Lead : V MORON (CEREGE) & P CAMBERLIN (CRC)

The variability of the low-level cloud cover in both time and space as well as its control by atmospheric dynamics and sea surface temperatures will be analysed using multi-year historical data, reanalyses and dedicated numerical simulations with Meso-NH model.
So far there are hardly any studies of (i) the timing of the low-level cloud season (onset and end), (ii) its intra-seasonal variability (i.e. phases with reduced low-level cloud cover) and interannual variations, and (iii) its eastward extent.

From a mean seasonal cycle perspective, the onset/end of the LLCC season coincides with several regional atmospheric and oceanic changes. The extent to which variations of these features affect the LLCC is not known. In terms of intra-seasonal variability, the potential impacts of equatorial waves, or variations in the monsoon flow remain unknown. In terms of interannual variability, whether the relationship between the stratus over the SE Atlantic and low SSTs holds for the inland extension of LLC must be clarified.

The main expected results are an identification of the main controls on the LLCC intraseasonal and interannual variability as well as an assessment of LLCC representation in coupled and atmosphere-only CMIP6 climate simulations.

Mis à jour le 31 January 2020