Pandemic to Present Ozone Analysis Comparison: LiDAR's Role in Urban Air Quality Monitoring

Ozone in the atmosphere can be identified to negatively impact the environment and human health. The air quality impacted by the ozone can be determined by obtaining backscattered ozone profiles using the Ozone Differential Absorption LiDAR (DIAL). The DIAL system works based on an on-band (289 nm) and off-band (299 nm) method. The LiDAR returned signals in the “on" band is strongly absorbed by ozone, while at nearly 299 nm, has a weak absorption. Comparing the received LiDAR signals at the two wavelengths, the ozone concentration is settled to deduce the ozone mixing ratio by dividing the LiDAR returns at the two wavelengths. In support of our analysis, we also use information retrieved from the Ceilometer, CIMEL, Microwave Radiometer, and HYSPLIT backward trajectories. These systems acquire data simultaneously with the Ozone DIAL from a determined day, allowing for the interpretation of atmospheric processes. Our analysis indicates that ozone is found in high concentrations above the allowed threshold level at altitudes as low as 2.5 km. The ozone alert threshold for human health has a severe impact at 240 µg/m³ (122.25 parts per billion- ppb). Our lungs can withstand at most a maximum of 120 µg/m³ (61.125 ppb) for no more than 25 days a year, while the safety health standard stands below 70 ppb concentrated over an average of 8 hours, which is surpassed by the concentrations measured at various altitudes above the location of our DIAL system, found at City College of The City University of New York. Additionally, we are conducting a comparison of ozone levels between the present day and during the COVID-19 pandemic, to understand the impact of reduced human activity on ozone concentrations in the lower atmosphere. This research aims to investigate the multifaceted aspects of ozone, focusing on three primary areas: tropospheric ozone sources and concentrations, ozone monitoring and measurement. By utilizing LiDAR data and in situ measurements of ozone concentrations, we are modeling ozone's consequence on the territory and notably on human health. Additionally, the research will examine the formation and sources of ground-level ozone, a significant component of urban smog, through air quality monitoring and data analysis. The health impacts of tropospheric ozone on respiratory and cardiovascular systems, as well as its effects on agriculture and natural vegetation, will be a key focus.