‘Weather detectives’ saving historical records
More than 50 “weather detectives” from 20 countries will be in Auckland next week to share their experiences saving snippets of meteorological history that will ultimately help scientists better understand the processes of climate variability and change.
This international group, known as ACRE or Atmospheric Circulation Reconstructions over the Earth, is dedicated to discovering weather observations recorded in diaries, aboard ships and voyages of exploration. Their aim is to detect patterns and changes that enrich our history, and may help reveal more about the planet’s future climate.
NIWA climate scientist and co-organiser of next week’s conference, Dr Andrew Lorrey says while there plenty of excellent weather records going back to 1950, before that information is more sparse and still spread in various archives and libraries around the world.
“Our effort takes weather observations from different places around the globe and pushes them into a supercomputer reconstruction of our weather. It’s designed to give us a better depiction of historic weather on a daily basis.”
Dr Lorrey says there are a lot of questions about the links between short term weather variability and long term climate change, and testing those links requires a larger amount of data going back much further than 50 to 60 years.
“If we had 150 years of weather data we could be more confident about our interpretations for the future.”
Last year Dr Lorrey and conference co-organiser NIWA climate scientist Petra Pearce published a paper about the diaries of Reverend Richard Davis, an English missionary stationed in the Far North of New Zealand in the 1800s. Davis made regular weather observations that offer insights into early colonial era meteorology and climate variability and his data has been used as part of the historic weather project.
Delegates to next week’s conference will visit Auckland Library to see the Davis diaries before heading to Albert Park to see New Zealand’s oldest official weather station and rain gauge.
NIWA leads two segments of the Acre work – one for the Pacific and one for Antarctica, the latter of which is funded by the Deep South National Science Challenge.
The scientists work with historians and librarians familiar with the structure of archives to seek out the historic weather data.
For the Antarctic work, research has focused on sealing and whaling missions. Information from ship logs which tracked conditions for these activities can now be used to reconstruct past weather.
A huge part of the effort involves digitising old records and there are several programmes under way around the world to do this work. NIWA retains old records for New Zealand in a climate-controlled room but Dr Lorrey says there is more work needed to improve custodianship of this old data.
Ms Pearce says there is an enormous amount of data to mine.
“So far just for the Antarctic part of the project, we have about 150,000 images of ship logs sent to us from archives in the UK and Scandanavia. Each image has several days’ observations and each day has multiple observations so we will have millions of observations to key over the course of the project.”
Next week’s conference also includes a workshop for delegates from developing countries to learn more about the rescue process.
Dr Lorrey says the project is very much about saving history and bringing inanimate data to life.
“When you take one data point and put it on a map, it doesn’t mean much. But when you put 1000 points on a map and you do it for days on end, you can make an animation and bring the weather to life.
“There are some really interesting events we can look at in the past by combining data points from New Zealand, Australia and the Southern Ocean to look at why particular weather patterns arise and if there are similar patterns today.”