Evidence of wintertime CO2 emission from snow-covered grounds in high latitudes

In order to measure CO2 flux in wintertime arctic ecosystems, CO2 gas was s ampled from various snow-covered grounds by using a closed chamber method d uring the First China Arctic Scientific Expedition from March to May in 199 5. The CO2 gas samples were measured by using an infra-red analyzer (IRGA). The results show-ed that (i) CO2 emission was detected from all kinds of t he snow-covered grounds, which provides direct evidence that the arctic tun dra is functioning as a source of atmospheric CO2; (ii) CO2 release was als o detected from the permanent ice profile and icecap, and (iii) CO, evoluti on from terrestrial ecosystems in higher latitudes increased with an increa se of surface temperature in accordance with the exponential function. This indicates a close coincidence with that under normal temperature condition s, and provides a useful method for predicting change in CO2 flux in the ar ctic ecosystems with the global climate change.