UK Smoke and Sulphur Dioxide Network

						Summary of Smoke Data 1997-98						Summary of SO2 Data 1997-98
				Grid ref to 100m		Valid Days	Max. Gap	Arith. Mean	Median	98th %ile	Max. Day	Valid Days	Max. Gap	Arith. Mean	Median	98th %ile	Max. Day
Code	Site Name	Region	Authority	East	North	Valid Days	Max. Gap	Arith. Mean	Median	98th %ile	Max. Day	Valid Days	Max. Gap	Arith. Mean	Median	98th %ile	Max. Day
SOUTH-WEST
205006	BATH 6	South-west	Bath & NE Somerset	3754	1656	252	1	13	10	40	50	252	1	19	20	40	87
470026	BRISTOL 26	South-west	Bristol	3634	1763	349	15	8	5	34	74	349	15	31	30	65	83
1305004	GLOUCESTER 4	South-west	Gloucester	3832	2179	357	7	8	5	38	73	357	7	14	13	26	39
453003	BRIDGWATER 3	South-west	Sedgemoor	3298	1373	335	21	7	5	30	50	335	21	16	13	37	70
3220002	SWINDON 2	South-west	Swindon	4147	1858	314	29	8	6	33	74	330	14	10	7	20	124

The following abbreviations are used in the table:
1. "Valid Days" denotes the number of valid days' data obtained for the year.
2. " Max. Gap" is the maximum number of consecutive days for which no valid value was obtained.
(Excludes periods when site was not in operation eg. those starting or ceasing part way through year.)
3. "Arith. Mean" is the arithmetic mean of all daily values, calculated by the usual method, as described in Appendix 1.
4. "Median" is the median of all daily values. Calculated by the usual method, see Appendix 1.
5. "98th %ile" is the 98th percentile for all daily values, see Appendix 1.
6. "Max. Day" is the maximum daily value measured during the year.