component listed in Table \[tab:unc\_cat\] must be combined to produce a total estimate of AEP uncertainty. While general guidelines on how to combine (measurement) uncertainty components exists [@iso1995guide] and can be applied to this task, we found no specific guidance in the literature for combining uncertainty components in an operational AEP estimate. On the other hand, considerable guidance exists for combining preconstruction AEP uncertainties [@lackner2007; @brower2012; @vaisala2014; @kalkan2015; @clifton2016]. In every case, recommended best practices assume that all uncertainties, $\sigma_\text{i}$, are uncorrelated and can therefore be combined using a sum of squares approach to give the total AEP uncertainty, $ \sigma_{\text{tot,uncorr}}$: $$\sigma_{\text{tot,uncorr}} = \sqrt{\sum_\text{i=1}^\text{N} \sigma_\text{i}^2}
    \label{unc_unc}$$

To better understand how uncertainties are combined in long-term operational AEP calculations, we reached out to several wind energy consultants who regularly perform these analyses. These conversations revealed that uncertainties in a long-term operational AEP calculation are also assumed uncorrelated and combined using Equation \[unc\_unc\].

Goal of Study
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The purpose of this study is to examine the extent to which the assumption of uncorrelated uncertainties—and, therefore, the combination of those uncertainties through a sum of squares approach—is accurate and appropriate for operational AEP calculations. Specifically, this study aims to identify potential correlations between 