A. Valente et al.: A compilation of global bio-optical in situ data 
my 
3dg(443Vada(490: 
41205 
adg(412Vadg(443) 
HT; 
1198 
aph(490)Vaph(443) tr 
4242 
aph(412)V/aph(443ı H> === 
>; 
1 
TE 
12724 
UL 
75 
15 
25 A 
EB 
Figure 13. The distribution of absorption coefficients band ratios: 
adg(443) / adg(490), adg(412) / adg(443), aph(490) / aph(443) and 
aph(412) / aph(443). Data within 2nm of the wavelengths were 
used. The graphical convention is identical to Fig. 2. The vertical 
dashed lines show the lower and upper thresholds used for qual- 
ity control in the IOCCG report 5. The total number of points 
for “adg” ratios are divided between NOMAD (89 %), COAST- 
COLOUR (7 %), MERMAID (3%), and Seabass (1%). The to- 
‚al number of points for “aph”” ratios are divided between NO- 
MAD (28 %), TPSS (23 %), AWI (23 %), COASTCOLOUR (14 %), 
SeaBASS (10 %), and MERMAID (2 %). 
Amundsen to Bellinghausen Sea of the Southern Ocean, the 
North Sea, the Arctic Ocean, the Indian Ocean, and the sub- 
:ropical and tropical Pacific. Coverage for the Arctic re- 
gion and northern seas of the North Atlantic is provided 
by SEADATANET, ARCSSPP, and BARENTSEA data sets. 
Observations from BIOCHEM and TPSS are mostly from 
che Northwest Atlantic, whereas CALCOFI, CCELTER, and 
CIMT provide data for the western coast of North Amer- 
ica. The data from IMOS mainly covers the coastal Aus- 
tralian waters. The remaining data sets provide observations 
for fixed locations: PALMER (western Antarctic peninsula), 
COASTCOLOUR (17 coastal sites across the world), BATS 
(Bermuda, North Atlantic), BOUSSOLE (Mediterranean), 
HOT (Hawaii, North Pacific), and ESTOC (Canaries, North 
Atlantic). Figure 9 shows all data sources that contribute with 
chlorophyll observations, but many overlap each other, es- 
pecially around Europe and North America. For additional 
analysis and as an example of the applications of the com- 
piled dataset, the combined chlorophyll data (“chla_fluor” 
and “chla_hple””) were partitioned into 5° x 5° boxes, and 
for each box the number of observations, average value, and 
standard deviation were computed (Fig. 10a, b, and c, re- 
spectively). The number of observations can be very high (> 
1000) in some boxes along the European and North Ameri- 
can coastlines and relatively low (< 20) in oceanic regions. 
The well-known global biogeographical features, such as the 
lower chlorophyll in the subtropical gyres and higher values 
in coastal and upwelling areas, clearly emerge in the aver- 
age value map (Fig. 10b). There is a close correspondence 
between the spatial patterns of the average and standard de- 
attos://doi.org/10.5194/essd-14-573 /-2027 
5759 
viation maps (Fig. 10b and c), which may be an indicator of 
the data quality. 
Coincident observations of chlorophyll-a concentration 
and remote-sensing reflectance are available at 3645 sta- 
tions. These observations are mostly from NOMAD (80 %), 
MERMAID (9 %), COASTCOLOUR (6 %), and SeaBASS 
(3 %). The maximum of three selected band ratios of remote- 
sensing reflectance is plotted against chlorophyll-a concen- 
tration (Fig. 11). The “chla” values used are the combined 
HPLC and fluorometric chlorophyll-a, and for the “rrs”, 
the closest spectral observation within 2nm was used. The 
maximum band ratios were calculated as the maximum of 
[rrs(443) / rrs(555), 1rs(490) / rrs(555), rrs(510) / rrs(555)] 
or [rrs(443) / rrs(560), rrs(490) / ı1s(560), 
rrs(510) / rrs(560)] if rrs(555) was not available. The 
relationship between maximum band ratio and chlorophyll 
is close to the NASA OC4 and OC4E v6 standard algo- 
rithm (http://oceancolor.gsfc.nasa. g0v/cms/atbd/chlor_a, last 
access: 18 December 2022) similarly based on maximum 
band ratios, providing confidence in the quality of the 
compiled data. Compared to the previous version (Valente 
et al., 2019), the relations between maximum band ratio 
and chlorophyll are not altered by the additional number of 
concurrent observations (N = 13). 
The inherent optical properties (“aph”, “adg”, and “bbp”) 
are available at 550 unique wavelengths between 300 and 
850nm. There is a total of 4265, 1654, and 792 observa- 
tions, for “aph”, “adg”, and “bbp”, respectively. For “aph”, 
the total number of observations is distributed among NO- 
MAD (1190), TPSS (966), COASTCOLOUR (593), AWI 
(991), SeaBASS (453), and MERMAID (72). For “adg”, 
the contributions are as follows: NOMAD (1079), COAST- 
COLOUR (531), SeaBASS (11), and MERMAID (33). The 
“bbp” observations come from NOMAD (371), COAST- 
COLOUR (154), SeaBASS (32), and MERMAID (235). 
Compared to the previous version (Valente et al., 2019), only 
“aph” was updated, resulting in a — 30 % increase (i.e. from 
3293 to 4265). Most of the new observations fall within 
the period 2012-2020, thus increasing the temporal cover- 
age (previous version had “aph” until 2012). Data distri- 
bution of “aph”, “adg”, and “bbp” at 44X nm and 55X nm 
for each data set is provided in Fig. 12a-f. Median values 
of “aph”, “adg”, and “bbp” at 44X and 55Xnm for each 
data set are summarized in Table 3. As a quality indica- 
tor, the following band ratios for the absorption coefficients 
were calculated: aph(490) / aph(443), aph(412) / aph(443), 
adg(443) / adg(490), and adg(412) / adg(443). Data within 
2nm of the wavelengths were used to maximize the number 
of points. The distribution of the ratios is shown in Fig. 13. 
Several observations were found to be outside the thresh- 
olds used in the International Ocean-Colour Coordinating 
Group (I0CCG) report 5 for quality control (IOCCG, 2006; 
see dotted vertical black lines in Fig. 13). These points are 
highlighted here for information but retained in the database, 
since these were mostly from NOMAD and there was an in- 
Earth Syst. Sei. Data, 14, 5737-5770. 2022