The Polar Encyclopedia

THE ARCTIC OCEAN AND THE OCEAN CURRENTS
GENESIS OF THE ARCTIC OCEAN
ARCTIC PLANKTON
MARINE BIODIVERSITY AND FOOD WEB
WHALES AND OTHER CETACEANS
SEALS AND WALRUSES

TERRESTRIAL LIFE

POLAR FLORA
POLAR FAUNA
THE POLAR BEAR
ARCTIC BIRDS
SPECIES EVOLUTION AND CLIMATE

HISTORY AND GEOGRAPHY

GEOGRAPHY OF THE ARCTIC REGIONS
GEOGRAPHIC NORTH POLE, MAGNETIC NORTH POLE
WHO OWNS THE ARCTIC?
THE EXPLORERS OF THE FAR NORTH
THE INUIT
OTHER PEOPLES OF THE FAR NORTH
THE ARCTIC TODAY

SATELLITES OBSERVE SEA ICE

REMOTE SENSING: THE EARTH SEEN FROM SPACE

Mapping the Earth, detailing road networks and urban areas, forecasting harvests, monitoring volcanoes, forests, oceans, or ice, observing clouds: artificial satellites have revolutionized our perception of the planet. They perform measurements and observations remotely, without physical contact with the studied surface: this is what is known as remote sensing.

IMAGES, EVEN AT NIGHT

Remote sensing satellites travel a few hundred kilometers above our heads, making about fifteen orbits around the world per day. They regularly and precisely observe each region. Some simply capture natural light reflected by the ground or atmosphere. Others send their own radar waves towards the ground, recording the echoes; this system allows them to ‘see’ even at night and through clouds.

GROUND VALIDATION OF SATELLITE IMAGE INTERPRETATION

The information received on Earth is analyzed, processed, and presented as ‘false-color’ images. Each type of surface (rock, water, field, etc.) reflects a series of waves that characterize it: this is its ‘spectral signature,’ translated by a color. To be sure of what is seen or measured, the images must be calibrated, meaning the interpretations of satellite images must be verified on the ground. For this, observations like those of Jean-Louis Etienne on the sea ice are essential.

WHEN QUIKSCAT MONITORS THE SEA ICE

The Arctic Ocean, vast and inhospitable, cannot be easily studied from the surface; it is an ideal domain for remote sensing. The American satellite QuikSCAT is equipped with a radar system capable of measuring, based on the surface appearance, the speed and direction of winds over the ocean and the movements of the sea ice. The maps produced help to understand the evolution of ice and its potential response to climate variations.

CRYOSAT FOR MEASURING SEA ICE THICKNESS

Satellites have made it possible to monitor the regression of the ice surface over the last ten years. The Cryosat satellite will allow for the measurement of its thickness, an important factor for monitoring its evolution and its consequences for global warming.

The Polar Encyclopedia

CONTENTS

ALONE ON THE ICE PACK

ATMOSPHERE AND WEATHER

ARCTIC ICE

OCEAN AND MARINE LIFE