POC data points is presented in
Figure 7b, together with the best-fit power function line (see Table 5for the equation parameters). Average values of the POM-specific particle scattering coefficient bp*(POM) (λ) for different wavelengths lie between 6.9 and 8.8 m2 g−1. The variability is rather similar at all wavelengths, but smallest at 650 nm (CV = 55%). The best-fit power function for that FDA approved Drug Library screening relation is given in the fifth row of Table 5. Figure 6b illustrates spectral values of the mass-specific backscattering coefficient bbp*(λ) (obtained by normalization of bbp(λ) values to SPM). If the spectral values of bbp(λ) for all samples are fitted with the power function of const × λη, the average spectral slope η obtained is –2.28 (± 1.35 (SD)) (the minimum and maximum of η are –5.97 and 0.184 respectively); this means that, on average, spectra of bbp are much steeper than those of bp. Average values of bbp*(λ) (see row 5 of Table 4) have CV ≥ 62%. The variability is lowest for the spectral band of 420 nm (see the data points in Figure 7c, and the best-fit power function between bbp(420) and SPM given in row 6 of Table 5). Note that if the statistical parameters of the fits are compared, bbp seems to
be a less attractive proxy for SPM than bp. The average values of bbp normalized to Chl a, POC, POM (i.e. values of bbp*(Chl a)(λ), bbp*(POC)(λ), bbp*(POM)(λ)) are listed in rows 6, 7 and 8 of Table 4. The variability of these www.selleckchem.com/products/GDC-0980-RG7422.html constituent-specific backscattering coefficients
is much greater than that of bbp*(λ) described earlier. In the ‘best’ spectral cases (with the lowest variability) CV = 83%, 70%, 70% and 92% for bbp*(Chl a) (550), bbp*(POC) (550), bbp*(POC) (620) and bbp*(POM) (420) respectively. The corresponding best-fit power functions are given in rows 7, 8, 9 and 10 of Table 5. Comparison of the statistical parameters of these fits with the corresponding statistical parameters of the fits found for the scattering coefficient bp shows that bbp also appears to be a less attractive proxy than bp for Chl a, POC or POM. The final characteristic of light scattering by particles is the particle volume scattering function measured for a light wavelength of 532 nm βp, 532(θ), and for three scattering angles θ (100°, 125° and 150°). Figure 6c lists mass-specific 17-DMAG (Alvespimycin) HCl particle volume scattering functions βp, 532*(θ) (i.e. values of βp, 532(θ) normalized to SPM) for all samples. The last four rows of Table 4 give the average different constituent-specific particle volume scattering functions. CV is the lowest for the mass-specific particle volume scattering function βp, 532(θ). Figure 7d presents the relationship between βp, 532(100) and SPM together with the best-fit power function (see row 11 in Table 5). The best power function fits for the relationships between βp, 532(100) and Chl a, POC and POM are given in the last three rows of Table 5.