Instrument: Air samples from CARIBIC flights were analysed for CH4, CO2, N2O, SF6, isotopic composition of CO (13CO, C18O, 14CO) and CO2 (13CO2, CO18O). For completeness and to aid interpretation, the continuously measured CO and O3 concentrations integrated over the sampling interval are also given (see CO and OM). CH4, CO2, N2O, and SF6 were determined by a gas chromatograph.Uncertainties are given as standard deviations of typically 20 replicate analyses. The delta13C(CO), delta18O(CO), delta13C(CO2), and delta18O(CO2) values were determined by an isotope ratio mass spectrometer [Brenninkmeijer, C.A.M., J. Geophys. Res. 98, 10595-10614,1993; Brenninkmeijer and Roeckmann, Geophys. Res. 102, 25477-25485, 1997; Brenninkmeijer et al., Chemosphere: Global Change Sci. 1, 33-52, 1999]. 14CO concentration was determined by an accelerator mass spectrometry (AMS) [Brenninkmeijer, C.A.M., J. Geophys. Res. 98, 10595-10614, 1993]. Data format: Dataset consists of 35 columns representing: Sample #, date, time, lon, lat (start, end, middle of the sampling interval), pressure[hPa], p_height[m], T[K], Tpot[K], CH4[ppb], uncertainty of CH4[ppb], CO2[ppm], uncertainty of CO2[ppm], N2O[ppbv], uncertainty of N2O[ppb], SF6[ppt], uncertainty of SF6[ppt], delta13C(CO)[0/00], delta18O(CO)[0/00], 14CO[molecule/cm3], delta 13C(CO2)[0/00], uncertainty of delta13C(CO2)[0/00], delta18O(CO2)[0/00], uncertainty of delta18O(CO2)[0/00], O3[ppb], CO[ppb]. Delta13C is given relative to V-PDB. For CO2, delta18O relative to V-PDB-CO2, for CO V-SMOW is used. 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 - for interpretation cf www.caribic-atmospheric.com Special comments to this flight: None.
The CH4, CO2, and N2O measurements were calibrated using a standard gas mixture from NOAA. SF6 measurements were calibrated using a standard gas mixtu...
Description
The CH4, CO2, and N2O measurements were calibrated using a standard gas mixture from NOAA. SF6 measurements were calibrated using a standard gas mixture from Heidelberg. The uncertainty in delta13C for CO is 0.2 0/00, for CO2 0.05 0/00. The uncertainty in delta18O for CO is 0.4 0/00, for CO2 0.1 0/00. Note that delta18O of CO2 has been affected by exchange with water vapor in the aircraft sampling cylinders. Note that delta18O of CO has been affected by the formation of CO in the aircraft sampling cylinders due to reaction of O3 with carbonaceous material. Details can be supplied separately.