Using 14C, 13C, 18O and 17O isotopic variations to provide insights into the high northern latitude surface CO inventory

[摘要] Measurements of the complete isotopic composition of atmosphericCO (³CO, ¹⁴CO, C¹⁷O, C¹⁸O) have been carried out at the high northern latitude stations Spitsbergen, Norway, andAlert, Canada. The annual changes of the isotope signatures reflect the seasonally varyingcontributions from the individual CO sources and the OH sink. Short-term variability is smallat the remote sampling locations. Nevertheless, the interannual variability is considerable, inparticular for the summer minimum. The most prominent event was a strong increase inCO in 1998 that persisted for several months. Using the isotope signatures it is possible to clearlyidentify extraordinarily strong biomass burning during that season as the cause for this large-scaleCO anomaly. In 1997, on the other hand, biomass burning emissions were very low,leading to an unusually low summer minimum and corresponding isotope signatures. Theresults underscore that monitoring of CO and its isotopic composition at remote high latitudestations is a valuable tool to better understand long-term variations ofCO that are representative for the whole high northern latitude region.

[学科分类] 大气科学