Infrastructures and instruments for MAGIC
SAFIRE: Flying research laboratories
Based at Toulouse-Francazal airport, SAFIRE (Service des avions français instrumentés pour la recherche en environnement – French instrumented aircraft service for environmental research) is a unique investigative tool in France for climate and environmental research, satellite validation and aeronautical development.
Created in 2005, this joint public structure of CNRS, Météo-France and CNES has the mission to implement research aircrafts for experimental campaigns. SAFIRE currently owns three aircrafts instrumented for flight measurement, which are real flying laboratories: the ATR 42, the Falcon 20 and the Piper-Aztec. Each of them have been heavily modified. They cover a wide range of carrying capacity, altitude measuring and projection. Pilots, engineers, technicians, managers and administrative support staff work in close collaboration with international scientific communities to better understand the Earth system, the preparation, calibration and validation of space systems, research and development.
With more than 3,000 hours of flight data, 500 on-board scientists and 50 user laboratories, Safire combines the technological excellence of embedded resources with the expertise of its staff to conduct specific flights in support of research and development and industry.
The Safire unit’s Dassault Falcon 20 f-GBTM is available for scientific operations since 2006. This aircraft is mainly used for multidisciplinary research in the upper troposphere and low stratosphere: remote sensing, chemistry, microphysics … It has been greatly modified in order to be able to board a wide variety of atmospheric and environmental measurement instruments. Nose perch, large portholes under and over the fuselage, underwater wing stakes, interior fittings including a specific electrical and computer network make it a true flying laboratory.
During the MAGIC campaigns, the Falcon 20 ships particularly with two G2401-m laser diode analyzers developed by the company Picarro and allowing the very precise measurement of the concentration of CO2, CH4 and CO. Under the wings, CDP (Cloud Droplet Probe) instruments measure the size of atmospheric particles (water droplets, aerosols). The crew on board a flight is composed of seven people: 2 pilots, 1 technician, 3 engineers and 1 scientist.
Aire-sur-l’Adour: balloon launching super site
The CNES Balloon Operations Center at Aire sur l’Adour (CLBA), in the Landes, maintains operational resources and permanent staff on site, to ensure the preparation of BSO and BPS balloon campaigns abroad (STRATEOLE 2, STRATOSCIENCES campaigns in Timmins, Kiruna, Alice springs), flight control of long-term balloons in control centers, and release of light dilatable balloons (BLD).
With the miniaturization of embedded electronics, the BLD activity has grown significantly over the last 5 years, and the CLBA operates annually, since 2014, dozens of BLD, which can carry small payloads up to 3 kg up to 35 km altitude, mainly for measurements of vertical profiles of atmospheric components. More than 140 flights have been completed in 5 years. The payloads are recovered within a radius of a little over 100 km around Aire sur l’Adour. The scientific instruments that flew or fly regularly are: LOAC, particle and aerosol counter of LPC2E, AMULSE from GSMA, AirCore from LMD, Pico SDLA Light from GSMA / DT INSU, the latter 3 instruments being dedicated to GHG measurements. The CLBA offers all the resources of a CNES operational center: guarding, various test facilities, mechanical workshop, VT caisson, offices, rest rooms, internet access, integration hall, launching track of 200 m. The nearby airfield runway allows the SAFIRE research aircraft to descend to a very low level.
Trainou-Orléans: a European supersite for greenhouse gas measurements
The Trainou observatory in the Orléans forest is dedicated to the measurement of atmospheric concentrations of greenhouse gases (CO2, CH4, N2O). Since it was installed in 2006 as part of a European research project, it has made it possible to precisely track, hour by hour, the evolution of the atmospheric contents of these gases. It is currently the only observatory in Europe combining greenhouse gas measurements at the surface level (from 5 to 180 m), in the lower atmosphere (from 100 to 3000 m) by air, in the high atmosphere (from 0 to 30 km) by balloon, and on the total atmospheric column by remote sensing from the ground. As such, the observatory is a reference station for the measurement of vertical profiles of greenhouse gases, and is part of several European research projects: European research infrastructure ICOS (www.icos-ri.eu), international network TCCON www.tccon.caltech.edu), European project H2020 RINGO (www.icos-ri.eu/ringo).
The CO-PDD observatory (Cézeaux-Opme-Puy de Dome) is an atmospheric instrumented site labeled by INSU/CNRS and involved in international infrastructures and observation networks such as GAW (Global Atmospheric Watch), ACTRIS (Aerosol Cloud and Trace gases Research Infrastructure), and ICOS (Integrated Carbon Observation System). Composed of three measurement sites located at different altitudes within a radius of about ten kilometers around the agglomeration of Clermont Ferrand, it hosts in-situ and remote sensing systems and produces measurements of aerosol and reactive and greenhouse gases, but also microphysical and chemical measurements of clouds and precipitation. In recent years, significant scientific advances have been obtained in the characterization of multi-scale atmospheric processes. The long-term continuous monitoring of a large number of climate-sensitive atmospheric compounds is fundamental for the estimation of their long-term climatologies and trends, and for satellite validation or synergy.
AirCore: An atmospheric sampler for measuring concentration profiles
The AirCore flown during MAGIC campaigns is an atmospheric sampler developed by the Laboratoire de Météorologie Dynamique (LMD, CNRS / Ecole Polytechnique / ENS Paris / Sorbonne University), flying under a meteorological balloon. It allows the measurement of the vertical profiles (from the surface up to 30 km of altitude) of atmospheric concentration of greenhouse gases (CO2, CH4 and CO). Its concept, based on an idea proposed by the NOAA, is extremely simple: it consists of a long tube of stainless steel placed under a meteorological balloon which, in the ascending phase, empties its air by its open end, to fill with air during its downward phase. The captured air column is then interpreted in terms of the vertical gas concentration profile using a Picarro type laser diode analyzer.
This system makes it possible to access altitudes not attainable by aircraft flights and to obtain very good vertical resolution. Since 2013, the LMD has developed several versions of this instrument and has deployed them, in partnership with CNES, LSCE (CNRS / CEA / University of Versailles-Saint-Quentin-en -Yvelines) and OPGC (CNRS, Blaise Pascal University), in various places of the globe.
During the MAGIC2018 campaign, 11 AirCore releases were made by the CNES teams at the Aire sur l’Adour site (Landes) and by a joint LSCE-LMD team at the Trainou site (Loiret), including the passage of Falcon20 and HALO search aircraft. The preparation of the instrument and the analysis of the results were carried out by LMD.
Amulse: A laser-diode spectrometer for measuring concentration profiles
The AMULSE light laser diode spectrometer developed by the Group of molecular and atmospheric spectrometry (GSMA, CNRS / University of Reims Champagne-Ardenne) since 2014 allows the measurement of greenhouse gases (CO2, CH4 and H2O) under different types of platforms including weather balloons, captive balloons and drones. The principle of this instrument is based on direct absorption laser spectrometry coupled to Wavelenght Modulation Spectroscopy (WF) spectrometry (2f / 1f) which allows accurate (<1%) and fast (<1s) measurement.
In recent years, the instrument still less than 3 kg (limit for legislation under expandable light balloon) has followed several evolutions in terms of the number of detectable gases and better sensitivity limits. Currently, the instrument’s performance allows a high spatial resolution (<10 m) with measurements @ 10 Hz and a precision of less than 0.2% on the ground and 3% at 30 km altitude.
During the MAGIC2018 campaign, 3 AMULSE releases were made by the CNES teams at the Aire sur l’Adour site in concomitance with the release of AirCore. The preparation of the instrument, its recovery and the analysis of the results were done by GSMA.
CHRIS (Compact High spectral Resolution Infrared Spectrometer)
The CHRIS infrared spectrometer is an instrumental prototype developed for the Laboratoire d’Optique Appliqué (LOA, CNRS / University of Lille) by Bruker. Its general characteristics (mass, volume) as well as its operation on battery, allow him to carry out measurements of ground with a autonomy of a dozen hours. Its optical characteristics allow the recording of solar transmission spectra with a spectral resolution of 0.135 cm-1 over a broad spectral range (680-5200 cm-1). They have been optimized to be perfectly adapted to the measurement of greenhouse gases (CO2, CH4, H2O), trace gases (SO2, HCl, NOx, etc.), but also clouds and aerosols with specific spectral signatures in the thermal part.
During the MAGIC campaigns, CHRIS is deployed to Aire sur l’Adour by a LOA team.
The EM27/SUN is a portable Fourier transform spectrometer. It is equipped with a camera-controlled heliostat that returns solar radiation to the spectrometer with constant direction. The high resolution (of 0.5 cm-1) makes it possible to solve the lines of the minority compounds of the atmosphere. The spectrometer records infrared spectra between 2.5 and 0.8 micrometers with two detectors. A radiative transfer software is then used to determine the total column of the different minority constituents of the Earth’s atmosphere from the recorded spectra.
During the MAGIC campaign, several EM27 / sun are deployed at various locations.