HC Deb 26 April 1993 vol 223 cc320-1W
Mr. Simon Hughes

To ask the Secretary of State for the Environment (1) what were the degrees of deviation from the normal recorded figures of total column ozone over Lerwick and Camborne for 5, 6 and 7 March;

(2) what were the levels of total column ozone over Lerwick and Camborne on 5, 6 and 7 March; and what they were for the same dates in each of the last 10 years;

(3) what was the average March level of total column ozone for 1993; and what degree of variation there was from the normal recorded levels for this period.

Mr. Maclean

Results of ozone column measurements made at Camborne and Lerwick on 5, 6 and 7 March for 1993 and for the same dates over the past 10 years are:

Total ozone (Dobson units)
Camborne Lerwick
Year 5 March 6 March 7 March 5 March 6 March 7 March
1987 354 389
1986 301 373 383 389 400
1985 392 351 320 345
1984 287 301 293 328
1983 359 279
1982 392 362 416 393 427
1981 361 399 441 444
1980 378 436

Blanks indicate days when measurements could not be made due to weather conditions. Recent data are subject to final calibration corrections. The measurements for 5, 6 and 7 March this year include the four lowest for March in the record, the previous lowest levels being 267 and 270 Dobson Units measured on 1 March 1983. The average ozone measurements for March this year are 335 Dobson Units at Camborne and 347 Dobson Units at Lerwick. These values are respectively 12.6 per cent. and 10.4 per cent. below the average for the last 10 years.