Bronnimann, S., G. P. Compo, P. D. Sardeshmukh, R. Jenne, and A. Sterin, 2005: New approaches for extending the twentieth century climate record. EOS Trans. AGU, 86, 2, 6-7.
Studying twentieth century climate is a key to understanding future climate change. Relatively little is still known, however, about climate variability in the first half of the century. Much could be learned from the relatively large climatic variations that occurred during that first half, including the decade-long "Dust Bowl" droughts of the 1930s and the warming of the Arctic from 1920 to 1945.
Poor digital data availability prior to around 1948 has hindered previous work to understand there important climatic variations.
Several projects are now focusing on digitizing earlier manuscript observations to create three-dimensional, gridded meteorological data sets for the first half of the twentieth century. These data sets are likely to provide further insights into processes governing interannual-to-interdecadal large-scale climate variability.