The Turner stability class or Turner stability index is a classification of atmospheric stability over an interval of time based on measurements of surface-level wind speed and net solar radiation. Classes range from 1 (most unstable) to 7 (most stable). The Turner stability class system was devised by D. B. Turner as a modification of the Pasquill stability class system.[1]
The following table is used to determine the Turner stability class for a given wind speed and net solar radiation:
Wind speed (knots) |
Net radiation index | ||||||
---|---|---|---|---|---|---|---|
4 | 3 | 2 | 1 | 0 | -1 | -2 | |
0, 1 | 1 | 1 | 2 | 3 | 4 | 6 | 7 |
2, 3 | 1 | 2 | 2 | 3 | 4 | 6 | 7 |
4, 5 | 1 | 2 | 3 | 4 | 4 | 5 | 6 |
6 | 2 | 2 | 3 | 4 | 4 | 5 | 6 |
7 | 2 | 2 | 3 | 4 | 4 | 4 | 5 |
8, 9 | 2 | 3 | 3 | 4 | 4 | 4 | 5 |
10 | 3 | 3 | 4 | 4 | 4 | 4 | 5 |
11 | 3 | 3 | 4 | 4 | 4 | 4 | 4 |
≥ 12 | 3 | 4 | 4 | 4 | 4 | 4 | 4 |
The net radiation index is determined by following a procedure (see flowchart) that takes into account the cloud cover, ceiling height, and solar altitude.
References
edit- ^ Turner, D. Bruce (1964). "A Diffusion Model for an Urban Area". Journal of Applied Meteorology. 3 (1): 83–91. Bibcode:1964JApMe...3...83T. doi:10.1175/1520-0450(1964)003<0083:ADMFAU>2.0.CO;2. Retrieved July 10, 2021.
- ^ Turner, D. Bruce (1961). "Relationships Between 24-Hour Mean Air Quality Measurements and Meteorological Factors in Nashville, Tennessee". Journal of the Air Pollution Control Association. 11 (10): 483–489. doi:10.1080/00022470.1961.10468029. PMID 13923192. Retrieved 2021-07-10.