Challenges associated with classifying urban meteorological stations: the Oklahoma City Micronet example

During 2007-2008, a dense network of meteorological stations was deployed across the Oklahoma City metropolitan area to collect real-time, research-quality observations of atmospheric variables throughout the urban environment: the Oklahoma City Micronet (OKCNET). Because surface characteristics can be vastly different between rural and urban areas as well as throughout a city, significant variability exists in the local microclimates observed by meteorological stations deployed in an urban area. As such, documenting the characteristics near any site (i.e., metadata) is critical to fully understand the overall representativeness of the site and the associated evolution of atmospheric conditions. To date, a universal classification system for urban meteorological stations does not exist. Thus, this study utilized four different methodologies to classify OKCNET sites and increase the metadata for the individual sites and the overall network. The results demonstrated that while each classification system had specific merits, significant challenges existed in establishing consistent metadata for the sites due to (a) limitations associated with the methodologies and (b) the heterogeneity of surface conditions. In particular, stations deployed within the transition zones form urban to suburban and suburban to rural posed the greatest challenges in establishing consistent metadata for the sites.