Interactions with Landscapes

While global and regional circulations were considered in earlier chapters, this chapter emphasizes several major relationships between circulation and local landscapes. Rugged terrain can enhance precipitation on the windward (i.e., upwind) side and suppress it on the leewardand leeward slope, or rain shadow, side. The slope angleSlope angle and the compass point direction that a slope faces—theSlope aspect slope aspect—affect net radiation (Q*), which in turn affects temperature. In general, north of the Tropic of CancerTropic of Cancer at 23.5° N—the Northern Hemisphere extratropics, south-facing slopes—south aspects—have greater Q* than north-facing slopes. Topography also impacts local winds, as colder air drains downhill, particularly at night in the form of mountain breezes or katabatic windsWindkatabatic, and warmer air ascends upslope, particularly during daytime hours in the form of valley breezesValley breeze, or anabatic windsAnabatic wind. Coastalcoastal areas often experience a shift in windWindanabatic direction between day and night, from sea breezes to land breezesTemperatureand land breeze. Desert, grassland, and forest land covers have characteristicEvapotranspirationand energy energy balancesEnergy balance that are affected by different albedoAlbedo (K \(\uparrow\) ) and evapotranspirationEnergyand evapotranspiration ratesevapotranspiration. Urban areasand urban areas also impact the thermal distribution, in the form of the urban heat islandUrban heat island, along with precipitation, humidityForestborealand humidit, and wind regimes in their local areas.