A compilation of global bio-optical in situ data for ocean-colour satellite applications

André Valente,Carlos García-Soto,David Mckee,Michael Twardowski,David Antoine,Mati Kahru,Susanne Kratzer,Tiffany Moisan,Giuseppe Zibordi,Ray Barlow,Holger Klein,Michael Grant,Kathryn Barker,Vanda Brotas,Michael Ondrusek,Alex J Poulton,Robert Arnone,Shubha Sathyendranath,Malcolm Taberner,Stuart W Gibb,Robert Frouin,Richard Crout,Şükrü Beşiktepe,Jeremy Werdell,William M Balch,Hervé Claustre,Jean-François Berthon,Elisabetta Canuti,Simon Bélanger,Hubert Loisel,Heidi M Sosik,Kenneth J Voss ,Stanford B Hooker ,Michel Répécaud ,Vittorio E Brando ,B Greg Mitchell ,Leonie O’dowd ,Francisco P Chávez ,Tim Smyth ,Marcel Robert Wernand ,Richard W Gould ,Steven Groom ,Frank E Müller-Karger

doi:10.5194/essd-8-235-2016

Abstract

Abstract. A compiled set of in situ data is important to evaluate the quality of ocean-colour satellite-data records. Here we describe the data compiled for the validation of the ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT, GeP&amp;CO), span between 1997 and 2012, and have a global distribution. Observations of the following variables were compiled: spectral remote-sensing reflectances, concentrations of chlorophyll a, spectral inherent optical properties and spectral diffuse attenuation coefficients. The data were from multi-project archives acquired via the open internet services or from individual projects, acquired directly from data providers. Methodologies were implemented for homogenisation, quality control and merging of all data. No changes were made to the original data, other than averaging of observations that were close in time and space, elimination of some points after quality control and conversion to a standard format. The final result is a merged table designed for validation of satellite-derived ocean-colour products and available in text format. Metadata of each in situ measurement (original source, cruise or experiment, principal investigator) were preserved throughout the work and made available in the final table. Using all the data in a validation exercise increases the number of matchups and enhances the representativeness of different marine regimes. By making available the metadata, it is also possible to analyse each set of data separately. The compiled data are available at doi:10.1594/PANGAEA.854832 (Valente et al., 2015).

Highlights

There are several bio-optical in situ datasets worldwide suitable for validation of ocean-colour satellite data
The Marine Optical Buoy (MOBY) is a fixed mooring system operated by the National Oceanic and Atmospheric Administration (NOAA) that provides a continuous time series of water-leaving radiance and surface irradiance in the visible region of the spectra from 1997 onwards
No band shifting was performed and no minimum number of wavelengths per observation was imposed

Summary

Introduction

There are several bio-optical in situ datasets worldwide suitable for validation of ocean-colour satellite data. The use of only one of these datasets would limit the number of data in validation exercises. The compiled dataset would be made available as a simple text table, to facilitate ease of access and manipulation. In this work such unification of multiple datasets is presented. Tually have been modified by the processing routines used by the repositories or archives To minimise these potential drawbacks, we have, for the most part, incorporated only datasets that have emerged from the long-term efforts of the ocean-colour and biological oceanographic communities to provide scientists with high-quality in situ data and implemented additional quality checks on the data to enhance confidence in the quality of the merged product.

Preprocessing and merging

Preprocessing of each set of data

Results

Conclusions