Project Number: 20-004

Research

Title: Galveston Offshore Ozone Observation (GO3)

Institution(s) Represented: University of Houston - James Flynn, St. Edward's University - Paul Walter

Lead PI: James Flynn, Paul Walter

AQRP Project Manager: Vincent Torres

TCEQ Project Liaison: Doug Boyer

Awarded Amount: $201,754.00

Abstract

This project addresses the 2020-2021 Texas Air Quality Research Program Priority Area of Monitoring Ozone in Galveston Bay and Offshore. The project aims to deploy two small automated sampling systems on commercial boats operating in Galveston Bay (Larry Willis, commercial shrimper) and the offshore waters adjacent to Galveston Island (Ryan Marine Services, crew launch boat operator) to collect routine measurements of ozone (O3) and meteorology, including boundary layer height, during July-October 2020 through a collaboration with the University of Houston (UH) and St. Edward's University (SEU). A third boat, owned and operated by UH, will be utilized for special studies in Galveston Bay, as well as for launches of up to 20 ozonesondes, to examine vertical profiles of O3 and confirm ceilometer measurements of boundary layer height. Coupled with three-dimensional (3-D) chemical transport modeling, this study will shed light on the conditions and processes that may result in high O3 over the water and subsequent impacts on the HGB urban area.

The study is designed to focus on the following primary science questions:

How frequently does high ozone reside over the water during the ozone season, and how does the observed frequency compare to that simulated by photochemical models?
How does O3 over water compare with O3 and OX (O3 + nitrogen dioxide (NO2)) over adjacent land?
How is O3 formation over the water impacted by local circulation patterns?
What are the characteristics of the boundary layer over the water during high O3 events, and how do the observed boundary layer heights compare to model predicted heights?
How do small O3 and meteorology sampling systems installed on commercial vessels help us better understand O3 in Galveston Bay and the Gulf of Mexico?

The proposed instrumentation packages will include an O3 monitor, global positioning system (GPS) receiver, all-in-one weather station, and a ruggedized PC with a cellular data connection. The package will operate autonomously when power is available. A ceilometer will be installed on one of the vessels to measure boundary layer height over the water, which is often parameterized in photochemical models and can have a significant impact on model results. The data, which is logged locally, will be sent to servers at UH when within cellular coverage.

Modeling activities will utilize the Weather Research and Forecasting (WRF) driven GEOS-Chem (WRF-GC). The model will simulate ozone distributions in the HGB region during the measurement periods with a focus on ozone over the water and land-water ozone gradient. WRF has a powerful and flexible grid system, including multiple nested grids and moving nested grids. For the proposed work, the inner-most model domain of WRF-GC will be set over the sampling areas as well as the area surrounding the bay which will include the monitors used for comparisons at a resolution of 1 km x 1 km, allowing replications of fine-scale temporal and spatial dynamics specific to coastal regions such as sea/bay breeze. In addition to confirming the presence or absence of high O3 over the water and the conditions which occur during high O3 events, the results from this project are expected to provide more accurate parameterizations for future modeling studies and to identify partners and methodologies for additional studies.

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Research

Research

FY 2020 - 2021

Project Number: 20-004