A Building-Block Urban Meteorological Observation Experiment (BBMEX) Campaign in Central Commercial Area in Seoul

Abstract

High-resolution meteorological information is essential for attaining sustainable and resilient cities. To elucidate high-resolution features of surface and air temperatures in high-rise building blocks (BBs), a 3-dimensional BB meteorological observation experiment (BBMEX) campaign was designed. The campaign was carried out in a central commercial area in Seoul during a heat-wave event period (5−6 August) in 2019. Several types of fixed instrument were deployed, a mobile meteorological observation cart (MOCA) and a vehicle were operated periodically. The surface temperature was determined to be strongly dependent on the facial direction of a building, and sunlit or shade by surrounding obstacles. Considerable increases in surface temperature on the eastern facades of buildings before noon, on horizontal surfaces near noon, and on the western facades in the afternoon could provide more energy in BBs than over a flat surface. The air temperatures in the BB were higher than those at the Seoul station by 0.1−2.2 • C (1.1−1.9 • C) in daytime (night-time). The MOCA revealed that the surface and air temperatures in a BB could be affected by many complex factors, such as the structure of the BBs, shades, as well as the existence of facilities that mitigate heat stresses, such as ground fountains and waterways.Atmosphere 2020, 11, 299 2 of 21 in urban areas are higher than those in rural areas, is a well-known and prominent feature [5][6][7][8]. Higher temperatures in urban areas and relatively lower temperatures in rural areas induce urban-rural circulation over highly populated urban areas e.g., [9].Most UHI studies assume that urban and rural areas are composed of land cover with kilometer-scale horizontal homogeneities to explain the temperature difference between two areas [10,11]. In real scenarios, urban areas are composed of various land-cover blocks: compact high-rise, open high-rise, compact low-rise, open low-rise buildings, commercial or industrial blocks, urban parks, water bodies, and so on [3]. The height and density of buildings, and land cover types become the main criteria for classifying urban climate zones. These are key factors in determining the surface roughness and zero-plane displacement lengths for describing wind and sky views, as well as temperature inside or over building-blocks (BBs) [12].Recently, high-resolution meteorological information has become essential for attaining sustainable and resilient cities [13,14].