Accounting for the effect of transport errors on tracer inversions
Accounting for the effect of transport errors on tracer inversions
复制标题
考虑传输误差对示踪剂反演的影响
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
C. Gerbig
中科院分区：
文献类型：
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作者：
John C. Lin;C. Gerbig
示踪剂的大气输送误差导致基于浓度观测的示踪剂通量估计误差。通常，这种“逆向”方法要么忽略传输误差，要么只是粗略地评估它们的影响。我们描述了一种定量计算运输误差的方法，该方法将风的不确定性纳入空运包裹的随机运动中。风场误差的大小及其时空协方差是通过将同化风与无线电探空仪观测结果直接比较来确定的。这些运输误差的统计是通过拉格朗日模型（STILT）中空运包裹的随机运动传播的。我们利用模拟的大陆CO2观测数据进行了反向分析，并检验了运输误差对区域陆地碳通量估算的影响，以此来说明这种方法。逆分析表明，传输误差可能导致显著的估计偏差。我们证明了所提出的方法可以很好地解释这些误差。
Errors in atmospheric transport of tracers lead to errors in estimates of tracer fluxes based upon concentration observations. Typically, such “inverse” methods either neglect transport errors or only assess their effects roughly. We describe a method to quantitatively account for transport errors by incorporating uncertainties in winds into stochastic motions of air parcels. The magnitude of errors in wind fields, as well as their spatiotemporal covariances, are determined by direct comparison of assimilated winds to radiosonde observations. These statistics of transport errors are propagated through stochastic motions of air parcels in a Lagrangian model (STILT). We illustrate this method by conducting an inverse analysis using simulated CO2 observations over the continent and examine the effect of transport errors on estimates of regional terrestrial carbon fluxes. The inverse analysis demonstrates that transport errors can cause significantly biased estimates. We show that the proposed method properly accounts for these errors.