Dicarboxylic acids, oxoacids, benzoic acid, α-dicarbonyls, WSOC, OC, and ions in spring aerosols from Okinawa Island in the western North Pacific Rim: size distributions and formation processes
Dicarboxylic acids, oxoacids, benzoic acid, α-dicarbonyls, WSOC, OC, and ions in spring aerosols from Okinawa Island in the western North Pacific Rim: size distributions and formation processes
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DOI：
10.5194/acp-16-5263-2016
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发表时间：
2016-01-01
影响因子：
6.3
通讯作者：
Boreddy, Suresh K. R.
中科院分区：
文献类型：
--
作者：
Deshmukh, Dhananjay K.;Kawamura, Kimitaka;Boreddy, Suresh K. R.
2008 年春季，在冲绳边户岬收集了按尺寸划分的气溶胶（直径从 < aEuro-0.43 到 > aEuro-11.3aEuro-A μ m 的九个阶段），并分析了水溶性二酸 (C-2-C-12)、omega-含氧酸 (omega C-2-omega C-9)、丙酮酸、苯甲酸和α-二羰基 (C-2-C-3) 以及水溶性有机碳 (WSOC)、有机碳 (OC) 和主要离子（Na+、NH4+、K+、Mg2+、Ca2+、Cl-、NO3-、SO42- 和 MSA(-)）。在所有尺寸分离的气溶胶中，草酸（C-2）被发现是最丰富的种类，其次是丙二酸和琥珀酸，而乙醛酸（omega C-2）是主要的含氧酸，乙二醛（Gly）比甲基乙二醛更丰富。二酸 (C-2-C-5)、omega C-2 和 Gly 以及 WSOC 和 OC 在精细模式 (0.65-1.1aEuro-A mu m) 下达到峰值，而壬二酸 (C-9) 和 9-氧壬酸 (omega C-9) 在粗略模式 (3.3-4.7aEuro-A mu m) 下达到峰值。硫酸盐和铵在精细模式下富集，而钠和氯化物在粗略模式下富集。在精细模式下观察到 C-2-C-5 二酸、omega C-2 和 Gly 与硫酸盐的强相关性 (r = aEuro-0.86-0.99)，表明它们的二次形成具有共性。它们与精细模式下的液态水含量的显着相关性（r = aEuro-0.82-0.95）进一步表明冲绳气溶胶中水相产生的重要性。它们也可能是在精细模式下直接从生物质燃烧中排放出来的，与钾（r = aEuro-0.85-0.96）（生物质燃烧的示踪剂）有很强的相关性。长链二酸 (C-9) 和含氧酸 (omega C-9) 的双峰尺寸分布（在粗模式下具有主峰）表明它们是从海面微层中释放出来的和/或通过海盐颗粒上生物不饱和脂肪酸的非均相氧化产生的。
Size-segregated aerosols (nine stages from < aEuro-0.43 to > aEuro-11.3aEuro-A mu m in diameter) were collected at Cape Hedo, Okinawa, in spring 2008 and analyzed for water-soluble diacids (C-2-C-12), omega-oxoacids (omega C-2-omega C-9), pyruvic acid, benzoic acid, and alpha-dicarbonyls (C-2-C-3) as well as water-soluble organic carbon (WSOC), organic carbon (OC), and major ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-, and MSA(-)). In all the size-segregated aerosols, oxalic acid (C-2) was found to be the most abundant species, followed by malonic and succinic acids, whereas glyoxylic acid (omega C-2) was the dominant oxoacid and glyoxal (Gly) was more abundant than methylglyoxal. Diacids (C-2-C-5), omega C-2, and Gly as well as WSOC and OC peaked at fine mode (0.65-1.1aEuro-A mu m) whereas azelaic (C-9) and 9-oxononanoic (omega C-9) acids peaked at coarse mode (3.3-4.7aEuro-A mu m). Sulfate and ammonium were enriched in fine mode, whereas sodium and chloride were in coarse mode. Strong correlations of C-2-C-5 diacids, omega C-2 and Gly with sulfate were observed in fine mode (r = aEuro-0.86-0.99), indicating a commonality in their secondary formation. Their significant correlations with liquid water content in fine mode (r = aEuro-0.82-0.95) further suggest an importance of the aqueous-phase production in Okinawa aerosols. They may also have been directly emitted from biomass burning in fine mode as supported by strong correlations with potassium (r = aEuro-0.85-0.96), which is a tracer of biomass burning. Bimodal size distributions of longer-chain diacid (C-9) and oxoacid (omega C-9) with a major peak in the coarse mode suggest that they were emitted from the sea surface microlayers and/or produced by heterogeneous oxidation of biogenic unsaturated fatty acids on sea salt particles.