Coupling of Important Physical Processes in the Planetary Boundary Layer between Meteorological and Chemistry Models for Regional to Continental Scale Air Quality Forecasting: An Overview

Abstract

A consensus among many Air Quality (AQ) modelers is that planetary boundary layer processes are the most influential processes for surface concentrations of air pollutants. Due to the many uncertainties intrinsically embedded in the parameterization of these processes, parameter optimization is often employed to determine an optimal set or range of values of the sensitive parameters. In this review study, we focus on the two of the most important physical processes: turbulent mixing and dry deposition. An emphasis was put on surveying AQ models that have been proven to resolve meso-scale features and cover a large geographical area, such as large regional, continental, or trans-continental boundary extents. Five AQ models were selected. Four of the models were run in real-time operational forecasting settings for continental scale AQ. The models use various forms of level 2.5 closure algorithms to calculate turbulent mixing. Tuning and parameter optimization has been used to tailor these algorithms to better suit their AQ models which are typically comprised of a coupled chemistry and meteorology model. Longer forecasts and long lead-times are inevitably under increasing demand for these models. Land Surface Models that have the capability for soil moisture and temperature data assimilation will have an advantage to constrain the key variables that govern the partitioning of surface sensible and latent heat fluxes and thus attain the potential to perform better in longer forecasts than those models that do not have this capability. Dry deposition velocity is a OPEN ACCESSAtmosphere 2011, 2 465 very significant model parameter that governs a major surface exchange activity. An exploratory study has been conducted to see the upper bound of roughness length in the similarity equation for aerodynamic resistance.

Quantifying the relationship between PM<sub>2.5</sub> concentration, visibility and planetary boundary layer height for long-lasting haze and fog–haze mixed events in Beijing

“…The fog droplets could substantially block the solar radiation and caused much less solar radiation heating in the daytime, so that the averaged reduction of surface solar total radiation caused by the fog-haze mixed event was almost double compared to that by the haze event. Since the solar radiation absorbed by the earth surface may heat the bottom of atmospheric column, producing convective eddies that transport heat and water vapour upward and driving the growth of the PBL (Lee and Ngan, 2011), the substantial reduction of surface solar radiation in both haze and fog-haze mixed events could induce much less surface heating and formed a much lower PBL height.…”

Long-term NOx trends over large cities in the United States during the great recession: Comparison of satellite retrievals, ground observations, and emission inventories

“…Inputs to the CMAQ model include emission data processed from NEIs and hourly meteorological data from NOAA's operational North American Mesoscale (NAM) meteorological model (Otte et al, 2005;Lee and Fong, 2011;Stajner et al, 2012). The NAM relies on the meteorology dynamic core of WRF-NMM (Nonhyrostatic Mesoscale Model) on the B grid (WRF-NMMB) with upgraded tracer advection scheme.…”

Summertime weekly cycles of observed and modeled NO<sub>x</sub> and O<sub>3</sub> concentrations as a function of satellite-derived ozone production sensitivity and land use types over the Continental United States

“…This paper is dedicated to the memory of NOAA ARL Air Quality Group Lead, Daewon Byun (1955-2011, whose leadership and pursuit of scientific excellence continue to inspire us. The authors are grateful to two anonymous reviewers, other members of the NOAA ARL Air Quality Group and NOAA NCEP modeling group members, particularly Rick Saylor and Ariel Stein, for contributing their insightful comments, Fantine Ngan for preparing for chemical boundary conditions, and Jeff McQueen and Ivanka Stajner for their technical input and discussion.…”