Use of the WC-130J reconnaissance aircraft for integrated atmospheric and oceanographic tropical cyclone (TC) observations in the Western North Pacific, Central Pacific and Atlantic basins: A national asset for the future

During the ONR-sponsored TCS08 experiment in the Western Pacific, WC-130J aircraft were used to sample tropical cyclones (TCs) from genesis through mature to extratropical transition stages. The extensive observational capabilities of the WC-130J were utilized to sample the atmosphere from 11km altitude (300 mb) to the surface with GPS dropsondes at the same time that AXBTs were deployed to sample the ocean from the surface to 300 m depth. These observations provided for an unprecedented view of the atmospheric and oceanic environment in pre-depression and depression stages of TC development. Later in TC lifetime, drifting buoys were deployed ahead of two mature TCs, Hagupit (CAT 3) and Jangmi (CAT 5) which provided time series of subsurface ocean thermal structure and surface currents over a period from one day before TC passage to several weeks after. This capability provides unique data for diagnosis of TC development and for initial data for devveloping coupled TC forecast models.

This strategy was initially developed in the Atlantic basin as part of the ONR-sponsored CBLAST experiment, utilizing air-deployed profiling floats as well as drifters, and its potential for simultaneous atmospheric and oceanic 3D observations demonstrated in Hurricane Francis (2004). Since then, this capability has been further exploited, with AXBT deployments provided from NOAA WP-3D aircraft, in four additional Atlantic-basin (Gulf of Mexico and Caribbean) TCs.

Examples of these observations from the recent TCS08 experiment are analyzed and their synergy demonstrated. The potential application of this strategy for improved model initialization and intensity forecast prediction throughout the tropical cyclone basins of the world where WC-130J reconnaissance capabilities exist is discussed in detail.