Identification of dust events in the greater Phoenix area

Abstract

Dust events are common in Arizona, USA, causing significant impacts on air quality and human health. Several previous studies have compiled an analysis of the dust event climatology for the state of Arizona, yet very few used multiple Meteorological Aerodrome Reports (METARs) to determine their occurrence, seasonality, cause, and duration. In this project, we identified dust events based on measurements taken from nine different METAR Automatic Surface Observation Systems (ASOS) from the greater Phoenix area in Arizona. A total of 531 dust events were identified from 2005 to 2021. Each dust event was examined for the meteorological disturbance (synoptic and convective) that caused it. Dust events were analyzed for different meteorological characteristics (temperature, dew point, relative humidity, wind speed, wind gust, and visibility), temporal patterns, and the impacts of different climatological indices and drought conditions. Each dust event was categorized based on its intensity as either a blowing dust event or a dust storm based on the lowest visibility recorded. Separation based on cause and severity was then performed to further analyze differences in the aforementioned meteorological characteristics and parameters during dust events. Notable seasonality, causality, and temporal trends consistent with the occurrence of the summer monsoon season were found, with differences in meteorological parameters when analyzed by cause and intensity consistent with previous studies. Observations of Particulate Matter (PM) concentrations during dust and non-dust times reveal the impact of these dust events on PM₁₀ and PM_2.5 concentrations.