55 1010 Twohy, Cynthia H. Oregon State University Citation CVI Residual Nuclei and Ambient Aerosol Chemical Composition CRYSTAL-FACE 1 1 2002 07 16 2003 05 30 0 Measurement Counter Index 8 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 999 999 999 999 999 999 999 999 Crustal, CRU; percent by number Carbonaceous/Organic, ORG; percent by number Carbonaceous/Soot, SOOT; percent by number Sulfate, SULF; percent by number Industrial, IND; percent by number Salts, SLT; percent by number Mixed, MIX; percent by number Unknown, UNK; percent by number 4 1.0 1.0 1.0 1.0 99999 99999 99999 99999 Start Time, STTIME; seconds Stop Time, ENDTIME; seconds Sample type, TYPE; 1=CVI LARGE, 2=CVI SMALL, 3=AMBIENT LARGE, 4=AMBIENT SMALL Number of particles analyzed per stage, N 0 26 Particles were collected by two methods. With the CVI, ice crytals (or in rare cases, water drops) were separated from the ambient aerosol and evaporated, leaving residual "nuclei" in the sample stream. On some occasions, the CVI counterflow was turned off so that ambient aerosol could be collected. Both kinds of aerosol were collected on electron microscope grids using a two-stage impactor with aerodynamic cut diameters of 0.5 and 0.1 microns (LARGE and SMALL particle types, respectively). All particles were then analyzed by transmission electron microscopy and energy dispersive spectrometry at Oregon State University. 50 particles were usually analyzed per stage; however, on two occasions only 25 and 40 particles were analyzed when grids were very lightly loaded. Since characteristics of the CVI and AMBIENT particles and LARGE and SMALL particles vary considerably, the "sample type" (1, 2, 3, or 4 as given above) is critical in interpreting these data! Criteria used to distinguish each particle type is given below: Crustal dust: silicates (rich in Si, variable Na, Mg, Al, K, Ca, and Fe), carbonates (Ca, Mg, C), phosphates (P, O). Carbonaceous/Organic: Amorphous and may contain O, N, and S as well as C. Carbonaceous/Soot: C only. Characteristic morphology (chain aggregates). Sulfates: Pure sulfuric acid or ammonium sulfate/bisulfate. S, O only. Industrial: Metal and oxides (Al, Fe, Cr, Ti, Mn, Co, Zn, Cu etc.), fly ash (rare). Salts: Chlorides and sulfates of Na, K, Ca and minor Mg. Mixed: Internally mixed, containing major elements of any two or more of the above types. Unknown: Could not be identified for various reasons. Contact Cynthia Twohy at twohy@coas.oregonstate.edu with questions about the data. COUNTER STTIME ENDTIME TYPE N CRU ORG SOOT SULF IND SLT MIX UNK 1 81180 81410 3 50 10 18 12 22 4 28 0 6 2 81180 81410 4 50 10 16 8 28 14 16 6 2