Airborne in-situ measurements of vertical, seasonal and latitudinal distributions of carbon dioxide over Europe

[摘要] Airborne in-situ observations of carbon dioxide (CO₂) were made during7 intensive measurement campaigns between November 2001 and April 2003 aspart of the SPURT project. Vertical profiles and latitudinal gradients inthe upper troposphere/lowermost stratosphere were measured along the westernshore of Europe from the subtropics to high northern latitudes duringdifferent seasons. In the boundary layer, CO₂ exhibits a strongseasonal cycle with the maximum mixing ratios in winter and minimum valuesin summer, reflecting the strength of CO₂ exchange with vegetation.Seasonal variations are strongest in high latitudes and propagate to thefree troposphere and lowermost stratosphere, although with reducedamplitude. In the lowermost stratosphere, the CO₂ seasonal cycle isphase-shifted relative to the free troposphere by approximately 3 months,with highest mixing ratios during the summer. Modelling studies support theinterpretation that altitude gradients of CO₂ are likely due tostratosphere-troposphere-transport.

[学科分类] 大气科学