LAUSR

1. The problem The upper bound derived in Kerswell (2016) is incorrect. This is because the I4 and I5 integrals centred at the top boundary are not exactly analogous to their counterparts at the lower boundary, counter to what is written just under equation (2.23) (in Kerswell 2016). Instead, in both cases, due to the roughness, the full volume integrals must be included which scale differently with `. Specifically, the estimates for the I4 and I5 integrals centred at the top boundary are I 5 := 〈∫ 1 1−` ∫∫∫ V(Λ) |u ·∇a| dV dΛ 〉