British Antarctic Survey
Ozone Bulletin 01/97 issued 1997 August 15
This bulletin presents total column ozone measurements made using Dobson ozone spectrophotometers. Note that all ozone values are preliminary and are subject to revision from time to time when the instrument constants are re-evaluated. All ozone data is reduced to the Bass-Paur scale as recommended by the WMO.
I have recently updated the BAS ozone web page, which contains earlier bulletins, data and general ozone information. The url is:
http://www.nbs.ac.uk/public/icd/jds/ozone
1. Data from the British Antarctic Survey (BAS) Halley station (76-deg south, 26-deg west, on the Brunt ice shelf).
a) Ozone. Routine ozone measurements from Halley station do not start until towards the end of August because the sun is not high enough to permit measurements, however a few observations using moonlight have been made. These suggest that total ozone values fell from an estimated 300 DU in early July to around 200 DU in mid August. This is comparable to the past few years, but well below the long term mean.
Halley preliminary mean daily total ozone, (DU)
Dobson No 103: Instrument constants revised 1997 May 2.
(0 indicates no data)
1997 August 1 - 1997 August 14
Halley provisional monthly mean total ozone (DU)
1996/97 172 155 149 181 260 278 265 245 242 216
1995/96 219 160 129 163 253 263 248 247 224 210
1957-72 295 285 300 355 350 320 300 295 285 310
b) Radiosonde data. Stratospheric temperatures at 100 hPa, near the peak of the ozone layer, can be used to reflect changes in ozone amount. Stratospheric clouds, which are crucial to the mechanism of ozone depletion, are likely to be present when the 100 hPa temperature is below -80 deg C and may persist whilst the temperature is below -75 deg C. Data from Halley show that the 100 hPa temperature is near the long term norm of -84 deg C. Stratospheric clouds have been observed from the station, and also from the BAS Rothera station (68-deg south, 68-deg west on Adelaide Island).
2. Data from the Ukrainian Antarctic Research Centre Vernadsky station (65-deg south, 64-deg west on the coast of the Antarctic Peninsula, formerly the BAS Faraday station).
Routine ozone measurements commence at Vernadsky in early August, but some observations, of lower accuracy, are made in July. Mean total ozone values fell from an estimated 350 DU in early July to 270 DU in mid August. Particularly low values were recorded on August 2nd, when the station was affected by one of the ozone reduction events associated with the forming ozone hole.
Vernadsky preliminary mean daily total ozone (DU).
Dobson No 31: Instrument constants revised 1997 August 15
1997 August 1 - 1997 August 9
1996/97 217 205 263 226 271 304 279 277 294 260
1995/96 237 194 251 228 298 285 287 278 266 258
1957-72 310 330 345 370 345 320 300 295 310 325
3 Information from other sources.
TOVS satellite images from the US NCEP/NWS/NOAA Climate Prediction Center show that intermittent ozone reduction events occurred during late July and early August. The ozone "hole" is beginning to grow and deepen, and is centred towards the Weddell Sea sector of Antarctica. The normal circumpolar high ozone belt is intensifying. UK Met Office analyses show that the polar vortex is centred around 82-deg south, 20-deg west, with temperatures inside the vortex as low as -86-deg C. A strong thermal gradient exists over the Wilkes - Victoria Land sector of Antarctica.
If you use or pass on this data please make acknowledgement to J D Shanklin, British Antarctic Survey.