Weather Dynamics Chapter 13 Page 495

Weather and Climate Weather is the set of environmental conditions encountered from day to day. Climate is the set of environmental conditions averaged over many years.

Meterologist: a person who studies the atmosphere and weather for the purpose of forecasting. Meterology: The science of weather

Global Weather Dynamics Weather dynamics is the study of how the motion of water and air causes weather patterns. Energy from the Sun drives the motion of clouds, air, and water.

Earth’s tilt at an angle of 23 Earth’s tilt at an angle of 23.5 degrees to the plane of its orbit around the Sun. Major components of Earth that influence weather are: atmosphere, land forms, and water. About 70% of Earth’s surface is covered by oceans.

The atmosphere contains air, water vapour, and particles of dust and chemicals, all of which affect weather, especially when the atmosphere is in motion.

Factors That Affect Weather and Climate Near Water

Latitude is the angle measured north or south of the equator. Global Geography Longitude is the angle measured east or west from the 0 degree line which passes through Greenwich, England. Latitude is the angle measured north or south of the equator.

L - Latitude Areas along the same line of latitude have similar climate because they receive the same angle of sunlight. As you move away from the equator the angle of sunlight decreases because Earth is a sphere. Sunlight travels further and is spread over a greater area which reduces the temperature.

O-Ocean Currents Currents affect the temperature and humidity of the air above them. Warm currents move north bring warm humid air to higher latitudes. Ex. North Atlantic Drift and Great Britain

W-Wind Prevailing winds cover large geographical areas and distribute heat to different latitudes. Local winds change direction quickly as H and L pressure systems move.

Low Pressure vs High Pressure

E-Elevation As elevation increases, air temperature decreases because the air becomes thinner so there in less kinetic energy. Air becomes thinner because it spreads out over a greater area

Temperatures generally decrease 4 degrees for every 1,ooo foot gain in elevation. As air rises, it expands and cools because air molecules slow down.

R-Relief Windward and leeward sides of elevated land forms have different climate due to the change in the air flow from prevailing winds. Rising air expands, cools, and condenses to form clouds Falling air is compressed and increases its kinetic energy.

Near Water Coastal regions experience mild winters and cool summers as compared with inland regions. Water heats up slowly and cool off slowly.