The proposal describes a multi-disiplinary approach which seeks to unite stratospheric aerosol data and improved state-of-the-art atmospheric modelling tools in order to investigate polar stratospheric cloud (PSC) formation and the heterogeneous chemistry involved in stratospheric ozone depletion. The scientific objectives of the proposal are
- to determine the extinction spectrum of PSC particles,
- to quantify the conditions under which polar stratospheric clouds form,
- to model ozone loss in the lower stratosphere,
with the aim of providing information to build a better quantitative understanding of the ozone layer so that the present state of the layer can be explained and its future evolution predicted.The proposal involves the use of measurements from two Arctic and two Antarctic lidar stations, from an airborne lidar, from a nove] in situ backscattering device, from an optical particle counter, and rrom instruments on the 'Upper Atmosphere Research Satellite (UARS) and from the Improv d Lim Arrat Spectrometer (ILAS). The use of such a disparate measurement-dataset is innovative in that it will tightly constrain PSC formation and heterogeneous chemical modelling and avoid biases that can be introduced in single instrument studies. Included in the proposal are fundamental laboratory measurements of PSC particles essential to the interpretation of existing and proposed PSC data. The project aims to develop an innovative inversion algorithm to estimate key PSC properties including surface area density (which will be validated by lidar and in situ measurements) from infrared spectral measurements. A clear advance in this proposal is the sampling of high resolution satellite data along Lagrangian trajectories so that the evolution and decay of a PSC can be examined. In doing so the chemical changes within an airparcel are effectively decoupled from the dynamics allowing a clear picture of PSC formation and heterogeneous processing to be obtained. This technique has only recently become available since the rovision of UARS data and will have wide application to future European atellite instruments. Quantitative understanding of stratospheric proceesses will be expressed within a numerical model of the atmosphere which includes the best possible descriptions of the important physical and chemical processes (PSC formation, heterogeneous processing, ozone depletion) obtained from fundamental laboratory and atmospheric studies.
the work proposed addresses objectives specified in Area 1.2 of the Environment and Climate RTD workprogramme.
The overall objective of the European Community is the improved and continued welfare of its citizens. By working together a European research team will make significant advances at the frontier of our
knowledge of the atmosphere.
Funding SchemeCSC - Cost-sharing contracts
OX11 0QX Didcot,harwell,chilton