How MERRA2 or GEOS5 initializes WACCAM?

[yugong]

WACCAM has a top level at about 140km, while MERRA2 and GEOS5 only reach 75km.

I am wondering how people use MERRA2 and GEOS5 to initialize WACCAM.

Is there any other reanalysis which can reach 140km?

Any comment would be appreciated!!!

 

[yugong]

For example, If I want to use the condition in Merra2 on 2013-01-01 to initial a ten-day run, I will replace the data below 75km with MERRA2, but what about data on 75~140km?