Daily Characteristics of West African Monsoon Rainfall and Impacts of Fine-Scale Surface Conditions in the CORDEX Regional Climate Models
Abstract
We analyze and intercompare the performance of a set of ten Regional Climate Models (RCMs) along with their ensemble in simulating daily precipitation characteristics during the West African Monsoon period (June-September). The experiments are conducted within the framework of the Coordinated Downscaling Experiments (CORDEX) for the African domain. We find that the RCMs exhibit substantial differences that are associated with a wide range of estimates of higher order statistics, such as intensity, frequency, and extremes. For instance, several RCMs accurately predict the number of wet days, however they overestimate precipitation intensity in oceanic regions adjacent to the Guinea Highlands due to a greater number of heavy events. In contrast, other models exhibit a larger frequency of wet days but much lower precipitation intensity over West Africa due to the occurrence of less heavy rainfall events. This indicates the existence of large uncertainties related to the simulation of daily rainfall characteristics in West Africa. The ensemble mean of the indexes improves the individual RCM members only in terms of the frequency and 95th percentile, thus highlighting the limitations inherent to the use of multi-model approach to quantify the precipitation response to climate change over West Africa at the daily time-scale.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.A32E..03P
- Keywords:
-
- 1817 HYDROLOGY / Extreme events;
- 3305 ATMOSPHERIC PROCESSES / Climate change and variability;
- 3354 ATMOSPHERIC PROCESSES / Precipitation;
- 3355 ATMOSPHERIC PROCESSES / Regional modeling