Impact of tropical convection and ENSO variability in vertical distribution of CO and O3 over an urban site of India
Impact of tropical convection and ENSO variability in vertical distribution of CO and O3 over an urban site of India
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热带对流和 ENSO 变化对印度城市地区 CO 和 O3 垂直分布的影响
DOI：
10.1007/s00382-016-3353-7
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发表时间：
2017
期刊：
影响因子：
4.6
通讯作者：
Herman G. Smit
中科院分区：
文献类型：
--
作者：
Sahu;L. K.;V. Seel;M. Kajino;M. Deushi;S. S. Gunthe;P. R. Sinha;R. Yadav;D. Pal;P. Nedelec;V. Thouret;Herman G. Smit
本研究是基于2005年11月至2009年3月期间海得拉巴上空垂直臭氧（O3）和一氧化碳（CO）的空中客车在役飞机（MOZAIC）的臭氧和水汽测量数据的分析。在对流层上层的测量显示最高值的O3（53-75 ppbv）和CO（80-110 ppbv）在前季风和后季风季节，分别。在季风/后季风月份，强风切变（>20 ms−1）频繁出现，而弱切变（<10 ms−1）则在冬季普遍存在。在各季节中，南风下的O3和CO浓度均低于北风下的浓度。研究区域的强风切变和弱风切变分别与厄尔尼诺和拉尼娜现象有关。出射长波辐射和风切变资料显示，从季风到季风后期对流活动增强。在强剪切条件下测得更高水平的O3，而CO和H2O显示增强弱剪切条件下。近地面观测和模拟结果表明，O3随OLR的增加而增加，而在上部区域的相关性不明显。在CO的情况下，MOZAIC和CCM 2显示较弱的依赖性，而MOZART-4显示快速增加，OLR表明对流输送的高估。一个修改后的Tiedtke对流方案提供了更好的代表性相比，哈克/张-McFarlane计划在季风季节的O3和CO。在厄尔尼诺向拉尼娜阶段过渡期间，观测和模拟之间的差异特别大。MOZART-4和CCM-2中对流方案和水平分辨率的不同似乎是造成这两个模式不一致的主要原因。在极端事件如热带气旋（TC）期间，孟加拉湾（BOB）上空的O3和CO垂直廓线显示出强烈的对流动力学影响。
This study is based on the analysis of the measurement of ozone and water vapor by airbus in-service aircraft (MOZAIC) data of vertical ozone (O3) and carbon monoxide (CO) over Hyderabad during November 2005–March 2009. Measurements in the upper troposphere show highest values of O3(53–75 ppbv) and CO (80–110 ppbv) during the pre-monsoon and post-monsoon seasons, respectively. The episodes of strong wind shears (>20 ms−1) were frequent during the monsoon/post-monsoon months, while weak shear conditions (<10 ms−1) were prevalent during the winter season. The profiles of both O3and CO measured under southerly winds showed lower values than under northerly winds in each season. The strong and weak wind shears over the study region were associated with the El Niño and La Niña conditions, respectively. The outgoing long-wave radiation (OLR) and wind shear data indicate enhancement in the convective activity from monsoon to post-monsoon period. Higher levels of O3were measured under the strong shear conditions, while CO and H2O show enhancements under weak shear conditions. The near surface observation and simulations show increase of O3with increasing OLR, while insignificant relation in the upper region. In case of CO, the MOZAIC and CCM2 show weaker dependence while MOZART-4 shows rapid increase with OLR indicating large overestimation of convective transport. A modified Tiedtke convective scheme provides better representation compared to the Hack/Zhang-McFarlane schemes for both O3and CO during the monsoon season. The difference between observation and simulations were particularly large during transition from El Niño to La Niña phases. The different convection scheme and horizontal resolution in the MOZART-4 and CCM2 seem to be the major causes of disagreement between these models. Vertical profiles of both O3and CO during extreme events such a tropical cyclones (TCs) show strong influence of the convective-dynamics over Bay of Bengal (BOB).