WP4.1 : Exploiting CCI products in CMIP like experiments Recent progresses: Interaction with the science leader of the CCI-Sea ice consortium : an updated product will become available in 2016. At Météo-France we have performed AMIP-like simulations as part of sensitivity experiments to the L4 CCI-SST product (v1.0). These simulations are performed with Arpege-Climat v6 T127L91 (a version close to the one that will be used for CMIP6) and they consist in 5-member ensemble simulations with either the “recommended” AMIP forcing or a forcing where only SST is substituted with the CCI product (same sea ice). The covered period is1992-2010.

Seal level pressure in DJF averaged over the period 1992-2010 (hPa)

January 1992 (5 members per ensemble) Seal level pressure difference between the ensemble averaged of CCI and AMIP simulations (Pa) January 1992 (5 members per ensemble)

10% significance level (t-test) in January 1992 CCI-AMIP (5 members)

WP4.1 : Exploiting CCI products in CMIP like experiments Some preliminary conclusions: No systematic impact of the SST differences on the performance of the model for the simulation of the seasonal mean sea level pressure (comparison with ERA-Interim climatology). No significant impact on the simulated sea level pressure when considering the 5-member ensemble simulations over a specific month (t-test).

WP4.1 : Exploiting CCI products in CMIP like experiments Future plans: Complete and analyse the sensitivity experiments to SST-CCI. Perform new CMIP6 AMIP-like simulations with Arpege-Climat low and high resolution with CCI SST and sea-ice forcings : need for sea ice data. Analyse model simulations and compare results with those of the simulations performed by CMUG partners (similar simulations planned at LMD and SMHI this year).

Seal surface temperature difference between CCI and AMIP in January 1992 (°C) CCI-AMIP (5 members)