ATR-42#
The French ATR-42 is a bi turbo-prop aircraft from SAFIRE that has the capability of flying in the lower troposphere (ceiling at about 8 km) with a maximum range of about 1000 km. It will fly a series of legs within the sub-cloud layer, near cloud base and in the mid-troposphere. The legs will be about 200 km long, and will sample shallow and deep convective clouds together with their environment. A particularity of the aircraft instrumentation is that it will include multi-directional remote sensing, including sideways and vertically-pointing lidars and radars that will probe the atmosphere horizontally and vertically, aiming at characterizing the cloud geometry (horizontal and vertical), horizontal distributions of water vapor, temperature, clouds and aerosols, cloud microphysical and optical properties (liquid and ice water content, particle size distribution, scattering phase function), and the three-dimensional wind around the aircraft.
Instrumentation#
AWALI Lidar
AWALI is the airborne version of the 355 nm eye-safe Raman lidar WALI (Water vapor and Aerosol Lidar). It will be deployed in sidewards looking mode (through the ATR-42 window, on the same side of the aircraft as BASTA) to characterize the horizontal heteorogeneities of water vapor and temperature, in addition to characterizing the horizontal distribution of clouds and aerosols. The along and across line-of-sight resolutions will depend on the sampling strategy.
PI: Patrick Chazette (LSCE/IPSL)
BASTA Radar
BASTA is a horizontally-staring cloud radar mounted on the right-hand side of the ATR-42. BASTA is a 1 W bistatic FMCW (Frequency Modulated Continuous Wave) 95 GHz Doppler cloud radar developed from the ground-based BASTA system. It was used in an aircraft for the first time during EUREC4A, with two antennas of 20 cm installed in back lateral windows of the ATR. The maximum range was 12 km, and the minimum detection range was about 80 m from the aircraft. The sensitivity of the radar is estimated at around -35 dBZ at 1 km.
PI: Julien Delanoë (LATMOS/IPSL)
Camera VIS
A high-resolution VIS-camera (Prosilica GT 1930) VIS-camera installed and looking through one of the aircraft window, next to the horizontally-looking lidar and radar. This camera will be used to characterize the environment of lidar/radar measurements, and to reconstruct the vertical structure of the cloud side surface by stereography.
PI: Céline Cornet (LOA/Université de Lille)
CLIMAT CE332
Three channel downward staring measurements of infrared irradiance at 8.7, 10.8, and 12.0 μm to measure sea-surface temperature.
PI: Jean-Louis Dufresne (LMD/CNRS)
FAST-WAVE
An airborne laser diode spectrometer that measures water vapour at a fast rate.
PI: [Lilian Joly] (GSMA/CNRS)
LNG Lidar
The LEANDRE New Generation (LNG) airborne Lidar system uses a Mach–Zehnder Interferometer (MZI) to measure optical parameters of aerosol and clouds and along-sight wind in the troposphere. The instrument operates in a direct detection mode (measurement of the backscattered light intensity), which has the advantage of relying on both particulate and molecular scattering, and allows extended ranges and capabilities. The High Spectral Resolution (HSR) analysis within LNG allows phase and intensity analysis simultaneously.
PI: Julien Delanoë (LATMOS/IPSL)
Microphysics
The aerosol and cloud droplet size distributions will be characterized by UHSAS (60 nm to 1μm), FSSP-300 (0.45-20 μm) and FCDP (2-50 μm droplets) spectrometers. Drizzle/rain drops and ice particles will be characterized by 2D-S (10-1280 μm) and HVPS (0.15-20 mm) imagers. A polar nephelometer (NP-IP) will measure the angular distribution of scattered light and a high-resolution imager (HSI) will characterize the morphology of ice crystals. The total water content will be measured by a CVI system (0-3 g/m³).
PI: Pierre Coutris (LaMP)
Pyrgeometer and Pyranometer
Hemispheric broadband upwelling and downwelling longwav (4.5 µm– 42 µm) and shortwave (200 nm – 3600 nm) radiative fluxes.
PI: SAFIRE
RASTA Radar
RASTA is a W-band pulsed Doppler cloud radar (95GHz). RASTA is capable of retrieving the 3D wind field, i.e. the three components of the wind on the vertical plane below/above the aircraft (6 antenna configuration), by combining independent Doppler velocity measurements from the multi-beam antenna system. These three components can be converted into Earth referential horizontal wind components. Dynamical and microphysical cloud properties can also be retrieved.
PI: Julien Delanoë (LATMOS/IPSL)
Thermodynamics and turbulence
Temperature, humidity, wind and pressure will be measured at high frequency. Temperature will be measured by a fine wire and Rosemount sensors. Humidity will be measured by several sensors, including a WVSSII sensor (laser diode), a dew point hygrometer and a capacitive hygrometer for slow measurements, and a Licor7500 (near-IR gas analyzer).
PI: Marie Lothon (LAERO)