适用于多年冻土区具有碳通量自动观测性能的OTC系统开发设计

在现有的OTC内碳通量观测仪器设备基础上, 设计开发出一套以AT89S51单片机为控制核心, 通过L293D控制电机正反转控制箱盖定时开关, 实现了多年冻土区OTC内碳通量自动观测. 观测主体箱用透明采光性良好的玻璃纤维材料制成, 电机传动采用齿轮传动, 箱口和箱盖接触地方用橡胶密封圈包裹, 防止箱盖密闭时漏气. OTC内碳通量自动观测仪最大可能性的减小了当前模拟增温条件下碳通量观测受自然条件和人为因素的影响, 极大的降低观测费用, 提高了数据的连续性, 基本上实现了多年冻土区模拟增温条件下碳通量较为精确地自动、连续观测. 试验表明: 在气象条件相对较好的2013年5月15日, OTC内碳通量自动观测仪观测结果和传统OTC内利用LI-COR6400观测结果规律性都较强, 野点较少, 二者相关性显著(R²=0.96); 而在气象条件相对较差的2013年9月1日, OTC内碳通量自动观测仪观测结果受外界干扰小, 观测结果规律性强, 野点较少; 而传统OTC内利用LI-COR6400 观测结果规律性较差, 野点较多, 数据可信度不高, 二者观测结果相关性不显著(R²=0.67).

Development of an OTC system with automatic carbon flux observation function in permafrost regions

In this paper, based on the up-to-date OTC carbon flux measurement instrument, a new instrument is developed, which takes AT89C51 single-chip as core of control, L293D to control positive and negative turn of motor to control timing switch of box cover, and DS1232 chipset watchdog circuit as reset circuit to avoid system halt of the single-chip. The main box is made by glass fiber material with superior transparency. The motor is driven by gear. Box mouth and cover are wrapped by rubber seal to avoid gas leakage in seal. OTC inner automatic carbon flux measurement instrument can solve problems such as high observation cost, discontinuous data, impact from natural and artificial factors and irregularity in carbon flux observation under current simulated warming. An automatic, continuous and accurate carbon flux observer in permafrost regions was realized. The test shows that under the favorable weather conditions on June 15^th 2013, the observer had similar observation accuracy with the traditional one, in which LI-COR6400 is made use of. They both had less error and significant correlation (R²=0.96), while under bad weather condition on September 1^st 2013, OTC inner automatic carbon flux measurement instrument had better observation accuracy as compared with the traditional one. The latter had more irregular data, more error and less reliability and had poor correlation (R²=0.67). The tradition ones are recommended to be discarded.