Re: [ferret_users] vertical levels shifts after apply @DIN

["Ansley C. Manke" <ansley.b.manke@xxxxxxxx>]

Hi,
Sometimes defining a very simple variable and applying the 
transformation to it is helpful. Do the integration operations on a 
variable like this
 
 let constant_var = 1 + 0*test
 
to see if it helps you understand what may be happening. Also looking 
at the indefinite integral of both your original variables and this 
simple one might be useful.
 
As you may know, transformations such as the definite integral always 
take the grid-cell sizes into account. This is described in detail 
here, "General Information about Transformations",
../../documentation/users-guide/variables-xpressions/XPRESSIONS.html#GeneralInfo
 
I wonder if there is something particular in the definition of the grid 
cells in Z that makes the computations inconsistent.
 
Ansley
 
On 6/10/2020 6:48 PM, Xiaoyu Bai wrote:
> Dearferreters,
>  
> I have 17 levels of v-wind data.
>  
> list/j=82/l=6 va_4CO2_MPAS_monthly_ave
>       VARIABLE : VA_4CO2_MPAS_MONTHLY[X=@AVE]
>       SUBSET  : 17 points (Z (Pa))
>       LONGITUDE: 1.2W(-1.2) to 1.2W
>       LATITUDE : 63.5N
>       TIME   : 16-JUN 00:00 NOLEAP
> 1000   / 1: -0.0394
> 2000   / 2: -0.0227
> 3000   / 3: -0.0209
> 5000   / 4: -0.0252
> 7000   / 5: -0.0219
> 10000  / 6: -0.0125
> 15000  / 7: 0.0496
> 20000  / 8: 0.1512
> 25000  / 9: 0.1367
> 30000  / 10: 0.0665
> 40000  / 11: 0.0014
> 50000  / 12: -0.0065
> 60000  / 13: -0.0048
> 70000  / 14: -0.0037
> 85000  / 15: -0.0020
> 92500  / 16: 0.0645
> 100000  / 17: 0.2435
> I corrected the noise of it first and then applied@DIN for the 
> vertical levels.
> list/j=82/l=6 test
>       VARIABLE : VA_4CO2_MPAS_MONTHLY_AVE-0.03951
>       SUBSET  : 17 points (Z (Pa))
>       LONGITUDE: 1.2W(-1.2) to 1.2W
>       LATITUDE : 63.5N
>       TIME   : 16-JUN 00:00 NOLEAP
> 1000   / 1: -0.0789
> 2000   / 2: -0.0622
> 3000   / 3: -0.0605
> 5000   / 4: -0.0647
> 7000   / 5: -0.0614
> 10000  / 6: -0.0520
> 15000  / 7: 0.0101
> 20000  / 8: 0.1117
> 25000  / 9: 0.0971
> 30000  / 10: 0.0270
> 40000  / 11: -0.0381
> 50000  / 12: -0.0460
> 60000  / 13: -0.0443
> 70000  / 14: -0.0433
> 85000  / 15: -0.0415
> 92500  / 16: 0.0250
> 100000  / 17: 0.2040
> When I listed out the results I found that the vertical levels shifted 
> 50 Pa comparing to the original data:
> list/j=82/l=6 test_re, test_up, test_down2
>       LONGITUDE: 1.2W(-1.2) to 1.2W
>       LATITUDE: 63.5N
>       TIME: 16-JUN 00:00 NOLEAP
> Column 1: TEST_RE[Z=500:103750] is TEST[K=1:17@DIN]/9.8
> Column 2: TEST_UP[Z=500:55000] is TEST[K=1:12@DIN]/9.8
> Column 3: TEST_DOWN2[Z=55000:103750] is TEST[K=13:17@DIN]/9.8
>      TEST_RE TEST_UP TEST_DOWN2
> I / *:   0.04177 -27.18  27.22
> Is there a reason for it?
>  
> Thank you in advance.
> --
> Xiaoyu
 
--
Ansley Manke
Science Data Integration Group
NOAA Pacific Marine Environmental Laboratory
7600 Sand Point Way NE
Seattle WA 98115
 
I am currently teleworking and am available Tue-Wed-Thu.