In the article by Rolt(Reference Rolt, Sethi, Jacob, Sebastiampillai, Xisto, Grönstedt and Raffaelli1), there was an error in Equation (2). The correct equation is republished here.
(2)
$$\begin{equation}
{W_c} = \ \frac{{{W_{\it cref}}\left( {{T_{\it grel}} - {T_{\it cref}}} \right){{({W_4}/{W_{\it 4ref}})}^{0.65}}}}{{\left( {{T_{\it gref}} - {T_c}} \right)}}\ \ \ \ \ \ \
\end{equation}$$
$$\begin{equation}
{W_c} = \ \frac{{{W_{\it cref}}\left( {{T_{\it grel}} - {T_{\it cref}}} \right){{({W_4}/{W_{\it 4ref}})}^{0.65}}}}{{\left( {{T_{\it gref}} - {T_c}} \right)}}\ \ \ \ \ \ \
\end{equation}$$
