The Dynamical Role of the Chesapeake Bay on the Local Ozone Pollution Using Mesoscale Modeling—A Case Study

Atmosphere

John T. Sullivan¹  Zhifeng Yang²  Belay Demoz²  Rubén Delgado²  Andrew Tangborn³  Pius Lee⁴ 

[1] Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA;Department of Physics, University of Maryland Baltimore County, Baltimore, MD 21250, USA;Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD 21250, USA;NOAA Air Resources Laboratory (ARL), NOAA Center for Weather and Climate Prediction, 5830 University Research Court, College Park, MD 20740, USA;

关键词: the Chesapeake Bay (CB);    O₃;    water;    bay breeze;    dynamics;    planetary boundary layer;   

DOI  :  10.3390/atmos13050641

来源: DOAJ

【 摘 要 】

This study investigated the dynamic influence of the Chesapeake Bay (CB) on local ozone (O₃) concentration and distribution using a weather forecasting model. The Weather Research and Forecasting model coupled with Chemistry (WRF–Chem) was employed to simulate O₃ production and transportation near the CB. Baseline (water) as well as sensitivity (nowater) model experiments of bay circulation were carried out with and without bay water by changing the water surface from water to land (loam). First, the model performance simulating O₃ was evaluated using the baseline experiment results and AirNow surface wind and O₃ observations. The results showed that the model overestimates surface O₃ by up to 20–30%. Further, the comparisons of the baseline and sensitivity experiments revealed higher O₃ mixing ratios, primarily due to the resulting bay breeze circulation. These increases, after considering model overestimation, represent a mean bay dynamics circulation-induced contribution of up to 10% at night and 5% during the day. Furthermore, the boundary layer over northern CB, where it is at its narrowest width, was higher (by 1.2 km on average) during daytime due to higher surface temperatures observed. The boundary layer depth difference between the northern, central, and southern regions of the bay leads to a differential in the role of bay circulation dynamics in the observed O₃ increase. The relatively wider swath of water surface over southern CB resulted in a lower boundary layer depth and stronger breeze circulation and this circulation contributed to O₃ concentrations. Moreover, since the case selected has a minimal bay breeze circulation, the associated surface ozone enhancements represent what is expected at least at a minimum.

【 授权许可】

Unknown