Shipl. | 
Shipz | 5 
Ship3 | 31 
Shipa | 36 
Ship5 | 41 
197 | +47 
n 
| +26 
+177 
77 | +114 
11 | 
ee 
823 
29 
28 
17 
+71 
34 
79 
25 
+46 
+17 
+182 
+106 
569 
570 3.4 Application on the FSC violations identification 
571 
572 
573 
574 
575 
576 
577 
578 
579 
580 
581 
582 
583 
584 
585 
586 
5387 
The method presented in the current work was developed to be applied in the identification 
of FSC violations. Initially, it can be used to examine the lowest FSC that can be detected by a 
particular MS with specific instrument sensitivity. The HORIBA APSA-370 used in the present 
MS had an SO- detection limit of 0.5 ppb. The sensitivity of the FSC estimation also depends on 
the CO2 but the instrument used (Licor LI-840A) can detect concentrations far below the 
background. One can therefore argue that the lowest detectable FSC is practically determined only 
by the sensitivity of the SO2 instrument and not the sensitivity of the CO2 one. Obviously, the 
lowest detectable FSC depends on weather conditions, plume size, actual vessel distance from MS, 
etc. However, assuming preferable weather conditions, like the ones in the measurements of Ships 
1,2, 3 and 4, a regression line can be drawn, as shown in Figure 13. The data points, corresponding 
to Ship 1, 2, 3, 4 and the zero FSC, result in the linear expression FSC = 0.029-x (%), where x is 
the mean measured SO2 concentration over the ship plume time-series. With the analyzer lower 
detection limit of 0.5 ppb SO2, the minimum detectable FSC in the specific monitoring station 
would be 0.0145%, which is almost one order of magnitude lower than the maximum allowed FSC 
in the region. Hence, the location of the sampling station is satisfactory in detecting FSC violations. 
Obviously, using the same method, one could further optimize e.g. the height of the measuring 
station to detect even lower FSC levels. 
5c5 
26