DATE2016-05-20 23:37:27
AUTHORSSaid Filahi (1,2), Yves Tramblay (3), Latifa Mouhir (1)
  1. Direction De La Meteorologie Nationale Casablanca (Morocco)
  2. Faculte Des Sciences Et Techniques Universite Hassan Ii Mohammedia (Morocco)
  3. Ird - Hydrosciences Montpellier (France)
ABSTRACTMorocco is located between the arid regions of the Western Sahara and the Mediterranean and Atlantic regions. Indices were computed based on a daily set of temperature and precipitation using a consistent approach recommended by the Expert Team on Climate Change Detection and Indices. Trends in these indices were calculated at 20 weather stations from 1970 to 2012. A large number of stations have significant trends and confirm an increase in temperature, showing increased warming during spring and summer seasons. The results also show a decrease in the number of cold days and nights and an increase in the number of warm days and nights. Increasing trends have been found in the absolute warmest and coldest temperatures of the year. A clear increase is detected for tropical nights and diurnal temperature range. Eight indices for precipitation were also analyzed. In general, the trends for the precipitation indices are much less significant than for temperature indices and show more mixed spatial patterns of change. Heavy precipitation events do not exhibit significant trends except at a few locations in the north and central parts of Morocco, with a general tendency towards drier conditions. In order to investigate the future climate characteristics, we compared four different regional climate model (RCM) simulations participating in EuroCORDEX (KNMI, IPSL and CLM) and MedCORDEX (CNRM) experiments. All simulations are available at a 12 km spatial resolution. The use of high-resolution models at 12km allows a good reproduction of orography. An evaluation of the ability of the different RCMs to reproduce climate indices of extremes indices in Morocco is first performed. To assess model performance, we use metrics such as Taylor diagrams to quantify the overall correspondence between simulated and observed fields. Overall, on most indices the four RCMs driven by reanalysis data are able to reproduce the spatial patterns and the inter-annual variability. The average projections provided by the four models are considered to provide an overview of projected changes in climate extremes indices defined by the ETCCDI. We present the results for two RCPs (4.5 and 8.5) and for two time period (2036-2065 and 2066-2095). Temperature is projected to increase in most parts of Morocco. For precipitation, most simulations agree on a decrease in precipitation totals, in particular in southern regions. For extreme precipitation, a much lower agreement between models is found