[Wrf-users] ungrib.exe float point precision problem?

[Grus Weir]

Hi All,

With January 2000 default case data

http://www.mmm.ucar.edu/wrf_tmp/WRF_OnLineTutorial/SOURCE_DATA/JAN00.tar.gz
       & WPS 3.0.1 & PGI 7.0-2 & RHEL4U4 (linux 2.6.9-42.ELsmp)

       I found my ungrib.exe results show some differences to the mmm
website
       http://www.mmm.ucar.edu/wrf/OnLineTutorial/CASES/JAN00/ungrib.htm

       diff my.ungrib_data.log  mmm.ungrib_data.log shows
-----------------------------------------
264,265c264
<  250.0  X        X        X  Begin rrpr
<                 X
X

---
>  250.0  X        X        X                 X
X

489,493c488,492
< Deleting file:  ./PFILE:2000-01-24_12
< Deleting file:  ./PFILE:2000-01-24_18
< Deleting file:  ./PFILE:2000-01-25_00
< Deleting file:  ./PFILE:2000-01-25_06
< Deleting file:  ./PFILE:2000-01-25_12
---
>           Deleting file:  ./PFILE:2000-01-24_12
>           Deleting file:  ./PFILE:2000-01-24_18
>           Deleting file:  ./PFILE:2000-01-25_00
>           Deleting file:  ./PFILE:2000-01-25_06
>           Deleting file:  ./PFILE:2000-01-25_12
-----------------------------------------

And diff my.rd_int.log  mmm.rd_int.log shows
-----------------------------------------
79c79
< DATA(1,1)=92.594933
---
> DATA(1,1)=92.594925
98c98
< FIELD = SNOW
---
> FIELD = SNOW
367c367
< DATA(1,1)=97.757370
---
> DATA(1,1)=97.505646
847c847
< DATA(1,1)=74.951317
---
> DATA(1,1)=74.687019
1327c1327
< DATA(1,1)=20.805838
---
> DATA(1,1)=20.724819
1407c1407
< DATA(1,1)=23.695192
---
> DATA(1,1)=23.602095
1487c1487
< DATA(1,1)=53.552029
---
> DATA(1,1)=53.453606
1567c1567
< DATA(1,1)=74.859764
---
> DATA(1,1)=74.764519
1647c1647
< DATA(1,1)=70.810417
---
> DATA(1,1)=70.666641
2384a2385
-----------------------------------------

Could this be a float point precision problem or just my fault somewhere?

Thank you all.

--
Grus
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