The Trainou Super Site
The Trainou tower station is dedicated to greenhouse gas measurements. It is located in the Orléans forest (47.96°N, 2.11°E, 131 meter above see level), about 15 km northeast of the city of Orléans (116 000 inhabitants) and about 100 km south of Paris. The surroundings of the station is covered by forest (30 %) and agriculture fields (50 %) (INSEE 2008, National Institute of Statistics and Economic Studies, 2008). Using the anthropogenic emissions estimated from bottom up studies for the Centre-Val de Loire region for 2012 (Lig’Air, 2017,Lig’Air-inventaire2012), we can identify the main regional sources by sector. For CO2 , the three main emission sector is transport (48 %). More than 75 % of the CH4 emissions in this region are released by livestock production. For N2O, again, the agriculture sector (fertilizer application in croplands) contributes for more than 90 % of the anthropogenic emissions in the region.
The Trainou station has been initiated in 2006 in the framework of the European projects CHIOTTO (Continuous HIgh-precisiOn Tall Tower Observations of greenhouse gases, http://www.chiotto.org) and CarboEurope IP (http://www.carboeurope.org). The site benefits from a tall telecommunication tower belonging to TdF (Télécommunication de France). The tall tower allows atmospheric measurements at 5, 50, 100 and 180 meters above ground level. The station has initially been designed for high precision and continuous measurements of CO2, CH4, N2O, SF6, CO and H2 at the four measurement levels of the tower. Since its initial installation, regular update has allowed to add in situ GHG proxy measurements such as Radon-222 (2009), 14CO2 integrated over 15 days (2008) or more recently COS (2016). In addition to the in situ measurements, total column abundances of CO2, CH4, CO and N2O are retrieved since 2009 in the framework of TCCON (Total Carbon Column Observing Network) network. The ground-based Fourier transform spectrometer (FTS) was installed and is managed by IUP Bremen (Germany). A complete description of the in situ instrumentation and associated time series from 2006 to 2013 in given by Schmidt et al. 2014.
The Trainou station has become one of the major greenhouse gas measurements station in France and Europe. Year 2018 has been a hinge year for the station as it has been integrated to the ICOS (Integrated Carbon Observation System) network making it one of the only few European station being part of two major networks for GHG measurements: ICOS and TCCON.