What is the term for the angle of the Earth's rotation axis?

The term for the angle of the Earth's rotation axis is obliquity. Obliquity specifically refers to the tilt of the Earth's axis in relation to its orbital plane around the Sun. This axial tilt is approximately 23.5 degrees and is responsible for the changing seasons as different parts of the Earth receive varying amounts of sunlight throughout the year. Understanding this concept is crucial for comprehending how the Earth's tilt affects climate, weather patterns, and agricultural practices.

Inclination generally pertains to the angle between a celestial body's axis and a perpendicular line to its orbital plane but is not the term typically used for Earth's rotation axis. Latitude is a coordinate that specifies the north-south position on the Earth and is not related to the angle of axial tilt. Declination refers to the angle between an astronomical object and the celestial equator, which is distinct from the concept of the tilt of the Earth's axis. Hence, obliquity is the most accurate term for describing this particular angle.