Approximation of diffuse attenuation, K_d, for MODIS high-resolution bands

ABSTRACT

A high resolution depth attenuation product (K_d^hires) was developed using MODIS 500 m and 250 m spectral bands. The K_d^hires was compared with Wang’s operational K_d for the Chesapeake Bay. Minimal differences were observed between the two methods, with greatest deviation occurring in areas of high turbidity in the tributaries. After tuning the new K_d^hires, the mean absolute error and bias between the two algorithms was 0.22 m⁻¹ and 0.026 m⁻¹, indicating good agreement. Higher spatial resolution provides for improved retrievals along the coast and into the narrow sections of the tributaries, coinciding with areas of concern to estuarine health and coastal management applications.

KEYWORDS:

• Depth attenuation
• MODIS
• water clarity

Acknowledgments

Assistance was provided by Gretchen Imahori, with partial support by the National Geodetic Survey Remote Sensing Division and NOAA’s United Kingdom Hydrographic Office program. Special thanks to Andrew Meredith for assistance in creating the figures and processing the K_d imagery.

Additional information

Funding

This work was supported by the National Geodetic Survey Remote Sensing Division; NOAA’s United Kingdom Hydrographic Office program MOA 2013—019/8650G.