19th century chart of ocean currents
Chart of ocean currents. The direction of the currents is marked by arrows.There are 17 major surface ocean currents. They circulate water around the world affecting the movement of energy and moisture between the oceans and the atmosphere thus affecting the world's weather. For example the Gulf Stream which originates in the Gulf of Mexico is a warm current making Western Europe warmer than other areas at the same latitiude. The Humboldt current is a cold low-salinity current flowing north-westwards from the southern tip of Chile to northern Peru. It has a cooling influence on Chile, Peru and Ecuador and is a major cause of the desert conditions in northern Chile and is the most productive marine ecosystem in the world providing about a fifth of the world's fish supply. Changes in temperature of the Earth's surface affect ocean currents and their impact.
© Copyright Sheila Terry
Europe, night-day satellite image
Europe, night-day satellite image. This composite image of the Earth is set against a background of stars, and is centred on Europe. North is at top. The left-hand half of the globe is at night, and city lights (yellow) show areas of dense population. The right-hand half of the globe is lit by sunlight and shows clouds (white), seas and oceans (blue), and land cover: vegetation (green) and arid areas (brown). This day-night line is the dawn terminator. This image, from 2001, combines data from a variety of satellite sensors (AVHRR, SeaWiFS, MODIS) for the sunlit areas. Night-time data is from the Defense Meteorological Satellite Program (DMSP). For the separate images, see E074/083 and E050/681.
© NASA/NOAA/SCIENCE PHOTO LIBRARY
Environmental fuel choices, artwork
Environmental fuel choices. Conceptual artwork of a car driver faced with a moral dilemma over his choice of fuel, represented by the devil and angel figures. The devil figure also represents the impact aeroplanes (red) have on the environment, with the aviation industry accounting for a large proportion of greenhouse gases. The angel figure is in a tanker (green) that has sails, representing the use of this technology to reduce fossil fuel use by the world's shipping.
© GLYN GOODWIN/SCIENCE PHOTO LIBRARY