In 2012, a NASA airborne science mission was launched to investigate hurricane formation and intensity change: What HS3 studied?

In 2012, a NASA airborne science mission was launched to investigate hurricane formation and intensity change. The mission was called the Hurricane and Severe Storm Sentinel, or HS3. It was a NASA airborne science mission conducted from 2012 to 2014. The campaign focused on the Earth's atmosphere over the Atlantic Ocean basin, the Caribbean and the Gulf of Mexico. NASA used Global Hawk uncrewed aerial systems to collect measurements around and over tropical storms. The mission examined the physical processes linked to storm formation and rapid intensification. It also studied how the surrounding environment and processes inside storms can affect their development.

In 2012, a NASA airborne science mission tried to understand hurricane formation and intensity change

The mission was known as the Hurricane and Severe Storm Sentinel, or HS3. HS3 was a targeted NASA airborne science mission. It operated between 2012 and 2014 and focused on hurricane formation and changes in storm intensity.


The campaign was classified under NASA's airborne science missions and airborne campaigns. Its target was Earth, with a specific focus on the atmosphere over regions where tropical storms and hurricanes develop.

What was the HS3 mission?

The Hurricane and Severe Storm Sentinel was designed to study the processes that lead to tropical storm formation and rapid intensification. The mission focused on the Atlantic Ocean basin, the Caribbean and the Gulf of Mexico. These areas provided the setting for observations of storms and their surrounding atmospheric conditions.

Scientists wanted to understand why some tropical storms develop and strengthen. The mission examined processes operating on different scales. The research looked at large-scale environmental conditions around storms. It also examined processes occurring within the storms themselves. This allowed researchers to compare conditions outside a storm with changes taking place inside its circulation and inner core.

Studying hurricane formation and intensity

One of the main objectives of HS3 was to understand the physical processes behind tropical storm formation. The campaign also examined rapid intensification. Rapid intensification refers to a period when a tropical cyclone gains strength over a short period.

Researchers examined the balance between large-scale environmental factors and storm-scale processes. Large-scale conditions can influence whether a storm develops. Processes within the storm can also affect its structure and intensity.

HS3 was designed to collect measurements that could help researchers examine how these factors interact. The mission therefore did not focus on only one part of a hurricane. It collected information from the surrounding atmosphere and from the storm's internal structure.

The role of the Saharan Air Layer

Another part of the research focused on the dry Saharan Air Layer, also known as SAL. The Saharan Air Layer consists of dry and dusty air that can move from North Africa over the Atlantic Ocean. HS3 investigated the role of this layer in tropical storm development and intensity changes.

Researchers wanted to understand how the surrounding atmospheric environment could influence storms. The SAL was one of the environmental factors included in the mission's research. The campaign also examined deep convection in the inner cores of storms.

Deep convection refers to strong upward movement of air that can produce tall clouds and precipitation. Studying this process helped researchers examine the internal activity of tropical storms.

NASA Global Hawk aircraft

NASA used Global Hawk uncrewed aerial systems during HS3. The Global Hawk aircraft could operate above 55,000 feet. The systems could also remain in flight for more than 24 hours. These capabilities allowed NASA to collect measurements over extended periods.

The aircraft could operate around storms and gather information from the atmosphere. This provided researchers with measurements that could be used to study environmental conditions and storm structure. Using uncrewed aircraft also allowed NASA to conduct measurements in and around tropical systems without placing an onboard crew inside the aircraft.

Instruments used to study the environment

HS3 used several instruments to measure conditions around tropical storms. The environmental payload measured temperature, humidity and winds around storms. Among the instruments used for these measurements were S-HIS, CPL and AVAPS dropsondes. These instruments provided information about atmospheric conditions surrounding the storms.

Temperature measurements helped researchers examine the thermal environment. Humidity measurements provided information about moisture in the atmosphere. Wind measurements helped scientists study the movement and structure of the surrounding air.

AVAPS dropsondes were also used to collect atmospheric measurements at different levels. The combination of these instruments allowed the mission to build information about the environment surrounding tropical storms.

Instruments used over storms

HS3 also carried a payload designed to study storm interiors. The over-storm payload measured precipitation and the structure of the inner core. The instruments included HIWRAP, HIRAD and HAMSR.

HIWRAP was used as a radar instrument for studying precipitation and storm structure. HIRAD and HAMSR provided additional measurements related to the storm environment and internal structure.

These observations helped researchers examine what was happening inside tropical systems. The information could then be considered alongside measurements of the atmosphere surrounding the storms.

Why the measurements mattered?

A tropical storm is influenced by conditions outside the storm and processes taking place within it. HS3 was designed to examine both areas. The mission collected information about temperature, humidity and winds around storms. It also measured precipitation and inner-core structure.

Researchers could use these observations to examine relationships between the storm environment and internal activity. The mission's questions included the role of large-scale environmental factors, storm-scale processes, the Saharan Air Layer and deep convection. Together, these areas formed the main scientific focus of the Hurricane and Severe Storm Sentinel.

What HS3 was designed to explain?

The Hurricane and Severe Storm Sentinel was part of NASA's effort to understand how tropical storms form and change intensity. Its research combined atmospheric measurements with observations of storm structure.

The campaign examined the environment surrounding storms and processes occurring within their inner cores. By collecting measurements using Global Hawk aircraft and multiple instruments, NASA gathered data on several parts of the hurricane system.

The research focused on the physical processes behind formation and rapid intensification rather than on storm tracking alone. HS3 therefore provided an airborne research approach to studying tropical cyclones over the Atlantic Ocean basin, Caribbean and Gulf of Mexico during the 2012 to 2014 campaign period.