Air samples were taken during the CARIBIC flights by a whole air sampler (WAS) into 12 21 litre stainless steel canisters. Since most of the sample (typically at about 20 bar, i.e. about 400 L) was consumed by the isotope analysis, an aliquot of the sample (about 10L) was transferred to a 2L can and analysed for NMHC at MPICH and then sent for halocarbon analysis to UEA. The halocarbons were analysed using a bench-top quadrupole GC-MS (Agilent 6890 5973 - former HP). The analytical procedure involved cryogenic enrichment of 1000 ml air followed by chromatographic separation on a 100m x 0.32mm DB5 column, temp. programmed from 30C to 200C. Flights analysed using this method: 19,20,21,22,23,24,25,26,28,29,30,31,32,33,34,35,36,37,38,40,41,43,46,47 - see also VG- datasets for 9 more flights. Data format: 42 columns representing: Sample no., Date(UT), Time(UT), Lon, Lat of sampling interval start, end, and middle, Press/hPa, Barometric height/m, T/C, and Tpot/K averaged over the sampling interval, CFC-12, CFC-11, CFC-113, HCFC-22, HCFC-142b, HCFC-141b, HFC-152a, CH3Cl, CH2Cl2, CHCl3, CCl4, CH3CCl3, CHClCCl2, C2Cl4, CH3Br, CH2Br2, CHBr3, CH3I, H-1301, CFC-114, H-1211, HCFC 123, HFC-134a, HCFC-124, HCFC 21, H-2402 all /pptv. For scientific names of the species see table in name conventions of CARIBIC website/ database section. Coordinates of data probes are given explicitly while the 'boundary box' meta entries just represent the coordinates of start and destination airports. The data rows are headed by a set of text lines in CARIBIC metadata format - cf www.caribic-atmospheric.com
Analytical precision was typically .le. 3% except for the following compounds: HCFC-124, HCFC-123, HFC-152a, H-2402, C2HCl3, CH2Br2, CHBr3, CH3I (.le....
Analytical precision was typically .le. 3% except for the following compounds: HCFC-124, HCFC-123, HFC-152a, H-2402, C2HCl3, CH2Br2, CHBr3, CH3I (.le. 5%) CFCs (11, 12, 113), HCFCs (22, 142b, 141b), CH3CCl3, CCl4 CH3Cl and CH3Br are referenced to the NOAA-CMDL 2002 calibration scale. CH2Cl2, CHCl3, CH3CCl3, CCl4, C2HCl3 and C2Cl4 are referenced to a preliminary NOAA-CMDL scale. The remaining compounds were calibrated at UEA. Where possible samples were analysed within 2-3 weeks of collection, although this was not always possible (particularly for the earlier flights). As certain halocarbons are known to decay during storage in dry stainless steel canisters (in particular CCl4, CH2Br2 and CHBr3), the data for these compounds should be treated with a degree of caution. Please consult with data provider (