Parameterization of phytoplankton spectral absorption coefficients in the Baltic Sea: general, monthly and two-component variants of approximation formulas
<p>This paper presents approximate formulas (empirical equations) for parameterizing the coefficient of light absorption by phytoplankton <i>a</i><sub>ph</sub>(<i>λ</i>) in Baltic Sea surface waters. Over a thousand absorption spectra (in the 350–750&...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-12-01
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| Series: | Ocean Science |
| Online Access: | https://www.ocean-sci.net/14/1523/2018/os-14-1523-2018.pdf |
| Summary: | <p>This paper presents
approximate formulas (empirical equations) for parameterizing the coefficient
of light absorption by phytoplankton <i>a</i><sub>ph</sub>(<i>λ</i>) in Baltic Sea
surface waters. Over a thousand absorption spectra (in the 350–750 nm
range), recorded during 9 years of research carried out in different months
of the year and in various regions of the southern and central Baltic, were
used to derive these parameterizations. The empirical material was
characterized by a wide range of variability: the total chlorophyll <i>a</i>
concentration (Tchl <i>a</i>) varied between 0.31 and 142 mg m<sup>−3</sup>, the
ratio of the sum of all accessory pigment concentrations to chlorophyll <i>a</i>
( <mo form="infix">∑</mo> <i>C</i><sub><i>i</i></sub>∕Tchl <i>a</i>) ranged between 0.21 and 1.5, and the
absorption coefficients <i>a</i><sub>ph</sub>(<i>λ</i>) at individual light
wavelengths varied over almost 3 orders of magnitude. Different versions of
the parameterization formulas were derived on the basis of these data: a
one-component parameterization in the <q>classic</q> form of a power function
with Tchl <i>a</i> as the only variable and a two-component formula – the
product of the power and exponential functions – with Tchl <i>a</i> and <mo form="infix">∑</mo> <i>C</i><sub><i>i</i></sub>∕Tchl <i>a</i> as variables. We found distinct differences between
the general version of the one-component parameterization and its variants
derived for individual months of the year. In contrast to the general variant
of parameterization, the new two-component variant takes account of the
variability of pigment composition occurring throughout the year in Baltic
phytoplankton populations.</p> |
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| ISSN: | 1812-0784 1812-0792 |