Vertical and meridional distributions of the atmospheric CO2 mixing ratio between northern midlatitudes and southern subtropics -: art. no. 8401

[1] The atmospheric CO2 mixing ratio was measured using a continuous measurement system onboard a Gulfstream-II aircraft between the northern midlatitudes and the southern subtropics during the Biomass Burning and Lightning Experiment Phase A (BIBLE A) campaign in September-October 1998. The vertical distribution of CO2 over tropical regions was almost constant from the surface to an altitude of 13 km. CO2 enhancements from biomass burning and oceanic release were observed in the tropical boundary layer. Measurements in the upper troposphere indicate interhemispheric exchange was effectively suppressed between 2degreesN-7degreesN. Interhemispheric transport of air in the upper troposphere was suppressed effectively in this region. The CO2 mixing ratios in the Northern and Southern Hemispheres were almost constant, with an average value of about 365 parts per million (ppm) and 366 ppm, respectively. The correlation between the CO2 and NOy mixing ratios observed north of 7degreesN was apparently different from that obtained south of 2degreesN. This fact strongly supports the result that the north-south boundary in the upper troposphere during BIBLE A was located around 2degreesN-7degreesN as the boundary is not necessary a permanent feature.