00185/29631/27993.pdf

Indo-Pacific Sea surface temperature perturbations associated with intraseasonal oscillations of tropical convection
Provedor de dados: 5
Autores: Duvel, Jean Philippe; Vialard, Jerome.
The intraseasonal variability (ISV; 20-90 days) of the SST is examined using 7 yr of data from the Tropical Rainfall Measuring Mission's (TRMM) Microwave Imager ( TMI). The ISV of the SST is larger in the summer hemisphere and in regions of relatively small ocean mixed layer depth (MLD). For these regions, the reddening of the SST spectrum in regard to the surface flux spectrum suggests that the ISV of the SST is mostly controlled by the integration of the local surface forcing by ocean mixed layer. However, the precise origin of large-scale organized perturbations of the SST also depends on region and season. Since the ISV of the convection is an intermittent phenomenon, the local mode analysis (LMA) technique is used to detect only the ensemble of...
Tipo: Text
Palavras-chave: Madden julian oscillation; Western indian ocean; Summer monsoon; Mixed layer; Warm pool; Variability; Fluxes; Model; Atmosphere; Bengal.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/00185/29638/27986.pdf

THE AEROCLIPPER A New Device to Explore Convective Systems and Cyclones
Provedor de dados: 5
Autores: Duvel, J. P.; Basdevant, C.; Bellenger, H.; Reverdin, Gilles; Vargas, A.; Vialard, Jerome.
Aeroclipper balloons, designed for taking measurements at the air-sea interface, can withstand extreme conditions encountered when they are drawn into tropical cyclones and then follow the eye trajectory.
Tipo: Text
Palavras-chave: Atmospheric research; Boundary layer; Surface fluxes; Arabian sea; Parameterization; Balloons; Ocean; Temperature; Enhancement; Evaporation.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00185/29635/27989.pdf

Physical control of interannual variations of the winter chlorophyll bloom in the northern Arabian Sea
Provedor de dados: 5
Autores: Keerthi, Madhavan Girijakumari; Lengaigne, Matthieu; Levy, Marina; Vialard, Jerome; Parvathi, Vallivattathillam; De Boyer Montegut, Clement; Ethe, Christian; Aumont, Olivier; Suresh, Iyyappan; Akhil, Valiya Parambil; Muraleedharan, Pillathu Moolayil.
The northern Arabian Sea hosts a winter chlorophyll bloom, triggered by convective overturning in response to cold and dry northeasterly monsoon winds. Previous studies of interannual variations of this bloom only relied on a couple of years of data and reached no consensus on the associated processes. The current study aims at identifying these processes using both similar to 10 years of observations (including remotely sensed chlorophyll data and physical parameters derived from Argo data) and a 20-year-long coupled biophysical ocean model simulation. Despite discrepancies in the estimated bloom amplitude, the six different remotely sensed chlorophyll products analysed in this study display a good phase agreement at seasonal and interannual timescales....
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00395/50625/51332.pdf

Ocean-Atmosphere Coupling in the Monsoon Intraseasonal Oscillation: A Simple Model Study
Provedor de dados: 5
Autores: Bellon, Gilles; Sobel, Adam H.; Vialard, Jerome.
A simple coupled model is used in a zonally symmetric aquaplanet configuration to investigate the effect of ocean-atmosphere coupling on the Asian monsoon intraseasonal oscillation. The model consists of a linear atmospheric model of intermediate complexity based on quasi-equilibrium theory coupled to a simple, linear model of the upper ocean. This model has one unstable eigenmode with a period in the 30-60-day range and a structure similar to the observed northward-propagating intraseasonal oscillation in the Bay of Bengal/west Pacific sector. The ocean-atmosphere coupling is shown to have little impact on either the growth rate or latitudinal structure of the atmospheric oscillation, but it reduces the oscillation's period by a quarter. At latitudes...
Tipo: Text
Palavras-chave: Madden julian oscillation; Tropical circulation model; Sea surface temperature; Asian summer monsoon; Convective perturbations; Walker circulation; Radiation budget; Indian ocean; Variability; Simulation.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00185/29637/27987.pdf

Supplement to RAMA The Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction
Provedor de dados: 5
Autores: Mcphaden, M. J.; Meyers, G.; Ando, K.; Masumoto, Y.; Murty, V. S. N.; Ravichandran, M.; Syamsudin, F.; Vialard, Jerome; Yu, L.; Yu, W.
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00185/29633/27991.pdf