Underwater Acoustic Measurements to Estimate Wind and Rainfall in the Mediterranean Sea

Table 4

Number of available sound pressure level spectra divided into (a) Beaufort wind speed and (b) Douglas seas state classes on the basis of 5-minute running average of wind speed and significant wave height measurements acquired by the anemometer and the wave meter system on board the buoy, respectively.

(a)

Beaufort scale	Wind speed (m/s)	Number of sound pressure level spectra	Percentage
F0—calm	0–0.2	0	0.00
F1—light air	0.3–1.5	5690	11.25
F2—light breeze	1.6–3.3	14616	28.90
F3—gentle breeze	3.4–5.4	12993	25.69
F4—moderate breeze	5.5–7.9	9197	18.18
F5—fresh breeze	8.0–10.7	5171	10.22
F6—strong breeze	10.8–13.8	2224	4.40
F7—near gale	13.9–17.1	689	1.36
Total		50580	100.00

(b)

Douglas scale	Significant wave height (m)	Number of sound pressure level spectra	Percentage
D0—calm (glassy)	—	0	0.00
D1—calm (rippled)	0.00–0.10	0	0.00
D2—smooth	0.10–0.50	1714	35.31
D3—slight	0.50–1.25	1599	32.94
D4—moderate	1.25–2.50	1012	20.85
D5—rough	2.50–4.00	416	8.57
D6—very rough	4.00–6.00	113	2.33
Total		4854	100.00