A. Valente et al.: A compilation of global bio-optical in situ data
al., 2002). This additional set of columns was provided di-
rectly by the NOMAD creators. The compiled variables were
“rs”, “chla_hple”, “chla_fluor”, “aph”, “adg”, “bbp”, and
“kd”. Conversion was necessary only for “aph”, “adg”, and
“bbp”, and followed the procedures described in Sect. 2.1.
For the calculation of “bbp”, the variable “bb” was used with
a smooth fitting to remove noise. A portion of NOMAD data
were optically weighted (for methods see Werdell and Bailey,
2005). These data are not consistent with the protocols cho-
sen in this work, but these observations were retained since
NOMAD is a widely-used data set in ocean colour validation.
2.2.6 MERIS Match-up In situ Database (MERMAID)
MERMAID provides in situ bio-optical data matched with
concurrent and comparable MERIS Level 2 satellite ocean
colour products (Barker, 2013a, b). The MERMAID in situ
database consists of data from multiple contributors, mea-
sured using a variety of instruments and protocols, from sev-
eral marine platforms such as fixed buoys, handheld radiome-
(ers, and profiling instruments. Comprehensive quality con-
trol and protocols are used by MERMAID to integrate all the
data into a common and comparable format (Barker, 2013a,
b). Access to MERMAID data is limited to the MERIS Val-
idation Team, the MERIS Quality Working Group, and to
che in situ data contributors. For this work, access has been
granted to the MERMAID database through a signed Ser-
vice Level Agreement. The MERMAID data include sub-
sets of several data sets used in this compilation (MOBY,
AERONET-OC, BOUSSOLE, NOMAD). These observa-
üons were removed from the MERMAID data set to avoid
duplication (as discussed in Sect. 2.1). The compiled vari-
ables were “rrs”, “chla_hple”, “chla_fluor”, “aph”, “adg”,
“bbp”, “kd”, and “tsm”. Remote-sensing reflectance was cal-
culated by dividing by x the original “fully-normalized”
water-leaving reflectance (“Rw_ex”), which is the water-
leaving reflectance (Rw = 7” Lw / Es), with a correction for
che bidirectional nature of the light field (Morel and Gen-
üli, 1996; Morel et al., 2002). Conversion was also necessary
for “aph”, “adg”, and “bbp” and followed the procedures de-
scribed in Sect. 2.1.
In comparison with the previous version of the com-
pilation, a set of “chla_fluor” observations from MER-
MAID were considered suspicious and excluded from
ihe compilation (N = 3241, from mermaid_MAREL-carnot,
mermaid_MAREL-itroise, and mermaid MAREL-vilaine).
2.2.7 Hawali Ocean Time-series (HOT)
HOT programme provides repeated comprehensive observa-
ons of the hydrography, chemistry, and biology of the water
column at a station located 100 km north of Oahu, Hawali,
since October 1988 (Karl and Michaels, 1996). This site is
representative of the North Pacific subtropical gyre. Cruises
are made approximately once a month to the deep-water
attos://doi.org/10.5194/essd-14-573 /-20U7,
5749
Station ALOHA (A Long-Term Oligotrophic Habitat As-
sessment; 22°45’N, 158°00’ W). Pigment data (“chla_hplc”
and “chla_fluor”) were extracted directly from the project
website. Radiometric measurements from the HOT project
are also available, but observations of “rrs” and “kd” from
the HOT project were acquired in this work as part of the
SeaBASS data set.
2.2.8 Geochemistry, Phytoplankton, and Color of the
Ocean (GeP&CO)
GeP&CO is part of the French PROOF programme and aims
to describe and understand the variability of phytoplankton
populations and to assess its consequences on the geochem-
istry of the oceans (Dandonneau and Niang, 2007). It is based
on the quarterly travels of the merchant ship Contship Lon-
don from France to New Caledonia in the Pacific. A scientific
observer sailed on each trip and operated the sampling for
surface water, filtration, various measurements, and check-
ing at several times of each day. The experiment started in
October 1999 and finished in July 2002. Pigment data were
extracted from the project website. Additional pigment data
obtained during the OISO-4 cruise in the south Indian Ocean
onboard R/V Marion-Dufresne (January-February 2000)
were added. The samples were measured by Yves Dandon-
neau following the method used in the GeP&CO project. The
compiled variable was “chla_hple” and “chla fluor”
2.2.9 Atlantic Meridional Transect (AMT)
AMT is a multidisciplinary programme which undertakes bi-
ological, chemical, and physical oceanographic research dur-
ing transects between the UK and destinations in the South
Atlantic (Robinson et al., 2006). The programme was es-
tablished in 1995 (e.g. Robins et al., 1996; Aiken et al.,
1998) and since then has completed 29 research cruises. Pig-
ment data between 1997 (AMTS) and 2018 (AMT28) were
mostly provided by the British Oceanographic Data Centre
(BODC) following a specific request for discrete observa-
tions of chlorophyll-a concentration since 1997. The AMT
data were isolated by searching for the string “AMT” in the
“cruise” columns and the respective Principal Investigators
were then searched individually in a separated metadata file.
Data not flagged with highest quality or without method of
measurement were not used. For any interest in the origi-
nal data, BODC is the point of contact, which ensures that if
there are any updates, the most recent data are supplied. In
the case of AMT 26, 27, and 28, data were provided to the
OC-CCI project by Gavin Tilstone, whereas in the case of
AMT 20 and 23, data were provided by Robert J. W. Brewin.
The compiled variables are “chla_hplec” and “chla_fluor”.
Earth Syst. Sci. Data, 14, 5737-5770, 2022
