Scheduled Downtime
On Tuesday 24 October 2023 @ 5pm MT the forums will be in read only mode in preparation for the downtime. On Wednesday 25 October 2023 @ 5am MT, this website will be down for maintenance and expected to return online later in the morning.
Normal Operations
The forums are back online with normal operations. If you notice any issues or errors related to the forums, please reach out to help@ucar.edu

CMIP5 CCSM4 raster levels

Hello, I am working with the CMIP5 CCSM4 AMIP and LGM model data at monthly intervals. When the data is loaded into R as a raster brick, I get warnings stating that there are 17 levels within the raster layers, however, when using GDALUTILS GDALinfo, the metadata does not identify what the levels are. I have used tsa, pr, hurs, and a few other variables from the models and they all have 17 levels with no information. I know the layers are all the different time intervals, but I need to know the levels for converting the netcdf files. Does anyone know what these levels are representing for this particular model/ experiments? Let me know if you need anymore information. Thank you!
 

strandwg

Moderator
Staff member
I'm not quite sure why you're seeing only 17 "levels"; can you tell me a specific filename of the data you're looking at? 
 
One of the files I am working with is this: hurs_Amon_CCSM4_lgm_r1i1p1_180001-190012.nc. I can see ~1000 year layers when I load the thing, but when I brick it, it gives a warning thatI have 17 levels. I'm assuming that levels and layers are not the same thing here. Out of 56 files/11 of them give me this error. 
 

strandwg

Moderator
Staff member

I don't know the software tools you're using, but I suspect they aren't reading the files you have correctly. I have no idea what the software you're using is reporting or the meaning of the message.

hurs_Amon_CCSM4_lgm_r1i1p1_180001-190012.nc is comprised of 101 years' worth of monthly data (1212 months) from model year 1800 through model year 1900. I examined it using the standard netCDF utility 'ncdump' and there is no "17" anything in that file.

 
I have been loading the files in R using the "raster" package. I just use brick(filename) and it converts the file into a viewable raster. I believe that you are probably right that it is not reading the file correctly. I can see all of the different years and monthly averages. I still get the warning about the levels, but when I view 2 separate levels in the raster they are identical.  Thank you for you help!
 
Top