AN OVERVIEW OF THE OKLAHOMA CITY URBAN MICRONET TEST FACILITY Thomas E. Winning Jr.*, Bradley G. Illston, Megan M. Ferris, and Jeffrey B. Basara, Oklahoma Climatological Survey University of Oklahoma, Norman, OK 1. INTRODUCTION In late 1999, the world’s population exceeded 6 billion people with an expected 9 billion by the year 2050. At the same time, the world is becoming more urbanized than ever before. Every week, the world’s urban population increases by about one million people. The United Nations projects that by the year 2015; there will be 21 mega-cities with populations exceeding 10 million people (Hinrichsen et al. 2002). The impact of this growth will lead to increased urban sprawl already prevalent during the last few decades. As such, it is of increased importance that meteorologists have the necessary tools to study and quantify the impacts of urban areas on meso-, micro-, and local scale environments. In order to monitor the urban atmosphere in Oklahoma City, the Oklahoma Climatological Survey (OCS) is in the early stages of developing and deploying The Oklahoma City Urban Micronet (OKCNET). The goals of the OKCNET project include: 1) operate a city– wide network of weather stations that measure core variables and transmit data in near real time, and at temporal resolution of one-minute; 2) relay the data via the Oklahoma City WiFi network used by city police, emergency managers, and first responders; 3) share aforementioned data with local, state, and federal governments; as well as, both public and private education institutions, private businesses and research communities. When operational, the OKCNET will consist of 30 – 40 stations deployed across Oklahoma City (with a higher density near the central business district) that will measure weather variables such as wind speed and direction, precipitation, barometric pressure, temperature and humidity In addition, there will be three to five Oklahoma Mesonet stations (Brock et al. 1995) strategically located within the metro area. Many individuals and agencies will benefit from the data collected by the Oklahoma City urban micronet. For example, the data information will be used to further study the process of urban dispersion, urban wind fields, and the impacts of the urban heat island on local and microclimate scale. Furthermore, the data can be used to increase the accuracy of local forecasts, monitor severe weather in and around urban areas, and provide improved road weather conditions. 2. SENSORS AND EQUIPMENT 2.1 The Vaisala WXT510 Weather Transmitter The sensor chosen for use in the OKCNet project is the Weather Transmitter WXT510 manufactured by Vaisala Oyj. The WXT510 collects observations of air temperature, relative humidity, pressure, wind speed, wind direction, and precipitation. The sensor package requires little maintenance once deployed, uses minimal power to collect observations, and has no moving parts. It is these qualities that make the WXT510 an ideal instrument package for OKCNet. 5.5 * Corresponding author address: Thomas E. Winning, Jr., Oklahoma Climatological Survey, 120 David L. Boren Blvd., Suite 2900, Norman, Oklahoma, 73072. E-mail: brutus@ou.edu Figure 1. The Oklahoma City Urban Micronet Intercomparison Facility. Figure 2. The Vaisala WXT510 Weather Transmitter