SC.D.1.2.3 CS The student knows that the water cycle is influenced by temperature, pressure, and the topography of the land. Content Limits: Items will assess only one variable affecting the water cycle at a time. Items may address climate and precipitation.

Climate vs. Weather Weather is the condition of the atmosphere at a particular time. Weather conditions include temperature, humidity, precipitation, wind, and visibility. Climate is the average weather condition in an area over a long period of time. Climate is determined by temperature and precipitation.

Factors That Affect Climate Latitude Latitude is the distance north or south, measured in degrees, from the equator. Solar Energy and Latitude: The amount of direct solar energy a particular area receives is determined by latitude. Prevailing Winds Winds that blow mainly from one direction are prevailing winds. Prevailing winds affect the amount of precipitation that a region receives.

Mountains Mountains can influence an area’s climate by affecting both temperature and precipitation. Elevation is the height of surface landforms above sea level. As the elevation increases, the ability of air to transfer energy from the ground to the atmosphere decreases. Therefore, as elevation increases, temperature decreases.

Large Bodies of Water Large bodies of water can influence an area’s climate because water absorbs and releases heat slower than land does. Sudden or extreme temperature changes rarely take place on land near large bodies of water. Surface Currents are stream-like movements of water that occur at or near the surface of the ocean. As surface currents move, they carry warm or cool water to different locations. The temperature of the water affects the temperature of the air above it.

Water Cycle Water in liquid, solid, and gaseous states is constantly being recycled through the water cycle. The amount of water vapor in the air is humidity. Relative Humidity is the ratio of the amount of water vapor in the air to the maximum amount of water vapor that the air can hold at a given temperature. Factors Affecting Relative Humidity: Two factors that affect relative humidity are amount of water vapor and temperature.

Condensation is the process by which a gas, such as water vapor, becomes a liquid. Dew Point: The dew point is the temperature at which a gas condenses into a liquid. A cloud is a collection of millions of tiny water droplets or ice crystals. Clouds form as warm air rises and cools. Clouds and Altitude: Clouds are classified by the altitude at which they form.

Cumulus Clouds: Puffy, white clouds that tend to have flat bottoms are called cumulus clouds. Stratus Clouds: Clouds called stratus clouds are clouds that form in layers. Cirrus Clouds: Cirrus clouds are thin, feathery, white clouds found at high altitudes.

Water, in solid or liquid form, that falls from the air to Earth is precipitation. Rain: A cloud produces rain when water drops in the cloud become large enough to fall. Sleet and Snow: Sleet forms when rain falls through a layer of freezing air. Snow forms when temperatures are so cold that water vapor changes directly to a solid. Hail: Balls or lumps of ice that fall from clouds are called hail.

Types of Precipitation Rain Hail Snow Sleet