Marine ecosystems are open and dissipative systems that rely on an external energy source – light – for their sustenance. The magnitude of the light flux and the spectral quality of the light field (which determines colour) determine the rate of marine photosynthesis by phytoplankton in the ocean, and the types of phytoplankton communities that flourish in different parts of the ocean and in different seasons. Ocean colour – determined by the spectral quality of light scattered out of the sea and back into the atmosphere – can be monitored using satellite sensors, and used to map the distribution of the major phytoplankton pigment, chlorophyll-a, at global scales. Remote sensing of ocean colour, first realised in 1977, has revolutionised the field of biological oceanography. Over the years, the quality of satellite products has continued to improve, and the range of products available has extended beyond chlorophyll concentration to encompass many variables of interest to biological oceanography and ocean biogeochemistry. However, it is well recognized that satellite observations have to be integrated with, and complemented by, field measurements and modelling, to obtain the full picture. The research topic proposed will cover a range of recent developments in ocean colour remote sensing and allied fields.

CLEO publications in Frontiers in Marine Science Foreword Josef Aschbacher, Director of ESA’s Earth Observation Programmes Satellite data have drastically changed the view we have of the oceans. Covering about 70% of Earth’s surface, oceans play a unique role for our planet and for our life – but large areas remain unexplored and are difficult to reach. Since the 1980s, Earth-orbiting satellites have helped to observe what is happening at the ocean surface. Sensors like CZCS, AVHRR, SeaWifs and MODIS provided the first ocean colour data from space. Starting in 2002, ESA's Medium Resolution Imaging Spectrometer (MERIS) on-board the environmental satellite Envisat, provided detailed information on phytoplankton biomass and concentrations of other matter in the global oceans. These satellite observations laid the groundwork for studying the marine environment and how it responds to climate change, and the research community has since delivered information on the variability of marine ecosystems. Part of this work is reflected in this stunning collection of peer-reviewed publications presented at the workshop, Colour and Light in the Ocean from Earth Observation (CLEO), held at ESA’s ESRIN site in Frascati, Italy, on 6–8 September 2016. The event attracted more than 160 participants from all over the world, including remote sensing experts, marine ecosystem modelers, in-situ observers and users of Earth observation data. Scientifically, the meeting covered applications in climate studies over primary productivity and ocean dynamics, to pools of carbon and phytoplankton diversity at global and regional scales. It also demonstrated the potential of Earth observation and its contribution to modern oceanography. Looking to the future, new satellites developed by ESA under the coordination of the European Commission will further our scientific and operational observations of the seas. With Sentinel-3A in orbit and its twin Sentinel-3B following in 2017, there is a new category of data available for operational oceanographic applications and climate studies for years to come. These data are free and easy to access by anyone interested. Looking at the role of oceans in our daily lives, I am sure that this collection of scientific excellence will be valued by scientists of today and will inspire the next generation to carry these ideas into the future.

Oceanography is a component of Encyclopedia of Earth and Atmospheric Sciences in the global Encyclopedia of Life Support Systems (EOLSS), which is an integrated compendium of twenty one Encyclopedias. These volumes deal with the oceans as an integrated dynamic system, characterized by a delicate, complex system of interactions among the biota, the ocean boundaries with the solid earth and the atmosphere. This set of volumes is designed to be a very authoritative reference for state-of-the-art knowledge on the various aspects such as: Physical Oceanography, Chemistry of the oceans, Biological Oceanography, Geological oceanography, Coral Reefs as a Life Supporting System, Human Uses of the Oceans, Ocean Engineering, and Modeling the Ocean System from a Sustainable Development perspective. These volumes are aimed at the following five major target audiences: University and College students Educators, Professional practitioners, Research personnel and Policy analysts, managers, and decision makers and NGOs.

First published in 1851, this two-volume work is a comprehensive nautical directory of the coastlines and islands of the Pacific.