The wind strength normally increases by a factor of 2 per 1000 feet up to the 850 hPa level.

The wind normally backs during climb out through the first 2000-3000 feet in the northern hemisphere.

The wind strength normally increases by a factor of 2 per 500 feet up to the 700 hPa level.

The wind normally veers during climb out through the first 2000-3000 feet in the northern hemisphere.

Convergence near the ground.

Convergence aloft.

Vertically increasing convergence.

Vertically decreasing divergence.

As pressure decreases the true altitude decreases.

As pressure increases the true altitude decreases.

At a constant flight level, variations in pressure do NOT affect the true altitude.

As pressure decreases the flight level will increase and true altitude will increase.

When temperature decreases, the relative humidity and the dew point remain constant.

When temperature increases, the relative humidity increases, and the dew point decreases.

When temperature increases, the relative humidity decreases, and the dew point remains constant.

When temperature decreases, the relative humidity decreases, and the dew point increases.

coming from an area of high pressure, the aircraft is flying towards a low pressure area.

Coming from an area of low pressure, the aircraft is flying towards a high pressure area.

The true altitude is increasing steadily.

The flight is conducted parallel to the isohypses.

clouds containing only ice crystals.

cirro-type clouds.

convective clouds.

stratified clouds.

Stratocumulus, altostratus, cirrus.

Cirrocumulus, altostratus, stratocumulus.

Cirrostratus, altostratus, stratus.

Cirrocumulus, altocumulus, cumulus.

50% oxygen, 40% nitrogen, and the rest other gases.

10% oxygen, 89% nitrogen, and the rest other gases.

21% oxygen, 78% nitrogen, and the rest other gases.

88% oxygen, 9% nitrogen, and the rest other gases.

Cirrostratus

 stratus

Nimbostratus

Altostratus

Cloud cover has NO effect on the amount of the Sun's radiated heat arriving at the Earth's surface.

The Earth only radiates heat into space between sunset and sunrise.

The Earth is heated by short-wave radiation from the Sun, but cooled by its own long-wave radiation into space.

The Earth is heated by long-wave radiation from the Sun, but cooled by its own short-wave radiation into space.