## 3 Related Works  
In this article, we explore in depth the influence of four main determinants for UOWC link quality: vertical chlorophyll distributions, the resultant effect on inherent optical properties, the underwater radiance fields, and UOWC hardware parameters. Even though there have been separate studies into each of these factors, there are none that have combined them into a single model under realistic ocean conditions. For example, the interactions between sunlight and the environment cannot be isolated in UOWC scenarios when the solar spectrum also fully encompasses the visible light spectrum that is used for UOWC. Figure 3: Spectral distribution of attenuation coefficient in Jerlov water types [36]. [PERSON] et al. [39] show how a well-selected thin-film (narrowband) filter may help to exclude sunlight better than colored glass ones, but under limits of certain orientations. This is due to thin-film filters being angle-of-incidence (AOI)-sensitive, where non-orthogonal AOIs shift the center frequency of the passband and lower the transmissivity of the spectra. A similar strategy has been explored by [PERSON] et al., where they suggest establishing narrowband UOWC links using lasers with wavelengths within a Fraunhofer line (narrow, dark lines in the solar spectrum) at the transmitter, and birefringent and interference filters at the receiver to discriminate other bands. Their results show significant improvement in link distance [40]. However, these are both non-ideal for mobile UOWC, where freedom of movement is a necessity, which demands the use of LEDs as emitters, where the emission's power spectral density could span a bandwidth of few tens of nanometers. Their investigations further applied the Jerlov water classifications [36], which for mobile UOWC do not capture the full scope for vertical UOWC channels due to the environment being inhomogeneous in composition in the vertical direction. Instead, for example, [PERSON] et al. [33] provide insight into how the attenuation may vary in a vertical channel based on the vertical chlorophyll concentration profile. Subsequently, investigations by [PERSON] et al. [41] and [PERSON] et al. [42] have provided insights into how transmitter parameters such as wavelength, beam divergence, and output power in such stratified environments may affect the path loss and range of a horizontal link at various depths. [PERSON] and [PERSON] [43] have attempted to model vertical sunlight attenuation using a basic downwelling solar intensity distribution profile for stratified environments. However, these studies provide separate insights, whereas modeling for realistic UOWC performance during the daytime would require the amalgamation of both. In addition to this, we have recognized some doubts in them due to the reproduced vertical Chl-\(a\) concentration profiles showing narrow, sharp peaks that do not correspond to those presented in the original study by [PERSON] et al. [34], which we have attempted to rectify in our investigation in Section 4.2 (to ease further investigation for the reader, we have also provided these re-parameterized, dimensioned coefficients in Appendix A). Nevertheless, there has been growing interest recently in estimating performance characteristics for vertical and oblique channels in environments of stratified water columns. [PERSON] and [PERSON] [44] modeled for the performance of oblique links under varying salinity and temperature gradients, also deriving close form expressions for the bit error rate (BER) of such channels. [PERSON] et al. [45] later expanded the investigation by estimating the performance of a 532 nm end-to-end link with real data and [PERSON] et al. [46] further included turbulence induced by air bubbles. Another example is a study on parameter optimization to mitigate link misalignments conducted for LED-based vertical links by [PERSON] et al. [47]. In their analysis, solar noise was neglected with the assumption that placement of the receiver beneath the shadow of the transmitting buoy would negate the solar noise.