Update Truth: For dtcenter/MET#3007

[JohnHalleyGotway]

Describe Expected Changes

Write a short summary of the differences that will likely be found in the GitHub Actions testing workflow that was triggered by the pull request that warranted this issue

• Link to relevant issue(s): Develop a class that supports reading both FCST and OBS from a IODA file to use with the new Pair-Stat tool MET#3007
• Link to relevant pull request(s): Feature #3006 pair_stat and #3007 vx_ioda MET#3057

Define the Metadata

Title

• Define the Title of this issue as Update Truth: For dtcenter/{REPO}#{PR_NUMBER} to indicate the repository and pull request that warranted this issue.

Assignee

Assign this issue to the author of the pull request that warranted this issue. Optionally assign anyone else who should review the differences in the output.

• Select engineer(s) or no engineer required
• Select scientist(s) or no scientist required

Milestone and Projects

• Select Milestone as the next official version if updating truth data for the develop branch OR select next METplus-Wrappers-X.Y.Z bugfix version if updating truth data for a main_vX.Y branch.
• If updating truth data for the develop branch, select the METplus-Wrappers-X.Y.Z Development project OR if updating truth for a main_vX.Y branch, select the Coordinated METplus-X.Y Support project

Update Truth Checklist

• Review the GitHub Actions workflow that was triggered by the PR merge
  • If no differences were found, note this in a comment.
  • If all of the differences are expected, note this in a comment.
    Include any details of how the review was performed.
  • If unexpected differences are found, the following instructions can
    help uncover potential explanations. If none of these apply and the
    source of the differences cannot be determined, contact the
    METplus wrappers lead engineer (@georgemccabe) for assistance.
    • Search for other open issues that have the label type: update truth
      applied by clicking on the label on this issue. Coordinate with the
      author of these issues to ensure all diffs are properly reviewed.
    • Check if any additional GitHub Actions testing workflows have been
      triggered since the workflow that corresponds to this issue was run.
      Review the latest run to ensure that there are no diffs that are
      unrelated to this issue.
    • If the incorrect differences are caused by the changes from the
      issue that warranted this issue, consider reverting the PR and
      re-opening the issue.
  • Iterate until one of the above conditions apply.
• Approve the update of the truth data
  • Contact the METplus wrappers lead engineer (@georgemccabe) or
    backup lead (@jprestop) to let them know that the truth data can
    be updated.
• Update the truth data.
  This should be handled by a METplus wrappers engineer.
  See the instructions to update the truth data
  for more info.
• Close this issue.

[JohnHalleyGotway]

Merging the dtcenter/MET#3057 pull request into develop triggered this METplus GHA testing workflow run. That run flagged differences in one of the existing METplus Use Cases:

 COMPARING marine_and_cryosphere/PointStat_fcstRTOFS_obsARGO_climoWOA23_temp/stats/rtofs.20230318/point_stat_RTOFS_ARGO_temp_Z50_240000L_20230318_000000V.stat
  file_A: /data/truth/marine_and_cryosphere/PointStat_fcstRTOFS_obsARGO_climoWOA23_temp/stats/rtofs.20230318/point_stat_RTOFS_ARGO_temp_Z50_240000L_20230318_000000V.stat
  file_B: /data/output/marine_and_cryosphere/PointStat_fcstRTOFS_obsARGO_climoWOA23_temp/stats/rtofs.20230318/point_stat_RTOFS_ARGO_temp_Z50_240000L_20230318_000000V.stat

The differences in the CNT and SAL1L2 are due to modified climatology inputs.
I ran the following plot_data_plane command to investigate, using versions of it before and after merging dtcenter/MET#3057:

plot_data_plane \
woa23/woa23_decav91C0_t03_04.nc \
woa23_decav91C0_t03_04_BEFORE.ps \
'name = "t_an"; level = "(0,@50,*,*)";' \
-v 4 -log run_pdp_BEFORE.log

Here's the relevant diff from the log files:

< DEBUG 4: NcCfFile::getData() -> setting the unset init time to the valid time of 20050315_000000.
---
> DEBUG 4: NcCfFile::getData() -> setting the unset init time to the valid time of 20050316_000000.
34c34
< DEBUG 4:    valid time: 20050315_000000
---
> DEBUG 4:    valid time: 20050316_000000
36c36
< DEBUG 4:    init time: 20050315_000000
---
> DEBUG 4:    init time: 20050316_000000

The valid time parsed from this file has changed from 20050315_000000 to 20050316_000000. And that change in valid time slightly changes the results of the time interpolation (POINT_STAT_CLIMO_MEAN_TIME_INTERP_METHOD = DW_MEAN) method selected in the METplus conf file.

Inspecting the input file with ncdump -v time I see:

netcdf woa23_decav91C0_t04_04 {
dimensions:
	time = UNLIMITED ; // (1 currently)
...
variables:
	float time(time) ;
		time:standard_name = "time" ;
		time:long_name = "time" ;
		time:climatology = "climatology_bnds" ;
		time:units = "months since 1991-01-01 00:00:00" ;
		time:calendar = "standard" ;
		time:axis = "T" ;
...
data:

 time = 171.4683 ;

And this slight change in the result of using "monthly" time step is consistent with the recent enhancements found in is_leap_year.cc.