Fast retrievals of tropospheric carbonyl sulfide with IASI
Fast retrievals of tropospheric carbonyl sulfide with IASI
复制标题
利用 IASI 快速反演对流层羰基硫
DOI：
10.5194/acp-17-2981-2017
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发表时间：
2016
影响因子：
6.3
通讯作者：
A. Dudhia
中科院分区：
文献类型：
--
作者：
R. Anthony Vincent;A. Dudhia
摘要。从卫星上反复提取微量气体，如羰基硫化物（OCS），可能非常缓慢。该算法甚至可能无法跟上数据采集的步伐，从而使分析仅限于具有特殊兴趣和短时间跨度的本地事件。考虑到这一点，我们开发了一种线性检索方案，以比典型迭代检索快104倍的速度估计OCS的总列数。该方案结合了以前发表的线性估计中未使用的两个概念。首先，所有影响信号的物理参数都包含在状态向量中并共同计算，而不是作为有效噪声处理。其次，通过将模式光谱与观测数据进行比较，从大气系综中确定初始点，从而提高了问题的线性度。对2014年红外大气探测干涉仪（IASI） A和B仪器的所有数据进行了分析，并显示了OCS总柱的空间特征，包括热带雨林上空的耗竭、海洋上空的季节性增强以及陆地上空明显的OCS特征。对于OCS，由于假设线性而产生的误差在11 %左右。然而，系统误差的影响，如变化的表面发射率和消光由于气溶胶尚未得到强有力的表征。与NOAA采集的原位样品的表面体积混合比相比，全球7个站点中有5个站点的季节相关性大于0.7。此外，该线性方案适用于OCS，但也可用于使用IASI或类似的最低点观测仪器对任何可检测的痕量气体进行快速估计。
Abstract. Iterative retrievals of trace gases, such as carbonyl sulfide (OCS), from satellites can be exceedingly slow. The algorithm may even fail to keep pace with data acquisition such that analysis is limited to local events of special interest and short time spans. With this in mind, a linear retrieval scheme was developed to estimate total column amounts of OCS at a rate roughly 104 times faster than a typical iterative retrieval. This scheme incorporates two concepts not utilized in previously published linear estimates. First, all physical parameters affecting the signal are included in the state vector and accounted for jointly, rather than treated as effective noise. Second, the initialization point is determined from an ensemble of atmospheres based on comparing the model spectra to the observations, thus improving the linearity of the problem. All of the 2014 data from the Infrared Atmospheric Sounding Interferometer (IASI), instruments A and B, were analysed and showed spatial features of OCS total columns, including depletions over tropical rainforests, seasonal enhancements over the oceans, and distinct OCS features over land. Error due to assuming linearity was found to be on the order of 11 % globally for OCS. However, systematic errors from effects such as varying surface emissivity and extinction due to aerosols have yet to be robustly characterized. Comparisons to surface volume mixing ratio in situ samples taken by NOAA show seasonal correlations greater than 0.7 for five out of seven sites across the globe. Furthermore, this linear scheme was applied to OCS, but may also be used as a rapid estimator of any detectable trace gas using IASI or similar nadir-viewing instruments.
影响因子：
5.2
作者：
S. Kremser;N. Jones;M. Palm;B. Lejeune;Yuting Wang;D. Smale;N. Deutscher
通讯作者：
S. Kremser;N. Jones;M. Palm;B. Lejeune;Yuting Wang;D. Smale;N. Deutscher
使用单色查找表进行快速辐射传输
DOI：
10.1016/j.jqsrt.2016.04.011
发表时间：
2017
影响因子：
2.3
作者：
Anthony Vincent R
通讯作者：
Anthony Vincent R