长江三角洲典型稻作区近地层二氧化碳等湍流通量的观测研究

A STUDY ON THE TURBULENCE FLUXES OF THE SURFACE LAYER CO_2, SENSITIVE AND LATENT EXCHANGE OVER THE TYPICAL RICE FIELD, CHANGJIANG DELTA

利用 1999年和 2 0 0 0年长江三角洲近地层大气与农田生态系统综合观测试验资料 ,对常熟地区水稻插秧、拔节、抽穗等不同生长期近地层二氧化碳和感热、潜热、动量等湍流通量特征及变化规律进行了初步研究 .研究结果表明 ,平均而言在水稻各生长期 ,近地面为二氧化碳的汇 ,白天水稻通过光合作用吸收二氧化碳、夜间则放出二氧化碳 ,抽穗期消耗的二氧化碳要多于拔节和插秧期 ;近地面为大气的热源 ,主要以潜热方式加热大气 ,尤其是在抽穗期 ,感热与潜热之比仅为 0 .0 5 8;二氧化碳等湍流通量的变化与辐射平衡各分量及气象要素有显著关系 .

Based on the integrated observation of the surface atmosphere and the agriculture ecosystem at Changjiang Delta, we study the fluxes of surface layer CO 2 as well as the turbulence such as the sensible heat, latent heat and momentum during the transplant, joint and tassel of the rice growth stages for the rice field at Changshu, Jiangsu Province. The result shows that the rise field acts as a sink of CO 2 for every growth stage. The rice absorbs CO 2 during daytime while emits it during nighttime. The absorption amount of CO 2 during the tassel stage is larger than that in the stages of transplant and joint. The surface layer is a heat source of atmosphere and the heating is mainly through latent exchange. The ratio of sensible to latent fluxes is only 0.058 during the tassel stage. Remarkable correlations exits between change of the turbulence fluxes of CO 2 and the components of radiation balance, as well as different meteorological factors.