Long-term atmospheric monitoring in Sydney using an MFRSR

We have been monitoring aerosols, ozone and water vapour in Sydney using a Multifilter Rotating Shadowband Radiometer (MFRSR) since December 1995. The aerosol optical thickness measurements have been used to monitor longterm and seasonal trends. Both trends are small, based on the data analysed to date. Inversion of the aerosol optical thickness measurements to obtain aerosol size distribution has shown that bimodal distributions dominate, comprising 82% of the sample. The MFRSR also has channels which are sensitive to ozone and to water vapour. We have applied a new technique, based on eigenvalue analysis, to determine the aerosol contribution to each of these channels. Using this correction we have derived the total column ozone and the total column water vapour. In the case of ozone, the values obtained using this method agreed with the TOMS satellite measurements to within 2%