September 9, 2012
NASA Flies Global Hawk Over Hurricane Leslie
Brett Smith for redOrbit.com — Your Universe Online
NASA has launched the part of its Hurricane and Severe Storm Sentinel (HS3) mission designed to study hurricanes in the field this week with the program´s first flight of an unmanned Global Hawk aircraft over Hurricane Leslie in the Atlantic Ocean.
The research drone took off from NASA's Dryden Flight Research Center at Edwards Air Force Base in California Thursday and landed at the federal agency's Wallops Flight Facility on Wallops Island, Va., on Friday after spending 10 hours in the air collecting data on the Category 1 storm.
Last week´s flight is the first of two scheduled flights for the program this month. The first Global Hawk carried a payload of instruments dedicated to measuring the environment during the storm.
"The primary objective of the environmental Global Hawk is to describe the interaction of tropical disturbances and cyclones with the hot, dry, and dusty air that moves westward off the Saharan desert and appears to affect the ability of storms to form and intensify," said HS3 mission principal investigator Scott Braun in a NASA statement.
As the plane approached and flew over the storm, it measured cloud structure, temperature, water vapor vertical profile, cloud properties, and particulate matter such as dust and sea salt. Once the craft was over the storm, it ejected small sensors parachuted down through the storm to record winds, temperature and humidity.
A second Global Hawk that takes flight in two weeks will focus on flying over a developing or established storm and looking and the internal mechanics that make it tick by measuring eyewall and rain-band winds and precipitation using Doppler radar.
"Instruments on the 'over-storm' Global Hawk will examine the role of deep thunderstorm systems in hurricane intensity change, particularly to detect changes in low-level wind fields in the vicinity of these thunderstorms," said Braun.
One of the key instruments used by this second drone is the High-Altitude MMIC Sounding Radiometer (HAMSR), which microwaves to measure temperature, water vapor, and precipitation from the top of the storm to the ocean´s surface.
"HAMSR was the first complete scientific instrument to come out of NASA's Instrument Incubator Program," said Bjorn Lambrigtsen, HAMSR principal investigator at NASA´s Jet Propulsion Laboratory (JPL). "An advanced version of instruments currently flying on satellites such as NASA's Suomi NPP, HAMSR provides a much more detailed view of the atmospheric conditions in a hurricane than is possible from satellites. HAMSR is one of a number of airborne instruments developed by JPL that are being used to carry out research in a variety of areas."
Both planes will attempt to construct a comprehensive picture of the forces surrounding the highly destructive storm system and the somewhat controversial role of the Saharan Air Layer in storm formation and intensification.
The HS3 program´s used of the Global Hawk aircraft is key is measuring and recording storm data because of its range and flight capabilities. The drones can fly higher than 55,000 feet and for up to 30 hours, making them able to reach storms and gather valuable data even if the hurricane season only produces a few major storms.