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You are here: Home / SARP / SARP 2015 / 2015 Student Presentations / Whole Air Sampling / Diurnal Variability of Regional Transport and its Effects on Air Quality in Palmdale

Diurnal Variability of Regional Transport and its Effects on Air Quality in Palmdale

Kylie A. Holmes, Ohio University

Abstract: Five research flights were conducted aboard NASA's DC-8 during the Student Airborne Research Program (SARP, 2015), based out of Palmdale, CA. Using UC Irvine’s whole air sampler onboard the DC-8, samples were collected and later analyzed by gas chromatography for 83 unique volatile organic compounds (VOCs). To study the effect of regional transport on air quality in Palmdale, the final portion of each flight (i.e. the landing in Palmdale) was analyzed. On June 23 and 24, the DC-8 flew two consecutive research flights (one in the morning and one in the afternoon on each day), which allowed for analysis of conditions at different times of day. During these four flights, higher mixing ratios of VOCs and criteria pollutants (such as ozone) were observed over Palmdale during the afternoon flights. Using NOAA's HYSPLIT trajectory model, it was found that the air in Palmdale was coming from two different regions depending on the time of day. To further investigate the source of these air masses, surface observations of ozone from an air quality monitoring station in Lancaster were analyzed for the entire month of June. Similar transport patterns were shown to be a regular occurrence and not an anomaly encountered only during SARP. From these surface measurements, we conclude that during the morning, Palmdale was strongly influenced by northerly flow from Bakersfield, and by southwesterly flow from Los Angeles during the afternoon. This work can help influence policy-makers to better understand air quality in regions that are downwind of LA.