内蒙古草原典型草地异戊二烯的排放特征

Emission characteristics of isoprene at typical grassland in the Inner Mongolia grassland

为准确了解内蒙古草原典型草地异戊二烯的排放状况 ,在 2 0 0 2和 2 0 0 3年观测实验的基础上 ,利用已有的经验模式和观测资料 ,计算了羊草样地 2 0 0 2和 2 0 0 3年生长季节异戊二烯的排放通量 .结果表明 :2 0 0 2和 2 0 0 3年异戊二烯排放具有明显的日、逐日、月、年变化 ,其排放通量首先依赖于可见光辐射 ,其次是温度 .2 0 0 2和 2 0 0 3年生长季羊草样地异戊二烯总排放 (以C计 )分别为 1 10 ,1 0 0g·m- 2 ,2 0 0 3年比 2 0 0 2年减少9 0 % .此现象主要是由于 2 0 0 3年可见光辐射减弱和气温降低造成的 .2 0 0 2和 2 0 0 3年生长季排放通量的最大值 (以C计 )分别为 2 3 3 2 0和193 3 8μg·m- 2 ·h- 1 ,当可见光辐射小时累计值小于 0 4MJ·m- 2 时 。

For understanding the emission status of isoprene at typical grassland, the emission fluxes of isoprene at an aneurolepidium chinese sample plot (ACSP) in the Inner Mongolia grassland during 2002 and 2003 growing seasons were calculated on the basis of measurements in 2002 and 2003 and an empirical model. Isoprene emission showed an obvious diurnal, daily, monthly, yearly variation, and was dependant on solar visible radiation and air temperature. The total emission of isoprene at ACSP during 2002 and 2003 growing seasons were 1.10、1.00 g·m^(-2), respectively (calculated by Carbon). The decrease of isoprene emission by (9.0%) in 2003 was caused by the decrease of solar visible radiation and air temperature. The maximum of emission fluxes during 2002 and 2003 growing season were 2332.0 and 1933.8 μg·m^(-2)·h^(-1), respectively (calculated by Carbon). There was basically no emission flux of isoprene, when the solar visible radiation below 0.4 MJ·m^(-2).