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How TREFHT (surface air temperature at reference height) is calculated ???

C

cam_iitd10@gmail_com

Member
Hi eaton.

i have successfully performed test run of CAM4 for different resolutions and dynamical core.
now i am analysing output history file of one model day run named camrun.cam2.rh0.0000-01-02-00000.nc using the Climate data analysis tool (CDAT). on plotting for the variable TREFHT (surface air temperature at reference height) i found the MAX,MIN and AVERAGE values are in the range 11000-15000 K.
how it can be??????:confused:

i read the the documentation and searched but i am not able to find how this variable has been calculated and coded. so i request you to please make my doubt clear, get the necessary calculation to understand.

Thank you sir.


Ram
Indian Institute of Technology Delhi.
New Delhi INDIA
 
E

eaton

CSEG and Liaisons
The file camrun.cam2.rh0.0000-01-02-00000.nc is a restart file for the history buffers which are used to accumulate the sums needed to compute time averages. So the large numbers you are seeing are the sums of TREFHT over the number of timesteps in a day, hence large numbers.

If you want to look at the results of the model for just a day you need to change the output frequency of the primary history file to be daily. By default it is monthly output which is why you aren't seeing a history file at the end of a one day integration. see the documentation for the namelist variable nhtfrq here:

http://www.cesm.ucar.edu/cgi-bin/eaton/namelist/nldef2html-cam5
 
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