Upper-tropospheric inflow layers in tropical cyclones

Wang, Shanghong; Smith, Roger K. und Montgomery, Michael T. (2020): Upper-tropospheric inflow layers in tropical cyclones. In: Quarterly Journal of the Royal Meteorological Society, Bd. 146, Nr. 732: S. 3466-3487

Abstract

Three-dimensional numerical simulations of tropical cyclone intensification with sufficient vertical resolution have shown the development of a layer of strong inflow just beneath the upper-tropospheric outflow layer as well as, in some cases, a shallower layer of weaker inflow above the outflow layer. Here we provide an explanation for these inflow layers in the context of the prototype problem for tropical cyclone intensification, which considers the evolution of a vortex on anf-plane in a quiescent environment, starting from an initially symmetric, moist, cloud-free vortex over a warm ocean. We attribute the inflow layers to a subgradient radial force that exists through much of the upper troposphere beyond a certain radius. An alternative explanation that invokes classical axisymmetric balance theory is found to be problematic. We review evidence for the existence of such inflow layers in recent observations. Some effects of the inflow layers on the storm structure are discussed.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0035-9009
• Sprache: Englisch