NAQFC Developmental Forecast Guidance for Fine Particulate Matter (PM2.5)

Abstract

The National Air Quality Forecasting Capability (NAQFC) upgraded its modeling system that provides developmental numerical predictions of particulate matter smaller than 2.5 μm in diameter (PM2.5) in January 2015. The issuance of PM2.5 forecast guidance has become more punctual and reliable because developmental PM2.5 predictions are provided from the same system that produces operational ozone predictions on the National Centers for Environmental Prediction (NCEP) supercomputers. There were three major upgrades in January 2015: 1) incorporation of real-time intermittent sources for particles emitted from wildfires and windblown dust originating within the NAQFC domain, 2) suppression of fugitive dust emissions from snow- and/or ice-covered terrain, and 3) a shorter life cycle for organic nitrate in the gaseous-phase chemical mechanism. In May 2015 a further upgrade for emission sources was included using the U.S. Environmental Protection Agency’s (EPA) 2011 National Emission Inventory (NEI). Emissions for ocean-going ships and on-road mobile sources will continue to rely on NEI 2005. Incremental tests and evaluations of these upgrades were performed over multiple seasons. They were verified against the EPA’s AIRNow surface monitoring network for air pollutants. Impacts of the three upgrades on the prediction of surface PM2.5 concentrations show large regional variability: the inclusion of windblown dust emissions in May 2014 improved PM2.5 predictions over the western states and the suppression of fugitive dust in January 2015 reduced PM2.5 bias by 52%, from 6.5 to 3.1 μg m−3 against a monthly average of 9.4 μg m−3 for the north-central United States.

Toward Improving Short‐Term Predictions of Fine Particulate Matter Over the United States Via Assimilation of Satellite Aerosol Optical Depth Retrievals

“…The initial conditions for all other CMAQ forecasts were based on the previous day's CMAQ run. Similar to the NAQFC, lateral boundary conditions for CMAQ chemical fields are represented using Goddard Earth Observing System (GEOS)‐Chem (Lee et al, ; Tang et al, ) simulated monthly median concentrations. The CMAQ simulations use a time step of 6 min for chemistry simulations, and the output is saved every hour for further analysis.…”

Satellite‐Based Daily PM2.5 Estimates During Fire Seasons in Colorado

“…Daily surface PM 2.5 concentrations at 12 km resolution were produced using an experimental version of the National Air Quality Forecast Capability (NAQFC) system operated by the National Oceanic and Atmospheric Administration (P. Lee et al, 2017;Pan et al, 2014;Tong et al, 2016). This modeling system used the Community Multiscale Air Quality (CMAQ) model version 4.6 (Byun & Schere, 2006) to predict surface O 3 and PM 2.5 concentrations.…”

A case study of aerosol data assimilation with the Community Multi-scale Air Quality Model over the contiguous United States using 3D-Var and optimal interpolation methods

“…Many contributions toward improving the NAQFC can be found in the literature, including updated emission, meteorology, chemical mechanism and lateral boundary conditions (Pan et al, 2014;Tang et al, 2008;Lee et al, 2017). However, biases still contaminate current predictions.…”