A nocturnal atmospheric loss of CH2I2 in the remote marine boundary layer
A nocturnal atmospheric loss of CH2I2 in the remote marine boundary layer
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远海边界层 CH2I2 夜间大气损失
DOI：
10.1007/s10874-015-9320-6
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发表时间：
2015
影响因子：
2
通讯作者：
Carpenter L
中科院分区：
文献类型：
--
作者：
Carpenter L
海洋排放的无机和有机碘化合物推动碘的地球化学循环，并产生破坏臭氧的活性碘自由基，影响大气的氧化能力。二碘甲烷（CH_2 I_2）和氯碘甲烷（CH_2 IC_1）是海洋边界层中两种最重要的有机碘前体物。2012年1月/2月在东热带太平洋进行的TORERO（热带海洋与大气层反应性卤素和含氧挥发性有机化合物交换）实地活动期间进行的船载测量显示，空气中CH 2 I2和CH 2 ICl以及海水中CH 2 I2的日变化周期很强。已知这两种化合物在白天会迅速光解，但模型假设夜间不会在大气中损失。令人惊讶的是，CH 2 I2的昼夜周期的振幅低于CH 2 ICl，尽管其更快的光解速率。我们推测，夜间损失的CH 2 I2发生由于与NO3自由基的反应。在大气边界层条件下的实验室研究的间接结果表明，CH 2 I2 +NO3的k ≤4 × 10−13 cm 3 molecule−1 s−1;之前在≤100 Torr下进行的动力学研究发现，CH 2 I2 +NO3的k为4 × 10−13 cm 3 molecule−1 s−1。利用一维大气THAMO模式，由海-气通量驱动，（CH 2 I2的平均值为1.8 +/-0.8 nmol m-2 d-1，CH 2 ICl的平均值为3.7 +/-0.8 nmol m-2 d-1），我们发现，该模型高估了夜间CH 2 I2> 60%，但当CH 2 I2 + NO3反应包括在2-4 × 10−13 cm 3 molecule−1 s−1。我们得出结论，该反应对CH 2 I2有显着影响，并有助于调和观察到的和建模的浓度。我们建议在大气条件下进一步直接测量该反应，包括产物的支化比。
Ocean emissions of inorganic and organic iodine compounds drive the biogeochemical cycle of iodine and produce reactive ozone-destroying iodine radicals that influence the oxidizing capacity of the atmosphere. Di-iodomethane (CH2I2) and chloro-iodomethane (CH2ICl) are the two most important organic iodine precursors in the marine boundary layer. Ship-borne measurements made during the TORERO (Tropical Ocean tRoposphere Exchange of Reactive halogens and Oxygenated VOC) field campaign in the east tropical Pacific Ocean in January/February 2012 revealed strong diurnal cycles of CH2I2 and CH2ICl in air and of CH2I2 in seawater. Both compounds are known to undergo rapid photolysis during the day, but models assume no night-time atmospheric losses. Surprisingly, the diurnal cycle of CH2I2 was lower in amplitude than that of CH2ICl, despite its faster photolysis rate. We speculate that night-time loss of CH2I2 occurs due to reaction with NO3 radicals. Indirect results from a laboratory study under ambient atmospheric boundary layer conditions indicate a k CH2I2+NO3 of ≤4 × 10−13 cm3 molecule−1 s−1; a previous kinetic study carried out at ≤100 Torr found k CH2I2+NO3 of 4 × 10−13 cm3 molecule−1 s−1. Using the 1-dimensional atmospheric THAMO model driven by sea-air fluxes calculated from the seawater and air measurements (averaging 1.8 +/− 0.8 nmol m−2 d−1 for CH2I2 and 3.7 +/− 0.8 nmol m−2 d−1 for CH2ICl), we show that the model overestimates night-time CH2I2 by >60 % but reaches good agreement with the measurements when the CH2I2 + NO3 reaction is included at 2–4 × 10−13 cm3 molecule−1 s−1. We conclude that the reaction has a significant effect on CH2I2 and helps reconcile observed and modeled concentrations. We recommend further direct measurements of this reaction under atmospheric conditions, including of product branching ratios.
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影响因子：
6.3
作者：
T. Sherwen;M. Evans;L. Carpenter;S. Andrews;R. Lidster;B. Dix;T. Koenig;R. Sinreich;I. Ortega;R. Volkamer;A. Saiz‐Lopez;C. Prados-Román;A. Mahajan;C. Ordóñez
通讯作者：
T. Sherwen;M. Evans;L. Carpenter;S. Andrews;R. Lidster;B. Dix;T. Koenig;R. Sinreich;I. Ortega;R. Volkamer;A. Saiz‐Lopez;C. Prados-Román;A. Mahajan;C. Ordóñez
影响因子：
64.8
作者：
Read, Katie A.;Mahajan, Anoop S.;Plane, John M. C.
通讯作者：
Plane, John M. C.
塔斯马尼亚西部陆架浮游植物大量繁殖：高产生态系统的证据
影响因子：
3.2
作者：
J. Kämpf
通讯作者：
J. Kämpf
CH2I O2 反应的多维研究：产物和大气影响。
DOI：
10.1002/cphc.201000575
发表时间：
2010
期刊：
Chemphyschem : a European journal of chemical physics and physical chemistry
影响因子：
--
作者：
T. Gravestock;M. Blitz;W. Bloss;D. Heard
通讯作者：
D. Heard
DOI：
--
发表时间：
2015
期刊：
--
影响因子：
--
作者：
通讯作者：
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