Mean height and period of sea waves observed once in 20 years in January, April, June and October

Conventions: Mean height h(m), period of sea waves t(s)
Reference: Hydrometeorology and Hydrochemistry of Seas (1992). Volume VI The Caspian Sea. Issue 1 Hydrometeorological regime. Eds. F.S. Terziev, A.N. Kosarev, A.A. Kerimov.

Mean height and period of sea waves observed once in 20 years
Mean height and period of sea waves observed once in 20 years in January
Mean height and period of sea waves observed once in 20 years in April
Mean height and period of sea waves observed once in 20 years in June
Mean height and period of sea waves observed once in 20 years in October