Using budgets to study tropical cyclones

Abstract

In this chapter, the general formulation and methodology of budget studies for tropical cyclones (TCs) are reviewed. Budget calculations are very useful for understanding the dynamical and thermodynamical processes taking place in TCs, because they could provide not only the relative magnitudes of the processes in budget equations but also insight into the most fundamental processes leading to the intensity and intensity changes as well as structural changes of TCs. Budget studies have evolved dramatically in the past 50 years, in response not only to increases in observational data quality and availability, but also to rapidly increasing computing power for numerical model simulations. Accordingly, the scales of interest to researchers have progressed downward with time, from early studies on the general synoptic-scale to recent mesoscale processes. More recent budget studies have begun to focus on even smaller scale features such as individual convective elements, which remain virtually unobservable within the TC inner core. Many of the early budget studies were limited by assumptions required because of data limitations, but today’s numerical models allow more rigorous and detailed investigation of dynamic processes taking place in TCs.