Quickstart

This example shows how to configure and run one emissions timestep. It mirrors how a host model (e.g. MPAS-A) drives MIEM directly in C++, without going through the YAML parsing layer.

Species mapping and inventory translation are handled upstream by MechanismConfiguration and musica::Translate(). By the time MIEMConfig reaches MIEM, species are already resolved.

Setting Up Sources

#include <miem/config.hpp>
#include <miem/emissions.hpp>
#include <miem/emissions_state.hpp>

using namespace miem;

SourceConfig cams_anthro{
  .name_                   = "cams anthro",
  .mode_                   = SourceMode::Offline,
  .type_                   = SourceType::Anthropogenic,
  .file_pattern_           = "/path/to/CAMS-GLOB-ANT_{YYYY}-{MM}.nc",
  .temporal_interpolation_ = TemporalInterpolation::Linear,
  .vertical_injection_     = VerticalInjection::Surface,
  .category_               = 0,
  .hierarchy_              = 1,
  .scaling_factor_         = 1.0,
  .sector_                 = "anthropogenic",
};

Assembling the Config and Running

MIEMConfig cfg{
  .sources_ = { cams_anthro },
};

EmissionsModule module(cfg, /*n_cells=*/163842, /*n_vert_levels=*/60);

EmissionsState state = module.Run(
  86400.0 * 180.0,  // sim_time_sec: day 180
  600.0             // dt_sec: 10 minutes
);

Reading the Output

double no_flux = state.surface_flux_(0, "NO");  // kg m-2 s-1 at cell 0

double anthro_no = state.sector_fluxes_.at("anthropogenic")(0, "NO");

See examples/full_example.cpp for the complete worked example including multiple layered sources and sector diagnostics.