The direction of the magnetic field at any location on the Earth`s surface is commonly specified in terms of both field declination and field inclination.

Field declination refers to the angle between the magnetic field direction and the true north direction in geographic coordinates. This angle can vary depending on the location on Earth and is measured in degrees.

Field inclination, also known as magnetic dip, refers to the angle between the magnetic field direction and the horizontal plane at a specific location. It represents the angle at which a magnetic compass would tilt when placed in a magnetic field. Like field declination, field inclination can also vary depending on the location on Earth.

By specifying both field declination and field inclination, we can accurately describe the orientation of the magnetic field at a specific location. This information is important for various applications, including navigation, geophysics, and studying the Earth`s magnetic field.