Decadal variability of rainfall extreme events in Senegal over the 20th century:observations and modelling

Aissatou Badji,Elsa Mohino,Amadou Thierno Gaye,Juliette Mignot,Moussa Diakhaté

doi:10.5194/egusphere-egu22-8335

Abstract

&lt;p&gt;The intraseasonal characteristics of rainfall are crucial in monsoon regions, in particular for&lt;br&gt;agriculture. Crop yields indeed depend on the rainfall seasonal amount, but also on other&lt;br&gt;intraseasonal characteristics such as the onset of the rainy season or the distribution of rainy days.&lt;br&gt;In the Sahel region, while the average amount of seasonal rainfall has been shown to be marked by&lt;br&gt;strong decadal variability over the 20 th century, the modulations of intraseasonal rainfall&lt;br&gt;characteristics has received less attention in the literature so far. In this study, we show that the&lt;br&gt;frequency and intensity of intraseasonal rainfall events in Senegal exhibit a marked decadal&lt;br&gt;variability over the 1918-2000 period, similar to that of mean seasonal rainfall in the Sahel during&lt;br&gt;the 20 th century, and in phase with the Atlantic Multidecadal Variability (AMV). The representation&lt;br&gt;of the decadal modulation of these rainfall indices is further investigated using the atmospheric&lt;br&gt;component of the IPSL-CM6 model forced by the historically observed SST. Preliminary results&lt;br&gt;show that the model represents fairly well the observed decadal modulation of these extreme events.&lt;br&gt;Thus, the model simulations allow an in-depth understanding of the associated mechanism.&lt;/p&gt;

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