[ncl-talk] large difference in relative humidity after using mixhum_ptrh and relhum

[Yang Yang]

 Dear Sir/Madam:
I have air T, pressure, and relative humidity(RH). I recalculate RH after using mixhum_ptrh and relhum. I found quite large differences in RH.
The codes are:;*******************************************
begin
;*******************************************
p = (/25132.156,27032.215,33876.102,39419.887/)  ;Pa
t = (/229.690,228.809,225.332,231.278/)         ;K
rh = (/2.008,1.884,62.117,103.124/)              ;%
q = mixhum_ptrh (p/100., t, rh, 1)
xxx = relhum (t,q,p)
print(xxx)
print(rh)
end
The results are: NCAR Command Language Version 6.0.0
 The use of this software is governed by a License Agreement.
 See http://www.ncl.ucar.edu/ for more details.
Variable: xxx
Type: float
Total Size: 16 bytes
            4 values
Number of Dimensions: 1
Dimensions and sizes:   [4]
Coordinates:
(0)     2.960429
(1)     2.796223
(2)     94.578
(3)     150.3954
Variable: rh
Type: float
Total Size: 16 bytes
            4 values
Number of Dimensions: 1
Dimensions and sizes:   [4]
Coordinates:
(0)     2.008
(1)     1.884
(2)     62.117
(3)     103.124

You can see the big differences in (2) and (3). Can you please tell me what is wrong? Thanks!
RegardsEd
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20150923/7c507e64/attachment.html