Grantee Research Project Results
2002 Progress Report: Real-Time Monitoring of Individual Atmospheric Aerosol Particles: Establishing Correlations Between Particle Size and Chemical Speciation
EPA Grant Number: R826240Title: Real-Time Monitoring of Individual Atmospheric Aerosol Particles: Establishing Correlations Between Particle Size and Chemical Speciation
Investigators: Prather, Kimberly A.
Institution: University of California - Riverside
EPA Project Officer: Hahn, Intaek
Project Period: February 1, 1998 through January 31, 2001
Project Period Covered by this Report: February 1, 2002 through January 31, 2003
Project Amount: $547,000
RFA: Ambient Air Quality (1997) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air
Objective:
The objectives of this research project involve using a newly developed aerosol analysis technique developed in our laboratory, aerosol time-of-flight mass spectrometry (ATOFMS), for taking real-time measurements of the individual particle size and composition of ambient aerosols in a variety of locations in the United States. ATOFMS couples time-of-flight aerodynamic sizing with laser desorption ionization (LDI) time-of-flight mass spectrometry, simultaneously measuring the size and chemical composition (as anions and cations) of individual aerosol particles in real time. One major objective of this research project involves establishing how particle size and composition vary at different locations. Single-particle signatures will be used to explore particle changes due to aging/chemistry, as well as to obtain information on particle sources in different regions of the United States. These studies will represent the first long-term studies, so efforts will be made to convert the qualitative data into more semiquantitative information on atmospheric particles that can be compared with other gas-phase, particle-phase, and meteorological data to further our understanding of aerosol chemistry on shorter time scales. The original objectives of this research project were modified slightly when the U.S. Environmental Protection Agency (EPA) Particulate Matter (PM) Supersites Program began. Originally, ATOFMS was going to be used for PM sampling in southern California, but when the EPA Supersites Program began, this was viewed as a unique opportunity to conduct research on PM in various air masses with unique chemistry across the United States, with the added benefit of having other state-of-the-art PM and gas-phase measurements made simultaneously.
Progress Summary:
Atlanta Ultrafine Study (August 2002). The final field study of this research project was a second study conducted at the Jefferson Street location in Atlanta (i.e., the same location as the 1999 Atlanta Supersite study). The data for this study have been imported into the data analysis package, Yet Another ATOFMS Data Analyzer, (YAADA), for scaling and comparison with other measurements. The most obvious findings in the initial stages of data analysis are the rapid changes in composition observed for ultrafine particles.
TexAQS 2000. The ATOFMS results were scaled using sizing instruments, and the results were shown to track temporally with other PM measurements including a nephelometer, Tapered Element Oscillating Microblanace, and Particle Into Liquid Sampler instruments.
1999 Atlanta Supersite. The ATOFMS data from this research project have been scaled and compared with semicontinuous data from other instruments.
New York PM2.5 Technology Assessment and Characterization Study. The analysis of the dataset was sorted into general particle types and their associations. The ATOFMS data are now in the form that will allow for comparison with other semicontinuous measurements made at the site once they become available.
Future Activities:
All of the data from these studies have been imported into a data analysis package in YAADA developed in collaboration between Professor Jon Allen (primary), Professor G. Cass and his group, and the Prather group (see the Web Site below). The next steps will be to compare the ATOFMS data with data from other instruments at these sites. One major objective will be to perform source apportionment of the data from the different locations using single-particle signatures acquired in ATOFMS studies on vehicle emissions (gas and diesel), biomass burning, cooking, dust samples collected in multiple regions in the United States, and coal combustion. In addition, a paper will be written describing how universal the ATOFMS quantitation procedures for nitrate, sulfate, and ammonium are for data acquired in different locations. Another paper will describe similarities and differences in the single particles observed in the Western (CA, AZ), Southeastern (GA), Northeastern (NY), and Central (TX) United States. These datasets will be used to determine whether the ATOFMS can be used to semiquantitatively measure organic carbon, elemental carbon, and metals in particles upon comparison with data from other semicontinuous methods. Ultimately, we plan to compare the data obtained in these studies with regional atmospheric models.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
| Other project views: | All 23 publications | 5 publications in selected types | All 5 journal articles |
|---|
| Type | Citation | ||
|---|---|---|---|
|
|
Liu D-Y, Wenzel RJ, Prather KA. Aerosol time-of-flight mass spectrometry during the Atlanta Supersite Experiment:1. Measurements. Journal of Geophysical Research: Atmospheres 2003;108(D7):8426. |
R826240 (2002) R826240 (Final) |
Exit Exit Exit |
|
|
Middlebrook AM, Murphy DM, Lee S-H, Thomson DS, Prather KA, Wenzel RJ, Liu D-Y, Phares DJ, Rhoads KP, Wexler AS, Johnston MV, Jimenez JL, Jayne JT, Worsnop DR, Yourshaw I, Seinfeld JH, Flagan RC. A comparison of particle mass spectrometers during the 1999 Atlanta Supersite Project. Journal of Geophysical Research: Atmospheres 2003;108(D7):8424. |
R826240 (2002) R826240 (Final) |
Exit Exit Exit |
|
|
Wenzel RJ, Liu D-Y, Edgerton ES, Prather KA. Aerosol time-of-flight mass spectrometry during the Atlanta Supersite Experiment: 2. scaling procedures. Journal of Geophysical Research: Atmospheres 2003;108(D7):8427. |
R826240 (2002) R826240 (Final) |
Exit Exit |
Supplemental Keywords:
air, aerosol, PM, particulate matter, measurement methods, Southeast, Western, Eastern, sulfates, organics, mobile sources, tropospheric, marine, chemical transport, visibility., RFA, Scientific Discipline, Air, particulate matter, Environmental Chemistry, tropospheric ozone, Ecology and Ecosystems, Environmental Monitoring, air sampling, ambient aerosol, chemical characteristics, particle size, aerosol time-of-flight mass spectrometry (ATOFMS), real time monitoring, atmospheric transport, chemical composition, chemical speciation sampling, particle transport, air pollution, ambient pollution control, fine particle formation, ambient measurement methods, aerosol samplingRelevant Websites:
http://atofms.ucsd.edu Exit
http://www.yaada.org Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.