EOL Seminar: Around the World in 21 days: Mapping the Global Aerosol during the Atmospheric Tomography (ATom) Project

Tuesday, February 28, 2017 - 09:15
FL2-1022 Large Auditorium
Contact Name: 
Holger Voemel
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Around the World in 21 days: Mapping the Global Aerosol during the Atmospheric Tomography (ATom) Project

Dr. Charles Brock


Aerosol particles in the atmosphere originate from direct emissions (biomass burning, dust, sea-spray) but also from condensation from the gas phase (secondary formation from sulfur, nitrogen, and organic species). Global models estimate that about half of cloud-nucleating particles originate from these secondary formation processes in the free troposphere, yet they are poorly studied. NASA's ATom project provides a unique opportunity to increase knowledge of the sources of particles in the remote free troposphere. ATom uses the NASA DC-8 aircraft to expand on the example provided by HIPPO by repeatedly profiling from 200 m to 12 km in the center of both the Pacific and Atlantic in four seasons.  Two of the four ATom missions have been completed to date.

During ATom, NOAA is operating a suite of instruments for measuring fast response aerosol size distributions from 3 to 3000 nm in diameter. These measurements show high concentrations of newly formed particles in the tropical upper troposphere. These particles grow in descending air outside of convection because of coagulation and condensation of gas-phase species, and ultimately become large enough to be effective cloud nucleating particles. This region of tropical particle production and growth is large enough to be a globally significant source of cloud-active particles. The ATom measurements provide strong constraints on global models, which must replicate the observed patterns of particle production and growth to accurately simulate cloud radiative properties in the remote troposphere.

Seminar webcast at: http://www.fin.ucar.edu/it/mms/fl-live.htm‚Äč

Tuesday March 7, 2017


3450 Mitchell Lane, Boulder