Reporter 432, 1 March 1999


And now the weather: cold with unoccasional patches of ice and snow

Next time you're caught in the rain without a brolly, blame the Arctic. Each crumbling iceberg and crack in the ice helps determine the rainfall, cloud cover and temperature across the whole of Western Europe. Four groups of University researchers will brave the hostile Arctic conditions to bring home the ultimate long-range weather forecast.

Uncertainty about future changes in the global climate is pushing the scientific search for clues into the frozen north. Armed with satellite imaging, box-kites and the British Antarctic Survey's ice-breaking ship, researchers from geography, earth sciences, chemistry and the environment centre will study the region. The projects have received over £500,000 funding under the Natural Environment Research Council's ARCICE initiative.

Global sea levels have risen 10-15cm in the last 100 years and there is enough frozen water in the Arctic to force them up by another 8m, submerging much of the UK. As the mighty Arctic glaciers move and melt they also expose to the air chemicals in the soil, previously covered for thousands of years. Chemical reactions between the newly exposed sediment and air alter the levels of carbon dioxide in the atmosphere and sealed-off seawater is similarly exposed by breaks in the ice.

Predictions for future climate change can also be helped by frozen sediment and ice samples from the region, which offer an accurate record of abrupt weather changes over the last 10,000 years. Until recently, however, the region's remoteness and size has made its climatic impact difficult to investigate.

Chemists Ally Lewis, Jim Hopkins and Jim McQuaid will take advantage of the ice-breaking ship James Clark Ross to study gases released by the Arctic ocean. A specially-adapted instrument on the ship will analyse the levels of organic compounds that react with sunlight to form ozone. "Ozone high in the atmosphere is a vital barrier to radiation but at ground level is a real problem," said Mr McQuaid. "It is bad for the health of people and plants, and can degrade rubber and paints." The reactions also lead to the formation of clouds, which can affect the climate by reflecting incoming sunlight.

As the earth warms, the glaciers melt and sea levels rise. To help predict which coastal regions should be investing in extra sandbags, geographer Tavi Murray is studying the rate this is happening. Using satellite images, historical records and geological mapping she will build up a picture of how glaciers in the Svalbard region have moved and shrunk over hundreds of years. "Svalbard ice has been estimated to contribute more to the rise of sea levels than any other Arctic region outside Greenland," said Dr Murray.

The region is particularly sensitive to changes as it is bathed by relatively warm water from the North Atlantic drift current, which helps the ice to melt.

Earth scientists Simon Bottrell and Rob Raiswell will also visit the Svalbard region to study the waterlogged sediment and soil exposed by the melting glaciers.

"The exchange of carbon dioxide between the air and ocean can be changed in glacial environments, causing the levels of this greenhouse gas in the atmosphere to rise significantly.

"For example, the largest and most rapid increases in atmospheric carbon dioxide occurred at the end of the most recent ice age, when all the ice melted," said Professor Raiswell.

In the fourth project Ian Jones and Stephen Mobbs of the Environment Centre will also sail on the ice-breaking ship to study the exchange of heat, moisture and radiation between the air and sea. Using instruments hung from tethered balloons and kites, they will obtain data to develop a computer model of the complex system. "The traditional method of making these kind of measurements is with weather balloons but they rise through the air very quickly, and also cost about £100 each," said Dr Jones. The data the kite-flying researchers gather will be used to refine the large-scale systems used by the Met office to predict changes in the weather.

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