GlobColour: a ten-year time series of global ocean colour products
Samantha
Lavender, University of Plymouth / ARGANS Limited, s.lavender@plymouth.ac.uk
(Presenting)
Odile
Fanton d'Andon, ACRI-ST, oha@acri-st.fr
Antoine
Mangin, ACRI-ST, am@acri.fr
Simon
Pinnock, ESA, simon.pinnock@esa.int
The GlobColour project (www.globcolour.info) is funded by the ESA Data User Element Programme to develop a satellite based ocean colour data service to support global carbon-cycle research and operational oceanography; key users within the project are the IOCCP, IOCCG and UKMO. It aims to satisfy the scientific requirement for a long (10+ year) time-series of global ocean colour information by merging together observations made with different satellite systems (ESA MERIS, NASA MODIS and GeoEye/NASA SeaWiFS). Prior to the delivery, characterisation and validation activities provided a deep understanding of the different input data streams, and led to the prototyping of three different merging methods: simple averaging, error-weighted averaging and an advanced retrieval based on fitting an in-water bio-optical model to the merged set of observed normalised water-leaving radiances (nLw’s) termed GSM because it originates from the Garver et al. (1997) bio-optical model (Maritorena & Siegel, 2005). This third technique is also being utilised by the NASA Ocean Color Time-Series Project, and a comparison has been made between the different merged time series datasets. Error statistics from the initial sensor characterisation are used as an input to both the weighted averaging and GSM merging methods, and propagate through the merging process to provide error estimates on the output merged products. The service is distributing global data sets of chlorophyll-a concentration, normalised water-leaving radiances, diffuse attenuation coefficient, coloured dissolved and detrital organic materials, total suspended matter or particulate backscattering coefficient, turbidity index, cloud fraction and quality indicators. In the future, this will feed into the Marine Core Services and utilise Sentinel-3.
NASA Carbon Cycle & Ecosystems Active Awards Represented by this Poster: