CLEARING INDEX TOTALS 1971-2000

The Clearing Index is used to evaluate vertical diffusion pollution potential in the valley. These are numerical nondimensional values ranging from less than 50 in the worst inversion conditions to more than 1000 in the least inversion conditions.

 

	0-100	101-250	251-500	501-1000	1000+	TOTAL DAYS	<250	AVG. (1971-2000)
1971	17	24	43	129	150	363	41	67
1972	20	14	43	104	185	366	34	67
1973	34	24	38	92	177	365	58	67
1974	13	26	52	125	146	362	39	67
1975	31	16	39	92	187	365	47	67
1976	43	43	41	79	160	366	86	67
1977	21	25	35	89	194	364	46	67
1978	5	29	41	89	200	364	34	67
1979	25	36	41	92	171	365	61	67
1980	40	29	48	86	155	358	69	67
1981	34	34	37	102	157	364	68	67
1982	24	34	38	96	170	362	58	67
1983	19	29	47	96	172	363	48	67
1984	56	34	50	98	124	362	90	67
1985	59	33	50	84	139	365	92	67
1986	57	45	75	64	123	364	102	67
1987	35	59	64	85	121	364	94	67
1988	44	38	64	105	113	364	82	67
1989	49	37	56	70	143	355	86	67
1990	25	44	62	66	165	362	69	67
1991	48	43	53	105	106	355	91	67
1992	40	38	56	87	141	362	78	67
1993	31	47	48	95	142	363	78	67
1994	17	29	55	83	179	363	46	67
1995	20	40	56	73	176	365	60	67
1996	23	30	44	73	196	366	53	67
1997	24	46	65	72	158	365	70	67
1998	30	35	43	79	178	365	65	67
1999	54	44	55	61	151	365	98	67
2000	53	44	51	36	182	366	97	67
TOTALS	991	1049	1490	2607	4761	10898	66.6333
YRLY AVG	33	35	50	87	159	363
YRLY %	9.09%	9.63%	13.67%	23.92%	43.69%