Das Projekt "Lightweight in-situ tracer experiment in the stratosphere" wird vom Umweltbundesamt gefördert und von Universität Frankfurt, Institut für Meteorologie und Geophysik durchgeführt. Objective: The main objective of the project is the development of a balloon borne Lightweight In-situ Tracer Experiment in the Stratosphere (LITES) for simultaneous profile observations of ozone and the long-lived trace gases sulphur hexafluoride (SF6) and the chlorofluorocarbon CFC 12 (CF2Cl2) in the stratosphere. The LITES - package is designed to make measurements up to altitudes of about 30 km ( deeper than 10 hPa) if launched on small research balloons with volumes of 10000 m3 or less. The instruments are fully automated. Measurements of the mixing ratios of CFC-12 and SF6 will be made at least every 2 minutes. For data transmission a digital lightweight telemetry system will be developed that is based on standard ozone sonde components that are presently used for routine operations at various radiosonde and ozonesonde stations. The chlorofluorocarbon CFC-12 is a long-lived trace gas, that represents the most abundant source gas of total reactive chlorine, Cly, in the stratosphere and is a good tracer for dynamic transport processes. SF6, is an inert tracer, that provides information about the age of the stratospheric air. In combination with the digital ozonesonde these instruments form a lightweight balloon payload to study the vertical distribution of total reactive chlorine in the stratosphere and quantitatively investigate the corresponding ozone depletion potential in the probed airmass. General Information: Two lightweight automated in-situ gas-chromatographs will be developed for the measurement of the long-lived trace gases CFC-12 and SF6 with a time resolution of 1 to 2 minutes onboard stratospheric research balloons. Both instruments will use electron capture detectors (ECD) for identification of the measured species. The radio transmitter of the standard Vaisala radiosonde will be modified for use as a telemetry system to transmit the data provided by the gas chromatographs together with the ozone data that will be simultaneously measured by means of commercially available ozone sondes, e.g. Science Pump ECC or EN-SCI ECC sensors. Two telemetry channels will be used, one for the meteorological and ozone data (PTU and O3) and another one for the CFC and SF6 concentration data plus related housekeeping information. The following tangible results are expected from the project: -Two lightweight in-situ gas chromatographs for the measurement of SF6 and CFC-12, respectively, in the lower and middle stratosphere with a time resolution of 1 - 2 minutes. -An improved electrochemical ozonesonde with a two channel radio transmitter that is fully compatible with the standard Vaisala radiosonde link (400 MHz). -A new modulator that allows transmission of data provided by the serial interface of the internal control computers of the digital gas chromatographs at a rate of 1200 baud employing one of the telemetry channels of the new Vaisala transmitter. -A set of vertical profile measurements of O3, SF6 and CFC-12 performed during a test fligh
Das Projekt "Vertikale Verteilung von Primaergasen in der suedlichen Hemisphaere" wird vom Umweltbundesamt gefördert und von Max-Planck-Gesellschaft zur Förderung der Wissenschaften, Max-Planck-Institut für Aeronomie durchgeführt. Objective: To understand the global distribution of ozone and its changes due to anthropogenic emissions. General Information: Balloon flights will be made in Mendoza (Argentine) in order to measure the vertical distribution (up to about 35 km altitude) of source gases which are important for the photo-chemistry of ozone: H2, CH4, N2O, CH3Br, CF4, C2F6, CO, CFC13, CF2C12, CF3C1, CHF2C1, C2F3C13, C2F4C12, C2F5C1, CH3CC13, CF3Br, C2H6, C3H8. The results of these measurements will be interpreted using model computations.