For this last reason, the energy efficiencies of these processes (RH and rH) are always greater than the corresponding quantum yields (ΦH and qH), that is, normally RH > ΦH and rH > qH. To calculate the energy efficiencies of heat production (RH and rH), we used the efficiencies, calculated earlier,

of the other two accompanying processes, i.e. chlorophyll a fluorescence (Rfl and rfl) and photosynthesis (Rph and rph) and the budget (13), (14), (15) and (16) given in the Introduction. In order to characterize the different quantum yields and energy efficiencies of all three processes in which the excited states of phytoplankton pigment molecules are deactivated, the

vertical profiles of these yields/efficiencies were modelled in sea waters of 11 trophic types (see Annex 2), in three climatic SCH727965 zones (tropical, temperate, polar) and in two seasons of the year (June – summer in the northern hemisphere and January – winter in the northern hemisphere). The model calculations of these yields/efficiencies were limited to oceanic Case 1 waters, according to the optical classification of Morel & Prieur (1977), which applies to more than 90% of the volume of the World Ocean. The three climatic zones of the ocean were represented by buy PD173074 waters adjoining the relevant latitudes in the northern hemisphere: tropical (0–10°N), temperate Sitaxentan (ca 40°N) and polar (ca 60°N). The input data for these

model calculations made for different depths in the sea z (representing the fundamental variable) were: • surface concentration of chlorophyll a Ca(0), expressed in [mg chla m− 3], The surface layer temperatures temp and surface irradiances PAR(0) were based on the geographical distributions and seasonal variations of these parameters, as given by Timofeyev (1983) and Gershanovich & Muromtsev (1982). The surface irradiances PAR(0), expressed as the surface density of a stream of light quanta in [μEin m− 2 s− 1], were calculated from the overall daily doses, given by those authors, of the energy of downward solar irradiance at the sea surface < ηday > month and the day length td  2. The specifications of these data are given in Table 2. The values of the optical depth in the sea τ(z) [dimensionless], which were used directly to calculate the PAR(z) irradiance and the yields/efficiencies of the three processes, were determined on the basis of the algorithm presented in Woźniak et al. (2003). They were worked out from a statistical model of the vertical distributions of chlorophyll a concentrations at particular depths in the sea Ca(z) in stratified oceanic basins ( Woźniak et al. 1992).