Toward a unified national dust modeling capability

Abstract

This study aims to improve the NOAA Operational Dust Forecasting Capability. NOAA has developed and is operating the U.S. Dust Forecasting Capability (DFC) in concert with one of its core missions to build a “Weather Ready Nation”. The current DFC is based on the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model (Draxler et al. 2010). The NOAA DFC has been in operations since November 2011. DFC gives dust forecast in the form of hourly surface fine particulate (particle small than 2.5 m in diameter (PM2.5)) concentration out to 48 h covering the continental United States (CONUS). It is based on the HYSPLIT simulations made at the National Centers for Environmental Prediction (NCEP) (forecast available at http://airquality.weather.gov). The DFC real-time dust forecast is widely used to help assessing and mitigating dust storm impact on the society and the environment such as on human health (e.g., Valley Fever), air and ground transportation safety, local economy such as estate value depreciation, and climate change. This study leverages the superiority of the High Resolution Rapid Refresh (HRRR) meteorological model. HRRR is a 3 km horizontal resolution regional numerical weather prediction (NWP) model for the CONUS, run operationally at NCEP. HRRR is proposed to provide the meteorology for the DFC. We propose to develop, test, and possibly select among several wind-blown dust emission schemes for the DFC dust-emission modeling. We considered the in-line emission modules in HRRR and the FENGSHA-CMAQ (the U.S. EPA Community Multiscale Air Quality model) windblown-dust module in the operational National Air Quality Forecasting Capability (NAQFC). The FENGSHA-CMAQ version 5.1’s wind-blown dust emission and diffusion module provides the initial wind-blown dust uptake and airborne suspension from the surface by using the surface wind from HRRR, and the HRRR low layer meteorology determines transport and turbulent mixing for the dust. These emission schemes are tested and evaluated over severe dust storms in the Western U.S. on May 11 2014.