CAS FGOALS-f3-L large-ensemble simulations for the CMIP6 Polar
Amplification Model Intercomparison Project
Abstract
Large-ensemble simulations of the atmosphere-only time-slice experiments
for the Polar Amplification Model Intercomparison Project (PAMIP) were
carried out by the model group of the Chinese Academy of Sciences (CAS)
Flexible Global Ocean-Atmosphere-Land System (FGOALS-f3-L). Eight groups
of experiments forced by different combinations of the sea surface
temperature (SST) and sea ice concentration (SIC) for pre-industrial,
present-day and future conditions were performed and submitted. The
time-lag method was used to generate the 100 ensemble members, with each
member integrating from 1st April 2000 to
30th June 2001 and the first two months as the spin-up
period. The basic model responses of the surface air temperature (SAT)
and precipitation were documented. The results indicate that Arctic
amplification is mainly caused by Arctic SIC forcing changes. The SAT
responses to the Arctic SIC forcing alone show an obvious meridional
gradient over high latitudes, which is similar to the results from the
combined forcing of SST and SIC. However, the change in global
precipitation is dominated by the changes in the global SST rather than
SIC, partly because tropical precipitation is mainly driven by local SST
changes. The uncertainty of the model responses was also investigated
through the analysis of the large-ensemble members. The relative roles
of SST and SIC, together with their combined influence on Arctic
amplification, are also discussed. All these model datasets will
contribute to PAMIP multimodel analysis and improve the understanding of
polar amplification.