Initial Development of a NOAA Emissions and eXchange Unified System (NEXUS)

The past decade has experienced rapid advances in global aerosols and atmospheric composition (AAC) model prediction capabilities. AAC models are key components of unified forecast systems that often employ the Earth System Model Framework (ESMF; i.e., a high-performance, flexible software infrastructure for building and coupling weather, climate, and related Earth science models) for weather and climate predictions. Emissions of trace gases and primary aerosols are a critical component of AAC models and are often the most important component to ensure accurate predictions of trace species distributions. However, developing these emissions inputs to AAC models is often a laborious, time-consuming process, especially to ensure that the datasets are suitable for a range of spatial scales and applications. Furthermore, inventory-based emission inputs are subject to a bottom-up approach that is prepared separately (offline) and suffers distinct time lags from the AAC models, which affects both the timing and accuracy of trace gas predictions. In this work, the Harvard-NASA Emission Component (HEMCO) is serving as the foundation of a new unified emissions modeling framework, which is capable of utilizing numerous emissions datasets (both global and regional), can be run offline (inventory-based) or online (processed-based), is ESMF-compliant, and can be easily linked to satellite data sources. Here we present the initial development of the NOAA Emissions and eXchange Unified System (NEXUS), which will interface both offline and online with different NOAA AAC models, including both global and regional models for both operational and research-oriented applications. Preliminary developments of a comprehensive, adaptable emissions and air-surface exchange (i.e., both emissions and deposition) processing system for use in conjunction with NOAA AAC models will be shown. This includes examples of model-ready anthropogenic emissions using a combination of global and regional anthropogenic emission inventories with the NEXUS platform, and an initial assessment of NOAA AAC model simulations using these emissions. We will also present preliminary results from initial implementation of advanced inline dust and fire emissions using new NOAA products and emission models in NEXUS.