A Physical Model for the Observed Inverse Energy Cascade in Typhoon Boundary Layers.

The knowledge of the observed inverse energy cascade in typhoon boundary layers holds significant implications for understanding the formation, enhancement, and deformation of typhoons. This study reveals that the observed inverse energy cascade originates from the rapid rotation of typhoons. The transition from the direct energy cascade regime to the inverse energy cascade regime can be characterized by the Zeman length scale. The turbulence structures behave as two dimensional above the Zeman length scale. Through symmetry analysis, it is discovered that the ratio of the inverse energy cascade flux to the direct energy cascade flux is proportional to the turbulence Rossby number with a power of −2. These findings offer a framework for incorporating the inverse energy cascade into the turbulence parameterizations and improving typhoon modeling. Plain Language Summary: The process of the energy flowing inversely to large scales in typhoon boundary layers is important for the evolution of typhoons. This study reveals that this process originates from the rotation of typhoons. This study also establishes a theoretical relation between the ratio of the inverse energy cascade flux to the direct energy cascade flux and the turbulence Rossby number. These findings have practical implications for improving the turbulence parameterizations in numerical models. Key Points: The observed inverse energy cascade in typhoon boundary layers originates from the rapid rotation of typhoonsThe Zeman length scale can characterize the transition from the direct energy cascade regime to the inverse energy cascade regimeThe ratio of the inverse energy cascade flux to the direct energy cascade flux is controlled by the turbulence Rossby number [ABSTRACT FROM AUTHOR]