4.7 Solar Radiation and Earth's Seasons

Insolation

The amount of solar radiation (energy from sun’s rays) reaching an area, measured in Watts/m2.

Solar Intensity

The intensity of incoming solar radiation, which depends on the angle of the sun's rays and the amount of atmosphere the rays pass through.

Albedo

The proportion of light that is reflected by a surface; higher albedo surfaces reflect more light and absorb less heat.

Equinox

The times in the year (March and September) when the Northern and Southern hemispheres are equally facing the sun.

Solstice

The times in the year (June and December) when either the Northern or Southern hemisphere is maximally tilted towards the sun, resulting in the longest and shortest days.

Northern Hemisphere Summer

Occurs when the Northern hemisphere is tilted maximally toward the sun, resulting in longer days and higher insolation.

Urban Heat Island

A phenomenon where urban areas are hotter than surrounding rural areas due to low albedo of materials like blacktop.

Tilt of Earth's Axis

The angle at which the Earth is tilted, causing variations in insolation, length of day, and the changing of seasons.

High Latitude

Regions closer to the poles that receive less insolation compared to equatorial regions.

Surface Temperature

The temperature of a surface, which is affected by the amount of sunlight absorbed and its albedo.