Bacci, Maurizio

Biasutti, Michela

Giannini, Alessandra

English

Michela Biasutti

Maurizio Bacci

Alessandra Giannini

PORTO@iris (Publications Open Repository TOrino - Politecnico di Torino)

04 August 2020POLITECNICO DI TORINORepository ISTITUZIONALEMonsoon Onset in West Africa: Regional Projections and Local Variability / Biasutti, Michela; Bacci, Maurizio; Giannini,Alessandra. - ELETTRONICO. - (2018). ((Intervento presentato al convegno AGU Fall meeting 2018 tenutosi aWashington D.C. (USA) nel 10-14 Dicembre 2018.OriginalMonsoon Onset in West Africa: Regional Projections and Local VariabilityPublisher:PublishedDOI:Terms of use:openAccessPublisher copyright(Article begins on next page)This article is made available under terms and conditions as specified in the  corresponding bibliographic description inthe repositoryAvailability:This version is available at: 11583/2721283 since: 2018-12-19T15:15:53ZAGU American Geophysical Union19/12/2018 AGU Fall Meeting 2018https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/362407 1/1A44C-06: Monsoon Onset in West Africa: Regional Projections and LocalVariability (Invited)Thursday, 13 December 201817:15 - 17:30Walter E Washington Convention Center - 144A-CWhile total rainfall and mean temperature are the main drivers of productivity for grains cultivated in the Sudanese andSahelian regions of West Africa–with higher rainfall and cooler temperatures correlating with higher yield–the onsettime of the rainy season provides a binary switch: if steady rains delay too long, plantings fail and the entire season islost. Previous work has indicated that global warming is projected to reduce early rainfall in parts of West Africa andthat rainfall might fall in more episodic downbursts. Both changes have the potential to increase the probability of rainyseason failures.Motivated by the need to provide regional farmers and policy makers with a reliable risk assessment for the spatialscale of their interest, we investigate the sources of uncertainty in the projected changes in rainy season failures atlocal and regional scales. First, we address the effect of temperature and evapotranspiration in exacerbating the effectof dry spells on crops and show that precipitation-based definition of agricultural monsoon onset remain relevant forfuture climate. Second, we use high-resolution observational datasets of daily rainfall to investigate the spatial scale ofvariability of monsoon onset when the latter is defined based on agricultural rainfall needs or on dynamics of the large-scale monsoon system; we then use the current relationship in a probabilistic framework linking local changes toregional predictions. Finally, we use global coupled models to investigate uncertainty in regional projections: the NCARLarge Ensemble (LENS) estimates the uncertainty that comes from natural variability and the CMIP5 ensembleestimates the role of structural (model) uncertainty. The source of model disagreement is discussed in terms oftheories of monsoon dynamics.AuthorsMichela BiasuttiMaurizio BacciAlessandra GianniniColumbia University of NewYorkC.N.R. - IBIMETPolitecnico di TorinoInternational ResearchInstitute for Climate andSociety, Columbia UniversityFind SimilarView Related EventsDay: Thursday, 13 December 2018

Monsoon Onset in West Africa: Regional Projections and Local Variability

https://iris.polito.it/retrieve/handle/11583/2721283/222715/AGU%20Fall%20Meeting%202018.pdf

Monsoon Onset in West Africa: Regional Projections and Local Variability

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