Analyse rétrospective de l'évolution climatique récente en Afrique du Nord-Ouest

Abstract

The following study aims to evaluate and understand the recent climatic trends and significant stationary breaks in Morocco, Mauritania, Senegal and the nearest ocean. It is therefore necessary to statistically analyze the annual evolution of the air temperature, the atmospheric pressure at sea level, the rainfall as well as the aeolian dynamic.The analyses bear out the climatic turning point since the 1970's, which does not lead to homogenous trends. Thus, the Atlantic Ocean between latitudes 40°N and 14°N but also Morocco and Northern Senegal are getting warmer. However, Southeastern Mauritania seems to have a tendency to cooling. Moreover, the strengthening of sea level pressure is followed by a shift of the harmattan trade wind and by a strengthening of its eastern component.Paleoclimatic data highlight the difficulty to find significant similarities with the last major climatic changes (Holocene Climatic Optimum and the Last Glacial Maximum). The littoral and continental warming as well as the wind reversal remembers the early Holocene. However, increase rainfalls in recent years remain less significant. Besides, the strengthening of sea level pressure reveals a strengthening of the subtropical high, but also a weakening of the Saharan low.The climatic signal is therefore very difficult to understand focusing to his spatiotemporal measurement. Several studies concerning other climatic parameters or past analogues are still required.

Keywords

• climate change
• rainfall
• breaks
• temperatures
• sea level pressure
• trade winds