Re-examining Tropical Cyclone Fullness Using Aircraft Reconnaissance Data

We use FLIGHT+ aircraft reconnaissance data for tropical cyclones (TCs) in the North Atlantic and Eastern Pacific from 1997 to 2015 to re-examine TC fullness (TCF) characteristics at the flight level. The results show a strong positive correlation between the flight-level TCF and the intensity of TCs, with the flight-level TCF increasing much more rapidly than the near-surface TCF with increasing intensity of the TCs. The tangential wind in small-TCF hurricanes is statistically significantly stronger near the eye center than that in large-TCF hurricanes. Large-TCF hurricanes have a ring-like vorticity structure. No significant correlation is observed between the flight-level TCF and the comparative extent of the vorticity-skirt region occupied in the outer core skirt. The proportion of the rapid filamentation zone in the outer core skirt increases with increasing flight-level TCF. The differences in entropy between the radius of the maximum wind and the outer boundary of the outer core skirt also increase with increasing flight-level TCF.