Readme file branch chamber dataset, Blodgett Forest 2005 by Nicole Bouvier-Brown and Allen Goldstein PTR-MS data processed by Rupert Holzinger University of California at Berkeley Department of Environmental Science, Policy and Management Ecosystem Science Division 250 Hilgard Hall Berkeley, CA 94720-3110 ph.: 1-510-643-6449 Fax: 1-510-643-5098 e-mail: nbouvier@nature.berkeley.edu, ahg@nature.Berkeley.edu ---------------------- General description: To measure emission rates of terpenes at Blodgett Forest, a coniferous forest in the Sierra Nevada mountains of California, we placed enclosures over branches of the dominant species at the site - Ponderosa pine, manzanita, and ceanothus - in the summer of 2005. Zero air, with ambient CO2 concentrations, flowed through the chamber system and volatile organic compound (VOC) emission measurements were made by proton transfer reaction mass spectrometry (PTR-MS), solid phase microextraction (SPME) on fibers followed by direct injection into a gas chromatograph with an ion trap mass spectrometer (GC-ITMS), and by in-situ GC with a flame ionization detector (GC-FID). For complete descriptions on instrument set-up, sampling timeline, standard procedures, etc. please see: Bouvier-Brown, N.C., R. Holzinger, K. Palitzsch, A.H. Goldstein, Quantifying sesquiterpene and oxygenated terpene emissions from live vegetation using solid-phase microextraction fibers, Journal of Chromatography A, 1161: 113–120, 2007. Bouvier-Brown, N.C., R. Holzinger, K. Palitzsch, A.H. Goldstein, Large emissions of sesquiterpenes and methyl chavicol quantified from branch enclosure measurements, Atmospheric Environment, 2008, in press (only ozone-free data was used in publications because there was no reasonable distinction between the ozone and ozone-free data due to incomplete chamber set up.) ------ PTR-MS data: for column headers, see "readme PTRchamber.doc" except "mX" stands for mass X Mixing ratios are given in ppbv; masses (m21-m219) are calibrated with the transmission curve and the 3 BLodgett gas standards (301,701, and 901) by Rupert Holzinger m149 = methyl chavicol and m205 = total sesquiterpenes both need to be multiplied by an extra standard factor "stdfactorMC" should be used to calibrate m149 (the factor is different depending on the branch) "stdfactorSQT" should be used to calibrate m205 GC-FID: monoterpene data specified in column headers, except "un9" is where methyl chavicol would show up if it didn't get stuck in the sampling system Mixing ratios are given in ppbv; monoterpene peak areas are calibrated using the Blodgett gas standards All chromatograms have been integrated manually for proper identification and quantification. Human error, however, is unavoidable. Zero mixing ratios were not set "NA". SPME fiber data: used for methyl chavicol and speciated sesquiterpenes Methyl chavicol and sesquiterpenes are calibrated with liquid standandards volatilized in zero air in Tedlar bags All time is local standard time (PST) in Day of Year format. Within the "PTR individual branches" folder, the PTR-MS data is separated by each branch with and without ozone: Ponderosa pine (Ppine) branch #1 - July 10-12 Manzanita - July 12-15 Ceanothus - July 15-18 Ppine #1 - Aug 1-4 Ceanothus - Aug 4-6 Ppine #2 - Aug 6-8 Manzanita - Aug 8-10 Ppine #3 - Aug 11-12 Ppine #2 - Aug 30-Sept 1 Manzanita - Sept 1-4 Ppine #3 - Sept 6-7 Ppine #1 - Sept 8-10 "branchMASS.txt" (comma delim) = the masses of each branch (in grams) for emission flux calculations "GCFIDchamber.txt" (tab delim) = GC-FID data, including monoterpenes and flow rates "PTRchamber.txt" (comma delim) = all PTR-MS data, including the chamber flows and conditions (see "readmePTRchamber.doc") "PTRfiberchamber.txt" (comma delim) = combining the PTR-MS masses (m21, m81, m137, m149, m205) with SPME fiber mixing ratios and emission rates, and chamber flows and conditions "PTRGCmtchamber" (tab delim) = combining monoterpene information (PTR-MS m 81, m137 and GC-FID data) "speciatedSQT.txt" (tab dlim) = SPME fiber sesquiterpene data divided by each individual sesquiterpene "stdfactorMC.txt" and "stdfactorSQT.txt" (comma delim) = used to calibrate PTR-MS masses for each specified branch i.e. m205*stdfactorSQT 0