[ncl-talk] Large differences in RH after using mixhum_ptrh and relhum

[Yang Yang]

Hi Marry:
I sent this ncl question to you because I am not sure if I have sent it to ncl-talk successfully. Pardon me if you have received it.


I have a few data of air T, P, and RH. I used mixhum_ptrh and relhum to recalculate RH. Both the RH should be the same, however, large differences were found.
Can you please tell me what is the reason? Thanks!
RegardsED
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 (todouble(p/100.), todouble(t), todouble(rh), 1)
rh1 = relhum (todouble(t),todouble(q),todouble(p))
print(rh1)
print(rh)
end
After run the codes:
 Copyright (C) 1995-2011 - All Rights Reserved
 University Corporation for Atmospheric Research
 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: rh1
Type: double
Total Size: 32 bytes
            4 values
Number of Dimensions: 1
Dimensions and sizes:   [4]
Coordinates:
(0)     2.960429399791643
(1)     2.796223142965527
(2)     94.57799164378163
(3)     150.3954363205561
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




    

  
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