Convict ship logs give insights into climate science

Weather data salvaged from the diaries of a Northland missionary and Australian first-fleet ships' logs is being used by scientists in an international effort to improve understanding of climate science.

The historical records are the focus of climate scientists from around the world who are meeting in New Zealand this month as part of a global effort to recover lost weather data.

National Institute of Water and Atmospheric Research climate scientist Andrew Lorrey said the diaries of missionary the Rev Richard Davis were playing an important role.

The self-taught missionary travelled to New Zealand in 1823 via Australia, on a ship of "murderous women convicts".

After arriving in Northland, Mr Davis kept a detailed record of the weather in his diaries, Dr Lorrey said.

"They were amazing weather diaries with two times daily recordings, with atmospheric pressure, comments, and more than 13,000 observations."

Dr Lorrey said the records were being compared with weather data recorded at Kaikohe from 1985 to 2004.

Also involved in the project is Melbourne University climate scientist Joelle Gergis, who said comparing the historic data with modern records would help scientists get a better understanding of how unusual recent weather events had been.

Dr Gergis was using ships' logs from the Australian first-fleet voyages and, after digitising the records, was putting the data into Google Earth to show the conditions those on board endured.

Digitising historic weather information would help scientists understand climate variability and climate change on local and international scales, she said.

"We hope this will help people understand natural climate variability and distinguish this from human-caused climate change."

Rob Allan, who is based at the British Met Office, is leading the international Atmospheric Reconstructions over the Earth initiative, which the historic data would feed into.

The group helped scientists around the world recover and digitise historic weather data so the records could be reconstructed for the public to access online.

Once in a digital format, historic written records and observations of weather events could be reconstructed in online animations, Dr Allan said.

The Dominion Post