Photosynthetic Active Radiation (PAR) was measured using single planar and two-bulb spherical light sensors. The attenuation coefficient (Kd ) was found to vary significantly during the year. The highest Kd values were obtained in the station with higher influence of currents and run-off. Our data suggested a reflection of 50% of light that reaches the bottom, which is associated with a decrease in the Kd value obtained with the spherical sensor of 0.15 m-1 . This means that flat sensors may underestimate PAR and that spherical sensor may underestimate Kd . This is a critical issue given that knowledge on light attenuation is essential for modeling approaches and quality assessments.
Brito, A. C., & Newton, A. (2013). Measuring Light Attenuation in Shallow Coastal Systems. Journal of Ecosystem & Ecography, 03(01). https://doi.org/10.4172/2157-7625.1000122