GEOS-FP implementation details

From Geos-chem
Revision as of 19:36, 7 November 2013 by Bmy (Talk | contribs) (Initial source code modifications for GEOS-5.7.2)

Jump to: navigation, search
NOTE: GEOS-FP is the current NASA/GMAO operational met data product. It is produced with a native resolution of 0.25° (lon) x 0.3125° (lat) x 72 hybrid vertical layers. GEOS-FP replaced the older GEOS-5.2.0 operational data product in June 2013.

GEOS-FP was originally given the designation GEOS-5.7.1, which was later updated to GEOS-5.7.2. Currently, GEOS-FP is being produced with version 5.11.0 of the GEOS Data Assimilation System (aka GEOS-DAS). This means that the "5.7.x" nomenclature is no longer correct. For this reason, we shall refer to this product as GEOS-FP from now on. (Bob Yantosca, 21 Aug 2013)

On this page we list the necessary modifications to GEOS-Chem for compatibility with the GEOS-FP meteorological data.

Overview

The GEOS-FP data product (aka GEOS5-FP) is the newest version of the operational meteorological data produced by NASA/GMAO. Overall, the structure of GEOS-FP is very similar to MERRA. Therefore, within GEOS-Chem we can (for the most part) treat GEOS-FP in the same way as we do for the MERRA meteorology.

Key similarities to MERRA

The following aspects of GEOS-FP are identical to the older GEOS-5.2.0 operational data product.

  1. The GEOS-FP vertical grid (72 hybrid levels) is identical to that of both MERRA and GEOS-5.2.0.
  2. By and large, the same data fields that were in the MERRA product are also contained in GEOS-FP:
    • GEOS-FP provides the same time-invariant fields (FRLAKE, FRLAND, FRLANDIC, FROCEAN, PHIS) as MERRA
    • The same correction that was applied to the MERRA SNOMAS (snow mass) field has also been applied to the GEOS-FP SNOMAS field.
    • GEOS-FP contains the same precipitation fields (DQRCU, DQRLSAN, PFICU, PFILSAN, PFLCU, PFLLSAN, REEVAPCN, REEVAPLSAN) as MERRA. This means that we can use the MERRA wet deposition algorithms with the GEOS-FP data.
  3. The GEOS-FP time archiving is identical to that of MERRA ...
    • ... with one exception: GEOS-FP instantaneous data is archived every 3 hours, as opposed to 6 hours in MERRA.

--Bob Y. 09:46, 21 August 2013 (EDT)

Key differences from MERRA

The following aspects of GEOS-FP differ from the MERRA operational data product:

  1. All GEOS-FP data are placed on a horizontal grid of 0.25° x 0.3125°.
    • MERRA data fields are placed on three different horizontal grids (0.5° x 0.666°, 1° x 1.25° and 1.25° x 1.25°).
  2. All GEOS-FP data are placed on the 72-level hybrid grid.
    • Some MERRA fields were only available on a 42-level pressure grid (thus requiring interpolation).
  3. The following data GEOS-FP data fields differ from the corresponding MERRA fields:
    • RH is now a 3-hour time-averaged field, as opposed to a 6-hour instantaneous field in MERRA.
    • QV and T are now instantaneous 3-hour fields, as opposed to 3-hour time-averaged fields in MERRA.
    • The 3-D precipitation fields now make the (e.g. DQIDTMST, DQVDTMST, DQLDTMST, etc.) obsolete. We no longer archive these.
  4. We have chosen to save the processed GEOS-FP data in netCDF format, as opposed to GEOS-Chem binary format.

--Bob Y. 09:47, 21 August 2013 (EDT)

Required coding changes in GEOS-Chem

NOTE: This section is still under construction. Not all tables have yet been updated.

As noted in the section above, the similarities between MERRA and GEOS-FP (especially of the vertical grids) means that in most cases we can just treat MERRA in the same way as for GEOS-5. In many areas of the code, the coding changes are straightforward and simply involve an extension of C-preprocessor statements such as:

#if defined( GEOS_5 ) || defined( MERRA )

to

#if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )

In other areas of GEOS-Chem the changes are more involved. Below we provide a description of the areas of GEOS-Chem that were modified for MERRA:

Top-level directory

File Modifications made
Makefile_header.mk
  • Starting with GEOS-Chem v9-02o, we now use Makefile variables to set the various C-preprocessor switches. In particular:
    • MET=___ selects the met field type( gcap, geos4, geos5, geosfp, merra)
    • GRID=___ selects the horizontal grid (4x5, 2x25, 05x0666, 025x03125)
    • NEST=___ specifies the nested-grid (CH, EU, NA, SE)

--Bob Y. 13:39, 7 November 2013 (EST)

Headers directory

The following modifications for GEOS-FP were made in the Headers/ directory:

File Modifications made
CMN_SIZE_mod.F
  • Added size parameters for GEOS-FP grids at 4° x 5° 2° x 2.5° and 0.25° x 0.3125° resolution
gigc_input_opt_mod.F90
  • This module was introduced to facilitate the Grid-Independent GEOS-Chem development.
  • gigc_input_opt_mod.F90 now collects the various logical switches, file paths, and related variables from logical_mod.F, directory_mod.F, unix_cmds_mod.F, and linoz_mod.F.
gigc_state_met_mod.F90
  • This module was introduced to facilitate the Grid-Independent GEOS-Chem development.
  • gigc_state_met_mod.F90 now holds all of the met field arrays that were formerly in GeosCore/dao_mod.F.
  • We now allocate all met field arrays in routine Init_GIGC_State_Met

--Bob Y. 13:52, 7 November 2013 (EST)

GeosUtil directory

The following modifications for GEOS-5.7.2 were made in the GeosUtil/ directory:

File Modifications made
bpch2_mod.F

In routine GET_MODELNAME:

  • Add GEOS5_47L and GEOSFP modelnames to the #if block

In routine GET_NAME_EXT:

  • Return grid name geos5 for GEOS-FP fields

In routine GET_RES_EXT:

  • Return resolution string 025x03125 for 0.25° x 0.3125° grids
grid_mod.F

In routine COMPUTE_GRID:

  • Overwrite YMID at poles for 0.25° x 0.3125° grids (+/- 89.3975)
  • Define YMID_R_W for 0.25° x 0.3125° nested grids

In routine INIT_GRID:

  • Define IIIPAR=1152 and JJJPAR=721 for 0.25° x 0.3125° global grid
pressure_mod.F

In routines GET_PEDGE and GET_PEDGE_FULLGRID:

  • Compute PEDGE for GEOS-FP in the same way as for GEOS-5 and MERRA

In routine INIT_PRESSURE:

  • Initialize Ap and Bp for GEOS-FP in the same way as for GEOS-5 and MERRA
time_mod.F

In routine GET_A1_TIME:

  • Compute the DATE array for GEOS-FP the same way as is done for MERRA.
transfer_mod.F

In several routines:

  • Changed code to #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )

--Bob Y. 13:55, 7 November 2013 (EST)

GeosCore directory

The following modifications for GEOS-5.7.2 were made in the GeosCore/ directory:

File Modifications made
calcrate.F Multiple instances:
  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
carbon_mod.F Multiple instances:
  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
cldice_HbrHOBr_mod.F Multiple instances:
  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
convection_mod.F

In routine DO_CONVECTION:

  • Changed code to: #if defined( MERRA ) || defined( GEOS_FP )
  • For GEOS-FP, PFICU and PFLCU fields are defined on level edges. Pass the top edge value at each level (stored in local arrays T_PFICU and T_PFLCU) to DO_MERRA_CONVECTION.
  • Add T_PFICU and T_PFLCU arrays to the PRIVATE statement of the OpenMP loop.
dao_mod.F

In routine COPY_I6_FIELDS:

  • Renamed this routine to COPY_I3_I6_FIELDS
  • Added #if block for GEOS-FP met

In routines IS_ICE, IS_LAND, IS_NEAR, IS_WATER:

  • Now use: #elif defined( GEOS_4 ) || defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )

In routine INTERP:

  • Add #if block for GEOS-FP
depo_mercury_mod.F

In routine ADD_Hg2_SNOWPACK

  • Changed code to: #if defined( MERRA ) || defined( GEOS_FP )
diag3.F
  • Add SCALE_I3 counter for instantaneous met fields
  • Modify ND66 diagnostic to divide by proper # of A3 increments (i.e. every 3 hours)
    • With the exception of T, SPHU, which are I3 fields
  • Modify ND67 diagnostic to divide by proper # of A1 increments (i.e. every hour)
    • With the exception of CLDTOPS, which is an A3 field
dust_mod.F

In routine SRC_DUST_DEAD:

  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
dust_dead_mod.F

In routine DST_MBL:

  • For GEOS-FP, add a new value for parameter FLX_MSS_FDG_FCT. The scale factor ensures that we get the same dust totals (w/in roundoff error) as for GEOS-5.
fast_j.F
  • Do cloud overlapping for GEOS-FP in the same way as for GEOS-5 and MERRA.
  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
gamap_mod.F

In routine INIT_TRACERINFO:

  • Changed code to: #elif defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
geosfp_read_mod.F90
  • Added this module w/ routines to read GEOS-FP met data (in netCDF format)
global_ch4_mod.F

In routines WETLAND_EMIS and READ_COPROD:

  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
global_hno3_mod.F

In routine GET_GLOBAL_HNO3:

  • Now use:
    #if defined( GEOS_3 ) || defined( GEOS_4 ) || defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
global_o3_mod.F

In routine GET_GLOBAL_O3

  • Now use:: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
initialize.F
  • Restructure USE statements for clarity
  • Now also reset the counter for I3 timesteps by calling routine  SET_CT_I3( RESET=.TRUE. )
input_mod.F

In routine READ_SIMULATION_MENU:

  • Read value for GEOS_FP_DIR from input.geos file and save into Input_Opt
  • Set LUNZIP=.FALSE. for GEOS-FP met

In routine READ_CONVECTION_MENU:

  • Change #if statement to allow non-local PBL mixing for GEOS-FP met data

In routine READ_EMISSIONS_MENU:

  • Turn off LMEGANMONO when LMEGAN is turned off

In routine VALIDATE_DIRECTORIES:

  • Error check GEOS_FP_DIR for start & end date
land_mercury_mod.F

In routines LAND_MERCURY_FLUX:

  • Changed code to: #if defined( MERRA ) || defined( GEOS_FP )

In routines SOILEMIS:

  • Changed code to: #if defined( MERRA ) || defined( GEOS_FP )
  • Extend #if statement for variable SOIL_EMIS_FAC to get the code to compile w/o error.
    (NOTE: Team Hg: you will have to submit a proper value for this later.
lightning_nox_mod.F

In routine LIGHTNING:

  • Eliminate the shallow-cloud inhibititon trap for GEOS-FP, as we already do for GEOS-5 and MERRA

In routine GET_OTD_LIS_SCALE:

  • Now use updated values for ANN_AVG_FLASHRATE computed by Lee Murray (2013-11-07).
Makefile
  • Added dependencies for new routines
  • Added the following targets
    • libnc: Compiles the code in the NcdfUtil directory and creates the libNcUtils.a library
    • ncdfcheck: Compiles a program that will test the integrity of the netCDF library installation.
main.F
  • Rewrote USE statements for clarity
  • Added calls to routines from geosfp_read_mod.F
  • Split off the code that reads met fields into internal subroutines READ_INITIAL_MET_FIELDS and READ_MET_FIELDS, for clarity.
  • Renamed NN to NNN to avoid name confusion
megan_mod.F

At top of module

  • For MERRA and GEOS-FP met: define DAY_DIM parameter = 24 for hourly temperature data
  • For all other met data: define DAY_DIM parameter = 8 for 3-hourly temperature data

In routine INIT_MEGAN:

  • For MERRA and GEOS-FP met: define G4AHEAD = 003000
  • Now call GEOS57_READ_A1 (from geosfp_read_mod.F90) to read surface temperature data
mercury_mod.F

In routine CHEM_Hg0_Hg2:

  • In the block that computes LWC, changed code to: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
  • In the block that computes Hg0 exchange, changed code to: #if defined( MERRA ) || defined( GEOS_FP )
nei2005_anthro_mod.F

In routines EMISS_NEI2005_ANTHRO and EMISS_NEI_ANTHRO_05x0666:

  • Changed code to: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
ocean_mercury_mod.F

Multiple instances:

  • Now use: #if defined( MERRA ) || defined( GEOS_FP )
planeflight_mod.F

In routine PLANEFLIGHT

  • Now use: #if defined( MERRA ) || defined( GEOS_FP )
strat_chem_mod.F90

Multiple instances:

  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
sulfate_mod.F

Multiple instances:

  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
tagged_ox_mod.F

Multiple instances:

  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
tpcore_bc_mod.F:

Multiple instances:

  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
tropopause_mod.F:

Multiple instances:

  • Now use: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )
vdiff_mod.F90

In routine VDIFFDR:

  • Changed code to: #if defined( MERRA ) || defined( GEOS_FP )
wetscav_mod.F

In routines DO_WETDEP, DO_WASHOUT_ONLY

  • Changed code to: #if defined( MERRA ) || defined( GEOS_FP )

In routine MAKE_QQ:

  • Add #if block for GEOS-FP met
  • Refer to PFILSAN(I,J,L+1) and PFLLSAN(I,J,L+1), since these fields are defined on level edges

In routine RAINOUT:

  • Changed code to: #if defined( GEOS_5 ) || defined( MERRA ) || defined( GEOS_FP )

--Bob Y. 14:23, 7 November 2013 (EST)

GeosApm directory

The following modifications for GEOS-5.7.2 were made in the GeosTomas/ directory:

File Modifications made
Makefile
  • Added dependencies for geos57_read_mod.F
  • Removed references to obsolete GEIA biogenic emissions
carbon_mod.F
  • Synchronized with GeosCore/carbon_mod.F
dao_mod.F
  • Synchronized with GeosCore/dao_mod.F
dust_mod.F
  • Synchronized with GeosCore/dust_mod.F
dust_dead_mod.F
  • Synchronized with GeosCore/dust_dead_mod.F
main.F
  • Synchronized with GeosCore/main.F
sulfate_mod.F
  • Synchronized with GeosCore/sulfate_mod.F
wetscav_mod.F
  • Synchronized with GeosCore/wetscav_mod.F
  • NOTE: Needs validation by APM team

--Bob Y. 13:49, 9 February 2012 (EST)

NcdfUtil directory

We have added the NcdfUtil/ directory, which contains routines for netCDF file I/O. These routines are based on the NcdfUtilities package by Bob Yantosca. These are built when you compile GEOS-Chem with the NETCDF=yes Makefile option.

File Description
Makefile GNU Makefile used to build the NcdfUtil code.
TestNcdfUtil.F90 Test program to verify that the netCDF libraries were built properly. (This is executed only when you issue a make ncdfcheck command.)
m_do_err_out.F90 Routine to print out netCDF error messages.
m_netcdf_io_checks.F90 Routines to check whether a netCDF file contains a specified variable or dimension.
m_netcdf_io_close.F90 Routines to close a netCDF file.
m_netcdf_io_create.F90 Routines used to open a netCDF file for output and to synchronize a netCDF file.
m_netcdf_io_define.F90 Routines to define netCDF variables and attributes. Use this when writing data to a netCDF file.
m_netcdf_io_get_dimlen.F90 Routines to return dimension information from a netCDF file.
m_netcdf_io_handle_err.F90 Routines for netCDF I/O error handling.
m_netcdf_io_open.F90 Routines for opening a netCDF file for reading or for writing.
m_netcdf_io_read.F90 Routines for reading variables (of INTEGER, REAL*4, REAL*8, and CHARACTER types) from a netCDF file.
m_netcdf_io_readattr.F90 Routines for reading global and variable attributes (of INTEGER, REAL*4, REAL*8, and CHARACTER types) from a netCDF file.
m_netcdf_io_write.F90 Routines for writing data to a netCDF file

--Bob Y. 10:34, 3 February 2012 (EST)

NcdfUtil/perl subdirectory

In this directory, we have added scripts for automatically generating Fortran code with the proper calls from the NcdfUtilities package. We anticipate that this will be a convenience for GEOS-Chem users, as it will relieve some of the drudgery of writing these calls by hand.

File Description
StrTrim.pm Perl module used by the ncCode* scripts. Contains routines for stripping withe space from strings.
ncCodeDef Perl script that generates Fortran code to open a netCDF file and define the various dimensions, variables, and attributes.
ncCodeWrite Perl script that will generate Fortran code to write data to a netCDF file.
ncCodeRead Perl script that will generate Fortran code to read data from a netCDF file.
nc_definitions.rc Generic input file used by the ncCode* scripts. You can edit this.
definitions_cn.rc Customized version of nc_definitions.rc that will generate Fortran code for reading GEOS-5.7.2 CN data.
definitions_a1.rc Customized version of nc_definitions.rc that will generate Fortran code for reading GEOS-5.7.2 A1 data.
definitions_a3cld.rc Customized version of nc_definitions.rc that will generate Fortran code for reading GEOS-5.7.2 A3cld data.
definitions_a3dyn.rc Customized version of nc_definitions.rc that will generate Fortran code for reading GEOS-5.7.2 A3dyn data.
definitions_a3mstc.rc Customized version of nc_definitions.rc that will generate Fortran code for reading GEOS-5.7.2 A3mstC data.
definitions_a3mste.rc Customized version of nc_definitions.rc that will generate Fortran code for reading GEOS-5.7.2 A3mstE data.
definitions_i3.rc Customized version of nc_definitions.rc that will generate Fortran code for reading GEOS-5.7.2 I3 data.

--Bob Y. 10:34, 3 February 2012 (EST)

Resolved issues

Fractional sea ice

In order to preserve some information about sea ice leads during the regridding process, we have binned the fractional sea ice coverage into deciles (0-10%, 10-20% ... 90-100% coverage) and saved those as separate fields in the GEOS-5.7.2 data archive for GEOS-Chem. We have used the same algorithm we developed for MERRA met fields to do the binning.

--Bob Y. 16:12, 24 January 2012 (EST)

SNOMAS

The SNOMAS (snow depth) fields in both GEOS-5.7.2 and MERRA differ from that in GEOS-5.2.0. It appears that in GEOS-5.2.0 a default snow mass value was applied to grid boxes that had > 90% land ice coverage. This was not done in MERRA or GEOS-5.7.2. Bob Yantosca had implemented an algorithm to adjust the MERRA SNOMAS field to be backwards-compatible with GEOS-5.2.0. We have used this algorithm to adjust the GEOS-5.7.2 SNOMAS field accordingly.

--Bob Y. 16:14, 24 January 2012 (EST)

Dust emissions

The dust emissions in GEOS-Chem rely on "tunable parameters" to scale the dust emissions to a specified total. This is because the dust emissions are very highly dependent on the surface winds, and a small difference in winds (e.g. from GEOS-5 to GEOS-FP) can cause a huge difference in dust emission flux.

In routine DST_MBL (in dust_dead_mod.f), we have added the following code:

     !----------------------------------------------------------------
     ! Based on results from GEOS-FP 4x5 for 04/2012-04/2013
     !
     !   (GEOS-5 - GEOS-FP)/GEOS-5 * 100 is 23.56% in each size bin.
     !
     ! We need to scale to the parameter FLX_MSS_FDG_FCT to make the
     ! dust emissions consistent.  Consequently, to bring GEOS-FP 4x5
     ! dust emissions up to GEOS-5 levels, we need to MULTIPLY the
     ! FLX_MSS_FDG_FCT used for GEOS-5 by:
     !
     !             1 / (1. - 0.2356) = 1 / 0.7644 = 1.3082
     !
     !    -- R. Yantosca, M. Sulprizio, 07 Nov 2013
     !----------------------------------------------------------------
     REAL*8,  PARAMETER     :: FLX_MSS_FDG_FCT = 7.0d-4 * 1.3082d0

--Melissa Sulprizio 11:42, 7 November 2013 (EST)

Lightning

TBD

Wet deposition and scavenging

Helen Amos, Bess Corbitt, and Qiaoqiao Wang had implemented an updated algorithm for wet scavenging that takes advantage of the new precipitation fields from the MERRA data archive. This was included in GEOS-Chem v9-01-01 and higher versions.

Because GEOS-5.7.2 contains the same precipitation data fields as MERRA (i.e. DQRCU, DQRLSAN, PFICU, PFILSAN, PFLCU, PFLLSAN, REEVAPCN, REEVAPLSAN), we can use the new wet deposition algorithm with the GEOS-5.7.2 met data.

--Bob Y. 16:16, 24 January 2012 (EST)

Implementation history

Initial source code modifications for GEOS-FP

This update was tested in the 1-month benchmark simulation v9-01-03g and approved on 27 Feb 2012.

NOTE: At the time of this update GEOS-FP has not been validated, so the #define GEOS_FP switch in define.h should not be used.

The following modifications are slated to be incorporated into the 1-month benchmark GEOS-Chem v9-01-03g:

  1. Modify the Headers, GeosUtil, and GeosCore directories for GEOS-5.7.2
  2. Update the GeosApm and GeosTomas directories, primarily to synchronize files with GeosCore
  3. Add NcdfUtil directory
  4. Resolve several issues, including: Fractional sea ice, SNOMAS, Wet deposition and scavenging

--Melissa Payer 17:29, 24 February 2012 (EST)

Bug fix for declaration of GEOS-5.7.2 PFICU, PFLCU, PFILSAN, PFLLSAN fields

This update was tested in the 1-month benchmark simulation v9-02g and approved on 24 Mar 2013.

In module file GeosCore/gigc_state_met_mod.F90, it was discovered that the PFICU, PFLCU, PFILSAN, and PFLLSAN met fields for GEOS-5.7.2 were being allocated with the wrong vertical dimension. In GEOS-5.7.2, these fields are placed on level edges and need to be allocated with LLPAR+1 levels. But in MERRA, these fields are placed on level centers and need to be allocated with LLPAR levels.

We have introduced the following fix in routine Init_GIGC_State_Met of Headers/gigc_state_met_mod.F90:

    INTEGER :: LX

    ... 

#elif defined( GEOS_57 ) || defined( MERRA )

    !=======================================================================
    ! GEOS-5.7.x / MERRA met fields
    !=======================================================================
#if defined( GEOS_57 )
    LX = LM + 1
#elif defined( MERRA )
    LX = LM
#endif

    ALLOCATE( State_Met%PFICU     ( IM, JM, LX   ), STAT=RC )
    IF ( RC /= GIGC_SUCCESS ) RETURN
    State_Met%PFICU    = 0d0

    ALLOCATE( State_Met%PFILSAN   ( IM, JM, LX   ), STAT=RC )
    IF ( RC /= GIGC_SUCCESS ) RETURN
    State_Met%PFILSAN  = 0d0

    ALLOCATE( State_Met%PFLCU     ( IM, JM, LX   ), STAT=RC )
    IF ( RC /= GIGC_SUCCESS ) RETURN
    State_Met%PFLCU    = 0d0

    ALLOCATE( State_Met%PFLLSAN   ( IM, JM, LX   ), STAT=RC )
    IF ( RC /= GIGC_SUCCESS ) RETURN
    State_Met%PFLLSAN  = 0d0

This will make sure that the fields will be declared properly for either GEOS-5.7.2 or MERRA. (NOTE: LM is set to LLPAR, and thus LM+1 = LLPAR+1.

--Bob Y. 11:32, 18 March 2013 (EDT)

Make sure State_Met%T is initialized properly for GEOS-FP simulations

For simulations with the GEOS-FP met fields, temperature is an I3 (i.e. 3-hr instantaneous) met field. We need to read temperature at times t and t+3hrs, and then interpolate linearly to the proper time.

At time t=0 of a GEOS-FP simulation, the initial temperature is read from netCDF files into State_Met%TMPU1. However, we must also save this into State_Met%T. Otherwise, temperature will be not initialized properly until the first call to INTERP. This can cause a floating-point error further upstream.

We have added the following code to routine Geos57_Read_I3_1 in GeosCore/geos57_read_mod.F90:

     ! For now, copy State_Met%TMPU1 to State_Met%T.  At the next met field 
     ! read, we will State_Met%T from the values of State_Met%TMPU1 and
     ! State_Met%TMPU2. (bmy, 9/6/13)
     State_Met%T = State_Met%TMPU1

This error condition was caught by the GEOS-Chem unit tester when compiling with option FPE=yes.

--Bob Y. 13:13, 12 September 2013 (EDT)