Connections Between the Ocean and Outflow in Hurricanes Iselle and Julio (2014)

During the summer of 2014, a group of Naval Academy midshipmen flew through Hurricanes Iselle and Julio with the USAF 53rd Weather Reconnaissance Squadron. Stemming from this experience, interest in the secondary circulation grew, particularly with regards to the potential connections between the ocean and outflow. Tropical cyclone outflow is the subject of the Office of Naval Research Tropical Cyclone Intensity field program, and here, links between ocean heat content, outflow, and intensity are investigated. Examination of the Navy Global Environmental Model (NAVGEM) analyses revealed a relationship between outflow and TC intensity in Hurricanes Iselle and Julio. In both TCs, it was shown that intensity increased during periods of greater outflow, when maximum outflow was located closest to the TC center, and when dual outflow channels were present. Along-track variation in ocean heat content was then analyzed to quantify and connect heat loss to intensity change. Connections between the ocean heat loss, intensity, and outflow magnitude in both TCs will be presented.