WORLD METEOROLOGICAL ORGANIZATION

UNITED NATIONS ENVIRONMENT PROGRAMME

CANADA

Monitoring

Column ozone, Umkehr profiles and W spectra are measured routinely by Brewer spectrometers at twelve locations in Canada. Preliminary values for ozone and CE weighted W irradiance are distributed a few minutes after the observations are made. These are used in the Regional Weather Offices and for input to the W forecast model that is run at the Canadian Meteorological Centre in Montreal. At most locations, all the data for the day are transferred automatically during the night to the Brewer Data Management System in Toronto. The software that operates the Brewers is normally controlled from Toronto.

Ozone profiles are obtained from ozonesondes flown once per week-from five locations (Alert, Resolute, Churchill, Edmonton, Goose Bay), from Brewer Umkehr measurements and from ozone Lidars at Toronto and Eureka.

Eureka Observatory of the Network for the Detection of Stratospheric Change ( NDSC). The Eureka site (85W, 80N, 600m) is Canada's contribution to the NDSC and its operation is a collaboration between Japan and Canada. Measurements there began in January 1993 and have been almost entirely during the winter months. The experiments are run mostly by Canadian (EC, York University, University of Western Ontario) and Japanese (Communications Research laboratory, Meteorological Research Institute, STEL) scientists with some contribution from the USA (Denver University). The experiments comprise an Ozone Differential Absorption Lidar with Raman shifted detection, a Lidar for observation of Polar Stratospheric Clouds and arctic haze, Fourier Transform Infrared Spectrometers for observation of radiation from the sun or moon and for observation of atmospheric thermal emissions a Brewer spectrometer that has been adapted to measure ozone using starlight and another adapted to use visible radiation from the sun. Several experiments that measure airglow and aurora are also installed at Eureka and operated by the University of Saskatchewan. These measurements combine with the Lidar data to increase the range of heights over which gravity waves can be observed. About thirty ozonesondes are flown from Eureka each winter, this year scheduled when requested in the Mini-Match experiment. It is anticipated that a new chlorine oxide microwave radiometer from Japan will be installed at the base camp by the Communications Research Laboratory in 1997.

Participation in the NASA ER-2 STRAT campaign.

Environment Canada's small array spectrometer that was originally developed for use the in the cabin of the Space Shuttle has been part of the ER-2 payload during the SPADE, ASHOE, MAESA and STRAT campaigns. The instrument measures upward and downward spectral irradiance and spectral radiance near the horizon. The measurements and radiation model results are combined to give estimates of photodissociative fluxes and of the ozone above the aircraft. These ER-2 projects and NASA's logistical support provide for constructive collaboration between scientists from different disciplines. Deployment of the spectrometer on other platforms is under consideration.

World Ozone and Ultraviolet Radiation Centre (WOUDC).

The World Ozone Data Centre (WODC) has been run by Environment Canada for the WMO since 1960. It was agreed in 1992 that the Centre should be augmented to carry UV data as well. The WOUDC is advised by the WMO Scientific Steering Committee on the UV-B and by an Environment Canada Advisory Committee. Currently the WOUDC contains about 25000 sonde profiles, 40000 Umkehr profiles, 3000 station-years of column ozone and fifty station years of spectral UV data from Brewers in Canada and Japan. Most of these data are posted for unrestricted access under ftp.

Some organizations that fly ozonesondes are not submitting their data. The WOUDC is committed to encourage and help research managers to submit their sonde data and asks those who are not currently doing so to contact the WOUDC in order to discuss and potentially resolve any problems.

Information on the submission of spectral UV measurements can be obtained from cmitsO2.dow.on.doe.ca. Submission of data from instruments other than Brewer spectrometers will require some discussion with WOUDC of procedures which are currently being developed with the WMO Scientific Steering Committee. Access to UV data in the WOUDC can be restricted if so required..

Middle Atmosphere Initiative.

A program to develop a forecast model that includes the stratosphere and mesosphere as well as interactive photochemistry is under development. It involves Environment Canada and several universities. Projects on assimilation techniques for new data and the addition of chemistry to the current forecast model have been started. The more obvious benefits of such a model are improved understanding of middle atmosphere dynamics and chemistry. It is hoped that the model could be used to compare objectively the merits of proposals for different types of satellite observations, and that the weather forecasts might be improved.

Health Effects.

Ocular effects of UV are investigated at the University of Guelph. The epidemiology of skin cancer is studied at various government cancer research institutes and at the University of British Columbia where there is a project to evaluate changes in behavior caused by public education programs on UV exposure.

Environmental Effects.

Research on the influence of UV-B on fresh water ecosystems is coordinated by the National Water Research Institute. This involves separate studies of effects in lakes and rivers including contributions from the Universities of Manitoba and Trent. There are also projects on UV-B and coastal waters and oceans in progress in the Department of Fisheries and at Dalhousie University. A project on the influence of UV-B on pine trees is run by the Department of Forestry and the University of New Brunswick.

Public Education Programs.

Two programs, "Ozone Watch" and "UV-Index", both initiated in 1992, are in operation. Ozone Watch comprises weekly information bulletins on ozone values over Canada. Its main impact appears to be on science journalists. The UV-Index program involves forecasting the strength of UV radiation the following day. Since 1995, a separate forecast timed for Europe has been produced in an experiment run jointly with the University of Thessaloniki. Opinion polls show that the forecasts are well received by the Canadian public.