Since last fall, NASA scientists have flown an advanced 3D Doppler wind lidar instrument across the United States to collect nearly 100 hours of data - including a flight through a hurricane. The goal? To demonstrate the unique capability of the Aerosol Wind Profiler (AWP) instrument to gather extremely precise measurements of wind direction, wind speed, and aerosol concentration - all crucial elements for accurate weather forecasting.
Weather phenomena like severe thunderstorms and hurricanes develop rapidly, so improving predictions requires more accurate wind observations.
"There is a lack of global wind measurements above Earth's surface," explained Kris Bedka, the AWP principal investigator at NASA's Langley Research Center in Hampton, Virginia. "Winds are measured by commercial aircraft as they fly to their destinations and by weather balloons launched up to twice per day from just 1,300 sites across the globe. From space, winds are estimated by tracking cloud and water vapor movement from satellite images."
However, in areas without clouds or where water vapor patterns cannot be easily tracked, there are typically no reliable wind measurements. The AWP instrument seeks to fill these gaps with detailed 3D wind profiles.
Mounted to an aircraft with viewing ports underneath it, AWP emits 200 laser energy pulses per second that scatter and reflect off aerosol particles - such as pollution, dust, smoke, sea salt, and clouds - in the air. Aerosol and cloud particle movement causes the laser pulse wavelength to change, a concept known as the Doppler effect.
The AWP instrument sends these pulses in two directions, oriented 90 degrees apart from each other. Combined, they create a 3D profile of wind vectors, representing both wind speed and direction.
