The Seasons and Energy Balance

Equatorial Plane

An imaginary surface that passes through all points on the Earth’s equator at 0 degrees latitude.

Declination

The angle of the Sun north or south of the equatorial plane as measured from the center of the Earth.

Diurnal cycle

The 24-hour daily cycle in atmospheric variables that is caused by the rising and setting of the Sun.

Solstice

The two times each year when the Sun reaches its farthest north or south position of the equator.

Equinox

The two times each year when the Sun is directly over the equator. The Earth’s axis is not tilted toward or away from the sun during these times.

Solar Constant

The amount of solar radiation reaching the top of the Earth’s atmosphere, assuming an average distance from the Sun.

1367 W/m²

Write the solar constant — numbers and units.

composition, roughness, slope, surface, geometry, orbit

Surface heating may be uneven because of variations in [TERM], [TERM], and [TERM] of the Earth’s [TERM], the Earth’s [TERM], and the geometry of the Earth’s [TERM] around the Sun.

latitude, declination

The angle of the sun over the horizon is determined by [TERM] and [TERM].

June 21, December 21, 0

During the equinoxes on [Month #Day] and [Month #Day], the Sun is directly overhead at [#] degrees latitude.

equator, concentrated, high, polar, less, low

Areas in the tropics, close to the [TERM], receive the most [TERM] solar intensity because of the sun’s [TERM] angle. The [TERM] regions receive [MORE/LESS] intense radiation because the Sun’s [TERM] angle spreads out emitted radiation.

equilibrium, lose, radiation, gains

To maintain a long-term [TERM] temperature, the Earth and atmosphere must [TERM] to space the same amount of [TERM] that it [TERMS] from the Sun.

23.5

The Earth’s axis is tilted at about (##.#) degrees.

365, geometry, weather cycles

The [###]-day revolution of the earth around the sun and the [TERM] of the earth’s orbit around the sun causes annual [TERM TERMS]