CO(2) Fluxes Measured by Eddy Correlation and Aerodynamic Techniques

To elucidate the seasonal and inter-annual variation of CO(2) exchanges between the atmosphere and cultivated field in Japan, the CO(2) flux has been measured by the eddy correlation technique at the experimental farm of Agricultural Faculty, Okayama University since December in 1998. The CO(2) sensor, however, does not work under rainy conditions. The improved aerodynamic technique was developed and used to cover CO(2) flux data which were not collected. This technique gives reasonable CO(2) fluxes even in rainy days. The reliability of the technique was also confirmed by comparing CO(2) fluxes with those measured by the eddy correlation technique using data in fine weather conditions

Measuring instrument of carbon dioxide concentration in seawater

The Measuring instrument of carbon dioxide concentration in seawater (pCO(2)) is developed. The instrument consists of an equilibrator, a non-dispersive infrared gas analyzer (NDIR), a carrier gas generator and a processing signal generator. The equilibrator has a cross section of 3 c㎡ and is 15 cm tall. The principle of pCO(2) measurement is based on the equilibration of a carrier gas phase with a seawater sample and subsequent determination of the carbon dioxide concentration in the carrier gas. The carrier gas circuit of the NDIR is opened to the atmosphere to maintain the carrier gas line at a barometric pressure. The present instrument can measure pCO(2) within the measuring error of about 2 ppm with sample water of about 180ml every 20 min