Namelist parameters are used to control the reading of corresponding BUFR files into WRFDA. For instance, USE_AMSUAOBS, USE_AMSUBOBS, USE_HIRS3OBS, USE_HIRS4OBS, USE_MHSOBS, USE_AIRSOBS, USE_EOS_AMSUAOBS, USE_SSMISOBS, USE_ATMSOBS, USE_IASIOBS, and USE_SEVIRIOBS control whether or not the respective file is read. These are logical parameters that are assigned to .FALSE. by default; therefore they must be set to .TRUE. to read the respective observation file. Also note that these parameters only control whether the data is read, not whether the data included in the files is to be assimilated. This is controlled by other namelist parameters explained in the next section.