The vertical eddy diffusion coefficient of heat has been computed from a least squares trigonometric fit of temperatures measured in the Gulf of Trieste (approximately 21 m depth), at four levels of the water column, from January 1986 to September 1989. This coefficient is supposed to be in the form of a constant plus a time and depth function. In climatological time scales, the constant coefficient is sufficient for the description of annual temperature changes in the lower part (approximately 10-21 m depth) of the water column. For the upper part of the column, the possible range of values of the coefficient for the shallow Gulf of Trieste is discussed. |