NASA's Hurricane and Severe Storm Sentinel (HS3) Investigation

The National Aeronautics and Space Administrations (NASA) Hurricane and Severe Storm Sentinel (HS3) investigation was a multi-year field campaign designed to improve understanding of the physical processes that control hurricane formation and intensity change, specifically the relative roles of environmental and inner-core processes. Funded as part of NASAs Earth Venture program, HS3 conducted five-week campaigns during the hurricane seasons of 2012-14 using the NASA Global Hawk aircraft, along with a second Global Hawk in 2013 and a WB-57f aircraft in 2014. Flying from a base at Wallops Island, Virginia, the Global Hawk could be on station over storms for up to 18 hours off the East Coast of the U.S. to about 6 hours off the western coast of Africa. Over the three years, HS3 flew 21 missions over 9 named storms, along with flights over two non-developing systems and several Saharan Air Layer (SAL) outbreaks. This article summarizes the HS3 experiment, the missions flown, and some preliminary findings related to the rapid intensification and outflow structure of Hurricane Edouard (2014) and the interaction of Hurricane Nadine (2012) with the SAL