Frequency and Character of Extreme Aerosol Events in the Southwestern United States: A Case Study Analysis in Arizona

Abstract

This study uses more than a decade’s worth of data across Arizona to characterize the spatiotemporal distribution, frequency, and source of extreme aerosol events, defined as when the concentration of a species on a particular day exceeds that of the average plus two standard deviations for that given month. Depending on which of eight sites studied, between 5% and 7% of the total days exhibited an extreme aerosol event due to either extreme levels of PM10, PM2.5, and/or fine soil. Grand Canyon exhibited the most extreme event days (120, i.e., 7% of its total days). Fine soil is the pollutant type that most frequently impacted multiple sites at once at an extreme level. PM10, PM2.5, fine soil, non-Asian dust, and Elemental Carbon extreme events occurred most frequently in August. Nearly all Asian dust extreme events occurred between March and June. Extreme Elemental Carbon events have decreased as a function of time with statistical significance, while other pollutant categories did not show any significant change. Extreme events were most frequent for the various pollutant categories on either Wednesday or Thursday, but there was no statistically significant difference in the number of events on any particular day or on weekends versus weekdays.

The Lake Urmia environmental disaster in Iran: A look at aerosol pollution

“…However, high NDVI values suggest that there should be suppressed dust emissions due to more vegetation (Indoitu et al, 2015; Lopez et al, 2015). Aside from NDVI, other environmental parameters in Table S1 did not exhibit anomalously different values in July of 2003.…”

The Effect of Ambient Titanium Dioxide Microparticle Exposure to the Ocular Surface on the Expression of Inflammatory Cytokines in the Eye and Cervical Lymph Nodes

“…16 This limit value for short-term PM 10 concentrations is often exceeded in various cities across Europe, Asia, and the United States. [17][18][19] In terms of exposure duration, a previous study 11 has shown distinct differences in results between rabbits that underwent TiO 2 instillation in the eye for 4 days and rabbits that underwent a single instillation of TiO 2 in the eye.…”

Impacts of climate and synoptic fluctuations on dust storm activity over the Middle East

“…They found a teleconnection between Sahel precipitation and exogenous (i.e., Saharan) dust emissions resulted from an increase in Saharan wind speed in years of above average Sahel precipitation. In addition to regional factors, long range transport of dust and other emissions such as from fires can also significantly impact surface dust levels in areas thousands of kilometers downwind (e.g., Crosbie et al, 2014; Lopez et al, 2016). …”