Concentrations and fluxes of biogenic volatile organic compounds above a Mediterranean macchia ecosystem in western Italy
Concentrations and fluxes of biogenic volatile organic compounds above a Mediterranean macchia ecosystem in western Italy
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DOI：
10.5194/bg-6-1655-2009
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发表时间：
2009-01-01
期刊：
影响因子：
4.9
通讯作者：
Hewitt, C. N.
中科院分区：
文献类型：
--
作者：
Davison, B.;Taipale, R.;Hewitt, C. N.
2007年5月7日至6月3日，作为ACCENT-VOCBAS生物圈-大气相互作用实地活动的一部分，在罗马西南约25公里的Castelporziano地中海沿岸地点测量了生物挥发性有机化合物（BVOCs）的排放率和浓度。浓度和排放率的测量使用间断涡动协方差（DEC）的方法，利用三种不同的质子转移反应质谱仪（PTR-MS），使仪器之间的比较。PTR-MS仪器的高分辨率数据大大增强了20世纪90年代中期的原始BEMA测量。根据测量周期，体积混合比的范围为甲醇1.6-3.5 ppbv，乙醛0.44-1.3 ppbv，丙酮0.96-2.1 ppbv，异戊二烯0.10-0.14 ppbv，和0.13- 0.30ppbv的单萜。甲醇、乙醛、丙酮和异戊二烯的混合比存在明显的昼夜循环，白天最大。甲醇的通量范围为370-440 μ g m（-2）h（-1），乙醛为180-360 μ g m（-2）h（-1），丙酮为180-450 μ g m（-2）h（-1），异戊二烯为71-290 μ g m（-2）h（-1），单萜为240-860 μ g m（-2）h（-1）。根据测量的通量数据（5月7日至6月3日），计算出Macchia植被的平均基础排放率，异戊二烯为430 μ g m（-2）h（-1），单萜为1100 μ g m（-2）h（-1）。
Emission rates and concentrations of biogenic volatile organic compounds (BVOCs) were measured at a Mediterranean coastal site at Castelporziano, approximately 25 km south-west of Rome, between 7 May and 3 June 2007, as part of the ACCENT-VOCBAS field campaign on biosphere-atmosphere interactions. Concentrations and emission rates were measured using the disjunct eddy covariance (DEC) method utilizing three different proton transfer reaction mass spectrometers (PTR-MS) so allowing a comparison between the instruments. The high resolution data from the PTR-MS instruments considerably enhances the original BEMA measurements of the mid 1990s.Depending on the measurement period, the volume mixing ratios were in the range 1.6-3.5 ppbv for methanol, 0.44-1.3 ppbv for acetaldehyde, 0.96-2.1 ppbv for acetone, 0.10-0.14 ppbv for isoprene, and 0.13-0.30 ppbv for monoterpenes. A diurnal cycle in mixing ratios was apparent with daytime maxima for methanol, acetaldehyde, acetone, and isoprene. The fluxes ranged from 370-440 mu g m(-2) h(-1) for methanol, 180-360 mu g m(-2) h(-1) for acetaldehyde, 180-450 mu g m(-2) h(-1) for acetone, 71-290 mu g m(-2) h(-1) for isoprene, and 240-860 mu g m(-2) h(-1) for monoterpenes. From the measured flux data (7 May-3 June) an average basal emission rate for the Macchia vegetation was calculated of 430 mu g m(-2) h(-1) for isoprene and 1100 mu g m(-2) h(-1) for monoterpenes.