Scot Turnbull Martin | Harvard University - Estados Unidos

• Grant number: 07/03300-4
• Support type: Research Grants - Visiting Researcher Grant - International
• Duration: October 01, 2007 - March 28, 2008
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal researcher: Paulo Eduardo Artaxo Netto
• Grantee: Paulo Eduardo Artaxo Netto
• Visiting researcher: Scot Turnbull Martin
• Visiting researcher institution: Harvard University, Cambridge, United States
• Home Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This FAPESP visiting scientist request is part of the experiment called AMAZE (Amazonian Aerosol characteriZation Experiment), that is being organized under the coordination of Scot Martin and Paulo Artaxo, with the participation of Meinrat O. Andreae from the Max Planck Institute. It aims at understanding the physical and chemical properties of natural biogenic aerosols in Amazonia, and their influence on cloud nucleation properties, with advanced aerosol characterization instrumentation, never before used to measure tropical aerosols. The two main questions to be addressed in Amaze are: 1) What SOA production mechanisms are active at a pristine continental site and what factors regulate their temporal variability?; 2) Can we predict and understand the cloud-forming properties of natural biogenic aerosols in Amazônia? Two different Aerosol Mass Spectrometers (AMS) will be used to measure the composition and size of particles, with very high resolution in time and chemical speciation. It will be possible to determine nitrates, sulfates and several components of organic aerosols with very high time resolution. This will allow detailed measurements of the diurnal variability of aerosol composition and chemical properties. Parallel measurements will be made of physical properties of particles. These will include light absorption and scattering (nephelometer), particle number size distributions (SMPS), cloud condensation nuclei measurements (CCNC instrument), and for the first time in Amazonia the measurement of ice nuclei concentrations (CFDC instrument). Ice nuclei are critically important in glaciated clouds, such as clouds that result from strong vertical convection. Several trace gases will also be measured in parallel, including CO, NOx, SO2, O3 and VOCs. Detailed VOC measurements will be done using a Proton Transfer Reaction Mass Spectrometer (PTR-MS) that will run in parallel to the AMS to observe the production of secondary aerosols from VOCs. Measurements will be done at the INPA ZF2 K34 tower, with the operation of a container to be installed at the base of the ZF2 K34 tower. Facilities are being upgraded to allow the extensive set of instruments to be operated at the tower. The experiment is scheduled to run in January and February 2008, while the visiting scientist program for Scot Martin will run from October 2007 to March 2008. (AU)