Detection of Ambient Ultrafine Aerosols by Single Particle Techniques During the SOAR 2005 Campaign

Figures & data

TABLE 1 Instrumentation

Instrument	Make & model	Measurement	Averaging interval
Scanning Mobility Particle Sizer (SMPS)	TSI Model 3936L10	Particle number concentration (15–866 nm)	5 min
Ultrafine Condensation Particle Counter (UF-CPC)	TSI Model 3025A	Particle number concentration (> 3 nm)	1 min
Ultrafine Aerosol Time-of-Flight Mass Spectrometer (UF-ATOFMS)		Chemical composition (50–400 nm)	Real-time
Aethalometer	Magee Scientific AE-3 Series	Optical absorption cross-section per unit mass	5 min
CO Analyzer (summer)	TEI Model 48CTL	CO concentration levels	30 min
CO Analyzer (fall)	Ecotech EC 9830	CO concentration levels	1 min
Chemiluminescence NO-NO2-NOx Analyzer	TEI Model 42C	NO & NOx concentration levels	1 min
UV Photometric O3 Analyzer	TEI Model 49C	O3 concentration levels	1 min
TEI: Thermo Environmental Instruments.

FIG. 1 Hourly UF-ATOFMS counts of single particles for which chemical information was obtained as a function of aerodynamic diameter during the summer (top) and fall (bottom). (Figure provided in color online.)

FIG. 2 Representative mass spectra for the general chemical classes of ultrafine particles as determined by the UF-ATOFMS. “CT” in the negative spectra represents crosstalk due to the interference of extremely intense peaks in the positive polarity.

FIG. 3 Relative size distribution (10 nm bins) of ultrafine particle types during the summer (a) and fall (b). The black trace represents the total number of ultrafine particles chemically analyzed by the UF-ATOFMS in each 10 nm size bin. (Figure provided in color online.)

FIG. 4 Hourly relative fractions of ultrafine particle types during the summer (top) and fall (bottom). The black trace represents the hourly total of ultrafine particles (50–100 nm) chemically analyzed by the UF-ATOFMS. (Figure provided in color online.)

FIG. 5 Temporal trends of gas- and particle-phase measurements, as well as meteorological variables, for one week (Sunday through Saturday) during the summer season. (Figure provided in color online.)

FIG. 6 Temporal trends of gas- and particle-phase measurements, as well as meteorological variables, for one week (Sunday through Saturday) during the fall season. (Figure provided in color online.)