10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Characterization of Haboob Dust Storms in Phoenix, AZ
PIERRE HERCKES, Denise Napolitano, Aurelie Marcotte, Jershon Eagar, Matthew Fraser, Arizona State University
Abstract Number: 888 Working Group: Aerosols in Earth System
Abstract During the summer monsoon season Arizona, very intense dust storms, or haboobs, can occur. These dust storms, characterized by a clear moving front can last from minutes to hours and can substantially impact the local air quality by a sharp increase in particulate matter (PM) and bring an influx of PM material from other locations, impacting local deposition fluxes.
During the monsoons seasons 2013 and 2014, background urban PM samples and the PM of haboob events (PM2.5 and PM>2.5) were collected on the Arizona State University Tempe Campus. Samples were analyzed for trace metals, organic and elemental carbon and organic molecular marker species such as polycyclic aromatic hydrocarbons (PAH) and sugars.
The PM10 concentrations in these dust storms are typically on the order of 100s µg/m3 and can exceed 1,000 µg/m3 for short periods of times. PM2.5 concentrations also increase typically by a factor 5-10 compared to pre-haboob conditions. The chemical characterization shows that the dominant component of these dust storms is mineral dust, consistent with the formation mechanism of these storms as storm fronts entrain desert soil in monsoon storm outflows. However chemical analysis also shows a general increase of all species, not only crustal component. In fact elements associated with an anthropogenic activities, such as lead, cadmium, and antimony are also substantially increased in the fine particles during these events. This suggests a strong resuspension of urban and street dust. The latter is consistent with organic molecular marker species which show also a substantial increases (e.g. factor of 5 for PAH in PM2.5). The composition data will be further discussed relative to non-haboob dust events and background urban PM.