Air Quality

AER scientists perform cutting-edge research on atmospheric chemistry, pollutant dispersion, and the dependence of both on meteorology for a variety of agencies (e.g. NSF, NASA, NOAA). AER’s Air Quality team uses the scientific and technical expertise gained in these efforts to support federal, regional, state, local, and tribal air quality agencies, as well as non-profit and industry clients, in addressing their air quality challenges. We work with our clients to design air quality modeling and data analysis studies that meet our clients’ scientific, technical, and regulatory needs while staying within the required schedule and budget.

AER Air Quality services include:

  • Photochemical and Air Quality Modeling at Urban to Global Scales
  • High-Resolution and Ensemble Meteorological Modeling
  • Air Quality and Meteorological Data Analysis
  • Modeling and Analysis Support for the Development of State Implementation Plans (SIPs) and Demonstrations of Exceptional Events
  • Lagrangian and Eulerian Dispersion Modeling
  • Emission Modeling
  • Inverse Modeling to Improve Emission Inventories at Urban to Global Scales
  • Air Quality Forecasting
  • Meteorological and Chemical Data Assimilation

Selected Projects

Questions? To discuss your Air Quality challenges, please contact Matthew Alvarado and Thomas Nehrkorn using the Contact Us page.

Selected Projects Details

On-site Air Quality Support for the NOAA Air Resources Laboratory
AER provides on-site scientific support for Air Quality Research and Development to the NOAA Air Resources Laboratory. Under this contract AER provides specified support for NOAA ARL’s research into developing optimal meteorological analyses for use in off-line dispersion modeling, data assimilation in air quality models, and computational methods for quantifying source-receptor relationships.

Meteorological Modeling for Texas Commission on Environmental Quality (TCEQ) Air Quality Studies
AER is developing and validating an improved configuration of the WRF model to provide the Texas Commission on Environmental Quality (TCEQ) with high spatial- and temporal-resolution meteorological fields for the NASA DISCOVER-AQ Houston campaign. The model configuration has an inner grid with a 1.33 km horizontal resolution to provide better representation of the meteorology leading to O3 exceedances in Houston. AER is incorporating a 1 km resolution sea surface temperature analysis into WRF to better represent the Galveston Bay Breeze, and is using an Urban Canopy Model to account for the interaction between the urban landscape of Houston and the atmosphere.

Investigating the Controls of Urban O3 and PM2.5 for TCEQ
AER is researching the controls of O3 and PM2.5 in six urban areas in Texas for the Texas Commission on Environmental Quality (TCEQ). For each urban area, AER is analyzing air quality data provided by TCEQ to:

  • Determine the effects of meteorology on trends in O3 and PM2.5 by fitting a generalized additive model for O3 and PM2.5 concentrations to selected meteorological variables.
  • Estimate the regional background concentrations of O3 and PM2.5.
  • Investigate the synoptic and urban-scale conditions that are associated with high concentrations of O3 and PM2.5.

Identifying and Quantifying Natural Gas Leaks in Boston for the EDF
AER participated in a Harvard-led study of the contribution of natural gas leaks to emissions of methane in the Boston area. The study, partially funded by the non-profit Environmental Defense Fund (EDF) and published in the prestigious journal Proceedings of the National Academy of Sciences, found that about 2.7% of all natural gas delivered to the region was being lost to leaks from homes, businesses, and electricity generation facilities, substantially more than estimated by government authorities (1.1%).

The WRF-STILT model used in this project was developed at AER and is the linchpin of multiple GHG-related efforts worldwide. On-going applications of WRF-STILT include studies of methane emissions over the Arctic and of carbon dioxide emissions over the Northeast corridor of the US.

Forecasting Dust Storms for the Air Force
AER substantially improved the ability of the Air Force to forecast dust storms using the WRF-Chem model. After determining that the original dust emission parameterization included in WRF-Chem resulted in a large number of false predictions of dust storms, AER designed and implemented a new dust emission parameterization with updated physics into WRF-Chem along with a high-resolution map of dust source regions, approaches for improved soil moisture handling, and a dynamic vegetation mask. AER then validated this updated dust storm forecast system using dust hazard reports, surface visibility observations, and aerosol optical depth (AOD) observations from surface and satellite instruments. The updated forecast substantially decreased the number of false dust storm predictions and improved overall forecast skill by 30%, and the new dust parameterization is now the recommended dust emission parameterization for WRF-Chem.

Advancing the Use of Satellite Observations to Study Air Quality
AER is a leader in the development, validation, and use of satellite retrievals for air quality and atmospheric chemistry studies. AER has worked on the development of trace gas retrievals from NASA’s Tropospheric Emission Spectrometer (TES) for species such as methane, ammonia, formic acid, and methanol. In 2014, AER led the Cross-track Infrared Spectrometer (CrIS) Atmospheric Chemistry Data User’s Workshop to develop a strategic plan to use CrIS observations in air quality and atmospheric composition research. AER is currently leading the development of ammonia and carbon monoxide retrievals from CrIS and their application to NOAA’s CalNex and SENEX air quality studies.

Expert Evaluation of Meteorological Inputs for Air Quality Modeling for SESARM
AER led a detailed analysis of the WRF meteorological fields provided by the Southeastern States Air Resource Managers, Inc. (SESARM) to determine if the data were suitable for subsequent use in air quality modeling. Ten WRF model configurations were evaluated using a combination of objective analysis (WRF-MET software to compare the model data to meteorological observations) and expert judgment. AER then designed a simple-to-use website that gave access to all of the objective evaluation results in graphical and text formats. This permitted rapid dissemination of hundreds of thousands of validation results to SESARM and its members.