Urban and Airborne Measurements with a PILS Desi Toom-Sauntry, Kathy Hayden, Gang Lu, Shao-Meng Li, Jeff Brook, Walter Strapp, Richard Leaitch Meteorological Service of Canada, Environment Canada Greg Evans University of Toronto Measurements of urban aerosol in downtown Toronto from the University of Toronto Chemical Engineering Building - Aug 20 to Sept 26, 2003 Airborne measurements as part of the Canadian SOLAS program off the coast of Nova Scotia from Oct 11 to Oct 17, 2003. Objective - aerosol indirect radiative forcing

PM Instrumentation University of Toronto PILS AMS R&P 8400N SMPS APS TEOM CPC C-SOLAS PILS AMS SMPS APS PCASP FSSP (100 & 300) Nephelometer

PILS Use a Rodney Weber PILS component Trace concentrator columns focus and inject entire 10 or 30 minute sample for increased sensitivity Use Dionex ICS 2000 Ion Chromatograph systems with eluent generation for compactness and ease of use Comparisons made here with AMS

Time series comparison of sulphate from AMS and from the PILS Time series comparison of sulphate from AMS and from the PILS. Agreement is very reasonable. The AMS collection efficiency is unity. Generally, for the period shown, organics dominated the fine particle mass.

Time series of nitrate from AMS and PILS Time series of nitrate from AMS and PILS. Good agreement again, with PILS occassionally showing higher values.

Ammonium time series comparison Ammonium time series comparison. Overal comparison reasonable, but PILS values are frequently higher and more variable. More work could be put into AMS NH4+ estimate.

Time series plot of selected flight data obtained as part of the C-SOLAS program over the Atlantic east of Nova Scotia. Comparison of sulphate from PILS and AMS. Also shown is ambient pressure and particle number concentration measured with a PCASP (about 140 nm to 2 um dia.). The yellow lines are measurements of cloud droplet number concentrations with an FSSP. Sulphate is referenced to the log scale on the right. The overall agreement is with some aspects of timing to be sorted out. The air above the BL was extremely clean. The DL of both the PILS and AMS for sulphate is a few tens of ng/m3.

Time series plot of sodium from the PILS (NaCl is not measured with this AMS at least), ambient pressure, particle number concentration from PCASP. Also shown are the number concentrations from an FSSP 300 (>0.3 um OD) and an APS (>0.54 um AD). The difference between the FSSP 300 and the APS may be due to two factors: the difference between the diameters (including AD and OD) of the particles and losses of particles before reaching the APS (inboard, intrusive) compared with the FSSP (outboard, non-intrusive). The comparison of Na+ with the variations in the number concentrations of all particles is consistent with the likelihood of sea-salt particles in the larger size fraction. Very high sensitivity to Na+ is implied.

Summary Comparisons of the PILS, AMS and R&P8400N on the ground at an urban site show good agreement for sulphate and nitrate, and reasonable agreement for ammonium. Comparisons between the PILS and AMS of 5-min ave’d airborne measurements of sulphate indicate reasonable agreement with sensitivity of a few tens of ng/m3. The comparisons for ammonium were poor in this case, but some work on the AMS analysis for NH4 is required. The combination of the PILS and AMS is a very strong combination. The need for more continuous measurements for airborne applications is obvious, including allowing more time for things other than collecting filters.

Acknowledgements We would like to thank Rodney Weber (Georgia Tech), Sandy Dasgupta (Texas Tech), Matt Hazelwood and the people at Dionex Corp. for their valuable time and advice with the PILS. We are also grateful to Aerodyne for their support with the AMS.

PILS IC analysis Air Sample in 15.5 LPM Vacuum pump DIW transport liquid in Denuders PILS IC analysis Steam generation anion cation Concentrator columns Sample out