Coordinated Ozone and UV project

DOAS measurements are carried out with the SAOZ instrument from Ny-Ålesund, Spistbergen and with the two SYMOCS instruments from the ALOMAR observatory at Andøya, Northern Norway. These instruments measure column densities of ozone, NO₂, OClO and BrO.

The UV radiation field in the troposphere and the lower stratosphere is measured by flying a NILU-CUBE instrument on balloons. The NILU-CUBE is a twelve channel narrow-band filter instrument. It has six input optics, each mounted on the face of a cubical frame. Data from these flights will be used to check the actinic flux calculations in models.

The degree of ozone loss and its geographical extent will be assessed by analysing observations and model results. The aim is also to get a handle on the processes and parameters that control ozone concentrations over the course of the winter, such as temperature, water vapour, HNO₃, halogens, aerosols, PSC incidence etc. Comparison of model output and observations is an important part of this task.

Two 3-D chemical transport models are being developed: 1. The Oslo CTM-2 will be used for process studies and for interpretation of observations. 2. The Oslo SCTM -1 is used for long term studies, both of the past and the future development of the ozone layer.

Dynamical models will be used to study northern hemisphere high latitude ozone budget in the spring and summer, i.e. after the breakdown of the polar vortex, and the ozone chemistry occurring in the vortex debris during the transition to summer regime. Ozone structures seen in lidar observations, esp. in winter and spring will also be studied.

A radiative transfer model will be used to calculate UV maps of Norway. Satellite data will be used to make maps of the past and present situations. Model output from the Oslo SCTM-1 will be used to make UV maps for the future.

Ground-based measurements of ultraviolet radiation are carried out at NTNU in Trondheim and in the Oslo area by the Univ. of Oslo. Both irradiance and radiance are measured. Such measurements are needed in order to verify radiative transfer models.

Ozone lidar measurements are carried out from the ALOMAR observatory at Andøya, 69N. These measurements are used to study rapid fluctuations in the ozone layer caused by dynamic effects. Long-term variations in the ozone profile can also be studied.

Ozonesondes are launched from Ørland on a bi-weekly basis. During Match campaigns and special meteorological conditions sondes are launched more frequently (2-3 times per week). The data are used both for long-term trend studies and for analysis of ozone loss during individual winters.

COZUV (Coordinated Ozone and UV project) is a joint Norwegian project within stratospheric ozone and UV research. It started in January 1999 and runs through 2002. The main objectives are to gain increased understanding of the processes that lead to ozone loss in the Arctic and at middle latitudes and to understand how changes in the ozone layer affects the amount of UV radiation that hits the ground. More details can be found by clicking on the buttons on the left. By clicking on the images along the lower and right border one can read more about the plans for and results from the various work packages that constitute COZUV.