The objective of this work is to analyse and define the variability in the yields/efficiencies of the processes deactivating excited phytoplankton pigment molecules under the various conditions prevailing in the World Ocean, that is, in different climatic zones, seasons, sea waters and at various depths in them. From such an analysis we can compare these yields/efficiencies Selleckchem RG7420 and hence the full budgets of the phytoplankton pigment excitation

energy expended on these three processes, which are complementary as regards the utilization of this energy. The methods and range of investigations undertaken in order to achieve this objective and the results obtained are given below. We analyse Selleckchem Ipilimumab the various yields and efficiencies defined by (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14), (15) and (16), the values of which vary widely, in accordance with the nature of the processes that they describe. In

the calculations we used a set of model formulas, listed in Table 1, covering the quantum yields (lines 1, 3, 5, 7, 8–12) and the energy efficiencies of the three processes (lines 2, 4, 6 8–12). The quantum yields of chlorophyll a fluorescence (Φfl and qfl), defined in the Introduction by

(2) and (8), being the ratios of the number of quanta absorbed to the number of quanta emitted during fluorescence, are not equivalent to the corresponding ratios of the amounts of absorbed and emitted energy carried Meloxicam by these quanta; in other words, they are not equivalent to the energy efficiencies of fluorescence (Rfl and rfl) as defined by (1) and (7). This due to the difference in the spectra of the absorbed and emitted light, i.e. the difference between the energy of the quanta absorbed by various pigments and the energy of the quanta emitted during chlorophyll a fluorescence. The differences between the quantum yields and the energy efficiencies vary in waters of different trophic types, and they also vary with depth in the sea. The energies of single quanta emitted by chlorophyll a during fluorescence are of course the same in all seas, and are equal to hco/λfl, where h = 6.62517 × 10− 34 J s – Planck’s constant, co ≈ 3 × 108 m s−1 – velocity of light in a vacuum, λfl ≈ 685 nm – wavelength of light quanta emitted by chlorophyll a. But the spectral compositions, i.e.