Assessing the relationship between dust events and water chemistry in the Tempe Town Lake time-series data

Printer-friendly version

The CAP-LTER has been monitoring basic water chemistry and dissolved organic carbon concentrations in Tempe Town Lake (TTL) since 2005. The lake is a man-made reservoir in the channel of the Salt River in Tempe, AZ and provides a range of ecosystem services. Complex patterns in dissolved organic carbon (DOC) concentration and in conductivity (salinity) suggest that biogeochemical cycling in the lake responds to meteorological  events and anthropogenic activity. We have also begun monitoring the frequency and intensity of dust storms (haboob events). Here we present results of a study to classify seasonal dust storms and model dust deposition from these events in the greater Phoenix area. Dust events were characterized by meteorological and air quality signatures including high PM10, wind speed, and visibility. Where possible, dust events were confirmed with news reports, webcam archives, and social media posts. The majority of the larger (> 125 mg/m³) dust events occur during the summer monsoon (Jul-Sep). We are now comparing dust deposition events with water chemistry in order to assess whether intermittent increases in conductivity and DOC concentration can be correlated with dust storms. Elucidating the importance of dust storms in transporting large amounts of airborne matter into the CAP-LTER region may be relevant to other urban areas experiencing years of unusual dryness