AMS analysis of aerosol composition from FLAME experiments: Chemically speciated mass loadings J. H. Kroll, T. B. Onasch, A. Trimborn Aerodyne Research, Inc. J. A. Huffman, I. Ulbrich, J. L. Jimenez University of Colorado

About the data 1) The AMS quantitatively measures non-refractory aerosol components (compounds which evaporate rapidly at 550-600C); this includes all organics as well as most ammonium compounds. However, in many of the burns, significant concentrations of K+ and Cl- (and sometimes Na+) are detected in the “closed” mode. This indicates the presence of refractory inorganics (such as KCl and NaCl); thus the stated concentrations of inorganics should be considered as lower limits. [In many of the burns, negligible levels of inorganics were detected, in both “open” and “closed” modes, so the contributions of inorganic ions is negligible.] 2) The mass concentrations given are relative values; at present they are not collection efficiency-corrected. BC measurements, combined with our SPMS data, will allow for such a correction (and possibly for a correction for the refractory compounds, described above). 3) Aerosol components were quantified by analyzing the high-resolution data; thus “oxygenated” (CxHyOz) and “not oxygenated” (CxHy) organics can be distinguished, and are tabulated separately. 4) Background aerosol was generally negligible; in cases where it was >5% of average loading during the burn (Burns 4, 8, 9, 10, and 12) it was subtracted out (though changes are insubstantial).

Overview: all burns All values presented (here and in subsequent slides): - are in mg/m3 - are the average for the entire burn (2-3 hours); changes in relative mass loadings were relatively minor (though this will be quantified soon)

Burn A/1: Ponderosa Pine Missing CxHy value

Burn B/2: SoCal chamise CxHy 4.6 CxHyOz 3.5 total organic 8.1 NO3 0.2   NO3 0.2 SO4 1.8 NH4 0.0 Cl 0.8 K total inorganic 3.6 TOTAL 11.8

Burn C/3: Ponderosa pine needles

Burn D/4: SoCal chamise (same as B)

Burn E/5: Rice straw

Burn F/6: Ponderosa pine duff

Burn G/7: Alaska tundra core duff

Burn H/8: SoCal manzanita

Burn I/9: Utah juniper foliage, sticks

Burn J/10: Utah sage, rabbitbrush

Burn K/11: Lignin

Burn L/12: lodgepole pine

Burn M/13: Puerto Rican Fern

Burn N: SoCal chamise No EI spectra

Burn O/15: Southern wax myrtle

Burn P/16: Southern pine needles

Burn Q/17: Puerto Rican Sticks

Burn R/18: Southeastern palmetto leaves

Burn S/19: Ceanothus