Overview of the Tropical Cyclone Intensity Experiment: Unique Observations of Hurricanes Patricia, Joaquin, and Marty

Tropical cyclone intensification and structural changes are investigated in a comprehensive manner using dropwindsondes deployed from the HDSS (High Definition Sounding System), and remotely sensed observations from HIRAD (Hurricane Imaging Radiometer) both onboard the NASA WB-57 as part of the Office of Naval Research (ONR) Tropical Cyclone Intensity (TCI) field program that took place in the North Atlantic and Eastern Pacific during 2015. During TCI, three noteworthy hurricanes were intensively observed: Joaquin in the Atlantic, and Marty and Patricia in the E. Pacific, as well as the remnants of tropical storm Erika. Hurricanes Patricia and Joaquin went through rapid intensification, with Hurricane Marty intensifying in the presence of moderate shear. Patricia was very noteworthy because it was the strongest storm on record in the Western Hemisphere, and Joaquin was the strongest Atlantic hurricane since Igor (2010).

The TCI program was focused on observing hurricanes from the surface to 60,000 feet above the Atlantic, Eastern Pacific, and Gulf of Mexico using a NASA WB-57 aircraft that deployed nearly 800 dropwindsondes with an unprecedented horizontal resolution in four tropical cyclones and obtained high-resolution measurements of the surface winds using HIRAD. Observational highlights detailed dropsonde transects of 2-5 nmi spacing through the inner core of Hurricane Patricia on multiple flights including during the formation, rapid intensification and near-peak-intensity stages. Dropsondes in Patricia, deployed along a 90 nm transect with an unprecedented 2 nm spacing when the storm was at a 175 kt intensity, highlight strong spatial gradients and shear. Likewise, dropwindsondes deployed during Hurricanes Joaquin and Marty reveal strong spatial gradients in winds and thermodynamic properties with a rich spectrum of structure in the horizontal and vertical. Systematic measurements of the hurricane outflow layer made at high-spatial resolution for the first time for a major hurricane will be presented.