Turbulent transport and reactions of plant-emitted hydrocarbons in an Amazonian rain forest
Turbulent transport and reactions of plant-emitted hydrocarbons in an Amazonian rain forest
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DOI：
10.1016/j.atmosenv.2022.119094
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发表时间：
2022-04-25
影响因子：
5
通讯作者：
Ruiz-Plancarte, Jesus
中科院分区：
文献类型：
--
作者：
Fuentes, Jose D.;Gerken, Tobias;Ruiz-Plancarte, Jesus
异戊二烯和单萜排放的热带雨林在巴西亚马逊河流域中部地区的时间和空间格局的过程进行了调查，使用现场实验和数值模拟相结合。具体而言，大涡模拟（LES）被用来解决排放的异戊二烯和单萜，湍流运输，和空气化学。耦合的化学运输LES包括异戊二烯和单萜反应性的影响，由于与羟基自由基和臭氧的反应。LES的结果被用来计算垂直分辨预算的异戊二烯和单萜烯在雨林冠层响应排放，湍流输送，表面沉积，和空气化学。结果表明，排放和扩散占主导地位的异戊二烯预算的气体被运出冠层空间。在一个受氮氧化物限制的地区（普遍的氮氧化物水平<0.5ppm），冠层内的化学破坏去除了大约10%的当地排放的单萜。臭氧分解单萜产生的羟基自由基的速率接近于2 × 10（6）个自由基cm（-3）s（-1），与光依赖性羟基自由基的形成具有相似的量级。一个关键的结论是，亚马逊雨林大量排放单萜，其在冠层臭氧分解产生的羟基自由基的数量类似于光依赖的形成。单萜和异戊二烯与羟基自由基和臭氧的反应是必要的亚马逊雨林冠层的光化学活性的环境，适合产生氧化剂和二次有机气溶胶的维护。
The processes governing the temporal and spatial patterns of isoprene and monoterpenes emitted by a rainforest in the central Amazon region of Brazil is investigated using a combination of field experiments and numerical simulations. Specifically, Large Eddy Simulations (LES) were used to resolve emissions of isoprene and monoterpenes, turbulent transport, and air chemistry. The coupled chemistry-transport LES included the effects of isoprene and monoterpenes reactivity due to reactions with hydroxyl radical and ozone. The LES results are used to compute vertically resolved budgets of isoprene and monoterpenes in the rainforest canopy response to emissions, turbulent transport, surface deposition, and air chemistry. Results indicated that emission and dispersion dominated the isoprene budget as the gases were transported out of the canopy space. In a region limited by nitrogen oxides (with prevailing nitric oxide levels of < 0.5 parts per billion), the in-canopy chemical destruction removed approximately 10% of locally emitted monoterpenes. Hydroxyl radical production rates from the ozonolysis of monoterpenes amounted to asymptotic to 2 x 10(6) radicals cm(-3) s(-1) and had similar magnitude to the light-dependent hydroxyl radical formation. One key conclusion was that the Amazonia rainforest abundantly emitted monoterpenes whose in-canopy ozonolysis yielded hydroxyl radicals in amounts similar to the magnitude of light-dependent for-mation. Reactions of monoterpenes and isoprene with hydroxyl radical and ozone were necessary for the maintenance of the Amazon rainforest canopy as photochemically active environment suitable to generate oxidants and secondary organic aerosols.