Development of the Harmonized Emissions Component (HEMCO) 3.0 as a general emissions component for atmospheric models

Abstract:

Emissions are a crucial component in modeling of atmospheric chemistry. Online emission components such as HEMCO (Keller et al., 2014) allow users to scale, mask and combine emissions through a configuration file and shared emissions database, without the need to change model source code. While HEMCO was designed to be versatile and ESMF-compliant, a tightly coupled interface to GEOS-Chem limited its applicability to other models. We present an updated version HEMCO 3.0 that increases the flexibility of the module for interfacing with different types of models and improves the accuracy of calculating emissions for any model resolution including intermediate and multiscale grids. HEMCO 3.0 preserves a shared emissions core while modularizing model specific input and speciation processes to allow the incorporation of HEMCO within different models and modeling frameworks such as ESMF. Through the shared emissions core, all models can share the same emission inventories in COARDS-compliant netCDF format without any modification, and also share an extensions interface for modules to compute emissions dependent on the local state such as from dust, the ocean, or the biosphere. We demonstrate implementations of HEMCO 3.0 in the NCAR Community Earth System Model (CESM), in the NASA GEOS-5 Earth System Model, and in the GEOS-Chem chemical transport model with both shared-memory and distributed-memory architectures.