AN OVERVIEW OF THE OKLAHOMA CITY MICRONET Jeffrey B. Basara*, Bradley G. Illston, Christopher A. Fiebrich, Renee A. McPherson, Jared P. Bostic, Phillip Browder, David B. Demko, Cynthia Morgan, and Kris Kesler Oklahoma Climatological Survey University of Oklahoma 1. INTRODUCTION Between the dates of 28 June and 31 July 2003, the Joint Urban 2003 field experiment (JU2003) was conducted in Oklahoma City to collect data used for the improvement of numerical models that simulate dispersion within urban environments (Allwine et al., 2004). During the six-week period, intensive observing periods occurred within a temporary array of various instrument systems deployed in and around the central business district of Oklahoma City (Allwine and Flaherty, 2006). Because of the complex atmospheric processes involved in urban areas, field experiments such as JU2003 have been critical to the advancement of science in urban meteorology and climate. To date, much of the current understanding of the impacts of urban areas on atmospheric processes results from field programs such as JU2003 including those conducted in other North American cities including St. Louis (Metropolitan Meteorological Experiment – METROMEX (Changnon et al., 1971; Lowry, 1974), Chicago (Changnon and Semonin, 1978), Los Angeles, Vancouver, Montreal (Mailhot et al., 1998), Mexico City, Tucson, Salt Lake City (Allwine et al., 2002), and Phoenix (Grimmond and Oke, 1995). During June and July 2003, the Joint Urban 2003 field experiment (JU2003; Allwine et al. 2004) was conducted in Oklahoma City (OKC). Unfortunately, once large field experiments complete the tasks associated with the projects, the scientific tools and instruments used to collect the necessary data are typically decommissioned. Such was the case with JU2003 whereby, upon the completion of the JU2003 activities, the temporary instrument networks were removed. At the same time, in North America, the majority of real-time, continuous, research-quality atmospheric observations are not collected within the core regions of cities. Thus, a general disconnect exists in which the majority of observing sites are collected in rural areas away from the densest populations. Yet, recent publications have addressed that urbanization has and will continue to increase worldwide (United Nations Human Settlements Program, 1997; Dabberdt et al., 2000; United Nations, 2003) and a growing need exists for improved atmospheric observations for a variety applications including public health and safety. The success of JU2003 did provide the opportunity to assess the feasibility of a permanent urban- atmospheric monitoring network deployed across the Oklahoma City metropolitan area. Thus, following JU2003 and with the assistance of the City of Oklahoma City, the Oklahoma City Micronet (OKCNET), a dense network of automated weather stations designed to improve atmospheric monitoring across the Oklahoma City metropolitan area was deployed after nearly five years of design and testing. The OKCNET project included the deployment of three new Oklahoma Mesonet sites (McPherson et al. 2007) within Oklahoma City and the installation of sites mounted on traffic signals. The Oklahoma City Micronet was officially commissioned on 8 November 2008. 2. OKLAHOMA CITY MESONET STATIONS As part of a joint effort between the OKCNET project and the Oklahoma Mesonet (Brock et al. 1995, McPherson et al. 2007), three new Mesonet sites were installed within Oklahoma City in early 2007 (Fig. 1). The first site (OKCN) was installed in February 2007 approximately 7 miles north of the central business district while in April 2007 two additional sites were deployed approximately 4 miles west of the central business district and approximately 4 miles east of the central business district (OKCE). More information regarding the specifics of the new Mesonet sites deployed in Oklahoma City can be found at: OKCW: http://www.mesonet.org/sites/sitedescription.php?si te=OKCW&dir=pr OKCN: http://www.mesonet.org/sites/sitedescription.php?si te=OKCN&dir=pr OKCE: http://www.mesonet.org/sites/sitedescription.php?si te=OKCE&dir=pr 3. TRAFFIC SIGNAL STATIONS The design, testing, and deployment of stations mounted on traffic signals would not be possible nor successful without extensive collaboration with the City of Oklahoma City, which boasts the largest IEEE 802.11 "Wi-Fi"(TM) mesh network in the world. With the assistance of Oklahoma City personnel, the traffic signal stations were designed to attach to this network of wireless access points across the metropolitan area. J1.1 * Corresponding author address: Jeffrey B. Basara, Oklahoma Climatological Survey, 120 David L. Boren Blvd., Suite 2900, Norman, Oklahoma, 73072. E-mail: jbasara@ou.edu