Development of air sampling system for eddy accumulation technique

本研究的目的是开发一套用于涡旋积累技术的空气采样系统，以测量地表或植被上的二氧化碳通量。第一年开发的空气采样系统由三个单元组成，即空气采样控制器单元、空气吸入单元、采样空气积累和排风单元。所开发的采样系统能够分别以10Hz的频率采集与上风风速和顺风风速成正比的空气样本。第二年，对采样系统进行了粘浆处理，使其经久耐用，适合长期测量。该系统在北海道的玻璃土地和泰国的稻田进行了测试。研究发现，该系统测量的二氧化碳通量与开路和闭路涡旋相关技术测量的二氧化碳通量基本一致。因此，所开发的空气采样系统可用于野外二氧化碳通量测量。

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.