Dear ferret users,
I have started using ferret recently. I am facing couple of problem in using the software.
1) I have data is sigma coordiante with the variables in listed below. I
want to present my result (varaibles) in pressure level. for that purpose i have used following commandyes? use ATMpentd_91AVG.CDF
yes? define axis/Z=1000:0:25/unit=millibar/depth plev
> yes? let ptop=100 ! as my model top is 100mb
> yes? let pk=tk*0.0+z*(ps-ptop)+ptop ! i don't know why one has to put tk*0.0 in the equation because it's value is zero anyway; there is blank display if i omit tk*0.0 in the equation
> yes? let h_on_p =ZAXREPLACE(hgt,pk,z[gz=plev])
> yes? shade/l=1 h_on_p[z=500] ! gives the hgt( geo. pot. ht.) for 500 mb level
> yes? let rh_on_p =ZAXREPLACE(rh,pk,z[gz=plev]) ! similarly for other variable say rh
> yes? list/l=1 rh_on_p[z=850] ! list the rh( rel. humidity) for 500 mb level
The output with this set of commands seems to be ok but i am not certain. can somebod verify if this is the correct set of command to get output in pressure levels with original file in sigma coordiante.
2 Next I want to get arial average of a number of neighbouring grids (however they don't form a rectangle) for example say grids having (I,J) values (37,36),(37,37),(38,35),(38,36). what will be the best method?
thanking in advance for your help
jagadish
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yes? show data
currently SET data sets:
1> ./ATMpentd_91AVG.CDF (default)
name title I J K L
TK Temperature 1:63 1:66 1:23 1:30
RH Relative Humidity 1:63 1:66 1:23 1:30
HGT Geopotentail Height 1:63 1:66 1:23 1:30
.......etc