<rahmann et al. 
FO 
5°S 
M77/2-076- 
M77/2-075-1 
M77/2-067-4 M77/2 5 
% 
M77/2-062-1 
M77/2-072-3 
M77/2-069-1 
M77/2-060-3 
M77/2-059-1 
M77/2-053-2 
Ad 
M77/2-052-1 
| 
M77/2-047-2 
M77/2-050-2 
| 
WM 7/2-054-' 
wa 
M77/1 
M77/2 
M92 
M135 
SFB754 Data Legacy 
M77/2-028. 
“J°S 
(5°S 
20 
W77/1-493 
WTT/T 494 
77“ 495 
77 49t 
77 197 
M77/7-502 
M77 ‚503 
M77/1-504 
177 
87 
A 
AA 
Do 
07 
ung 
80V 
MATT" 
1 
M77/2-022-1 
M92-265-GC7 
5 qq 
M7 
aM 
05-, 
-005-3 
*92-268-Gu- 
PO 
MO“ 
M7r 
MT H4-uu3-2 "+ 
M77/1-4:7 
75°W 
M77/1-413 
M77/1-414 
77’ 415 
A777 AT 
M77/1-477 
M77/1-4 7 
Pa 
25-002-3 
135-002-4 
"435-003-3 
M735-004-" 
‘96.007 
70°W 
FIGURE 8 | Map of the Eastern Tropical South Pacific showing the location of the gravity cores and piston cores taken during cruises M77/1 (black circles), M77/2 
red triangles}), M92 (blue diamonds} and M135 (green squares) 
into 15 ml combusted (450°C, 8 h) amber—glass vials and 
at —20°C. 
FDOM was determined using 3D-—Excitation-Emission- 
Matrix (EEM) fluorescence spectroscopy followed by parallel 
factor analysis (PARAFAC). EEM spectra were obtained using 
a Cary Eclipse Fluorescence Spectrophotometer (Agilent 
Technologies) within 230-455 nm excitation wavelength range 
in 5 nm intervals and within 290-700 nm emission wavelength 
range in 2 nm intervals. All FDOM samples were brought to 
room temperature before the analyses, the measurements were 
performed under temperature-controlled conditions at 19°C 
using Cary Single Cell Peltier Accessory (VARIAN). All the 
-rontiers in Marine Science | www.frontiersin.ore 
fluorescence measurements were performed at 0.2 s integration 
ümes and 5 nm slit width on both monochromators. 
The 3D fluorescence spectra were corrected and analyzed 
by PARAFAC (Stedmon and Bro, 2008), using “drEEM toolbox 
for MATLAB” after Murphy et al. (2013). The humification 
and biological indexes were calculated after (Zsolnay et al., 
1999). CDOM samples were collected into combusted (450°C, 
8 h) 40 ml amber—glass vials. All samples were passed through 
0.2 wm polyethersulfone syringe filters (CHROMAPHIL® Xtra 
PES—45/25, MACHEREY-NAGEL GmbH & Co.KG) before 
storage at 4°C. Samples were processed within 1-90 days. 
The measurements were performed at room temperature 
3eptember 2021 | Volume 8 | Article 72330«