Atmospheric composition and thermodynamic retrievals from the ARIES airborne FTS system - Part 1: Technical aspects and simulated capability
Atmospheric composition and thermodynamic retrievals from the ARIES airborne FTS system - Part 1: Technical aspects and simulated capability
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DOI：
10.5194/amt-7-1133-2014
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发表时间：
2013-12
影响因子：
3.8
通讯作者：
S. Illingworth;G. Allen;S. Newman;A. Vance;F. Marenco;R. Harlow;Jonathan P. Taylor;D. Moore;J. Remedios
中科院分区：
文献类型：
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作者：
S. Illingworth;G. Allen;S. Newman;A. Vance;F. Marenco;R. Harlow;Jonathan P. Taylor;D. Moore;J. Remedios
摘要。在本研究中，我们对机载研究干涉仪评估系统（ARIES）的检索能力进行了评估：该系统是在英国机载大气测量设施（FAAM）飞机上运行的机载遥感傅立叶变换光谱仪（FTS）。本文模拟了部分柱状微量气体浓度的最大后验反演，以及整个对流层和行星边界层的热力学垂直剖面，并对在最低点观测几何结构下运行的ARIES系统的模拟红外光谱进行了模拟。我们还描述了从FAAM平台进行常规检索所需的预处理的操作和技术方面，以及先验信息的选择和构建。以ARIES检索系统的能力为例，讨论了ARIES在全球典型环境下对温度、水蒸气（H2O）、一氧化碳（CO）、臭氧（O3）和甲烷（CH4）的模拟检索，以及它们相应的误差来源和潜在的垂直灵敏度。假设飞行高度为7 km，对于指定的先验约束，温度、H2O、CO、O3和CH4的最大信号自由度（DOFS）分别为3.99、2.97、0.85、0.96和1.45。温度的反演显示出显著的垂直灵敏度（在整个高度范围内DOFS在2.6到4.0之间）和优异的模拟精度，H2O的垂直灵敏度也扩展到较低的高度（DOFS在1.6到3.0之间）。结果表明，在所有情景下，CO、O3和CH4的最大敏感性约在模拟高度以下1 ~ 2 km。通过对检索到的部分大气柱和模拟真值的比较，对ARIES测量系统的能力进行了评估。对于温度、H2O、CO、O3和CH4，部分列（即飞机总列以下）的最大平均偏差（和偏差标准偏差）分别为+0.06（±0.02 at 1σ）%、+3.95（±3.11）%、+3.74（±2.97）%、- 8.26（±4.64）%和+3.01（±2.61）%，说明与最优方案相比，检索系统表现良好。结果表明，温度、H2O、CO、O3和CH4的最大后验误差分别为0.20、22.57、18.22、17.61和16.42%。
Abstract. In this study we present an assessment of the retrieval capability of the Airborne Research Interferometer Evaluation System (ARIES): an airborne remote-sensing Fourier transform spectrometer (FTS) operated on the UK Facility for Airborne Atmospheric Measurement (FAAM) aircraft. Simulated maximum a posteriori retrievals of partial column trace gas concentrations, and thermodynamic vertical profiles throughout the troposphere and planetary boundary layer have been performed here for simulated infrared spectra representative of the ARIES system operating in the nadir-viewing geometry. We also describe the operational and technical aspects of the pre-processing necessary for routine retrieval from the FAAM platform and the selection and construction of a priori information. As exemplars of the capability of the ARIES retrieval system, simulated retrievals of temperature, water vapour (H2O), carbon monoxide (CO), ozone (O3), and methane (CH4), and their corresponding sources of error and potential vertical sensitivity, are discussed for ARIES scenes across typical global environments. The maximum Degrees of Freedom for Signal (DOFS) for the retrievals, assuming a flight altitude of 7 km, were 3.99, 2.97, 0.85, 0.96, and 1.45 for temperature, H2O, CO, O3, and CH4, respectively, for the a priori constraints specified. Retrievals of temperature display significant vertical sensitivity (DOFS in the range 2.6 to 4.0 across the altitude range) as well as excellent simulated accuracy, with the vertical sensitivity for H2O also extending to lower altitudes (DOFS ranging from 1.6 to 3.0). It was found that the maximum sensitivity for CO, O3, and CH4 was approximately 1–2 km below the simulated altitudes in all scenarios. Comparisons of retrieved and simulated-truth partial atmospheric columns are used to assess the capability of the ARIES measurement system. Maximum mean biases (and bias standard deviations) in partial columns (i.e. below aircraft total columns) were found to be +0.06 (±0.02 at 1σ)%, +3.95 (±3.11)%, +3.74 (±2.97)%, −8.26 (±4.64)%, and +3.01 (±2.61)% for temperature, H2O, CO, O3, and CH4, respectively, illustrating that the retrieval system performs well compared to an optimal scheme. The maximum total a posteriori retrieval errors across the partial columns were also calculated, and were found to be 0.20, 22.57, 18.22, 17.61, and 16.42% for temperature, H2O, CO, O3, and CH4, respectively.