Page 734 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

G-15 Glossary
Earth’s surface are exposed to physical and chemical weathering processes.
Westerlies (6) The predominant surface and aloft wind-flow pattern from the subtropics to high latitudes in both hemispheres.
Western intensification (6) The piling up of ocean water along the western margin of each ocean basin, to a height of about 15 cm; produced by the trade winds that drive the oceans westward in a concentrated channel.
Wetland (9) An area that is permanently or seasonally saturated with water and charac- terised by vegetation adapted to hydric soils; highly productive ecosystem with an ability to trap organic matter, nutrients, and sediment.
Wilting point (9) That point in the soil- moisture balance when only hygroscopic wa- ter and some bound capillary water remain.
Plants wilt and eventually die after prolonged stress from a lack of available water.
Wind (6) The horizontal movement of air rel- ative to Earth’s surface; produced essentially by air pressure differences from place to place; turbulence, wind updrafts and down- drafts, adds a vertical component; its direc- tion is influenced by the Coriolis force and surface friction.
Wind vane (6) A weather instrument used to determine wind direction; winds are named for the direction from which they originate.
Winter (December) solstice (2) The time when the Sun’s declination is at the Tropic of Capricorn, at 23.5° S latitude, December 21–22 each year. The day is 24 hours long south of the Antarctic Circle. The night is 24 hours
long north of the Arctic Circle. (Compare Summer [June] solstice.)
Yardang (16) A streamlined rock structure formed by deflation and abrasion; appears elongated and aligned with the most effective wind direction.
Yazoo stream (15) A small tributary stream draining alongside a floodplain; blocked from joining the main river by its natural levees and elevated stream channel.
Zone of aeration (9) A zone above the water table that has air in its pore spaces and may or may not have water.
Zone of saturation (9) A groundwater zone below the water table in which all pore spaces are filled with water.