Publications des scientifiques de l'IRD

Cretat J., Braconnot P., Terray Pascal, Marti O., Falasca F. (2020). Mid-Holocene to present-day evolution of the Indian monsoon in transient global simulations. Climate Dynamics, 55 (9-10), 2761-2784. ISSN 0930-7575.

Titre du document
Mid-Holocene to present-day evolution of the Indian monsoon in transient global simulations
Année de publication
2020
Type de document
Article référencé dans le Web of Science WOS:000559366500002
Auteurs
Cretat J., Braconnot P., Terray Pascal, Marti O., Falasca F.
Source
Climate Dynamics, 2020, 55 (9-10), 2761-2784 ISSN 0930-7575
The low-frequency evolution of Indian rainfall mean-state and associated interannual-to-decadal variability is discussed for the last 6000 years from a multi-configuration ensemble of fully coupled global transient simulations. This period is marked by a shift of Indian Summer Monsoon Rainfall (ISMR) distribution towards drier conditions, including extremes, and a contraction of the rainy season. The drying is larger in simulations with higher horizontal resolution of the atmosphere and revised land surface hydrology. Vegetation-climate interactions and the way runoff is routed to ocean modulate the timing of the monsoon onset but have negligible effects on the evolution of seasonal rainfall amounts in our modeling framework in which carbon cycling is always active. This drying trend is accompanied by changes in ISMR interannual-to-decadal variability decreasing over north and south India but increasing over central India (20 degrees-25 degrees N). The ISMR interannual-to-decadal variability is decomposed into six physically consistent regimes using a clustering technique to further characterize its changes and associated teleconnections. From 6 to 3.8 kyrbp, the century-to-century modulations in the frequency of occurrence associated to the regimes are asynchronous between the simulations. Orbitally-driven trends can only be detected for two regimes over the whole 6-0 kyrbpperiod. These two regimes reflect increased influence of ENSO on both ISMR and Indian Ocean Dipole as the inter-hemispheric energy gradient weakens. Severe long-term droughts are also shown to be a combination of long-term drying and internally generated low-frequency modulations of the interannual-to-decadal variability.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du milieu [021] ; Hydrologie [062]
Description Géographique
INDE ; OCEAN INDIEN
Localisation
Fonds IRD [F B010079500]
Identifiant IRD
fdi:010079500
Contact