NZ combing archives for old weather records

The project is expected to help improve forecasts of how weather is changing. Photo / Brett Phibbs

Ever wondered what the weather was like the day your grandmother was born, or the day New Zealand won the Rugby World Cup?

New Zealand scientists are digging out weather reports from the archives for a global project that promises to be able to tell you.

Scientists from around the world met in Queensland last week to discuss the first stage of an international project to reconstruct more than 200 years of world weather.

The Acre (Atmospheric Circulation Reconstructions over the Earth) project aims to have weather records from every day from 1891 to the present available on the internet within six months.

Apart from satisfying people's curiosity about the weather on important days, the project is expected to improve forecasts of how weather might change in response to global warming.

It could also help determine whether storms are already changing because of rising greenhouse gas levels.

National Institute of Water and Atmospheric Research (Niwa) climate scientist Dr Andrew Lorrey is helping rescue and digitise South Pacific weather records, including ships' logs, lighthouse-keepers' records and harbour-masters' notes.

He said the results would allow scientists to improve the models used by the United Nations Intergovernmental Panel on Climate Change (IPCC) to predict future climate changes.

IPCC models are tested by running them over historical weather records.

The Acre project is expected to improve them by allowing them to be tested over a longer period of time.

Dr Lorrey said the effort could help relieve suffering for millions of Pacific Islanders vulnerable to extremes in climate and weather variability.

Niwa's involvement would contribute to understanding the causes of Pacific rainfall patterns - helping island-dwellers plan where to build roads, towns and farms in a future expected to be significantly affected by climate change.

Dr Lorrey said scientists had a relatively poor understanding of South Pacific weather before the establishment of modern instrument networks.

By drawing on an array of paper archives, they would be able to improve their knowledge by seeing how weather had operated over a long period of time, he said.

Organisers are collaborating with Google to make historical weather records available on the internet.

Records from when modern instrumental recordings overlapped with older records would be used to check the accuracy of the older records.