The water mass found north of the North Pacific subtropical convergence region between 50N and the Alaskan coast. It has a temperature of 2-6C and a salinity below 33 psu.
When considering the case of the Earth, thesub-auroral region typically refers to two latitudinal bands, one in thenorthern hemisphere and the other in the southern hemisphere extending fromabout 50 d
egrees to low 60 degrees. The concept sub-auroral regions does notapply to all bodies in the solar system and different latitudinal rangeswould apply for each body case by case. The sub-auroral regions may bedefined by using either planetographic or magnetic coordinates if themagnetic dipole is closely aligned with the spin axis of a magnetized body.Ground magnetometers located at sub-auroral latitudes on the Earth measure amixture of activity driven by auroral zone currents and the ring current.
A metal-poor main-sequence star with spectral type later than M7 and luminosity class VI. They are population II dwarfs which appear less luminous than their solar metallicity counterparts due to the
dearth of metals in their atmospheres. Subdwarfs are halo members with high proper motions and large heliocentric velocities. They are important tracers of the chemical enrichment history of the Galaxy and belong to the first generation of stars formed in the Galaxy (at least 10 billion years old).
A star with a lower absolute magnitude than a normal giant star of its spectral type. It is a star that has exhausted the hydrogen at its center and is evolving into a red giant. Subgiants are luminos
ity class IV.