Solar Magnetic - A geocentric coordinatesystem where the Z axis is northward along Earth's dipole axis, X axis is inplane of z axis and Earth-Sun line, positive sunward. See Russell, 1971.
This system has its Z axis parallel to the Earth's magnetic dipole axis (positive North) and its Y axis perpendicular to the plane containing the dipole axis and the Earth-Sun line (positive in direct
ion opposite to the Earth's orbital motion). The direction of the geomagnetic field in the outer magnetosphere is well-ordered by this system. It is the preferred system for defining magnetic local time in the outer magnetosphere.
A hard, compact mass or aggregate of mineral matter, normally subsperical but commonly oblate, disc-shaped or irregular. Formed by precipitation of mineral from solution in the pores of a granular ro
ck, localized around a nucleus or center, to define a discrete, sharply separated object. Size ranges from cm to decimeter for application as a compoundMaterialConstituentPart; larger concretions should be considered GeologicUnit parts.
Precipitation of translucent ice particles, which falls from a cloud. These particles are almost always spherical and sometimes have conical tips. Their diameter may attain or even exceed five millime
tres.