The energy on Earth comes from the Sun, which heats up Earth’s surface and all things on it. Matter that absorbs heat energy tends to rise, and matter that loses heat energy tends to fall. This constant churning of hot and cold is called convection.
Wind is caused in part by the differences in thermal energy absorption at Earth’s poles and equator. Warmer air has less pressure than cooler air. Differences in air pressure cause movement of air, which is wind. High pressure air pushes low pressure air.
Ocean currents are driven by wind at the surface, but deeper currents are influenced by temperature and salinity differences. Warm water is less dense than cold water, and water with more salt is denser than ocean water with less salt.
Weather maps show weather systems, such as storms and fronts, over a large area and are used for predicting weather patterns in smaller regions like cities.
Atmospheric conditions are predictable and can be tracked and measured over time by meteorologists.
Air pressure is a measure of the weight of the air over a given area, as indicated by a barometer.
Fronts occur in association with low pressure air masses where the air circulation causes the interaction between air masses with different temperatures and pressures. The front is the line of contact at ground level marking the boundary between the two air masses.
A warm front is the leading edge of a warm, humid air mass, which rises into the atmosphere as it is pushed up by the surrounding, colder air. Warm fronts are represented by lines of red half circles on a weather map.
A cold front is the leading edge of a cool, dry air mass moving into an area, displacing the warmer air, and contributing to storm formation. On a map, lines of blue triangles represent cold fronts.
Ocean currents are important in regulating weather patterns around the globe.
Weather is created by differences in temperature and moisture levels in a given area.
As warm water moves into an area, it raises the humidity and temperature because more evaporation takes place.
As cold water moves into an area, it can lower the temperature by absorbing more heat from the surrounding area, leading to colder and drier conditions on land.
Hurricanes use warm, moist, tropical air as their fuel; they form when this air rises up from the ocean surface and creates a low-pressure system underneath. As the clouds form and rotate, they spin faster and are fed by the warm, evaporating water from the ocean’s surface.