Surface Meteorological Measurement in a Polluted Environment FUW Trends in Science & Technology Journal, www.ftstjournal.com e-ISSN: 24085162; p-ISSN: 20485170; April, 2017: Vol. 2 No. 1B pp 384 – 390 384 NEAR SURFACE METEOROLOGICAL MEASUREMENTS IN THE VICINITY OF A SCRAP-IRON RECYCLING FACTORY IN SOUTHWESTERN NIGERIA O. E. Abiye 1 *, L. A. Sunmonu 2 , M. A. Ayoola 2 , A. I. Ajao 2 , O. E.Akinola 2,3 and O. A. Babatunde 2 1 Centre for Energy Research & Development, Obafemi Awolowo University, Ile-Ife, Nigeria 2 Atmospheric Physics Research Group, Department of Physics & Engineering Physics, Obafemi Awolowo University, Ile-Ife, Nigeria 3 Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing, China *Corresponding author: waleabiye@gmail.com; eabiye@cerd.gov.ng Received: January 07, 2016 Accepted: March 25, 2017 Abstract: This study presents an overview of near surface meteorological measurements carried out in a dense air-pollution plume environment of a scrap-iron recycling factory (7 o 29'N, 4 o 28'E, 262 m a.s.l) located at Ile-Ife, southwest Nigeria. This was done with a view to providing test meteorological dataset that could be used as input in advanced regulatory air pollution dispersion models. Gradient and single level continuous measurements of near surface atmospheric parameters comprising air temperature (1 and 5 m), relative humidity (1 and 5 m), global and net radiation fluxes (both at 1.5 m), soil heat flux (5 cm below surface), wind speed (1.5 and 5.5 m) and wind direction (5.5 m) were made between August 2012 and June 2014. The assay of sensors deployed includes two (2) pulse type cup anemometers (model A100ML), two (2) air temperature and relative humidity sensors (model HMP45), a potentiometer type wind vane (model W200P), a net radiometer (model NR-LITE), a pyranometer (model CS300), a soil heat flux plate (model HFP01) and a soil temperature probe (model T108). All the sensors for the measurement were instrumented to a 6 m meteorological mast and connected to a Campbell Scientific datalogger (model CR1000). The data obtained were sampled at 10 s resolution and stored as 10 min averages, later reduced to hourly averages. Generally, the location is characterized by daily mean air temperature (≥ 26 o C), high relative humidity (RH > 70%) and weak winds (< 2.0 ms -1 ). Hourly mean of net radiation reached a peak of 422.7, 382.0 and 477.0 Wm -2 in the years 2012, 2013 and 2014, respectively. On the other hand, hourly mean of soil heat flux reached a peak of 108.2, 93.2 and 119.2 Wm -2 , respectively for the same period. This high quality and extensive site-specific meteorological dataset would be useful for hands-on testing and deployment of air pollution dispersion models and for use in other environmentally related applications. Keywords: Air temperature, dispersion models; net radiation, soil heat flux Introduction Indiscriminate release of harmful gaseous emissions from operations within the industrial sectors (e.g., scrap-iron recycling) into the atmosphere could constitute serious human health and environmental issues. This problem is exacerbated in Nigeria by lack of in-situ measurements of air pollutant and enforcement of guidelines that regulate short- and long-term impacts. There is also the problem of inadequate and improper control strategies caused by prohibitive costs of equipment and inadequate skilled manpower to monitor criteria air pollutants’ concentration at all locations of interest. An approach that has proven to be efficient and cost effective in obtaining estimates of the concentrations of these pollutants (e.g. SO 2 , NO X , CO, etc.) is the use of advanced regulatory (Gaussian-based) air pollution dispersion models. AERMOD, one of the most widely used regulatory air pollution dispersion model (Carruthers et al., 2011; Nadoushan et al., 2016) requires as input, basic meteorological variables to characterize the surface layer dynamical parameters that are needed in estimation of lateral (  ) and vertical dispersion (  ) coefficients, as well as pollutants’ concentrations at downwind locations from a known source of atmospheric pollution. Unfortunately, the meteorological inputs required by the dispersion models are often compromised in the sense that location-specific measurements are not always available (Capelli et al., 2013). As a consequence of this limitation, most atmospheric dispersion estimates of pollutants’ concentrations are made from meteorological data obtained from sources different from the location of application thereby failing to fully represent the prevailing surface layer conditions at the required location. As such, the reliability of dispersion models’ concentration estimates is strongly dependent on the representativeness of the input meteorological parameters to fully describe the atmospheric dynamics and surface layer characteristics at the source location (Pearce et al., 2011). Thus, providing regulatory air pollution dispersion model with site-specific, quality-assured surface layer meteorological data is therefore essential for obtaining plausible estimates of pollutants concentrations downwind from the released source. The basic routine meteorological measurements required include air temperature, relative humidity, wind speed and direction among others (Batterman et al., 2010). This study was therefore carried out with a view to providing a less capital- and equipment-intensive methodology for reliable use of near surface meteorological data for possible application as input in advanced regulatory air pollution dispersion models. Materials and Methods Description of the study area The study site (7 o 29'N, 4 o 28'E, 262 m a.s.l) is located at Fashina, Ile-Ife, a rural settlement in Ife-Central Local Government Area (LGA), Osun State, southwestern Nigeria (Fig. 1). Located off a high-traffic Ife-Ibadan expressway, Fashina is an agrarian community surviving on subsistence farming, animal husbandry and cottage industry like palm oil and cassava processing. A little distance inwards from the expressway, there are patches of declining cocoa plantation due to developmental encroachment of residential buildings. The road network in the area is unpaved except for the abandoned old Ife-Ibadan motorway. Generally, vehicular traffic in the interior areas is very low, being mostly plied by lorry tippers bearing sand and construction materials. Neighbouring communities around Fashina settlement include Ipetumodu and Akinlalu. The Obafemi Awolowo University Campus is about 7 km (as the crow flies) in the NE direction Supported by