Chapter 1: INTRODUCTION
9
1
exp
R
i
i
i
f z
a
z
D
¦
,
(1.62)
where i
a are the weights corresponding to the spectrally distributed
absorption coefficients D i . The absorption coefficients in this
parameterization were determined for pure water only based on
measurements of Schmidt (1908). The more recent determination of the
absorption coefficients in clear water by Pope and Fry (1997) produced
similar results.
Table 1-2. Irradiance absorption coefficients D i and spectral weighting coefficients a i
according to Paulson and Simpson (1981) and the modification of coefficient D proposed by
Soloviev and Schl ssel (1996), based on Jerlov’s water-type classification.
Wavelength
(Pm)
a i
D L
m
0.2 - 0.6
1
0.2370
2.874 x 10
-2
0.6 - 0.9
2
0.3600
4.405 x 10
-1
0.9 - 1.2
3
0.1790
3.175 x 10
1
1.2 - 1.5
4
0.0870
1.825 x 10
2
1.5 – 1.8
5
0.0800
1.201 x 10
3
1.8 – 2.1
6
0.0246
7.937 x 10
3
2.1 – 2.4
7
0.0250
3.195 x 10
3
2.4 – 2.7
8
0.0070
1.279 x 10
4
2.7 – 3.0
9
0.0004
6.944 x 10
4
Water
type
I
IA
IB
II
III
1
3
5
7
9
D 1
(m
-1 )
0.066 0.076 0.088 0.132 0.382 0.49
0.70
1.00
1.09
1.60
To extend the calculations to real ocean water, Soloviev and Schl ssel
(1996) proposed a small modification of the Paulson and Simpson (1981)
parameterization. For wavelengths smaller than 0.6 Pm, the absorption is
strongly modified by phytoplankton, suspended inorganic matter, and yellow
substance (Jerlov, 1976). These substances are not important at longer
wavelengths because of a strong decrease of their absorption coefficients
with wavelength. Therefore, taking Jerlov (1976) into account, Soloviev and
Schl ssel (1996) replaced the absorption coefficient for the spectral band
0.2 to 0.6 Pm by average values calculated from narrow-band spectral values
for different types of water representing varying oceanic (types I, IA, IB, II,
and III) and coastal turbidity (types 1, 3, 5, 7, 9). Furthermore, they excluded
the spectral range below 0.31 Pm because of the strong absorption by
atmospheric ozone. The absorption coefficients from Soloviev and
Schl ssel (1996) are listed in Table 1-2. Verevochkin and Startsev (2005)
33
i
ü
ü
ü
ü
9
1
exp
R
i
i
i
f z
a
z
D
¦
,
(1.62)
where i
a are the weights corresponding to the spectrally distributed
absorption coefficients D i . The absorption coefficients in this
parameterization were determined for pure water only based on
measurements of Schmidt (1908). The more recent determination of the
absorption coefficients in clear water by Pope and Fry (1997) produced
similar results.
Table 1-2. Irradiance absorption coefficients D i and spectral weighting coefficients a i
according to Paulson and Simpson (1981) and the modification of coefficient D proposed by
Soloviev and Schl ssel (1996), based on Jerlov’s water-type classification.
Wavelength
(Pm)
a i
D L
m
0.2 - 0.6
1
0.2370
2.874 x 10
-2
0.6 - 0.9
2
0.3600
4.405 x 10
-1
0.9 - 1.2
3
0.1790
3.175 x 10
1
1.2 - 1.5
4
0.0870
1.825 x 10
2
1.5 – 1.8
5
0.0800
1.201 x 10
3
1.8 – 2.1
6
0.0246
7.937 x 10
3
2.1 – 2.4
7
0.0250
3.195 x 10
3
2.4 – 2.7
8
0.0070
1.279 x 10
4
2.7 – 3.0
9
0.0004
6.944 x 10
4
Water
type
I
IA
IB
II
III
1
3
5
7
9
D 1
(m
-1 )
0.066 0.076 0.088 0.132 0.382 0.49
0.70
1.00
1.09
1.60
To extend the calculations to real ocean water, Soloviev and Schl ssel
(1996) proposed a small modification of the Paulson and Simpson (1981)
parameterization. For wavelengths smaller than 0.6 Pm, the absorption is
strongly modified by phytoplankton, suspended inorganic matter, and yellow
substance (Jerlov, 1976). These substances are not important at longer
wavelengths because of a strong decrease of their absorption coefficients
with wavelength. Therefore, taking Jerlov (1976) into account, Soloviev and
Schl ssel (1996) replaced the absorption coefficient for the spectral band
0.2 to 0.6 Pm by average values calculated from narrow-band spectral values
for different types of water representing varying oceanic (types I, IA, IB, II,
and III) and coastal turbidity (types 1, 3, 5, 7, 9). Furthermore, they excluded
the spectral range below 0.31 Pm because of the strong absorption by
atmospheric ozone. The absorption coefficients from Soloviev and
Schl ssel (1996) are listed in Table 1-2. Verevochkin and Startsev (2005)
33
i
ü
ü
ü
ü