Time-varying missing value in REMSS-PRW

[lee1043]

Time varying missing value (blue in above screen capture) is set to -500, without described in attributions.

ncdump -h /p/user_pub/PCMDIobs/obs4MIPs/RSS/REMSS-PRW-v07r01/mon/prw/gn/v20220201/prw_mon_REMSS-PRW-v07r01_PCMDI_gn_198801-201812.nc

Below is capture of prw part from the above command.

	float prw(time, lat, lon) ;
		prw:standard_name = "atmosphere_mass_content_of_water_vapor" ;
		prw:long_name = "Water Vapor Path" ;
		prw:comment = "vertically integrated through the atmospheric column" ;
		prw:units = "kg m-2" ;
		prw:cell_methods = "area: time: mean" ;
		prw:cell_measures = "area: areacella" ;
		prw:history = "2022-02-01T17:40:22Z altered by CMOR: replaced missing value flag (-999) and corresponding data with standard missing value (1e+20)." ;
		prw:missing_value = 1.e+20f ;
		prw:_FillValue = 1.e+20f ;