Database Construction of Global Urban Geometric and Aerodynamic Parameters for mesoscale to global climate simulations

In this study, we constructed the global urban geometric parameter database for use in mesoscale and global climate simulations. The database has a spatial resolution of 30 arcseconds in latitude and 45 arcseconds in longitude and is designed to meet the Single layer urban canopy model (Kusaka et al., 2001) input requirements. Specifically, the database includes five building parameters (average building height, maximum building height, standard deviation of building height, plane area index, and frontal area index), along with aerodynamic parameters (zero-plane displacement, aerodynamic roughness length) calculated according to Macdonald et al. (1998) and Kanda et al. (2013).

Lack of detailed building information required to calculate urban geometric has prevented the development of extensive databases. To address this issue, this study used 3 approaches to calculate the urban morphological parameters according to the availability of building data. For areas where detailed building data including building heights are available, urban geometric parameters were calculated in straightforward manner simply by collecting these data (referred to as Level 1 product). For areas where building height information is not available, we estimate building heights by generating Normalized Digital Surface Model (nDSM) from JAXA Advanced Land Observing Satellite World-3D-30 m (ALOS AW3D30), a DSM with a spatial resolution of 30 m, referring to the neighborhood analysis proposed by Huang et al. (2020), and calculated urban geometry parameters (referred to as Level 2 product). Level 2 products are available almost all over the world. Finally, the global database was completed by using Local Climate Zones (Stewart and Oke, 2012) to supplement the slight deficiencies in the level 2 product. The details of the database will be presented in the conference.