Objective
The STREAM activity involves improvement of an instrument package for a high flying aircraft (12-13 km) to perform fast response in situ measurements, enabling relatively low cost and flexible participation in process studies and measurement intensives to study the chemistry and exchange processes between the free troposphere and lower stratosphere. More specifically, the scientific objectives are:
1) To improve the understanding of the processes that control stratosphere-troposphere ex-change (STE) in mid-latitudes, notably cross-tropopause transport of air associated with synoptic disturbances and fronts. This will reduce the uncertainties about downward transport of ozone and nitrogen oxides from the stratosphere and upward transport of (polluted) tropospheric air into the lower stratosphere.
2) To study the chemistry of the mid-latitude lower stratosphere, in particular the role of nitrogen oxides in local production/destruction of ozone. This will improve quantification of local chemical processes relative to transport of O3 depleted air from high latitudes, to explain the observed mid-latitude O3 changes in the tropopause region. 3) To collect experimental information about the background atmospheric chemical composition in the tropopause region. This will enable assessment of the roles of aircraft exhausts and long-range pollution transports in the chemistry of the lower stratosphere and upper troposphere.
The following activities will be carried out to meet the above mentioned objectives:
1) Improvement of the chemiluminescence NOy measurement technique (Mainz). The sensitivity of the
chemiluminescence instrument will be enhanced and tests will be performed by comparing the results with those
of the Heidelberg mass spectrometer (HNO+HNO3+HNO4).
2) Improvement of the alkyl nitrate and NMHC/halocarbon measurements by optimisation and automation of
the sampling systems and the analysis techniques.
3) Improvement and size/weight reduction of the tunable diode laser spectrometer.
4) Improvement and size/weight reduction of the aerosol measurement system.
5) Improvement and size/weight reduction of the mass spectrometer. 6) Integration of the Lyman-a fluorescence hygrometer and the in-situ gas chromatograph into the aircraft
payload.
7) Development of de-icing devices for the gas and aerosol inlets, so that flights can be per formed under a
wide range of meteorological conditions.
8) Further development and application of a regional transport-chemistry model (domain Europe and the eastern
Atlantic region, nested within the global model TM2) to relatively high resolution (100 km horizontal, 19 layers
vertical), prescribing ECMWF analyzed meteorology, to simulate stratosphere-troposphere exchange processes.
9) Provide meteorological forecasts, including special products (e.g. forward trajectories, PV surfaces,
tropopause altitudes, cross-tropopause mass fluxes) to support 2 measurement campaigns, and meteorological
analyses in measurement interpretation.
10) Perform a measurement campaign during spring in 1996 over western Europe. Flight tracks will be mostly
in the east-west direction to study the influences of extratropical cyclones on mixing processes.
11) Perform a measurement campaign during winter/early spring in 1997 over north-western Europe. Flights
will be mostly in the north-south direction to study southward transport of O3 depleted air in the lower
stratosphere after break-up of the polar vortex.
12) Perform regional and global modelling of the influence of vertical mixing processes on CO, NOy and O3
distributions and compare the results with the aircraft and other available measurements.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- social sciencessociologyindustrial relationsautomation
- natural sciencesearth and related environmental sciencesenvironmental sciencespollution
- natural sciencesearth and related environmental sciencesatmospheric sciencesmeteorologytroposphere
- natural sciencesphysical sciencesopticslaser physics
- natural scienceschemical sciencesorganic chemistryorganohalogen compounds
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Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
3584 CC UTRECHT
Netherlands