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MATCH Architecture

Overview

MATCH (Model for Atmospheric Transport and CHemistry) is a global offline chemical transport model driven by meteorological reanalysis data. It is used within the NASA CERES project to produce global aerosol datasets via assimilation of satellite observations (MODIS).

The model reads NCEP reanalysis fields, advects trace species on a Gaussian grid, and applies aerosol source/sink processes including emission, dry and wet deposition, and chemistry. MODIS aerosol optical depth observations are assimilated using a 3-D optimal interpolation scheme.

Source Directory Map

src/              Main model core: dynamics, physics, I/O, grid
  slt/            Semi-Lagrangian transport advection
  spitfire/       Spitfire spectral advection (FFT-based)
dst/              Mineral dust aerosol module (mobilization, transport, deposition)
src_scyc/         Sulfur cycle chemistry (DMS, SO2, sulfate)
src_assim/        3-D aerosol optical depth assimilation
readers/          Meteorological input readers
  ncep/           NCEP GRIB format reader
  netcdf/         NetCDF format reader
utils/            Post-processing utilities (ccm2nc, hsum)
build/            Build system (Makefile, dependency generation)
control/          Run scripts (csh) and run generation tools (Python)
grib/             GRIB field listing tables for NCEP reanalysis
reform/           SAGE aerosol data reformatting tools

Preprocessor Flags

The build is configured via CPP defines that enable aerosol and process modules. These are set in build/Makefile via usrCPP_DEFS_AER:

Flag Module Purpose
-DDST dst/ Mineral dust aerosol
-DCAER src/caer.F90, src/caerbnd.F90 Carbonaceous aerosol (black/organic carbon)
-DSCYC src_scyc/ Sulfur cycle (DMS, SO2, sulfate)
-DWETDEP src/wetdepdr.F Wet deposition
-DDRYDEP src/drydep.F, src/drydepdr.F Dry deposition
-DASSIM src_assim/ AOD assimilation
-DLINUX (always set) Platform conventions

Precision is controlled separately via usrCPP_DEFS_PRC:

  • -DRPREC=12 and -DREALSIZE=8 select double precision (r8).

Major Functional Areas

Dynamics and Transport

  • main.F — Program entry, time stepping loop
  • dyninp.F — Reads and interpolates meteorological input
  • mass.F, drymass.F — Mass diagnostics and conservation
  • etadot.F — Vertical velocity computation
  • div.F — Divergence
  • slt/advect.F — Semi-Lagrangian advection
  • spitfire/ — Spectral advection (FFT, Lagrangian transport)
  • advfix.F — Advection mass fixer

Physics and Cloud

  • aphys.F — Column physics driver
  • cldfrc.F — Cloud fraction
  • cldwat.F — Prognostic cloud water
  • cloud.F — Cloud processes
  • conv_zhang.F, conv_hack.F, conv_pjr.F — Convection schemes
  • vdiff_mod.F — Vertical diffusion

Aerosol Modules

  • srcsnk.F — Tracer source/sink driver
  • dst/ — Dust: mobilization (dstmbl), chemistry (dstchm), deposition (dstdpsdry, dstdpswet), radiation (dstrad)
  • src_scyc/ — Sulfur: emissions (sulemis), chemistry (sulchem), boundary conditions (sulbnd, soxbnd, dmsbnd, acbnd)
  • caer.F90, caerbnd.F90 — Carbonaceous aerosol emission and transport
  • getsslt.F — Sea salt aerosol
  • optDepth.F — Aerosol optical depth computation

Data Assimilation (src_assim/)

  • aod_assim_3d.F90 — Main assimilation driver
  • analysis_3d.F90 — 3-D analysis update
  • covariances_3d.F90 — Background error covariances
  • obs_operator.F90 — Observation operator (model-to-obs mapping)
  • sat_obs.F90 — Satellite observation ingestion
  • avg_kernel.F90 — Averaging kernels

I/O and Utilities

  • ccmhist.F, histout.F — History file output (CCM format)
  • mass2nc.F, ncUtil.F — NetCDF output
  • rec_io.F — Record I/O
  • restart.F — Checkpoint/restart
  • control.F — Namelist and run control
  • grid.F — Gaussian grid setup
  • calendar.F — Date/time management

Meteorological Readers (readers/)

  • readers/ncep/dyninp.F + grib.c, gribr.c — Read NCEP GRIB reanalysis
  • readers/netcdf/dyninp.F — Read NetCDF reanalysis
  • rgi.c, rgip.F — Grid interpolation
  • utim.c — Time utilities

Post-processing Utilities (utils/)

  • ccm2nc — Convert CCM history files to netCDF
  • hsum — Compute hash checksums of history files

Include Files

Two types of include files are used throughout the Fortran source:

  • .h headers — Preprocessor parameter definitions and derived-type declarations (e.g., pmgrid.h defines grid dimensions, dst.h defines dust preprocessor tokens)
  • .com files — Fortran COMMON block declarations shared across compilation units (e.g., control.com, grid.com, calendar.com)

Both are pulled in via #include and are required for compilation.

Grid

MATCH uses a global Gaussian grid. Grid dimensions are set at compile time via pmgrid.h and params.h in the build directory. The standard CERES configuration uses the NCEP T62 resolution.