Photochemistry of ozone over the western Pacific from winter to spring
Photochemistry of ozone over the western Pacific from winter to spring
复制标题
DOI：
10.1029/2004jd004871
复制
发表时间：
2004-12
影响因子：
--
通讯作者：
Y. Kondo;Kazuaki Nakamura;Guimin Chen;N. Takegawa;M. Koike;Y. Miyazaki;K. Kita;J. Crawford;M. Ko;D. Blake;S. Kawakami;T. Shirai;B. Liley;Yang Wang;T. Ogawa
中科院分区：
文献类型：
--
作者：
Y. Kondo;Kazuaki Nakamura;Guimin Chen;N. Takegawa;M. Koike;Y. Miyazaki;K. Kita;J. Crawford;M. Ko;D. Blake;S. Kawakami;T. Shirai;B. Liley;Yang Wang;T. Ogawa
[1]2002年1月和4 - 5月，在亚洲大陆排放太平洋探测（PEACE）-A和B活动期间，对西太平洋20°-45 °N区域的臭氧（O3）及其前体物（包括NO、CO、H2O和非甲烷碳氢化合物（NMHCs））进行了飞机测量。这些测量提供的数据集，结合运输和化学演变在太平洋（TRACE-P）的数据在2001年3月，使研究从冬季到晚春的O3光化学。一个光化学箱模型被用来计算臭氧的形成（F（O3））和破坏（D（O3））率所观察到的物种浓度的限制。F（O3）和D（O3）的值直接由NO、J（O 1D）（O3光解频率）、H2O、OH和HO 2控制。HO 2浓度的变化引起F（O3）和D（O3）的相应变化，导致它们的耦合。这些物种的浓度，这是强烈的影响，从亚洲大陆的光化学和运输，经历了很大的季节性变化。在边界层（0-3公里），NO是高得多，在1月比4 - 5月，因为更强的风，对流活动少，在冬季OH氧化率较低。1月，30°-45 ° N边界层的O3净生成率（P（O3）= F（O3）− D（O3））基本为正值，主要是因为NO含量高，H2O含量低。从1月到3月底，净O3的形成持续，表明西太平洋是一个重要的O3源区在这个季节。由于NO的减少和H2O的增加，净O3的形成在4月下旬/5月几乎停止。在20° ~ 30 ° N范围内，边界层中的P（O3）在1月份为正值，到3月份为负值。较之30° ~ 45 ° N，较低的NO浓度和较高的H_2O浓度以及较弱的输送和较高的温度是较早转变的主要原因。对流层上部（6-12公里）已被证明是一个区域的净O3形成全年大部分时间，因为高NO和低H2O。结果表明，从冬季到晚春，北纬20°-45 ° N地区O3净生成率的下降可以用J（O 1D）、H2O、OH和HO 2的增加（主要是由于温度和太阳辐射的增加）和NO的减少（主要是由于来自亚洲大陆的输送减少）来系统地解释。北美大陆上空观察到的O3光化学季节变化的差异可以根据控制O3形成和破坏的因素的差异来解释。
[1] Aircraft measurements of ozone (O3) and its precursors, including NO, CO, H2O, and nonmethane hydrocarbons (NMHCs), were made over the western Pacific in the 20°– 45°N latitude range in January and April–May 2002 during the Pacific Exploration of Asian Continental Emission (PEACE)-A and B campaigns. These measurements have provided data sets that, in combination with Transport and Chemical Evolution over the Pacific (TRACE-P) data taken in March 2001, enable studies of O3 photochemistry from winter to late spring. A photochemical box model is used to calculate ozone formation (F(O3)) and destruction (D(O3)) rates constrained by the observed species concentrations. The values of F(O3) and D(O3) are controlled directly by NO, J(O1D) (O3 photolysis frequency), H2O, OH, and HO2. Changes in HO2 concentration cause corresponding changes in both F(O3) and D(O3), leading to their coupling. Concentrations of these species, which are strongly influenced by photochemistry and transport from the Asian continent, underwent large seasonal variations. In the boundary layer (0–3 km), NO was much higher in January than in April–May, because of stronger winds, lower convective activities, and lower oxidation rates by OH in winter. The net O3 formation rate, given by P(O3) = F(O3) − D(O3), was largely positive in the boundary layer at 30°–45°N (1.5 − 4 ppbv d−1) in January, mainly because of high NO and low H2O values. Net O3 formation continued from January to the end of March, demonstrating that the western Pacific is an important O3 source region during this season. Net O3 formation nearly ceased by late April/May because of the decrease in NO and the increase in H2O. In the latitude range of 20°–30°N, P(O3) in the boundary layer was positive in January and turned negative by March. The earlier transition was mainly due to lower NO and higher H2O concentrations, combined with weaker transport and higher temperatures than those at 30°–45°N. The upper troposphere (6–12 km) has been shown to be a region of net O3 formation throughout most of the year because of high NO and low H2O. The present study illustrates that a decrease in the net O3 formation rate at 20°–45°N latitude from winter to late spring is explained systematically by the increases in J(O1D), H2O, OH, and HO2 (primarily due to increases in temperature and solar radiation) and the decrease in NO (primarily due to decrease in transport from the Asian continent). Differences in the seasonal variation of O3 photochemistry observed over the North American continent are interpreted in terms of the differences in factors controlling O3 formation and destruction.