Atmospheric station

An atmospheric station has been built in the hills of Houdainlecourt, northeast France, as part of the OPE. It has a 120-metre-tall mast that is equipped with weather sensors and air samplers connected to analysers on the ground, and is used to continuously measure air quality and greenhouse gases over extended periods of time. Unveiled in September 2011, the station is part of the ICOS (Integrated Carbon Observation System) infrastructure, whose aim is to improve air and greenhouse gas monitoring across Europe.

Background

The atmosphere is a free-flowing environment, a mixture of gases and particles that is defined by its chemical, optical, dynamic and thermodynamic properties such as composition, temperature, pressure, precipitation and speed.

Many of these atmospheric properties affect the surrounding environment, especially soil and watercourses, and the life that is found there. The chemical composition of the Earth's atmosphere is the product of the planet's natural geological history and, since the beginning of the industrial era, human activity. Similarly, the climate and statistics are mostly determined by geological factors (e.g. distribution of the continents, orography) and the Earth's orbit (solar radiation, rotation of the Earth), but are also now affected by man as well.

Monitoring the atmosphere across the OPE territory means that the observed variables and parameters must be defined, as well as the networks these observations are linked to. In fact, the meteorological variables that are observed (temperature, pressure, humidity, wind, precipitation, clouds, etc.) only yield information through the spatial coverage provided by observation networks (particularly important for weather forecasting) and long time-series, which give statistical descriptions of the atmosphere. This requirement for coverage in both space and time is essential in helping us understand observations of a varied range of phenomena caused by both natural processes and human activity. This means that joint observation protocols need to be shared, and the data collected pooled.

Methodology

The principal weather observation and monitoring programmes are defined and outlined at an international level by the World Meteorological Organisation. They are then implemented locally and nationally by national weather agencies, such as Météo-France. Some programmes, such as the World Weather Watch Programme and the Global Atmosphere Watch Programme, focus exclusively on monitoring the climate. In France, the RAMCES (Atmospheric Network for Measuring Greenhouse Compounds) Observation System monitors the main greenhouse gases (CO2, CH4, N2O) and helps standardise observations Europe-wide in preparation for the ICOS scheme. Monitoring air pollution is also enshrined in various international conventions, some stricter than others. Examples include the 1979 Geneva convention on long-range transboundary air pollution, or the 1992 Rio conference on climate change. These conventions have led to observation networks being set up in Europe and in France, such as those established as part of the EMEP programme (a concerted effort in monitoring and evaluating the long-distance movement of air pollutants through Europe). In Europe, monitoring and assessing air quality is the responsibility of the individual member states, and is defined in Directive 2008/50/CE of the European Parliament and Council of 21 May 2008 on ambient air quality and pure air for Europe. The directive sets the conditions for the regulatory assessment of the following pollutants: sulphur dioxide, nitrogen oxides, carbon monoxide, benzene, particles (PM10/PM2.5), lead and ozone.

Location

The OPE atmospheric station is situated on a peak almost 395 m high between the Paris Basin and the Vosges, on the side towards the coast, in open farmland that is several hundred metres away from the nearest homes and roads. There, it is subject to the prevailing winds from the observation area, the OPE reference sector, and the areas of interest to the Cigeo project. Built on a site measuring 2 ha and surrounded by electrified fencing, the station has two 18 m² technical rooms and one 120 m guyed mast that can conduct weather testing and sampling at heights of 10 m, 50 m and 120 m.

Map of the OPE area showing the location of the atmospheric station.Map of the OPE area showing the location of the atmospheric station.

Photo of the OPE atmospheric station seen from the air.

Photo of the OPE atmospheric station seen from the air.

Which atmospheric measurements are taken?

The OPE atmospheric station takes several kinds of readings, in line with regional or national partners:

  • Meteorological parameters: P, T, humidity, wind, precipitation, solar radiation: Météo-France/WMO
  • "Regulation" ambient air quality: analysers for CO, O3, SO2, NOx, + PM10/PM2.5 (TEOM 1405-DF) + Partisol-Plus samplers and DA80 for PAH analysis (weekly) and heavy metal analysis (monthly): Air Lorraine
  • Monitoring CO2/CH4 greenhouse gases and the boundary layer with lidar: LSCE/ICOS
  • Radioactivity: Very high flow rate samplers + deposit collectors (for a radioactivity analysis every 10 days), C14 and tritium bubblers: IRSN/OPERA
  • Aerosols: vertical profiles using lidar (Leosphere ALS300), photometer, mass/size distribution (APS/OPC + SMPS), optical properties (diffusion, absorption), anions/cations, tracers (levoglucosan etc.): LGGE and LOA.

With regards to particulate matter, the atmospheric station must be capable of providing:

  1. an overview of the physical, chemical and optical properties of aerosols;
  2. an understanding of natural and manmade "source functions", and whether they are local or imported;
  3. an overview of aerosol movement (from various origins) caused by the weather.

Chemical tests of ambient aerosols and deposits, as well as the sampling methods used, must be standardised in accordance with existing networks and protocols (such as EMEP and EUSAAR/ACTRIS). The point of this is so that the results can be fed into databases like those belonging to EBAS and NILU.

Types of observation conducted by the atmospheric station
Type of observationPartnerFrench networkEuropean network
Pressure, temperature, humidity, wind, radiation Météo France RADOME EUCOS
Greenhouse gases- CO2, CH4, N2O, tracers LSCE RAMCES ICOS
Pollutants- SO2, CO, NOx, O3 et PM10/PM2.5 AIR LORRAINE MERA EMEP
Particles (size, composition, etc.) LGGE/LOA ORAURE ACTRIS
Radioactivity: aerosols and deposits IRSN OPERA
Parameters measured by the atmospheric station
Parameter measuredMethodPartner
Gas analyser
CO2/CH4/H2O Picarro G1301 LSCE
Fluctuations in CO2/H2O (eddy covariance) Licor 7200-Gill HS50 LSCE
CO/N2O Los Gatos Research Inc. LSCE
CO Thermo Scientific 48i AIR LORRAINE
O3 Thermo Scientific 49i AIR LORRAINE
NOx Thermo Scientific 42i AIR LORRAINE
SO2 Thermo Scientific 43i AIR LORRAINE
Air lines at 120m, 80m and 40m LSCE
Aerosols - deposits
Aerosol optical thickness CIMEL CE-318 photometer (Aeronet) LOA
Aerosol vertical distribution Lidar Leosphere ALS 300
Aerosol size/concentration distribution TSI APS+SMPS or (adapted EUSAAR) LGGE
7-wavelength aethalometer Magee Scientific AE31 (EUSAAR method) LGGE
Nephelometer Thermo Scientific 3563 LGGE
PM10/PM2.5 mass fractions TS TEOM 1405-DF AIR LORRAINE
Low flow rate dust sampler - metals Partisol Plus AIR LORRAINE
High flow rate dust sampler - PAH + other chemical measurements still under discussion (EC/OC, major ions, trace species, etc.) Digitel DA80 AIR LORRAINE
LGGE
High volume sampler OPERA/IRSN IRSN
1m2 passive sampler (total and wet deposits) OPERA/IRSN IRSN
C14-tritium bubblers SDEC IRSN
Weather
Surface weather station (wind, temperature, precipitation, pressure, relative humidity) RADOME station Météo France
Vertical temperature/humidity profile at 120m, 50m and 10m Vaisala HMP155 probe + CS MET21 radiation shield LSCE
Wind at 120m, 50m, 40m and 10m Gill WindObserver II sonic anemometer LSCE

Partners

Air Lorraine logo IRSN logo LOA logo LSCE logo
LGGE logo Météo France logo

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