Comments on "Symmetric and asymmetric structures of hurricane boundary layer in coupled atmosphere-wave-ocean models and observations"

Abstract

In a recent paper, Lee and Chen (2012, hereafter LC12) presented numerical simulations of symmetric and asymmetric hurricane boundary layer structures in a fully coupled atmosphere–wave–ocean model and used these simulations to compare aspects of the boundary layer structure against an analysis of observations. One of their main conclusions was that ‘‘the azimuthally averaged inflow layer tends to misrepresent the overall inflow structure in tropical cyclones, especially the asymmetric structure’’ (p. 3593). Another main conclusion was that the complicated asymmetric three-dimensional boundary layer structures (attributed by them to be) due in part to the air–sea and wind–wave coupling ‘‘make it difficult to parameterize the atmosphere–wave–ocean coupling effects without a fully coupled model’’ (p. 3593). After careful examination of their study, we have a number of questions regarding their methodology, their interpretations (including their interpretations of previous literature), and their conclusions. Specifically, we inquire about aspects of the methodology for defining the dynamical boundary layer depth, the selection of the boundary layer scheme, and we question the conclusions inferred. In addition to the foregoing concerns, inaccuracies in their literature review are noted and inconsistencies between their conclusions and reported results are identified.