This project is supported by the European Commission - DG XII - Environment and Climate Programme

Objectives

The objectives are:

To quantify precisely the rate of chemically-induced ozone loss as a fonction of time both inside the Arctic vortex and at middle latitudes during two consecutive years. The cumulative chemical ozone loss and its geographical extent will also be determined.

To obtain a better agreement between measured ozone loss and ozone loss calculated by 3-D CTMs and thereby improve their predicitive capability. This will also help toidentify and quantify the causes of ozone reduction inside and outside the polar vortex.

In order to meet these objectives we propose:

To mesure the chimically-induced ozone loss rates during the 1998-99 winter by carrying a Lagrangian ozonesonde/lidar campaign where forecast trajectories are used to coordinate the measurements. The measurements will be carried out both inside the polar vorte, along the vortex edge and at middle latitudes. Model calculated diabetic heating rates will be used to derive the non-isentropic motion of the air parcels. The ozonesonde data will be subject to careful and detailed quality control.

To assess the amount of chemical ozone loss by comparaison of total ozone and profile ozone measurements with 3-D CTMs. By running these models with the assumption that ozone is an inert tracer one can calculate the chilmical ozone change by comparing measured and modelled ozone. The models' ability to describe the transport (including the diabatic heating used in the calculation of ozone loss) will be tested using profile measurements of passive tracers such as methane and chlorofluorocarbons. It is also the aim to provide modelling groups with data for improving the models' capability to calculate chemical ozone loss.

Project Methodology

The project consists of the following two work packages:

1 - MATCH

Direct measurement of ozone change by a lagrangian ozone experiment. Quality control of sonde data.

2 - Ozone Loss - the full picture

Measurement of ozone loss by other techniques and comparaison with 3-D model calculations. The intention is to provide a full picture of the ozone loss in Arctic and middle lattitudes.

Operation / Schedule

The following time schedule is based on the assumption that the project starts on 1 January 1998. The timing of the project has to be based on “calendar dates” rather than “dates relative to project start” because the field activities take place during the winter months. If the formal commencement date is different from 1.1.98, some of the mile-stones and deliverables will appear at slightly different times. Milestones will be in the form of meetings where project progress will be reviewed. Deliverables are reports, scientific results, data and computer code which will be made available to all PIs at various times during the project.

Participants

NILU, Norway	Geir O. Braathen geir@nilu.no
CNRS / Service d'Aéronomie, France	Florence Goutail florence.goutail@aerov.jussieu.fr
Alfred Wegener Institut, Germany	Peter von der Gathen gathen@awi-potsdam.de
University of Cambridge, UK	John A. Pyle pyle@atm.ch.cam.ac.uk
Finnish Meteorological Institute, Finland	Esko Kyrö Esko.Kyro@fmi.fi
University of Weles, UK	Geraint Vaughan gvx@aber.ac.uk
Swedish Institute of Space Physics, Sweden	Sheila Kirkwood sheila@irf.se
National Physical Laboratory, UK	Peter Woods ptw2@newton.npl.co.uk
Central Aerological Observatory, Russia	Valery Dorokhov vdor@ozone.mipt.ru
Institue of Meteorology and Water Management, Poland	Zenobia Lityñska zenoblit@pol.pl