Boundary Layer Profiles of Particle Size Distribution and Trace Gases over Huron, CA during DISCOVER-AQ

The NASA DISCOVER-AQ field campaign is attempting to improve air quality observations from satellites by combining data with surface and airborne sampling platforms. This would enable forecasters to make better predictions about ozone levels and particulates in the air, being better able to differentiate between surface and high altitude phenomena. A high ambient particulate concentration is what made California's San Joaquin Valley (SJV) an area of interest for the study. The SJV is home to a large number of agricultural operations due to its long growing season and a sufficient nearby supply of water from the Sierra Nevada Mountains. During the winter months (Nov-Feb) most of the fields are planed and tilled, processes which throw great quantities of dust and soil into the air. Exacerbating the problem is the mountains themselves, which form the SJV's southern, eastern, and western borders and inhibit free flow of air through the valley. The winter months also typically see strong nighttime temperature inversions that suppress vertical air motion. All these factors combine to put the SJV local population at risk for aggravated respiratory diseases (asthma, silicosis) and infections such as coccidioidomycosis (a/k/a San Joaquin Valley Fever). Millersville University staged operations in Huron, California, and was responsible for profiling the lower atmosphere between the surface and 500 meters. Profiles were obtained using an aerostat capable of carrying two instrument packages; one outfitted for particle size distribution and the other for trace gas (NOx and Ozone) measurements. PM data was acquired using a TSI Aerodynamic Particle Sizer (APS). Trace gas profiles were obtained using 2B Technologies NOx and Ozone monitors. Aerostat profiles of particulate matter and chemical concentrations were combined with those taken by the NASA P3-B during spirals between 300 and 3000 meters. This paper will discuss preliminary findings of particle size distribution and trace gas concentrations and their relation to meteorological parameters during aircraft flyovers.