• Lighter-than-air ships  
  • How man copes with the cold  
  • Organisation of the measurement flights  
  • Flying conditions and risks during the expedition  
  • The measurement campaign  
  • Communications - Safety - Emergency assistance  
  • Earth observation satellites  
  • Our airship  
  • The earth's atmosphere  
  • Weather forecasting and modeling  
  • The climate and the north pole  
  • The solar energy balance  
  • The greenhouse effect  
  • The ice pack: frozen saltwater  
  • Icebergs : frozen seawater  
  • The arctic ice: climate archives  
  • Ice ages and landscapes  
  • The Arctic Ocean and the ocean currents  
  • Genesis of the arctic ocean  
  • Arctic plankton  
  • Oceanic biodiversity and the food chain  
  • Whales and other cetaceans  
  • Seals and walruses  
  • Arctic flora  
  • Arctic fauna  
  • Polar bears  
  • Birds of the arctic  
  • Evolution of species and climate  
  • Geography of the Arctic regions  
  • Geographic North Pole and magnetic North Pole  
  • Who owns the arctic?  
  • Exploring the deep north  
  • The Inuit people  
  • The other peoples of the deep North  
  • The Arctic today  
  • Man and arctic biodiversity  
  • Pollution in the arctic  
  • Climate warming: the natural cycles  
  • The increase in the greenhouse effect  
  • The impact of global warming  
 

Arctic ice
The arctic ice: climate archives
 

Fossilised air in the Polar ice caps
Over the years, continental ice caps form when snow accumulates and is packed down and transformed into ice by subsequent snowfalls. This ice contains bubbles of air as well as all sorts of airborne particles and pollen. Once this air is imprisoned in the ice, it conserves its original composition, so study of the air bubbles and their particles can yield invaluable information about the Earth’s climate in the past.

Ice cores: veritable time-travel machines
Scientists frequently take core samples of the polar ice. The further the core goes down, the older the ice sample, so by analysing older and older ice the scientists travel back in time, gradually writing the history of the Earth’s climate. A lot of data has been gathered by studying the Greenland ice cap, while the “climate archives” in the Antarctic have also yielded invaluable information.

The Greenland ice cap
In the thickest part of the Greenland ice cap, glaciologists have extracted and studied core samples from as deep as 3,050 metres before they struck the underlying rock. The cores contain ice that fell as snow over the past 2,500 centuries! And of course evidence of various climate fluctuations: droughts, climatic catastrophes, periods of global warming, ice ages, etc.

Our pollution is sealed up in the ice too
The bubbles of air trapped in the polar ice show that the amount of methane and CO2 in the atmosphere has increased markedly over the past two centuries, i.e. since the beginning of the industrial era. The more recent ice in Greenland also contains much more pollution than ice from the Antarctic, because of the proximity of human activity in the Northern Hemisphere.