Remotely sensed data are increasingly becoming an essential resource in applications to improve the quality of life and safety of citizens, for risk assessment, environmental monitoring, surveillance, scientific discovery, as well as economic exploitation. WaterColours is a project that exploits the use of remotely sensed multispectral imagery for the estimation of ocean colour parameters in the Malta Channel (the stretch of sea that divides our archipelago from Sicily) with a focus on the sea around the Maltese Islands. The primary aim is to generate (or paint), high resolution (with a very fine brush), maps that show the quality of the water (as different colours) in this marine domain.
The first phase of the project that is nearing completion, focused on the computation of climatologies and statistical trends for surface Chlorophyll-a (Chl-a) concentrations and Total Suspended Matter (TSM). Apart from identifying the baseline variability of the biogeochemical properties of our sea, the results will provide very important markers of eutrophication as well as suspended sediment loading or starvation areas. This was possible through the processing of ten years of data captured between 2002 and 2012 by the MEdium Resolution Imaging Spectrometer (MERIS) sensor, on-board the polar-orbiting Envisat-1 research satellite by the European Space Agency (ESA). While the raw data products are contaminated by gaps due to cloud coverage and biases caused by turbulences in the atmosphere, the merging of the long time-series allowed the generation of high-quality climatologies that show how Chl-a and TSM vary on a daily, weekly, and monthly basis.
The second phase of the project will focus on the operational computation of ocean colour products at an unprecedented quality and resolution. Frequent data captured over Malta by the SENTINEL 3A and 3B satellites, that were recently launched by ESA in February 2016 and April 2018 respectively, will be used. Although estimates for Chl-a and TSM are being generated for coastal management and research purposes, WaterColours will help to significantly improve the quality of these products, and will make them more relevant to the Water Framework Directive (WFD) as well as the Marine Strategy Framework Directive (MSFD). In the coming months, dedicated field surveys with transects between Malta, Pozzallo, and Lampedusa will be organised for the collection of in-situ measurements that will help to calibrate and fine-tune regional algorithms. For this activity, the team from the Physical Oceanography Research Group of the University of Malta will be working with experts from the Institute of Marine Sciences within the Italian National Research Council (CNR-ISMAR) to collect information about the bio-optical properties of the surrounding waters, that will help to improve and fine-tune the satellite-derived water quality maps.
All data generated in the project will be uploaded to an online portal that will render the near real-time publishing and visualisation of targeted products, fitting for uptake by users, and more specifically by the local environmental agency. The user interface will be enhanced by an intelligent backend system that will embed Machine Learning methods for the detection of isolated phenomena such as turbidity plumes after heavy rainfall, and algal blooms.
WaterColours was approved for funding by the Malta Council for Science & Technology, for and on behalf of the Foundation for Science and Technology, through the Space Research Fund. The project is coordinated by Dr Adam Gauci and Prof. Aldo Drago from the Physical Oceanography Research Group within the Department of Geosciences of the University of Malta. Apart from further utilising and exploiting the COPERNICUS marine platform to produce tailor made services at the coastal scale, this initiative is helping to strengthen the local capacity in the exploitation of satellite data, and is paving the way for a stronger presence of Malta in the European space sector.
More information on the project can be obtained online.