Don's diary: An arctic voyage to study hot current events

Monday

Meet scientists, artists and film-makers who will share this trip to highlight the effects of ocean currents on us and our climate. We will sail on a 100-year-old schooner around Spitsbergen, an island in the Svalbard archipelago, north of Norway. I know just two of the 24 Cape Farewell project members before leaving, but after sailing across the aptly named Devil's Dancefloor from Troms?, Norway, to Bear Island, I know them inside and out... literally.

Wednesday

My job is to measure the temperature of the sea to determine where the cold, fresh Arctic water meets the warm, salty Atlantic water driven northwards by the Gulf Stream. The task is mainly demonstrative, but we should get an educational docu-film or two out of it.

Two humpback whales alert us to an upwelling zone, where water is forced up by the continental shelf, bringing nutrients to the surface.

This encourages phytoplankton growth, and fuels a rise in zooplankton, which attracts whales, fish and seabirds. It's a great place for a plankton trawl to study the diversity of life. It's also a good location for measuring light (essential for plant growth) in the water column. The sea ice around Bear Island makes it impossible to anchor, but a polar bear swims out to visit. I'm glad he stays in the water though.

Saturday

Drop anchor near a Polish research station in Hornsund, the southern-most fjord. The station monitors the weather and ionosphere (a high layer of the atmosphere that plays host to the northern lights). I fall asleep to the calls of bearded seals.

Sunday

The next fjord up, Bellsund, has a long history of whaling. Many seabirds nest here, particularly kittiwakes and little auks (the northern hemisphere's equivalent of the penguin, except they can flyI just about).

Set off for an after-dinner stroll. After 4km we reach our target - a beach covered in Beluga whalebones - but it is buried deep in snow. Head back disheartened.

Tuesday

Stop at Longyearbyen, the administrative centre of Spitsbergen.

A few hours' shopping, then we head back out to sea.

Thursday

Ny Alesund, 79xN, is a collection of scientific bases from numerous countries. We spend the day with Norwegian scientists who monitor glacial and ionosphere changes. Then head south, visiting walruses along the way.

Saturday

We find the Gulf Stream between Spitsbergen and Greenland. Here it cools, sinks and heads south. We carry out a transect from within the Gulf Stream current to the entrance of Isfjorden, the largest fjord on the west coast of Spitsbergen. We sample at four locations, but the current is farther west than anticipated, which means we start in the transition zone rather than Atlantic water as planned.

Sunday

After covering 1,890km in the most exciting and environmentally friendly way practicable, it's time to head home to educate people about the causes of climate change. Our data aren't groundbreaking, but they help to show non-scientists that climate change is a hot topic and is constantly monitored. It is a natural occurrence, but one that we have recently exacerbated.

Sarah Fletcher is a research assistant at the Southampton Oceanography Centre, University of Southampton. www.capefarewell.com