NASA’s Cutting-Edge Aerosol Wind Profiler: Advancing Weather Forecasting with 3D Wind Lidar Technology
Since last fall, scientists at NASA have been utilizing an advanced 3D Doppler wind lidar instrument to conduct extensive research across the United States. This innovative tool, known as the Aerosol Wind Profiler (AWP), has been instrumental in collecting close to 100 hours of crucial data, including a daring flight through a hurricane. The primary aim of deploying AWP is to showcase its exceptional ability to acquire precise measurements of wind direction, wind speed, and aerosol concentration, all of which are vital components for enhancing the accuracy of weather forecasts.
Weather phenomena such as severe thunderstorms and hurricanes can develop with startling speed, making it essential to improve prediction capabilities through more precise wind observations. Kris Bedka, the principal investigator for AWP at NASA’s Langley Research Center in Hampton, Virginia, explains that there is a significant gap in global wind measurements above the Earth’s surface. Traditionally, winds have been measured by commercial aircraft during flights and by weather balloons launched up to twice daily from about 1,300 sites worldwide. Satellite images also provide wind estimates by tracking the movement of clouds and water vapor. However, in regions where clouds are absent or water vapor patterns are elusive, reliable wind measurements are often lacking. This is where the AWP instrument steps in, providing detailed 3D wind profiles to bridge these gaps.
AWP is mounted on an aircraft equipped with viewing ports underneath. It emits 200 laser pulses per second, which scatter and reflect off aerosol particles such as pollution, dust, smoke, sea salt, and clouds in the atmosphere. This interaction results in a change in the laser pulse wavelength, a phenomenon known as the Doppler effect. By sending these pulses in two directions, oriented 90 degrees apart, AWP creates a comprehensive 3D profile of wind vectors, capturing both wind speed and direction.
Bedka emphasizes the capability of the Aerosol Wind Profiler to measure wind speed and direction across different altitudes in the atmosphere simultaneously, with remarkable detail and accuracy. This capability is crucial for researchers and meteorologists to gain a better understanding of weather patterns. As a result, AWP’s measurements hold significant potential to advance weather modeling and forecasting.
The significance of AWP’s contribution to weather forecasting is underscored by its inclusion in the National Oceanic and Atmospheric Administration’s (NOAA) Joint Venture Program. This program seeks data from new technologies that can address gaps in current weather forecasting systems. NASA’s Weather Program also recognized the mutual benefits of NOAA’s investments, providing additional support to maximize the return on investment for both agencies.
AWP was paired with NASA’s High-Altitude Lidar Observatory (HALO) on a NASA Gulfstream III (G-III) aircraft. HALO is a sophisticated tool that measures water vapor, aerosols, and cloud properties using a combination of differential absorption and high spectral resolution lidar. This collaboration marked the first time AWP and HALO worked together, with AWP focusing on wind measurements, HALO collecting water vapor and aerosol data, and NOAA dropsondes gathering temperature, water vapor, and wind information.
Bedka describes the combined capabilities of AWP and HALO aboard a small, cost-effective aircraft as a powerful tool. This next-generation airborne weather remote sensing package represents a significant step forward, and the hope is to eventually deploy it aboard satellites for global benefit.
An animation based on AWP data reveals the complexity and structure of aerosol layers in the atmosphere. According to Bedka, current prediction models struggle to accurately simulate the organization of aerosols throughout the atmosphere. During one particular flight, Bedka anticipated a relatively clear atmosphere due to the onset of cool Canadian air in the fall. However, the team discovered an aerosol-rich environment, providing an excellent signal for accurately measuring winds.
During the Joint Venture flights, Hurricane Helene was approaching Florida, prompting the AWP crew to quickly devise a flight plan to gather wind measurements along the hurricane’s outer bands. NOAA’s acting Joint Venture Program manager, Harshesh Patel, highlights the potential of 3D wind profiles to significantly improve weather forecasts, especially for storms and hurricanes. NASA Langley’s expertise in developing coherent Doppler wind lidar technology positions the AWP concept as a promising solution to meet NOAA’s needs.
The flights of the AWP lidar serve as a testing ground for potential integration into future satellite missions. Patel emphasizes the necessity of a space-based platform to enhance global 3D wind models, aligning with NOAA’s mission to provide critical data for improving weather forecasting.
Following the NOAA flights, AWP and HALO were deployed to central California for the Westcoast & Heartland Hyperspectral Microwave Sensor Intensive Experiment and the Active Passive Profiling Experiment. These missions, supported by NASA’s Planetary Boundary Layer Decadal Survey Incubation Program and NASA Weather Programs, focused on studying atmospheric processes within the planetary boundary layer, the lowest part of the atmosphere that drives the weather conditions we experience on the ground.
For those interested in learning more about lidar instruments at NASA, visit NASA Langley Research Center’s Generations of Lidar Expertise.
In summary, NASA’s Aerosol Wind Profiler represents a significant advancement in weather forecasting technology. By providing detailed 3D wind profiles, AWP addresses critical gaps in current measurement systems, contributing to more accurate predictions of severe weather events. The collaboration between AWP and HALO, along with ongoing research and experimentation, holds the promise of enhancing our understanding of atmospheric processes on a global scale.
For more Information, Refer to this article.
