3.2.3.4 Urban Climate Flashcards
Albedo
The reflectivity of a surface
Anticyclonic
High atmosphere pressure = fine weather. Dry, calm conditions. In summer, can lead to heat wave conditions. In winter, will be cold, clear with blue skies
Channelling
Wind redirected down long, straight canyon-like streets where there is less friction (urban canyons)
Hygroscopic (nuclei)
Water-attracting e.g. dust in the atmosphere around which raindrops can form = hygroscopic nuclei.
Insolation
Incoming solar radiation
Isotherm
A line joining places with equal temperature (like contours joining places of equal height).
Microclimate
The small-scale variations in temperature, precipitation humidity, wind speed and evaporation than occur in a particular environment such as an urban area.
Particulates
Microscopic matter referred to as PM10 (from exhausts, cement dust, tobacco smoke and ash) and PM2.4.(fine particulate matter)
Photochemical pollution
A form of air pollution that occurs mainly in cities and can be dangerous to health. Exhaust fumes become trapped by temperature inversions and, in the presence of sunlight, low-level ozone forms. It is associated with high- pressure weather systems.
Temperature inversion
An atmospheric condition in which temperature, unusually, increases with height. As inversions are extremely stable conditions and do not allow convection, they trap pollution in the lower layer of the atmosphere
Urban climate
A set of climatic conditions that prevail in a large metropolitan area, which differ from the climate of the rural surroundings.
Urban dome
The urban microclimate is sometimes called an Urban Dome. This is the area within which the weather is different from that of surrounding rural areas.
There are 2 levels in the dome: the Urban Canopy & the Urban Boundary layer.
Urban heat island (UHI)
Urban heat island effect (UHIE)
The zone around and above an urban area, which has higher temperatures than the surrounding rural areas.
