23.08.2020
NOAA and World View Enterprises, an Arizona company that specializes in gathering data during long-duration, high-altitude balloon flights, are teaming up to take a uniquely detailed look at the composition of Earth’s stratosphere.
Under the agreement, World View’s “Stratollite” balloons will carry a miniaturized NOAA instrument to measure atmospheric particles on a series of flights in 2021 that will last weeks and cover thousands of miles at altitudes above 55,000 feet.
The flights will allow NOAA”s Chemical Sciences Laboratory to explore the potential of using new autonomous platforms to acquire key scientific data in the stratosphere for extended periods over large geographic regions, said David Fahey, director of the Chemical Sciences Laboratory. World View is donating space for the instrument on its balloon platform to NOAA at no cost.
“There really is no other platform right now that can allow us to make detailed, uninterrupted measurements in the stratosphere for this length of time,” Fahey said. “We’re not only going to be evaluating high-altitude balloons as a potential research platform, we also anticipate capturing important observations about the stratosphere on both sides of the equator during these flights.”
Stratospheric particles, or aerosols, play a key role in moderating Earth’s climate system by scattering or reflecting sunlight as it nears the surface and by modifying the formation of clouds. The stratosphere also holds the Earth’s protective ozone layer, which absorbs ultraviolet radiation that can damage cellular structure, increase the risk of skin cancer and cataracts, and suppress the human immune system. Aerosols in the stratosphere act as surfaces for chemical reactions to occur, such as those that lead to depletion of the ozone layer.
WHAT IS A STRATOLLITE?
Scientists currently study the stratosphere from instruments on satellites, aircraft or weather balloons. Endurance high-altitude balloons, such as the Stratollite, might provide higher resolution measurements than satellites and would afford longer observational periods than aircraft or small weather balloons.
World View’s platform carries a wide variety of commercial instruments, such as sensors, telescopes, and communications arrays. Using winds at different altitudes, the vehicles can be navigated to and from desired locations and loiter above them for long durations. They can be quickly launched on demand, and return back to Earth after each mission.
In 2021, NOAA’s Portable Optical Particle Spectrometer, or POPS, will be added to the World View Stratollite for several flights. The POPS uses an on-board laser to measure particles between 140 nanometers to 2.5 micrometers in diameter. Particles in this size range are particularly important for climate since they are both small enough to accumulate in the atmosphere instead of settling out, and large enough to efficiently reflect sunlight.. Designed by researchers in NOAA’s Chemical Sciences Laboratory in Boulder, Colorado, the instrument weighs 1.3 pounds and is about the size of a lunch box.
The Chemical Sciences Lab is embarking on an expanded research effort to better understand the distribution and characteristics of stratospheric aerosols under background conditions, as well as improving the capacity to investigate injections of gases and aerosols from volcanic eruptions and very large fires.
POPS
POPS aerosol data collected in Boulder over the course of a full year of conventional weather balloon launches yielded 11 vertical profiles or days of data between altitudes of 50,000 and 75,000 feet, said Elizabeth Asher, a CIRES scientist working at NOAA.
“By comparison, we expect one flight with World View could generate on the order of 40 days worth of data in this altitude range,” Asher said.
As is typical with NOAA research data, it will be available for public use and research after six months.
"This program represents World View’s commitment to contributing to a more comprehensive and complete scientific understanding of the stratosphere,” said Ryan M Hartman, World View President and CEO.
Quelle: NOAA