the tendency of urban areas to be warmer then the surrounding rural areas are caused by greenhouse effect.
the tendency of urban areas to be warmer then the surrounding rural areas are caused by greenhouse effect.
the tendency of urban areas to be warmer then the surrounding rural areas are caused by?
greenhouse effect
the urban heat island temperature difference is not only usually larger at night than during the day, but also larger in winter than in summer. this is especially true in areas where snow is common, as cities tend to hold snow for shorter periods of time than surrounding rural areas (this is due to the higher insulation capacity of cities, as well as human activities such as plowing). this decreases the albedo of the city and thereby magnifies the heating effect. higher wind speeds in rural areas, particularly in winter, can also function to make them cooler than urban areas. regions with distinct wet and dry seasons will exhibit a larger urban heat island effect during the dry season. the thermal time constant of moist soil is much higher than that of dry soil. as a result, moist rural soils will cool slower than dry rural soils and act to minimize the nocturnal temperature difference between urban and rural regions.
urban heat island
there are several causes of an urban heat island (uhi); for example, dark surfaces absorb significantly more solar radiation, which causes urban concentrations of roads and buildings to heat more than suburban and rural areas during the day; materials commonly used in urban areas for pavement and roofs, such as concrete and asphalt, have significantly different thermal bulk properties (including heat capacity and thermal conductivity) and surface radiative properties (albedo and emissivity) than the surrounding rural areas. this causes a change in the energy budget of the urban area, often leading to higher temperatures than surrounding rural areas. another major reason is the lack of evapotranspiration (for example, through lack of vegetation) in urban areas. the u.s. forest service found in 2018 that cities in the united states are losing 36 million trees each year. with a decreased amount of vegetation, cities also lose the shade and evaporative cooling effect of trees.
urban heat island