VOLUME 27 JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY SEPTEMBER 2010 The University of South Alabama Mesonet and Coastal Observing System: A Technical and Statistical Overview SYTSKE K. KIMBALL Department of Earth Sciences, University of South Alabama, Mobile, Alabama MADHURI S. MULEKAR Department of Mathematics and Statistics, University of South Alabama, Mobile, Alabama SHAILER CUMMINGS AND JACK STAMATES National Oceanographic and Atmospheric Administration/Atlantic Oceanographic and Meteorological Laboratory, Ocean Chemistry Division, Miami, Florida (Manuscript received 13 August 2009, in final form 1 March 2010) ABSTRACT The University of South Alabama Mesonet consists of 26 sites across the north-central Gulf of Mexico coast. Although the original purpose of the mesonet was monitoring landfalling tropical systems, meteoro- logical data are collected and disseminated every 5 min year-round to serve a multitude of purposes, including weather forecasting, education, and research. In this paper a statistical analysis and like-sensor comparison demonstrates that variables, measured by different sensor types or by sensors at different heights, correlate well. The benefits of sensor redundancy are twofold, offering 1) backup sensors in the case of sensor failure during severe weather and 2) the ability to perform a large number of internal consistency checks for quality control purposes. An oceanographic compliment to the University of South Alabama Mesonet system, which was deployed by NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML) to measure surface waves and ocean currents in an area south of Mobile, Alabama, is described. A preliminary comparison of mesonet wind data and ocean wave data show good agreement, offering promising opportunities for future research. 1. Introduction Hubbard 1992) identified 100 such networks and 831 stationary stations in the United States and Canada. Since Not just federal agencies collect surface weather data. their survey many more mesonets have been established, As costs decline and needs increase, more state and lo- including the Oklahoma Mesonet, with 120 stations cally operated surface meteorological networks are be- (Brock et al. 1995; McPherson et al. 2007); the West coming available. These so-called mesoscale networks Texas Mesonet, with 56 stations (Schroeder et al. 2005); of weather stations, or ‘‘mesonets,’’ typically collect data the Kentucky Mesonet, with 45 stations (information at finer space and time resolution than that of the tra- online at http://www.kymesonet.org/index.html); the ditional national networks, make data available in (near) Missouri Mesonet, with 16 stations (online at http:// real time, and record more variables than just tempera- www.eas.slu.edu/People/CEGraves/Mesonet/mesonet. ture and precipitation. Mesonet data serve a multitude of html); and the Alabama A&M Mesonet, with 14 sites needs, including forecasting, education, agriculture, lei- (online at http://wx.aamu.edu/ALMNet.php). sure, hydrology, and research applications in a wide va- The University of South Alabama (USA) built its first riety of fields. A survey conducted in 1991 (Meyer and mesonet station in January 2005, with the primary focus being hurricane and tropical storm landfall monitoring. Hence, most stations were installed in coastal counties Corresponding author address: Sytske Kimball, LSCB 136, De- partment of Earth Sciences, University of South Alabama, Mobile, and the line of counties to the north of the coastal AL 36688. counties. As of April 2010, 26 stations were fully oper- E-mail: [email protected] ational. The location of all of the sites is shown in Fig. 1 DOI: 10.1175/2010JTECHA1376.1 Ó 2010 American Meteorological Society 1417 Unauthenticated | Downloaded 10/02/21 04:21 PM UTC 1418 JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY VOLUME 27 FIG. 1. Map depicting all 26 stations of the University of South Alabama Mesonet. State and county names are included, station names are not. and listed in Table 1. The mesonet stretches about 325 km Administration’s (NOAA’s) Atlantic Oceanographic and in an east–west direction, across three states. The north– Meteorological Laboratory (AOML) in an area south of south dimension ranges from about 100 km at the western Mobile Bay. Three bottom-mounted acoustic wave and end to about 30 km in southeast Alabama north of the current (AWAC) instrument platforms were set out du- Florida Panhandle. The spacing between the stations ranges ring the 2007–09 hurricane seasons to monitor surface from 5.4 to 55.6 km, with an average of about 30 km. The waves, ocean currents, and bottom temperature. Data majority of the station hosts are public schools, which pro- from the USA Mesonet and these instruments will help vide a safe, well-maintained environment with free access form an integrated picture of offshore conditions during to the Internet. All of the stations are surrounded by a severe storms and to help validate storm surge models. barbed wire fence, which has no doubt contributed to A technical overview of mesonet hardware, instru- the fact that no vandalism has been encountered to date. mentation, communication, and maintenance, as well as Schools also offer the opportunity to integrate weather AWAC specifications are given in section 2. Section 3 station data with public education. Near–real time, ar- discusses a statistical analysis and like-sensor comparison chived, and metadata are available online (see http:// as well as a preliminary comparison of AWAC and chiliweb.southalabama.edu/). The University of South mesonet data for Hurricanes Gustav and Ike of 2008. A Alabama Mesonet maintains strong ties with the Na- summary and look to the future are provided in section 4. tional Weather Service (NWS) office in Mobile, Alabama, and provides valuable real-time observations in data- 2. Technical overview sparse regions of Alabama directly inland from the coastal a. Station hardware configuration counties. An oceanographic compliment to the USA Mesonet sys- Figures 2 and 3 show schematics of the USA Mesonet tem was deployed by National Oceanic and Atmospheric station layout, while Fig. 4 shows a station photograph. Unauthenticated | Downloaded 10/02/21 04:21 PM UTC SEPTEMBER 2010 K I M B A L L E T A L . 1419 TABLE 1. Geographic details of USA Mesonet stations. Elevation is the height of the surface above sea level. County, state Lat (8N) Lon (8W) Elev (m) Agricola George, MS 30.82 288.52 68.58 Andalusia Covington, AL 31.29 286.50 109.73 Ashford Houston, AL 31.20 285.26 94.80 Atmore Escambia, AL 31.02 287.45 86.87 Bay Minette Baldwin, AL 30.89 287.8 81.5 Castleberry Conecah, AL 31.30 287.03 76.20 Dauphin Island Mobile, AL 30.25 288.08 1.52 Dixie Covington, AL 31.16 286.70 89.92 Dog River Mobile, AL 30.56 288.10 2.97 Elberta Baldwin, AL 30.41 287.59 22.10 Fairhope Baldwin, AL 30.54 287.88 38.10 Florala Covington, AL 31.00 286.34 86.87 Foley Baldwin, AL 30.37 287.65 17.00 Gasque Baldwin, AL 30.24 287.85 1.22 Geneva Geneva, AL 31.06 285.82 68.58 Grand Bay Mobile, AL 30.51 288.37 16.46 Jay Santa Rosa, FL 30.95 287.17 79.25 Kinston Coffee, AL 31.22 286.17 80.77 Leakesville Greene, MS 31.18 288.60 71.60 Loxley Baldwin, AL 30.64 287.73 56.00 Mt. Vernon Mobile, AL 31.09 288 16.04 Pascagoula Jackson, MS 30.36 288.52 2.74 Robertsdale Baldwin, AL 30.58 287.73 47.00 Saraland Mobile, AL 30.83 288.07 6.10 USA Campus Mobile, AL 30.70 288.18 38.10 Walnut Hill Escambia, FL 30.90 287.48 76.20 Each station is built within a 9.14 m 3 9.14 m fenced was chosen because of the relatively frequent occur- enclosure. The fence is 2.44 m tall, including three rence of severe weather in the area, including tropical strands of barbed wire at the top of a chain-link base. A storms and hurricanes. 3.05-m-wide gate is located on the north side of the On 29 August 2005 Hurricane Katrina made landfall enclosure. In the center of the enclosure is a 1.22 m 3 on the Louisiana–Mississippi state line. Two USA Meso- 1.22 m concrete foundation that anchors the tower base net stations were operational at the time: Pascagoula plate. The concrete foundation is 0.61 m deep. Two and Agricola. Pascagoula, located near the coast, re- smaller concrete pads measuring 0.46 m 3 0.46 m are corded the higher wind speeds of the two sites: a maxi- located to the north of the tower foundation and form mum 10-m wind speed of 34.07 m s21 was measured at the base of the rain gauge supports. The tops of the rain 0715 central standard time (CST). Between this time gauge funnels are 82.5 cm above the ground. The wir- and 1215 CST the wind speeds frequently peaked to ing from the rain gauges is routed to the tower through around 30 m s21 and rarely dropped below 25 m s21. a conduit buried underground. At a distance of 1.12 m After 1215 CST the winds remained below 25.0 m s21 south of the tower foundation there is a ‘‘tower lift until a wind speed of 26.23 m s21, which was recorded at anchor pipe’’ that supports a winch used to raise and 1324 CST. Five minutes later, at 1329 CST, several in- lower the towers that are hinged at the northern end of struments stopped recording data, including the 10-m the base plate. Two 3-m-long, east–west oriented cross anemometer. A post storm survey revealed that the tower arms are mounted on the tower to support instruments was leaning sideways by about 58 (Fig.