Acronym to quasi bienal oscillation.

Refers to any process which decreases the fluorescence intensity of a given substance. A variety of processes can result in quenching, such as excited state reactions, energy transfer, complex-formation and colisional quenching. As a consequence, quenching is often heavily dependent on pressure and temperature.

Quiet Sun prominence, at an altitude of up to 100,000 kilometers and a magnetic field of about ten Gauss (1E-3 Tesla).

It is a day with low activity geomagnetic, characterized by the planetary index Ap and Kp.