The contribution of oceanic methyl iodide to stratospheric iodine
The contribution of oceanic methyl iodide to stratospheric iodine
复制标题
海洋甲基碘对平流层碘的贡献
DOI：
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
F. Ziska
中科院分区：
文献类型：
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作者：
S. Tegtmeier;K. Krüger;B. Quack;E. Atlas;D. Blake;H. Boenisch;A. Engel;H. Hepach;R. Hossaini;M. Navarro;S. Raimund;S. Sala;Qiang Shi;F. Ziska
我们研究了海洋甲基碘(CH3I)对平流层碘收支的贡献。根据三个热带航次的CH3I测量和拉格朗日输送模式FLEXPART，我们详细分析了CH3I从海洋表面到热带对流层上层冷点(TTL)的输送。虽然不同运动之间的平均海洋排放量相差不到50%，但测量结果显示，每个运动之间的差异要大得多。在某些航段中，海洋CH3I排放量与CH3I对流层-平流层输送效率之间存在正相关。强水平地面风引发大量排放的机制，一方面与热带对流系统，如发展中的台风有关，另一方面可以解释已确定的相关性。由于大量的CH3I排放和强烈的垂直抬升同时发生，在西太平洋沿岸的SHIVA(平流层臭氧：变化大气中的Halo-gen影响)期间观测到的峰值排放的局地最大冷点混合比为0.6ppt CH3I。另外两个凸轮的最大值要小得多，在开阔的西太平洋只有0.1ppt的CH3I，而在东大西洋沿海只有0.03ppt。为了评估大的局地混合比的代表性，我们使用气候排放情景来推导出全球高空对CH3I丰度的估计。模型的结果与现有的高空测量数据进行了比较，其中包括最近ATTREX和HIPPO2飞机战役的数据。在东太平洋地区，TTL上层的可用测量活动的位置，比较得到了很好的一致，表明大约有0.01-0.02ppt的CH3I进入平流层。然而，受到较强对流活动影响的其他热带地区显示出更大的CH3I夹带，例如西太平洋的0.08ppt。总的来说，我们的模式结果给出0.04ppt CH3I对平流层碘收支的热带贡献。CH3I夹带的地理分布的强烈差异表明，目前可用的高空测量不能代表全球估计数，为了更好地了解CH3I对平流层碘的贡献，需要开展进一步的运动。
We investigate the contribution of oceanic methyl iodide (CH3I) to the stratospheric iodine budget. Based on CH3I measurements from three tropical ship campaigns and the Lagrangian transport model FLEXPART, we provide a detailed analysis of CH3I transport from the ocean surface to the cold point in the upper tropical tropopause layer (TTL). While average oceanic emissions differ by less than 50 % from campaign to campaign, the measurements show much stronger variations within each campaign. A positive correla- tion between the oceanic CH3I emissions and the efficiency of CH3I troposphere-stratosphere transport has been identi- fied for some cruise sections. The mechanism of strong hor- izontal surface winds triggering large emissions on the one hand and being associated with tropical convective systems, such as developing typhoons, on the other hand, could ex- plain the identified correlations. As a result of the simulta- neous occurrence of large CH3I emissions and strong verti- cal uplift, localized maximum mixing ratios of 0.6 ppt CH3I at the cold point have been determined for observed peak emissions during the SHIVA (Stratospheric Ozone: Halo- gen Impacts in a Varying Atmosphere)-Sonne research vessel campaign in the coastal western Pacific. The other two cam- paigns give considerably smaller maxima of 0.1 ppt CH3I in the open western Pacific and 0.03 ppt in the coastal eastern Atlantic. In order to assess the representativeness of the large local mixing ratios, we use climatological emission scenarios to derive global upper air estimates of CH3I abundances. The model results are compared with available upper air measure- ments, including data from the recent ATTREX and HIPPO2 aircraft campaigns. In the eastern Pacific region, the loca- tion of the available measurement campaigns in the upper TTL, the comparisons give a good agreement, indicating that around 0.01 to 0.02 ppt of CH3I enter the stratosphere. How- ever, other tropical regions that are subject to stronger con- vective activity show larger CH3I entrainment, e.g., 0.08 ppt in the western Pacific. Overall our model results give a trop- ical contribution of 0.04 ppt CH3I to the stratospheric iodine budget. The strong variations in the geographical distribution of CH3I entrainment suggest that currently available upper air measurements are not representative of global estimates and further campaigns will be necessary in order to better understand the CH3I contribution to stratospheric iodine.
影响因子：
5.2
作者：
Jones, Charlotte E.;Hornsby, Karen E.;Carpenter, Lucy J.
通讯作者：
Carpenter, Lucy J.
三溴甲烷、二溴甲烷和碘甲烷的全球海空通量气候学
影响因子：
6.3
作者：
Ziska F
通讯作者：
Ziska F