BAS ozone bulletin 05/95 issued 1995 Sept 22. Preliminary ozone values from the British Antarctic Survey Faraday station (65 south, 64 west on the coast of the Antarctic Peninsula) show mean ozone values declining from around 290 Dobson Units (DU) at the beginning of August to 180 DU in mid September. Planetary wave activity as the edge of the ozone hole moves over the station is giving day to day variation in mean daily values of around 50 DU. Overall the mean daily value is comparable to last year. Data from our long term record for the station indicate normal values of around 330 DU for this period (with a range of 280 DU to 380 DU), giving a depletion of around 45%. Faraday preliminary mean daily total ozone, 1995 Aug 1 - Sep 21 (DU) 306 272 276 265 289 333 307 277 241 229 235 218 213 217 277 278 280 268 219 224 232 237 226 214 201 210 205 232 218 208 223 207 203 204 243 201 196 184 186 189 153 194 272 247 220 269 228 167 206 159 142 140 Routine ozone measurements from the British Antarctic Survey Halley station (76 south, 26 west on the Brunt ice shelf) started towards the end of August when the sun became high enough to permit measurements. The measurements show that ozone values dropped from around 250 DU at the beginning of August to around 140 DU in mid September. Overall the mean daily value is comparable to last year with a decline of about 1% per day and a day to day variation of around 15 DU. Data from our long term record for the station indicate normal values of around 300 DU for this period (with a range of 260 DU to 340 DU), giving a depletion of around 55%. 100 hPa temperatures (near the peak of the ozone layer) are close to normal at around -80xC and stratospheric clouds are expected to be present. Halley preliminary mean daily total ozone 1995 Aug 1 - Sep 21 (DU) (0 indicates no data) 0 0 0 0 0 0 0 221 228 231 248 244 0 0 0 0 0 0 0 0 0 0 0 0 0 0 202 215 187 215 229 199 204 225 217 224 205 213 189 183 206 210 167 188 187 180 160 141 155 160 142 134 TOVS satellite images from the US NCEP/NWS/NOAA Climate Prediction Center show that ozone depletion has intensified over the past month, with the ozone "hole" now covering most of the Antarctic continent. It is currently elongated towards South America and the axis of elongation is rotating around the Antarctic continent with a period of about a month. This rotation of the "hole" gives rise to the variation in ozone amount seen at Faraday. If you use or pass on this data please make acknowledgement to J D Shanklin, British Antarctic Survey. Regards, Jon Shanklin