How Consistent are Surface Data for Climate Change Studies?: A Localized Analysis with Surface Air Temperature Observations from Cooperative Observer Station Data

The consistency of surface air temperature records is critical in local climate change studies. Here, the homogeneity of Cooperative Observing Network data is assessed using station history information and a comparative analysis between the individual stations and respective climate divisions, using central North Carolina as an example. Results suggest there are several discrepancies in the observations that bias data continuity and quality due to micrometeorological and instrumentation changes. On average, these changes occur every thirteen years and cause variable impact on the data homogeneity. The discrepancies in the temperature dataset are often not explained by the documented changes in location, instrumentation, or observation time. Generally, there is one discrepancy every six years in a station's temperature data, but only a small fraction of these inconsistencies match documented changes to station location or observation time.

This indicates that it would be difficult to account for and correct data inconsistencies in the surface temperature records. By themselves, surface temperature records appear to have significant uncertainties for assessing warming or cooling trends. Future climate change studies should quantify the consistency of datasets to be used on a station-by-station basis and select only the more consistent stations for climate trend analyses.