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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
Table 1. Fluorescence properties of seawater containing CDOM and cyanobacteria. 
  
Constituent Absorption peak (nm) Fluorescence emission maximum (nm) 
CDOM 355 450 
Cyanobacteria - PC 620 650 
Cyanobacteria - Chl-a 440,680 685 
Cyanobacteria - tryptophan 280 340 
Cyanobacteria - NADPH 340 460 
  
  
Excitation (nm) 
  
  
  
  
500 600 
Emission (nm) 
Figure 1. Excitation-Emission Matrix (EEM) of the 
concentrated seawater sample, and intensity of fluorescence 
emission is shown on an arbitrary Log;o scale. The blue 
horizontal lines display the excitation wavelengths at 280, 390, 
550 nm that induced fluorescence peak from measured samples, 
and the red vertical lines show the fluorescence emission with 
the corresponding excitation. 
There are three emission peaks related to cyanobacteria 
fluorescent signatures in this region. The first fluorescence 
emission peak at 345 nm is from tryptophan excited at a 
wavelength of 285 nm. The second emission peak, 685 nm, is 
from Chlorophyll-a excited at a wavelength of 390 nm. The 
third peak is from phycocyanin which is excited at a wavelength 
of 555 nm with maximum fluorescence emission at 650 nm. To 
better understand the detailed fluorescence spectra features of 
these three fluorophores, their spectro-fluorescence curves are 
produced using excitation at these three wavelengths, which is 
shown in figure 2. 
Fluorescence Spectra of Cyanobacteria cellular fluorophores 
F : 3 iL ^ 55 E peu en 3 
  
1000 
  
= Trp (285nm) : 
^. Chka (390nnj) . 
Hs 
  
100 
Fluorescence Intensity(a.u.) 
YET > ri T 
  
  
1 Mood i ; PEN SA b i sd 
300 400 700 800 
  
  
0 6 
Emission(nm) 
Figure 2. Fluorescence emission curves of three cyanobacteria 
cellular fluorophores: tryptophan, chlorophyll-a and 
    
phycocyanin stimulated at wavelength of 285, 390 and 555 nm, 
respectively. Fluorescence emission intensity is shown on a 
Log, scale. Dashed curves correspond to the emissions that are 
out of the region made by the first and second diagonal strips in 
figure 1, and the solid curves indicate relevant fluorescence 
emission spectra for each fluorophore, which correspond to the 
region between the first and second diagonal lines in figure 1. 
3.2 PAHs fluorescence properties of crude oil samples 
Although five different oil samples were all measured for 
fluorescence and reflectance features, four of the five oil 
samples did not show relevant information on PAHs 
fluorescence which is caused by their optical properties being 
either too thick or too thin. Only one oil sample exhibits related 
features on PAH fluorescence. The PE-LS55 Luminescence 
spectrometer was used to record the emission spectra between 
240 and 600 nm using a excitation wavelength range between 
240 and 500 nm with 15 nm increment of each step. The 
spectro-fluorescence feature of the oil sample is illustrated in 
figure 3. From the EEM, there is an emission peak at 425 nm 
excited at the wavelength between 260 and 300 nm. This 
fluorescence emission signature is from PAHs of the oil sample 
excited at these wavelengths when compared against constituent 
PAH EEMs (Dartnell et al., 2012). 
500 
  
Excitation (nm) 
s 2 = 
> = = 
Lab 
e 
> 
250 
  
  
  
  
250 300 350 400 450 500 550 600 
Emission (nm) 
Figure 3. The EEM generated for the weathered crude oil 
sample. The fluorescence intensity is shown on the right hand 
side of the EEM on a Log scale. 
In order to explore the detailed fluorescence features of PAHs at 
an excitation wavelength of 285 nm, a fluorescence emission 
intensity plot was produced together with its reflectance 
spectrum illuminated using a Solux light source, which is 
presented in figure 4. 
From the fluorescence emission curve shown in figure 4, there 
appears to be a high fluorescence emission between 410 and 
440 nm with a peak reaching 100 a.u. at a wavelength of 425 
nm. Whilst from the reflectance spectrum, the oil sample has a 
strong absorption feature in the violet region with a maximum