Hi Ashraf,Bi and RegCM3 users,

  Now I am very interested in the simulation of dust aerosol over East Asia with RegCM3 model. I have got much information about dust simulation from reading some papers (e.g. “Implementation and testing of a desert dust module in a regional climate model”,ACP,2006). Also, there are some questions which I want to ask you for help.

  In the paper, I know the parameter of fc is the fraction of aerosol assumed to be incorporated in cloud droplets. The fc of 4 transport bin sizes are as follows: 0.3, 0.15, 0.05, 0.05. Is fc the same to chtrsol which is in regcm.in file. If so, why they differ greatly from regcm.in_4dust file which are set to 0.5 0.6 0.7 0.8?

  As far as I know, the present version of RegCM3 model doesn’t include the indirect effect of aerosol. My thought is as follows: the experiment (chtrsol are set to 0) is as the sensitivity experiment, and the experiment (chtrsol don’t change)is as the control experiment, can the difference (control-sensitivity) be thought to indirect effect of aerosol?

  I will appreciate any help.

Best regards,

Su