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Abstract Substantial numerical difficulties associated with the computational modeling of multiscale global atmospheric chemical transport impose severe limitations on the spatial resolution of nonadaptive fixed grids. The crude spatial discretization introduces a large amount of numerical diffusion into the system, which, in combination with strong flow stretching, causes large numerical errors. To resolve this issue, we have developed an optimized wavelet‐based adaptive mesh refinement (OWAMR) method. The OWAMR is a three‐dimensional adaptive method that introduces a fine grid dynamically only in the regions where small spatial structures occur. The algorithm uses a new two‐parameter adaptation criterion that significantly (by factors between 1.5 and 2.7) reduces the number of grid points compared with the more conventional one‐parameter grid adaptation used by wavelet‐based adaptive techniques and high‐order upwind schemes, which enable one to increase the accuracy of approximation of the advection operator substantially. It has been shown that the method simulates the dynamics of a pollution plume that travels on a global scale, producing less than 3% error. To achieve such accuracy, conventional three‐dimensional nonadaptive techniques would require five orders of magnitude more computational resources. Therefore, the method provides a realistic opportunity to model accurately a variety of the most demanding multiscale problems in the area of atmospheric chemical transport, which are difficult or impossible to simulate on existing computational facilities with conventional fixed‐grid techniques. 

Abstract The Eulerian multifluid mathematical model is developed to describe the marine atmospheric boundary layer laden with sea spray under the high-wind condition of a hurricane. The model considers spray and air as separate continuous interacting turbulent media and employs the multifluid E –ϵ closure. Each phase is described by its own set of coupled conservation equations and characterized by its own velocity. Such an approach enables us to accurately quantify the interaction between spray and air and pinpoint the effect of spray on the vertical momentum transport much more precisely than could be done with traditional mixture-type approaches. The model consistently quantifies the effect of spray inertia and the suppression of air turbulence due to two different mechanisms: the turbulence attenuation, which results from the inability of spray droplets to fully follow turbulent fluctuations, and the vertical transport of spray against the gravity by turbulent eddies. The results of numerical and asymptotic analyses show that the turbulence suppression by spray overpowers its inertia several meters above wave crests, resulting in a noticeable wind acceleration and the corresponding reduction of the drag coefficient from the reference values for a spray-free atmosphere. This occurs at much lower than predicted previously spray volume fraction values of ∼10 −5 . The falloff of the drag coefficient from its reference values is more strongly pronounced at higher altitudes. The drag coefficient reaches its maximum at spray volume fraction values of ∼10 −4 , which is several times smaller than predicted by mixture-type models.