title: Estimating the Underwater Diffuse Attenuation Coefficient with a Low-Cost Instrument: The KdUINO DIY Buoy.
abstract: A critical parameter to assess the environmental status of water bodies is the transparency of the water, as it is strongly affected by different water quality related components (such as the presence of phytoplankton, organic matter and sediment concentrations). One parameter to assess the water transparency is the diffuse attenuation coefficient. However, the number of subsurface irradiance measurements obtained with conventional instrumentation is relatively low, due to instrument costs and the logistic requirements to provide regular and autonomous observations. In recent years, the citizen science concept has increased the number of environmental observations, both in time and space. The recent technological advances in embedded systems and sensors also enable volunteers (citizens) to create their own devices (known as Do-It-Yourself or DIY technologies). In this paper, a DIY instrument to measure irradiance at different depths and automatically calculate the diffuse attenuation Kd coefficient is presented. The instrument, named KdUINO, is based on an encapsulated low-cost photonic sensor and Arduino (an open-hardware platform for the data acquisition). The whole instrument has been successfully operated and the data validated comparing the KdUINO measurements with the commercial instruments. Workshops have been organized with high school students to validate its feasibility.
authors.affiliation: Department of Physical and Technological Oceanography, Marine Sciences Institute (ICM-CSIC), 37-49 Passeig Marítim de la Barceloneta, Barcelona E-08003, Spain. bardaji@icm.csic.es.
authors.forename: Raul
authors.initials: R
authors.lastname: Bardaji
authors.affiliation: Department of Physical and Technological Oceanography, Marine Sciences Institute (ICM-CSIC), 37-49 Passeig Marítim de la Barceloneta, Barcelona E-08003, Spain. amsanchez@icm.csic.es.
authors.forename: Albert-Miquel
authors.initials: AM
authors.lastname: Sánchez
authors.affiliation: Department of Physical and Technological Oceanography, Marine Sciences Institute (ICM-CSIC), 37-49 Passeig Marítim de la Barceloneta, Barcelona E-08003, Spain. carine.simon@csic.es.
authors.forename: Carine
authors.initials: C
authors.lastname: Simon
authors.affiliation: Department of Physical Oceanography, Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59. 1790AB Den Burg, Texel, The Netherlands. marcel.wernand@nioz.nl.
authors.forename: Marcel R
authors.initials: MR
authors.lastname: Wernand
authors.affiliation: Department of Physical and Technological Oceanography, Marine Sciences Institute (ICM-CSIC), 37-49 Passeig Marítim de la Barceloneta, Barcelona E-08003, Spain. jpiera@icm.csci.es.
authors.forename: Jaume
authors.initials: J
authors.lastname: Piera
keywords: Arduino; KdUINO; buoy; citizen science; diffuse attenuation coefficient; do-it-yourself; light; low-cost sensor; oceanography