Prior to CDMP, very little at-hour digital weather observational data for the period prior to 1948 were available either in the archives or online. Through CDMP's SAO keying project, which began in 2001 and is still ongoing, data from about 200 stations have been keyed. More than 40 million at-hour weather observations, all of which have undergone rigorous quality control at the Northeast Regional Climate Center and at NCDC, have been added to NCDC's digital database holdings through this project.
Many of these new data come from the earliest airport observations, which began at some stations as early as 1928. Most of these airport stations made observations 24 hours per day. CDMP's contractor partners key these observations through the previously available data record (typically through June 1948). Prior to these so-called “Airways” obs, many U.S. Weather Bureau city office locations took observations. These sites typically made two to four observations per day, beginning as early as 1893. These obs have also been keyed and placed online through CDMP for about 150 city office locations, which have typically been selected to match the towns where airport data were also collected.
Thus, CDMP has helped make a continuous period of record of over 100 years of at-hour observations available for some 150 U.S. locations. What's more, the SAO keying project is still underway; more than 100 additional sites have been selected and are in the process of being keyed under this multi-year task as funding permits. NCDC will add these additional observations to the database as they are completed.
These newly available data will certainly be an invaluable resource for climate research and numerous other scientific endeavors.
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