Tropical cyclones (TC) consist of a large range of interacting scales from hundreds of kilometers to a few meters. The energy transportation among these different scalesthat is, from smaller to larger scales (upscale) or vice versa (downscale)may have profound impacts on TC energy dynamics as a result of the associated changes in available energy sources and sinks. From multilayer tower measurements in the low-level (<120 m) boundary layer of several landing TCs, the authors found there are two distinct regions where the energy flux changes from upscale to downscale as a function of distance to the storm center. The boundary between these two regions is approximately 1.5 times the radius of maximum wind. Two-dimensional turbulence (upscale cascade) occurs more typically at regions close to the inner-core region of TCs, while 3D turbulence (downscale cascade) mostly occurs at the outer-core region in the surface layer.

https://doi.org/10.1175/JAS-D-14-0373.1

Journal Article

Grant no. NA14NWS4680028

Office of Oceanic and Atmospheric Research (OAR)