Fix bug setting destination grid object sigma vector passed to MESSy

This update only affects models which use HEMCO to vertically regrid
input data that are not on the model vertical grid, i.e. CESM and WRF-GC.
Previously the 3D vertical sigma array was collapsed into a 1D array
passed to MESSy with the wrong ordering of latitudes and longitudes.

Signed-off-by: Lizzie Lundgren <elundgren@seas.harvard.edu>

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.10.3] - TBD
+### Fixed
+- Fixed bug setting destination grid object sigma vector passed to MESSy for vertical regridding
+
 ## [3.10.2] - 2025-03-04
 ### Added
 - Added `.zenodo.json` for auto-DOI generation upon version releases

src/Core/hcoio_messy_mod.F90

@@ -790,8 +790,8 @@ SUBROUTINE AXIS_CREATE( HcoState, lon, lat, lev, ax, RC )
        ! -------------------------------------------------------------
        LOW = 1
        UPP = 1
-       DO J = 1, YLEV !lat
        DO I = 1, XLEV !lon
+       DO J = 1, YLEV !lat
           UPP                   = LOW + ZLEV - 1 ! Upper index
           ax(N)%dat%vd(LOW:UPP) = lev(I,J,:)     ! Pass to vector
           LOW                   = UPP + 1        ! Next lower index