Bioluminescence in a complex coastal environment: 2. Prediction of bioluminescent source depth from spectral water‐leaving radiance

Abstract

Many bioluminescence observations are made from the ocean's surface. However, the depth of the bioluminescent source is difficult to estimate on the basis of surface observations alone, given the variable light attenuation of unknown concentrations of water column constituents such as phytoplankton, colored dissolved organic matter, and detritus. Part 1 of this paper showed that bioluminescent water-leaving radiance signals are detectable, even in extremely turbid and dynamic coastal waters. Here, in part 2 of this paper, we analyze the waterleaving radiance patterns of bioluminescence modeled by HydroLight 4.2 to determine if the depth of the bioluminescent source can be estimated from its spectral signature. We find that the depth of the bioluminescent source is contained within the spectral signal and can be elucidated by simple neural networks. These networks can predict the depth of a bioluminescent layer with great accuracy, solely on the basis of the spectral shape of bioluminescent water-leaving radiance in a variety of water column and bottom type conditions. In addition, we found that as little as three wavelengths from the spectrum of water-leaving radiance are sufficient for an accurate determination of the depth of the bioluminescent source.

Bioluminescence in a complex coastal environment: 1. Temporal dynamics of nighttime water‐leaving radiance

“…BL w as shown in Figure 9 is slightly different as it is the waterleaving radiance integrated over the 20 nm centered around the maximum wavelengths shown in Figures 6 and 7, and not over the entire spectrum, to simulate a spectral sensor's response. Although there is significant variability in BL w , there is an expected decrease with increasing t(l) as well as increasing l. The significant differentiation of t with changing wavelengths suggests that spectral information may be used to delineate the depth of the bioluminescence source, and will be explored in part 2 of this paper [Oliver et al, 2007]. The range of t(l) further illustrates the high spectral attenuation at this site and allows these results to be portable to other locations.…”

“…Although there is significant variability in BL w , there is an expected decrease with increasing τ ( λ ) as well as increasing λ . The significant differentiation of τ with changing wavelengths suggests that spectral information may be used to delineate the depth of the bioluminescence source, and will be explored in part 2 of this paper [ Oliver et al , 2007]. The range of τ ( λ ) further illustrates the high spectral attenuation at this site and allows these results to be portable to other locations.…”

“…This quantitative approach also takes into account the variability in the spectral light field, which provides additional information about the BL w and the depth of a particular light source. Important to this discussion will be the recognition that the applied interest in BL w is driven primarily by the opportunities and hazards that result from bioluminescent events, and a path toward sensing and prediction of these events in the ocean, the topic of part 2 of this paper [ Oliver et al , 2007].…”

Stimulation of bioluminescence in Noctiluca sp. using controlled temperature changes

“…There have been previous studies on bioluminescence. Oliver et al (3) studied the source depth of bioluminescence from waterleaving radiance in a complex coastal environment. McCown et al (4) investigated the effects of electromagnetic fields on dinoflagellate bioluminescence.…”

Dynamic Modeling of Marine Bioluminescence and Night Time Leaving Radiance

“…Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. bioluminescence inversion Oliver et al, 2007) and development of a methodology for short-term bioluminescence predictions (Shulman et al, 2003 and. The proposed research is being significantly leveraged by the interdisciplinary and multi-institutional modeling and field efforts of the NRL BIOSPACE and MURI ESPRESSO projects.…”