Development of air sampling system for eddy accumulation technique

本研究的目的是发展一套适用于涡积技术测量地表或植被上方CO2通量的空气取样系统，第一年所发展的空气取样系统由三个单元组成，即空气取样控制单元、吸气单元、取样空气累积和排气单元。实验结果表明，所研制的采样系统能够在10 Hz的频率范围内采集到与上、下风向风速成正比的空气样品，并在第二年对采样系统进行了改进，使其能够长期稳定地进行测量。该系统在北海道的玻璃地和泰国的稻田中进行了检查。实验结果表明，该系统测量的CO2通量与开放通道和封闭通道涡动相关技术测量的CO2通量基本一致，表明该系统可用于野外CO2通量的测量。

The objective of the present research is to develop an air sampling system for eddy accumulation technique to measure carbon dioxide flux above terrestrial surface or vegetation.The developed air sampling system in the first year is consist of three unit, that is air sampling controller unit, air suction unit, sampled air accumulation and exhaust unit. The developed sampling system was found to be able to collect air samples proportional to the wind speed of up-wind and the down-wind respectively by 10Hz.In the second year, the sampling system was slimed and made durable to long term measurement. The system was checked in glass land in Hokkaido and in a paddy field in Thailand,. It was found that the carbon dioxide flux measured by the developed system was almost sama with those by both eddy correlation techniques of open path and close path. Accordingly, the developed air sampling system was found to be useful for carbon dioxide flux measurement in the field.