Flexinvert has been updated to include the option of using a log-normal distribution for the prior flux errors. In this case, the inversion optimises a scalar of the prior fluxes. The log-normal distribution has the added advantage that it imposes a non-negative constraint the state vector – this means that positive fluxes will remain positive (and vice-versa) a posteriori. This is especially useful for species with only positive fluxes to the atmosphere.
For the log-normal optimisation, Flexinvert solves for the median of the posterior distribution. The median has been shown to be the most robust statistic to use.
A paper is in preparation on the log-normal optimisation.