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19990414: pwater

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  • Subject: 19990414: pwater
  • Date: Mon, 19 Apr 1999 09:48:26 -0600
Calculation of PWTR is done in $GEMPAKHOME/src/gemlib/pc/pcpwtr.f.

Looking at your data below- aside from the fact that there are no column
lables to tell me what the values are, I see at least 2 strange things.
1) The first level(815mb) you show is from a different time (and is
above the presumable surface level of 838mb.

2) You have 2 entries for 303 mb. You probably want to check how you
handle duplicate levels with dp=0 in your calculations.

When using GEMPAK SN programs to calculate PWAT or PWTR, be aware that
PWTR allows you to calculate precipitable water in any layer- not just
the entire sounding- so you would need to specify the entire atmosphere.

Steve Chiswell
Unidata User SUpport



On Wed, 14 Apr 1999, Unidata Support wrote:

> 
> ------- Forwarded Message
> 
> >To: address@hidden
> >From: jasbir singh naul <address@hidden>
> >Subject: Gempak help!
> >Organization: .
> >Keywords: 199904142022.OAA01008
> 
> Hi!
> 
>   This is naul , and i am Atmospheric Sciences 
> student at UIUC . I am working on a class project 
> and i wanted to use gempak souding data to restrieve
> Precipitable water from remote sensing . I  tried 
> to use gempak soundings and the Precipitable water 
> from  it to verify the results from remote sensing 
> equations and i am not sure as to how gempak 
> computes Precipitable water , caus my  own calculations 
> show an error of appx 0.3 mm  in all soundings that i 
> generated using gempak . I would  really appreciate if you 
> can explain me as to how gempak computes this value .
> Our Calc of ppt water for the below sounding is - 3.80206
> 
> The output file that i generated from gempak looks like this ..
> with ppt water = 3.5 mm .
> 
> ABQ 95010300     815.65  1829.00     2.94     1.33      .29
> ABQ 95010100     838.00  1620.00     8.80     2.67      .00
> ABQ 95010100    1000.00   146.00 -9999.00 -9999.00 -9999.00
> ABQ 95010100     925.00   799.00 -9999.00 -9999.00 -9999.00
> ABQ 95010100     850.00  1497.00 -9999.00 -9999.00 -9999.00
> ABQ 95010100     835.00  1649.41     7.00     1.56      .06
> ABQ 95010100     816.42  1829.00     5.33     1.56      .36
> ABQ 95010100     785.81  2134.00     2.49     1.56      .85
> ABQ 95010100     756.45  2438.00     -.34     1.56     1.31
> ABQ 95010100     728.09  2743.00    -3.18     1.56     1.77
> ABQ 95010100     700.00  3057.00    -6.10     1.56     2.21
> ABQ 95010100     680.00  3283.68    -6.50      .59     2.43
> ABQ 95010100     648.11  3658.00    -7.50      .48     2.61
> ABQ 95010100     642.00  3731.85    -7.70      .46     2.64
> ABQ 95010100     598.86  4267.00   -10.16      .41     2.83
> ABQ 95010100     553.21  4877.00   -12.97      .35     3.01
> ABQ 95010100     548.00  4949.84   -13.30      .35     3.03
> ABQ 95010100     500.00  5640.00   -18.90      .24     3.17
> ABQ 95010100     489.71  5791.00   -20.13      .23     3.20
> ABQ 95010100     469.56  6096.00   -22.62      .20     3.24
> ABQ 95010100     400.00  7260.00   -32.10      .12     3.35
> ABQ 95010100     379.41  7620.00   -35.11      .11     3.38
> ABQ 95010100     303.37  9144.00   -47.86      .06     3.44
> ABQ 95010100     303.37  9144.00   -47.86      .06     3.44
> ABQ 95010100     260.00 10141.72   -55.90      .03     3.46
> ABQ 95010100     250.00 10390.00   -56.10      .03     3.46
> ABQ 95010100     239.29 10668.00   -56.45      .03     3.46
> ABQ 95010100     217.38 11278.00   -57.21      .02     3.47
> ABQ 95010100     215.00 11347.77   -57.30      .02     3.47
> ABQ 95010100     200.00 11810.00   -53.30      .04     3.48
> ABQ 95010100     196.00 11939.61   -52.50      .04     3.48
> ABQ 95010100     168.00 12932.61   -51.50      .05     3.49
> ABQ 95010100     150.00 13660.00   -54.10      .04     3.50
> 
> 
>  
> 
> Hard work is the only investment that never fails . 
> 
> _____________________________________________________________
> 
> 
> Naul Jasbir Singh .  ( MS Atmospheric Sciences ) 
> 
> 
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> ------- End of Forwarded Message
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