GOAMAZON-TEM

Observations and Modeling of the Green Ocean Amazon: TEM of Aerosol Particles

1 February 2014 - 14 October 2014

Lead Scientist: Peter Buseck

Observatory: AMF , MAO

Atmospheric samples collected from the Amazon Basin, a major source of natural continental aerosols impacted seasonally by biomass burning and urban emissions, are important indicators of atmospheric reactions and their effects on climate and health. We used transmission electron microscopy (TEM) to determine the spatially resolved compositions, sizes, morphologies, mixing states (aggregated, coated, embedded), and reactions to changes in relative humidity of aerosol particles of natural and anthropogenic origin. Specific goals were to: 1) determine the compositions, sizes, shapes, mixing states, and phases of different particle types such as ns-soot, tar balls, mineral dust, and organic particles as well as coarse particles such as fragments of plants and insects, pollen grains, algae, fern spores, and fungal spores in Amazonia and near Manaus; 2) develop new TEM methods for characterizing the organic material (OM) on or within individual particles in order to obtain compositional details and properties of primary and secondary biogenic organic particles; 3) apply those results to explain micro-chemical processes between reactive gases (e.g., BVOC, SO2, and NOx) and particles during particle growth; and 4) compare monitoring-mode measurements, as well as those from fast-throughput techniques like AMS, with detailed TEM particle measurements.