Comparison of Size-Resolved Aerosol Chemical Composition Measurements Made Under Ambient and Low Relative Humidity Conditions at Trinidad Head During the ITCT 2k2 Experiment

Two co-located, 8-stage rotating drum impactors were deployed at the Trinidad Head site from April 21 - May 26, 2002 as part of the Intercontinental Transport and Chemical Transformation (ITCT) 2k2 experiment. One of the samplers operated at ambient relative humidity while the other had a heated inlet tube that maintained the relative humidity at a low value. The impaction substrates from these samplers were analyzed using synchrotron X-ray fluorescence at the Advanced Light Source (Lawrence Berkeley National Laboratory). The extreme sensitivity of this analytical technique permitted the quantification of nearly all elements between sodium and lead with 3-hour time resolution. The data from these paired samples will be used to show how drying the aerosol affected the mass distribution of the common soil elements, sea salt, and non-sea-salt sulfate at this coastal site.