A Serially Complete Simulated Observation Time Metadata File for U.S. Daily Historical Climatology Network Stations
Abstract A procedure to infer time of observation based on day—to—day temperature variations is refined and applied to the 1060—station daily Historical Climatology Network (HCN), creating a set of ersatz observation time metadata. Testing of the observation time inference procedure on the HCN data, as well as a set of U.S. normals stations at which no reported observation time changes occur from 1951 to 1991, indicates that, on average, the correct observation time category is identified in nearly 90% of the station years. Classification success decreases, however, at stations at which average annual interdiurnal temperature range falls below 1.9°C. At these stations, which represent only 4% of the HCN daily station years, the percentage of correctly classified years falls to 78%. Application of the observation time inference procedure yields a set of annual observation times for stations in the HCN. Primarily, this surrogate dataset provides a means of identifying observation time during years when docu...