Analysis of the atmospheric distribution, sources, and sinks of oxygenated volatile organic chemicals based on measurements over the Pacific during TRACE‐P
Analysis of the atmospheric distribution, sources, and sinks of oxygenated volatile organic chemicals based on measurements over the Pacific during TRACE‐P
复制标题
DOI：
10.1029/2003jd003883
复制
发表时间：
2004-08
影响因子：
--
通讯作者：
H. Singh;L. Salas;R. Chatfield;E. Czech;A. Fried;J. Walega;M. J. Evans;B. S. Field;D. Jacob;D. Blake;B. Heikes;R. Talbot;G. Sachse;J. Crawford;M. Avery;S. Sandholm;H. Fuelberg
中科院分区：
文献类型：
--
作者：
H. Singh;L. Salas;R. Chatfield;E. Czech;A. Fried;J. Walega;M. J. Evans;B. S. Field;D. Jacob;D. Blake;B. Heikes;R. Talbot;G. Sachse;J. Crawford;M. Avery;S. Sandholm;H. Fuelberg
[1]2001年冬/春（2月24日至4月10日），在太平洋对流层（0.1-12公里）进行了大量含氧挥发性有机化学品（OVOC）的空中测量。具体而言，这些测量包括丙酮（CH 3COCH 3）、甲基乙基酮（CH 3COC 2 H5，MEK）、甲醇（CH 3OH）、乙醇（C2 H5 OH）、乙醛（CH 3CHO）、丙醛（C2 H5 CHO）、过氧酰基硝酸酯（PAN）（CnH 2n +1COO 2NO 2）和有机硝酸酯（CnH 2n +1 ONO 2）。甲醛（HCHO），甲基氢过氧化物（CH 3 OOH）和选定的示踪剂的补充测量也可用。OVOC在清洁对流层中含量丰富，在亚洲流出区中大大增强。背景混合比通常在对流层下部最高，并向对流层上部和平流层最低处下降。它们的总丰度（AOVOC）几乎是非甲烷碳氢化合物（NOC 2-C8 NMHC）的两倍。在整个对流层中，OVOC的OH反应性与甲烷相当，远远超过NMHC。将这些数据与大约7年前（1994年2月至3月）收集的西太平洋观测数据进行比较，没有发现重大差异。OVOC的混合比彼此之间以及与化石和生物质/生物燃料燃烧的示踪剂密切相关。分析选定的OVOC相对于CH 3Cl和CO在12羽源火灾和采样在自由对流层（3-11公里）的相对增强被用来评估其主要和二次排放量从生物质燃烧。这些羽流的组成还表明活性氮大量转移到PAN储层中，从而限制臭氧的形成。一个三维的全球模型，使用最先进的化学和源信息的状态是用来比较选定的OVOC的测量和模拟混合比。虽然在许多情况下存在合理的一致性，但测量的醛浓度显著大于预测值。在他们所观察到的水平，乙醛混合比被证明是一个重要的来源HCHO（和HOx）和PAN在对流层。在目前已知的化学的基础上，醛和PAN的测量混合比是互不相容的。我们提供了几种OVOC的全球来源的粗略估计，并得出结论，这些总体上是非常大的（150-500 Tg C yr-1），但仍然很难量化。
[1] Airborne measurements of a large number of oxygenated volatile organic chemicals (OVOC) were carried out in the Pacific troposphere (0.1–12 km) in winter/spring of 2001 (24 February to 10 April). Specifically, these measurements included acetone (CH3COCH3), methylethyl ketone (CH3COC2H5, MEK), methanol (CH3OH), ethanol (C2H5OH), acetaldehyde (CH3CHO), propionaldehyde (C2H5CHO), peroxyacylnitrates (PANs) (CnH2n+1COO2NO2), and organic nitrates (CnH2n+1ONO2). Complementary measurements of formaldehyde (HCHO), methyl hydroperoxide (CH3OOH), and selected tracers were also available. OVOC were abundant in the clean troposphere and were greatly enhanced in the outflow regions from Asia. Background mixing ratios were typically highest in the lower troposphere and declined toward the upper troposphere and the lowermost stratosphere. Their total abundance (ΣOVOC) was nearly twice that of nonmethane hydrocarbons (ΣC2-C8 NMHC). Throughout the troposphere, the OH reactivity of OVOC is comparable to that of methane and far exceeds that of NMHC. A comparison of these data with western Pacific observations collected some 7 years earlier (February–March 1994) did not reveal significant differences. Mixing ratios of OVOC were strongly correlated with each other as well as with tracers of fossil and biomass/biofuel combustion. Analysis of the relative enhancement of selected OVOC with respect to CH3Cl and CO in 12 plumes originating from fires and sampled in the free troposphere (3–11 km) is used to assess their primary and secondary emissions from biomass combustion. The composition of these plumes also indicates a large shift of reactive nitrogen into the PAN reservoir thereby limiting ozone formation. A three-dimensional global model that uses state of the art chemistry and source information is used to compare measured and simulated mixing ratios of selected OVOC. While there is reasonable agreement in many cases, measured aldehyde concentrations are significantly larger than predicted. At their observed levels, acetaldehyde mixing ratios are shown to be an important source of HCHO (and HOx) and PAN in the troposphere. On the basis of presently known chemistry, measured mixing ratios of aldehydes and PANs are mutually incompatible. We provide rough estimates of the global sources of several OVOC and conclude that collectively these are extremely large (150–500 Tg C yr−1) but remain poorly quantified.