Science Inventory

Performance Evaluation of the Meteorology and Air Quality Conditions From Multiscale WRF-CMAQ Simulations for the Long Island Sound Tropospheric Ozone Study (LISTOS)

Citation:

Torres-Vazquez, A., J. Pleim, R. Gilliam, AND G. Pouliot. Performance Evaluation of the Meteorology and Air Quality Conditions From Multiscale WRF-CMAQ Simulations for the Long Island Sound Tropospheric Ozone Study (LISTOS). JOURNAL OF GEOPHYSICAL RESEARCH: ATMOSPHERES. American Geophysical Union, Washington, DC, 127(5):e2021JD035890, (2022). https://doi.org/10.1029/2021JD035890

Impact/Purpose:

The Long Island Sound Tropospheric Ozone Study (LISTOS) was a multi-agency collaborative field campaign conducted during the summer of 2018 with the goal to improve the understanding of ozone chemistry and transport from New York City to areas downstream, especially the Long Island Sound and adjacent Connecticut coastline. Measurements made during this campaign were leveraged to test and evaluate the WRF-CMAQ coupled model at high spatial resolutions (12 km, 4 km and 1.33 km grid lengths). Special focus was paid to the model’s representation of sea breeze circulations, low level jets and boundary layer evolution. The evaluation suggests using higher resolutions resulted in improved surface meteorology statistics throughout the whole summer, while 4 km grid spacings were found to provide the biggest advantage when simulating ozone over the region of interest. Case studies of two high ozone concentration events that summer (July 10 and August 6) revealed that sound breezes and low-level jets had a critical role in transporting pollutant rich shallow marine air masses from the Long Island Sound inland over the Connecticut coast. Modifications were made to the representation of sea surface temperatures to improve the model’s near-surface temperatures, resulting in better surface ozone concentrations.

Description:

The Long Island Sound (LIS) Tropospheric Ozone Study was a multi-agency collaborative field campaign conducted during the summer of 2018 to improve the understanding of ozone chemistry and transport from New York City to areas downstream, especially the LIS and adjacent Connecticut coastline. Measurements made during this campaign were leveraged to test and evaluate the coupled WRF-CMAQ model at 12 km, 4 and 1.33 km horizontal grid spacing. Special attention was placed on the model's representation of sea breeze circulations, low level jets, and boundary layer evolution. The evaluation suggests using higher resolutions resulted in improved surface meteorology statistics throughout the whole summer, with temperature biases seeing the biggest statistical improvements when using 1.33-km grid spacing, going from −0.12 to 0.08 K. Additionally, 4-km grid spacing provided the biggest advantage when simulating ozone over the region of interest, with biases being reduced from 2.40 to 0.57 to 0.37 ppbV with increased resolution. Case studies of two high ozone concentration events (July 10 and August 6) revealed that sound breezes and low-level jets had a critical role in transporting pollutant-rich, shallow marine air masses from the LIS inland over the Connecticut coast. Modifications were made to the representation of sea surface temperatures, which subsequently improved the simulation of surface ozone predictions.