[ncl-talk] (I)PV units?

[Kacie Shourd]

Hi all,

I am encountering some problems with my potential vorticity (PV) and subsequent isentropic potential vorticity calculations (IPV). The patterns I am getting look right, but the magnitude of the values does not make sense. I assume pot_vort_isobaric() function outputs in raw units rather than PVUs?

I have checked my units/script over and over and over again, and cannot figure out why the values are a few orders of magnitude off. It seems as though maybe my pressure values are being input into the equations wrong (or some other variable is). The patterns of PV make sense for the event, but the magnitude is most certainly wrong.

Any insight into what I am doing wrong or any other reasons the calculated PV values are coming out  really large. Scripts, output, and necessary files to run script can be found here: ftp://pubfiles.dri.edu/pub/kshourd/nclTalkIPVHelp/ , and variable summaries are as follows:

---
Variable: tkReGr
Type: float
Total Size: 32485452 bytes
            8121363 values
Number of Dimensions: 3
Dimensions and sizes:   [lv_ISBL3 | 29] x [lat | 337] x [lon | 831]
Coordinates:
            lv_ISBL3: [100..1000]
            lat: [   1..  85]
            lon: [ 150..358.5]
Number Of Attributes: 15
  sub_center :  The North American Regional Reanalysis (NARR) Project
  center :      US National Weather Service - NCEP (WMC)
  long_name :   Temperature
  units :       K
  _FillValue :  1e+20
  level_indicator :     100
  grid_number : 221
  parameter_table_version :     131
  parameter_number :    11
  model :       North American Regional Reanalysis (NARR)
  forecast_time :       0
  forecast_time_units : hours
  initial_time :        09/26/2010 (18:00)
  remap :       remapped via ESMF_regrid_with_weights: Bilinear
  missing_value :       1e+20

---
Variable: uN
Type: float
Total Size: 32485452 bytes
            8121363 values
Number of Dimensions: 3
Dimensions and sizes:   [lv_ISBL3 | 29] x [lat | 337] x [lon | 831]
Coordinates:
            lv_ISBL3: [100..1000]
            lat: [   1..  85]
            lon: [ 150..358.5]
Number Of Attributes: 15
  sub_center :  The North American Regional Reanalysis (NARR) Project
  center :      US National Weather Service - NCEP (WMC)
  long_name :   u-component of wind
  units :       m/s
  _FillValue :  1e+20
  level_indicator :     100
  grid_number : 221
  parameter_table_version :     131
  parameter_number :    33
  model :       North American Regional Reanalysis (NARR)
  forecast_time :       0
  forecast_time_units : hours
  initial_time :        09/26/2010 (18:00)
  remap :       remapped via ESMF_regrid_with_weights: Bilinear
  missing_value :       1e+20

---
Variable: vN
Type: float
Total Size: 32485452 bytes
            8121363 values
Number of Dimensions: 3
Dimensions and sizes:   [lv_ISBL3 | 29] x [lat | 337] x [lon | 831]
Coordinates:
            lv_ISBL3: [100..1000]
            lat: [   1..  85]
            lon: [ 150..358.5]
Number Of Attributes: 15
  sub_center :  The North American Regional Reanalysis (NARR) Project
  center :      US National Weather Service - NCEP (WMC)
  long_name :   v-component of wind
  units :       m/s
  _FillValue :  1e+20
  level_indicator :     100
  grid_number : 221
  parameter_table_version :     131
  parameter_number :    34
  model :       North American Regional Reanalysis (NARR)
  forecast_time :       0
  forecast_time_units : hours
  initial_time :        09/26/2010 (18:00)
  remap :       remapped via ESMF_regrid_with_weights: Bilinear
  missing_value :       1e+20

---
Variable: p
Type: integer
Total Size: 116 bytes
            29 values
Number of Dimensions: 1
Dimensions and sizes:   [lv_ISBL3 | 29]
Coordinates:
            lv_ISBL3: [100..1000]
Number Of Attributes: 2
  long_name :   isobaric level
  units :       Pa

---
Variable: thetaN
Type: float
Total Size: 32485452 bytes
            8121363 values
Number of Dimensions: 3
Dimensions and sizes:   [lv_ISBL3 | 29] x [lat | 337] x [lon | 831]
Coordinates:
            lv_ISBL3: [100..1000]
            lat: [   1..  85]
            lon: [ 150..358.5]
Number Of Attributes: 5
  _FillValue :  1e+20
  long_name :   potential temperature
  units :       K
  remap :       remapped via ESMF_regrid_with_weights: Bilinear
  missing_value :       1e+20

--- (FROM tkReGr&lv_ISBL3)
Variable: p
Type: integer
Total Size: 116 bytes
            29 values
Number of Dimensions: 1
Dimensions and sizes:   [lv_ISBL3 | 29]
Coordinates:
Number Of Attributes: 2
  long_name :   isobaric level
  units :       Pa

---
Variable: ipv
Type: float
Total Size: 4480752 bytes
            1120188 values
Number of Dimensions: 3
Dimensions and sizes:   [thlev | 4] x [lat | 337] x [lon | 831]
Coordinates:
            thlev: [325..370]
            lat: [   1..  85]
            lon: [ 150..358.5]
Number Of Attributes: 4
  _FillValue :  1e+20
  long_name :   Isentropic Potential Vorticity at 325K
  short_name :  IPV
  units :       K m2/kg/s


Thanks!!
Best,
Kacie
---
Kacie N. Shourd
드림

Graduate Research Assistant
Desert Research Institute
Kacie.Shourd at dri.edu<mailto:Kacie.Shourd at dri.edu>
Work: (775) 674-7049


PUBLIC RECORDS NOTICE: In accordance with NRS Chapter 239, this email and responses, unless otherwise made confidential by law, may be subject to the Nevada Public Records laws and may be disclosed to the public upon request.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20160907/8ecc45af/attachment.html