| Description |
Covering December 1997 through December 2008, over 13,000 tropical cyclone (TC) overpasses of 945 TCs by the Tropical Rainfall Measuring Mission (TRMM) satellite are used to document the observed passive microwave ice scattering magnitudes, radar reflectivity, IR cloud top height, total lightning, and derived rainfall parameters including rain rate, raining area, and volumetric rain. A semimanual method is used to divide TC raining area into inner core (IC), inner rainband (IB), and outer rainband (OB) regions. Precipitation features (PFs) within these regions are compared for their convective vigor and rainfall characteristics based on passive microwave, IR, radar, and lightning properties. These properties in the IC region are further examined in terms of different TC intensity and intensity change categories. TC intensity categories include tropical depressions (TDs), tropical storms (TSs), category 1-2 hurricanes (CAT12s), and category 3-5 hurricanes (CAT35s). The 24-h TC intensity change categories include weakening (W), neutral (N), slowly intensifying (SI), and rapidly intensifying (RI). The stronger tails of the convective intensity distributions are found to be similar for features in both the IC and OB regions, while the features in the IB region yield the weakest convective signatures. However, at the middle to weaker end of the convective spectrum, ice scattering signatures and reflectivity profiles are the strongest for features in the IC region, followed by those in the IB, then those in the OB. The same order is found for the whole distribution spectrum of feature conditional mean rain rates in these regions. The convective intensity of features in the IC region are found to increase as storm intensity increases, except at the strongest end of the spectrum, where ice scattering signatures and reflectivity profiles are stronger in features associated with TS and TD strength storms rather than those associated with hurricane strength storms. The IC conditional mean rain rate and volumetric rain increase as storm intensity increases. It is found that necessary conditions for RI are that the minimum 85 GHz PCT in the IC region must be less than 256 K and the minimum 37 GHz PCT must be less than 275 K. Over 98% of RI minimum 11?m brightness temperatures in the IC region are less than 212 K. RI storms always have larger raining area and volumetric rain in the IC region than storms in other intensity change categories. |
