Airborne observation of CO2 mixing ratio in the Arctic troposphere and lower stratosphere

Abstract

Tropospheric and lower stratospheric CO2 mixing ratios were measured onboard an aircraft in the Arctic Airborne Measurement Program 1998. Steep vertical gradients in CO2 mixing ratio were observed in the lower stratosphere. Small gradients were seen in the troposphere, reflecting weak sources and sinks for CO2 in winter. A significant increase in CO2 mixing ratio was found during level flight in the lower stratosphere. Back trajectory analysis indicated that rapid upward transport brought high CO2 to the observation area. Spatial variations of CO2 mixing ratio were highly correlated with O3 mixing ratio. It is suggested that CO2 distribution was produced mainly by air transport and mixing.