Weather 3 (Ocean Currents, etc.) Flashcards
When cold, dense air displaces warm air, it forces the warm air, which is less dense, up along a steep slope.
Cold Front
Advancing warm air displaces cold air along a warm front, which develops a gradual slope.
Warm Front
When two air masses meet but neither advances, the boundary between them stalls. The resulting —— front often occurs between two modified air masses with small temperature and pressure differences. The air masses can continue moving parallel to the front.
Stationary Front
Sometimes a cold air mass moves so fast that it overtakes a warm front, forcing warm air up. As the warm air is lifted, the advancing cold air mass collides with the cold air mass in front of the warm front. (—— means obstructed.)
Occluded Front
A zone that develops as a result of the meeting of two air masses with different characteristics. They usually bring precipitation.
Front
High altitude, fast moving winds in the troposphere that generally flows from west to east over the mid-latitudes. They are caused by pressure differences between the warm and cold regions of the world. They separate cold polar air to the North from warmer air to the South.
Jet streams
This effect causes circulating air to be deflected in different directions in the northern and southern hemisphere.
Coriolis Effect
A movement of air from a high pressure system to a low pressure system.
Wind
The current which forms near the Caribbean and follows the east coast of North America up to Newfoundland. (Slow and Warm)
Gulf Stream
Large bodies of air in which temperature and moisture content at a specific height are the same. Vary in size, from 100 Km’s across to 1000 km’s across. Most form where air above the surface is fairly still for days or weeks and air takes on the moisture and temperature properties of the surface.
Air Mass
Refers to the direction wind usually blows in. These winds are formed from a combination of global convection current and the Coriolis effect.
Prevailing Winds
It is a cold current in the North Atlantic Ocean which flows from the Arctic Ocean south along the coast of Labrador and passes around Newfoundland, continuing south along the east coast of Canada near Nova Scotia. (Fast and cold)
Labrador Current
When an air mass cools over an ocean or a cold region on land a ——- pressure system forms. In the northern hemisphere, wind travels clockwise around a center of —— pressure. The movement of air from an area of high pressure to an area of lower pressure is wind. ——- pressure systems often brings clear skies.
High pressure system
Air masses that travel over warm land or oceans may develop into —— pressure systems. When an air mass warms, it expands and rises, making the layer of air thicker. However, as the air rises, it cools. Water vapour in air may condense, producing clouds or precipitation. This is why —- pressure systems often bring wet weather. Winds travels counterclockwise around a —– pressure center.
Low pressure system
What kind of air mass brings cold and wet weather?
Maritime Polar air mass
