An adaptation of the CO2 slicing technique for the Infrared Atmospheric Sounding Interferometer to obtain the height of tropospheric volcanic ash clouds
An adaptation of the CO2 slicing technique for the Infrared Atmospheric Sounding Interferometer to obtain the height of tropospheric volcanic ash clouds
复制标题
红外大气探测干涉仪采用二氧化碳切片技术来获取对流层火山灰云的高度
DOI：
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发表时间：
2019
影响因子：
3.8
通讯作者：
A. Cristaldi
中科院分区：
文献类型：
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作者：
D. Andronico;S. Scollo;A. Cristaldi
抽象的。火山灰云是一种与火山爆发有关的地理上影响深远的危险。为了最大限度地减少这些对飞机造成的风险，并限制对航空业的干扰，必须密切监测这些羽流的排放和大气扩散。羽流的高度是一个重要的考虑因素，是许多灰云传播模型的重要输入。CO2切片是一种获得水云顶部高度的成熟技术，以前的研究表明，这种方法有可能用于火山灰。在这项研究中，CO2切片技术已被改编为火山灰和应用到红外大气探测干涉仪（IASI）获得的光谱。模拟灰光谱首先用于选择最合适的通道，然后证明该技术具有确定灰的高度的优点。这些结果表明，一个强有力的匹配之间的真实高度和CO2切片输出的均方根误差（RMSE）小于800米。在此之后，该技术被应用于2010年和2011年分别在埃亚菲亚德拉冰盖和格里姆火山爆发期间使用IASI获得的光谱，这两次爆发都将灰云排放到对流层，并已通过卫星图像进行了广泛研究。的CO2切片结果进行了比较，从最佳的估计方案，也为IASI开发，和一个卫星搭载的激光雷达用于验证。与激光雷达相比，CO2切片高度返回的RMSE值为2.2 km。这低于最佳估计方案（2.8 km）的RMSE。CO2切片技术是一种相对快速的工具，结果表明，这种方法可以用来获得灰云高度的第一近似值，可能用于减灾，或作为其他检索技术或灰云传播模型的输入。
Abstract. Ash clouds are a geographically far-reaching hazard associated with volcanic eruptions. To minimise the risk that these pose to aircraft and to limit disruption to the aviation industry, it is important to closely monitor the emission and atmospheric dispersion of these plumes. The altitude of the plume is an important consideration and is an essential input into many models of ash cloud propagation. CO2 slicing is an established technique for obtaining the top height of aqueous clouds, and previous studies have demonstrated that there is potential for this method to be used for volcanic ash. In this study, the CO2 slicing technique has been adapted for volcanic ash and applied to spectra obtained from the Infrared Atmospheric Sounding Interferometer (IASI). Simulated ash spectra are first used to select the most appropriate channels and then demonstrate that the technique has merit for determining the altitude of the ash. These results indicate a strong match between the true heights and CO2 slicing output with a root mean square error (RMSE) of less than 800 m. Following this, the technique was applied to spectra obtained with IASI during the Eyjafjallajökull and Grímsvötn eruptions in 2010 and 2011 respectively, both of which emitted ash clouds into the troposphere, and which have been extensively studied with satellite imagery. The CO2 slicing results were compared against those from an optimal estimation scheme, also developed for IASI, and a satellite-borne lidar is used for validation. The CO2 slicing heights returned an RMSE value of 2.2 km when compared against the lidar. This is lower than the RMSE for the optimal estimation scheme (2.8 km). The CO2 slicing technique is a relatively fast tool and the results suggest that this method could be used to get a first approximation of the ash cloud height, potentially for use for hazard mitigation, or as an input for other retrieval techniques or models of ash cloud propagation.