Toward Physically Constrained Low-Level Tangential-Wind Profiles in Tropical Cyclones: A Review

Low-level tangential-wind profiles are compact descriptors of mature tropical cyclone (TC) structure, but they are often treated mainly as empirical curves. This review examines the azimuthal-mean low-level tangential wind from the radius of maximum wind (RMW) outward in mature, primarily over-water TCs and assesses how existing profile descriptions can be tied to physical constraints. We trace the development from Rankine and modified-Rankine representations to stress-based, outflow-constrained, angular-momentum, boundary-layer, radiative-subsidence, and complete radial-structure frameworks. The literature indicates that no single universal law governs the profile, and no accepted framework yet provides a complete profile that is simultaneously physically closed, observationally robust, and portable across storms. The near-RMW transition reflects inner-core thermodynamics, outflow-layer stratification, angular-momentum redistribution, and boundary-layer adjustment; the outer core reflects surface stress, wind-dependent drag, angular-momentum storage, and inner-outer matching; and the far outer circulation is constrained by radiative subsidence and environmental control. Profile shape is dynamically important because it affects storm size, radial angular-momentum storage, rapid filamentation, rainband organization, moat width, secondary eyewall formation, and simplified intensity-change pathways. At the same time, fitted parameters such as the modified-Rankine decay exponent remain conditional structural descriptors whose physical interpretation depends on wind level, radial fitting interval, boundary-layer transformation, and radial regime. Future progress will depend less on adding empirical profile families than on developing observation-tested, regime-aware frameworks with standardized diagnostics, explicit wind-level definitions, and clearer matching between physical closures across the inner core, outer core, and far outer circulation.