Isoprene and monoterpene fluxes measured above Amazonian rainforest and their dependence on light and temperature

摘要

Canopy scale emissions of isoprene and monoterpenes from Amazonian rainforest were measured by eddy covariance and eddy accumulation techniques. The peak mixing ratios at about 10 m above the canopy occurred in the afternoon and were typically about 90 ppt_v of α-pinene and 4-5 ppb_v of isoprene. α-pinene was the most abundant monoterpene in the air above the canopy comprising ≈ 50/100 of the total monoterpene mixing ratio. Measured isoprene fluxes were almost 10 times higher than α-pinene fluxes. Normalized conditions of 30℃ and 1000 μmol m~(-2) s~(-1) were associated with an isoprene flux of 2.4 mg m~(-2) h~(-1) and a β-pinene flux of 0.26 mg m~(-2) h~(-1).