TITLE:
Diurnal Cycle of Heating and Water Vapor in the Metropolitan Area of Porto in Portugal
AUTHORS:
Hugo Abi Karam, Jorge Fernando Soares Gonçalves, Augusto José Pereira Filho
KEYWORDS:
Metropolitan Area of Porto (Oporto) Climatology, Urban Heat Island Development, Urban Boundary Layer, Mesoscale Atmospheric Circulations
JOURNAL NAME:
Journal of Geographic Information System,
Vol.14 No.1,
February
25,
2022
ABSTRACT: In this work, it is investigated the Urban Heat Island (UHI) using conservative thermodynamic variables observed by surface weather stations on the Metropolitan Area of Porto (Oporto) in Portugal, under adiabatic conditions at the surface. These conditions are usually present and associated with the development of a mixture layer into the diurnal Convective Boundary Layer (CBL), which residual layer in the late afternoon defines the initial state for the development of the nocturnal UHI. Both the spatial structure and temporal variation of potential temperature and specific humidity were considered, along the hours and days of the year, from a statistical point of view, resulting in hourly climatology. Details of the hourly evolution of the meteorological variables on the Oporto surface are presented and discussed. Results show a seasonal variation of the potential temperature up to 17°C throughout the year, which is associated with horizontal thermal gradients that can control and trigger mesoscale circulations such as sea-land, urban and valley-mountain breezes.