Grantee Research Project Results
Enhanced Characterization of Ambient Fine Particulate Matter Through Complementary Data Integration and Improved Measurement InstrumentationEPA Grant Number: F5B10206
Title: Enhanced Characterization of Ambient Fine Particulate Matter Through Complementary Data Integration and Improved Measurement Instrumentation
Investigators: DeCarlo, Peter Francis
Institution: University of Colorado at Boulder
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 2005 through December 31, 2007
Project Amount: $99,874
RFA: STAR Graduate Fellowships (2005) RFA Text | Recipients Lists
Research Category: Academic Fellowships
Ambient fine particulate matter (PM2.5) has many important effects including visibility degradation, effects on radiation balance (climate) and the hydrological cycle, and adverse effects on human health. An improved characterization of particulate matter is critical to our understanding of its effects and to the development of rational and effective mitigation policies. The effects of fine PM are strongly dependent on one extensive property (its concentration) and 3 intensive physical properties: size, chemical composition, and physical shape (or morphology). If we are to quantify the effects of PM we must measure these four properties with high time resolution (minutes). No single instrument is capable of measuring concentration, size, composition, and shape with high time resolution for all particle types. This project focuses on integration of complementary measurements from different instruments in order to fully characterize the ambient particulate matter as well as improvement of current measurement techniques through instrument development.
The objectives of this research project are to:
- Improve fine particulate matter characterization through the integration of data from complementary measurements into a chemically and size resolved description of fine particulate matter.
- Further develop the Aerodyne Aerosol Mass Spectrometer for improvements in sensitivity, time resolution, and single particle capabilities.
To address objective one, an algorithm is in development hat integrates scanning mobility particle sizer data (SMPS) with Aerodyne Aerosol Mass Spectrometer (AMS) data, and determines a size and chemically resolved particle population that is consistent with both measurements. This algorithm is being applied to ambient data. This algorithm will also allow for "closure studies" to be performed in which aerosol measurements are used to predict aerosol behavior such as light scattering or cloud condensation nuclei (CCN) activation, and then compare the predicted behavior with the measured behavior.
To address objective two, the next generation Aerosol Mass Spectrometer (AMS) instrument improves upon the original version by switching from a quadrupole (Q-AMS) to a time-of-flight mass spectrometer (ToF-AMS), while maintaining the quantitative capabilities. My part of the project involves the development of a new data-acquisition and instrument control software required for the development of the next-generation AMS. I am leading the implementation and testing of this software, in collaboration with Aerodyne Research (ARI).
Improvements in fine particle characterization will allow for a more complete understanding of the processes particle in the atmosphere undergo. The integration of complementary measurements into a compact mathematical form, allows for ease of transfer from particle measurements to models, leading the way for closure studies. We expect to be better able to characterize and transfer ambient data to models of aerosol behavior. In addition better measurement techniques with higher sensitivity and selectivity will enhance the quality of data, which in turn allows for better understanding of particulate matter in the atmosphere.