Correction: Olaguer et al. Landfill Emissions of Methane Inferred from Unmanned Aerial Vehicle and Mobile Ground Measurements. Atmosphere 2022, 13, 983

Supplementary Materials

There was an error in the original publication [1]. Equation (S2) had a missing factor in the first exponential term.

A correction has been made to the transfer matrix in Paragraph 2:

A transfer matrix $P_{ij}$ is defined such that each matrix element denotes the dispersion of a plume from a point source j with emission rate $Q_j$ to a receptor i with net concentration $C_i$.

$$C_i=P_{ij}{Q}_j+B$$

(S1)

$$\begin{gathered} P_{ij}={\displaystyle \frac{exp\left(-\frac{x_{ij}^2{sin}^2{\beta }_{ij}}{2{\sigma }_y^2}\right)}{2\pi U{\sigma }_y{\sigma }_z}}\sum _{m=0}^1\left\{exp\left[-{\displaystyle \frac{{\left(z_i-h_{sj}-2m{z}_{mix}\right)}^2}{2{\sigma }_z^2}}\right] \\ +exp\left[-{\displaystyle \frac{{\left(z_i+h_{sj}+2m{z}_{mix}\right)}^2}{2{\sigma }_z^2}}\right]\right\} , \end{gathered}$$

(S2)

where B is the background concentration, $x_{ij}$ is the horizontal distance of receptor i from the emission source j, ${\beta }_{ij}$is the angular difference between the displacement vector associated with $x_{ij}$ and the wind vector (i.e., $x_{ij}$ sin ${\beta }_{ij}$ is the cross-wind distance), $z_i$ is the vertical height of receptor i, $h_{sj}$ is the effective height of source j, and $z_{mix}$ is the mixing height. The dispersion parameters are computed based on two cases: (1) a stable boundary layer (SBL), and (2) a convective boundary layer (CBL). For simplicity, updrafts and downdrafts in the CBL are not accounted for so that the plume centerline height is independent of the vertical velocity. Plume contributions resulting from the downward dispersion of lofted material near or above the mixing height in the CBL are likewise ignored. In USEPA (2004), these contributions are referred to as the indirect and penetrated sources, in contrast with the direct plume accounted for in Equation (S2). Because only fugitive emission sources are considered (i.e., no plume rise from combustion sources), $h_{sj}$ is simply the source elevation.

The authors state that the scientific conclusions are unaffected. This correction was approved by the Academic Editor. The original publication has also been updated.