In the cookbooks/ Van-Keken-discontinue.PRm example, the upper and lower viscosity ratios are set

Dear teacher, I saw this calculation example in the ASPECT manual that the viscosity ratio of upper and lower layers of fluid can be set, but I don’t know how to achieve it. What changes should be made in the original calculation example to achieve the model effect in the manual
截图20220816152339

@xiyuan930809 This corresponds to pages 217 and following in the manual at https://www.math.clemson.edu/~heister/manual.pdf . I must admit that I don’t know whether the input file that corresponds to this picture was added to the source directories. The manual doesn’t reference a .prm file, and I don’t readily see where such a file would be in the cookbooks/ directory either. You might have to ask the authors of this section (Grant Euen, Tahiry Rajaonarison, and Shangxin Liu) for help.
Best
W.

thank you teacher