Vertical wind velocity measurements using a five-hole probe with remotely piloted aircraft to study aerosol–cloud interactions
The importance of vertical wind velocities (in particular positive vertical wind velocities or updrafts) in atmospheric science has motivated the need to deploy multi-hole probes developed for manned aircraft in small remotely piloted aircraft (RPA). In atmospheric research, lightweight RPAs ( &...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-05-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://www.atmos-meas-tech.net/11/2583/2018/amt-11-2583-2018.pdf |
| Summary: | The importance of vertical wind velocities (in particular positive vertical
wind velocities or updrafts) in atmospheric science has motivated the need to
deploy multi-hole probes developed for manned aircraft in small remotely
piloted aircraft (RPA). In atmospheric research, lightweight RPAs
( < 2.5 kg) are now able to accurately measure atmospheric wind vectors,
even in a cloud, which provides essential observing tools for understanding
aerosol–cloud interactions. The European project BACCHUS (impact of Biogenic
versus Anthropogenic emissions on Clouds and Climate: towards a Holistic
UnderStanding) focuses on these specific interactions. In particular,
vertical wind velocity at cloud base is a key parameter for studying
aerosol–cloud interactions. To measure the three components of wind, a RPA
is equipped with a five-hole probe, pressure sensors, and an inertial
navigation system (INS). The five-hole probe is calibrated on a multi-axis
platform, and the probe–INS system is validated in a wind tunnel. Once
mounted on a RPA, power spectral density (PSD) functions and turbulent
kinetic energy (TKE) derived from the five-hole probe are compared with sonic
anemometers on a meteorological mast. During a BACCHUS field campaign at Mace
Head Atmospheric Research Station (Ireland), a fleet of RPAs was deployed to
profile the atmosphere and complement ground-based and satellite observations
of physical and chemical properties of aerosols, clouds, and meteorological
state parameters. The five-hole probe was flown on straight-and-level legs to
measure vertical wind velocities within clouds. The vertical velocity
measurements from the RPA are validated with vertical velocities derived from
a ground-based cloud radar by showing that both measurements yield
model-simulated cloud droplet number concentrations within 10 %. The
updraft velocity distributions illustrate distinct relationships between
vertical cloud fields in different meteorological conditions. |
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| ISSN: | 1867-1381 1867-8548 |