Want to be part of an innovative citizen science project to better understand past – and future – weather patterns? Check out oldweather.org, a program inspired by the need to better understand what winds and waves swirled around our planet 150+ years ago. A citizen scientist program now in its sixth year, Old Weather asks volunteers to transcribe weather data from 19th century ship logs. The latest project in Old Weather, whaling.oldweather.org, allows you to join a whaling vessel and recover crucial climate data about the Arctic, its weather and sea ice. These data sets are then used to better inform scientific analysis of Earth’s climate and climate change.

One of the researchers helping lead the Old Weather program is Gil Compo, a CIRES climate scientist at ESRL's Physical Sciences Laboratory who also leads the 20th Century Reanalysis Project (20CR). The 20CR uses supercomputers to reconstruct the weather from the surface of Earth up to the level of the jet stream as far back as the Old Weather data can go.

Reanalysis is a scientific method for developing a comprehensive record of how weather and climate are changing over time. Observations and computer models that simulate one or more aspects of the Earth system are combined to generate an estimate of the state of the climate system. Reanalysis products are used extensively in climate research and services, including for monitoring and comparing current climate conditions with those of the past, identifying the causes of climate variations and change, and preparing climate predictions.

The 20CR originally incorporated decades of station and ship data from established archives and from old hand-drawn weather maps, which had been digitized. Now, the transcribed data from the Old Weather project is extending the reach of that dataset back even further.

“By improving our knowledge of past weather and climate, we can better understand the future,” says Compo.

Posted: December 4, 2015