Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: July 18, 2002
Publication Date: November 4, 2002
Citation: Sumner, D.M., Sigua, G.C. 2002. Estimating high-resolution atmospheric deposition of chloride in coastal florida. 2002 American Society of Agronomy Meetings, Indianapolis, IN.
A method is presented to discern hourly fluctuations in atmospheric deposition of precipitation-derived chloride from weekly composites of collected rainfall. The scavenging of atmospheric chloride by rainfall was conceptualized as intense during the initial part of a rainfall event, but decreasing in intensity as the event progressed and the atmosphere became progressively depleted in chloride. The method was applied to rainfall data collected during 1997-1998 over a 61-week period at a site about 20 kilometers inland near Daytona Beach, Florida. Data included hourly rainfall totals, chloride concentrations of weekly rainfall composites, and wind speed and direction. An atmospheric scavenging model explained 70 percent of the variation in measured weekly atmospheric deposition. The model results indicated that more than 91 percent of precipitation-deposited chloride is derived from the Atlantic Ocean. The effectiveness of strong winds from the ocean in transporting chloride landward was defined. The removal efficiency index function for seaward winds indicates that the potential for removal of atmospheric chloride by rainfall decreases sharply after the initial few millimeters of an event.