NSIDC's website will undergo planned maintenance on Wednesday, January 15, from 10 a.m. to 12 p.m. (U.S. Mountain Time). During this time, the NSIDC.org website and most NSIDC data access may be briefly unavailable.
electromagnetic wave
an oscillation of the electric or magnetic field associated with the propagation of energy; characterized by their wavelengths and amplitude; propagate at the speed of light.