link to homepage

Institute of Energy and Climate Research

Navigation and service

Brief Overview

The Environmental Simulation Facility established at the Forschungszentrum Jülich (FZJ) is designed to investigate the performance of different types of balloon borne ozone sensors as well as air borne humidity sensors to measure the vertical distribution of atmospheric ozone and water vapor, respectively. Key component of the facility is a temperature and pressure controlled simulation chamber with a test room volume of about 500 liter (80x80x80 cm) whereby pressure as well as temperature can be dynamically regulated between 5 and 1000 hPa and between 200 and 300 K (-2K/min £ rate £ +2K/min) respectively. The volume mixing ratio of ozone can be dynamically regulated between 5 and 10000 ppbv up to a simulation altitude of about 35 km. The relative humidity in the chamber can be varied from about 95% down to 2% over a temperature range between +30°C and -70°C and pressure range between 1000 and 100 hPa. Ozone and humidity sensing devices can be calibrated against accurate reference instruments. A fast response dual beam UV-photometer serves as ozone reference. For the calibration of the water vapor sensors a dew point hygrometer is used for lower/middle tropospheric humidity conditions, while for middle/upper tropospheric conditions a Lyman (a) fluorescence hygrometer serves as reference. The entire simulation process is computer controlled to provide reproducible conditions with respect to pressure, temperature, ozone concentration and humidity.

Since 1994 the chamber is used for the regular (monthly) calibration of water vapor sensing devices which are flown aboard 5 civil "in-service" aircraft (Airbus-A340) within the frame of the European project MOZAIC (Measurement of Ozone and Water Vapor on Airbus In-Service Aircraft) for automatic monitoring of the water vapor distribution in the troposphere. The facility is also established as World Calibration Center for Ozone Sondes (WCCOS) as part of the Global Atmosphere Watch (GAW) program of the World Meteorological Organization (WMO). In the scope of this frame work several intercomparison experiments, JOSIE (= Jülich Ozone Sonde Intercomparison Experiment), were conducted to assess the performance of the major types of ozone sondes used within the global network of ozone sounding stations. Furthermore, the facility serves as platform to investigate the performance of new developed airborne sensing devices.