Old Weather - WW2

Detail from The "Campbell's" Epic, paintings by LIFE artist Lieut. Commander Anton Otto Fischer. Life Magazine, Volume 15. No.1: July 5, 1943

Where the data go

Over a decade of service, Old Weather has contributed 14 million new-to-science weather records to the international data rescue effort. These data are then used to improve the models and reanalysis systems used for climate and weather research, such as NOAA's Twentieth Century Reanalysis for example. Over this period, the logbook digitization program motivated by Old Weather has also contributed more than 1.5 million page images to the U.S. National Archives Catalog where they are freely available in the public domain.

Articles in the popular press

Old weather “time machine” opens a treasure trove for researchers: One key to the past is crowd-sourcing data recovery
NOAA Research News, 2019

It’s been the stuff of science fiction for generations: a time machine that would allow researchers to reach back into yesteryear and ask new questions about long-ago events. This month, a NOAA-funded research team published an update to a weather “time machine” they’ve been developing since 2011. This third version of the 20th Century Reanalysis Project, or 20CRv3 for short, is a dauntingly complex, high-resolution, four-dimensional reconstruction of the global climate that estimates what the weather was for every day back to 1836.
https://research.noaa.gov/article/ArtMID/587/ArticleID/2560/Old-weather-time-machine-opens-a-treasure-trove-for-researchers

ICEBOUND: The climate-change secrets of 19th century ship's logs
Reuters, 2019

An eccentric group of citizen-scientists called Old Weather has transcribed millions of observations from long-forgotten logbooks of ships, many from the great era of Arctic exploration. As the polar regions grow ever warmer, the volunteers have amassed a rich repository of climate data in a 21st century rescue mission.
https://www.reuters.com/investigates/special-report/climate-change-ice-shiplogs/

Shipping logs show how quickly Arctic sea ice is melting
The Economist, 2019

CLIMATE CHANGE is affecting all parts of the globe. But no place is feeling the heat quite like the Arctic. Although average global temperatures have risen by about 1°C since pre-industrial times, warming in the Arctic is happening two to three times as fast. The area of ice covering the Arctic ocean is at a record low, according to America’s National Snow and Ice Data Centre. Over the past 30 years, the minimum coverage of summer ice has fallen by half.
https://www.economist.com/graphic-detail/2019/08/13/shipping-logs-show-how-quickly-arctic-sea-ice-is-melting

Deep read: selected science papers

Slivinski, L. et al. Towards a more reliable historical reanalysis: Improvements for version 3 of the Twentieth Century Reanalysis system. Q J R Meteorol Soc., 2019; 145: 2876-2908. https://doi.org/10.1002/qj.3598

Historical reanalyses that span more than a century are needed for a wide range of studies, from understanding large‐scale climate trends to diagnosing the impacts of individual historical extreme weather events. The Twentieth Century Reanalysis (20CR) Project is an effort to fill this need.

Freeman, E. et al. The International Comprehensive Ocean-Atmosphere Data Set – Meeting Users Needs and Future Priorities. Front. Mar. Sci., 2019. https://doi.org/10.3389/fmars.2019.00435

The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is a collection and archive of in situ marine observations, which has been developed over several decades as an international project. ICOADS contains observations from many different observing systems encompassing the evolution of measurement technology since the 18th century.

Schweiger, A. J., K. R. Wood, and J. Zhang. Arctic Sea Ice Volume Variability over 1901–2010: A Model-Based Reconstruction. J. Climate, 2019; 32: 4731–4752, https://doi.org/10.1175/JCLI-D-19-0008.1.

We compare the magnitude and patterns of sea ice variability between the first half of the twentieth century (1901–40) and the more recent period (1980–2010), both marked by sea ice decline in the Arctic. The first period contains the so-called early-twentieth-century warming (ETCW; ~1920–40) during which the Atlantic sector saw a significant decline in sea ice volume, but the Pacific sector did not. The sea ice decline over the 1979–2010 period is pan-Arctic and 6 times larger than the net decline during the 1901–40 period. Sea ice volume trends reconstructed solely from surface temperature anomalies are smaller than PIOMAS-20C, suggesting that mechanisms other than warming, such as changes in ice motion and deformation, played a significant role in determining sea ice volume trends during both periods.