  The phenomenon of the Gnevyshev gap was first identified in the solar-corona
irradiance data (green line). Later, it was studied in the sunspot, coronal,
and heliospheric data. We have investigated the Gnevyshev gap in the magnetic
field data and have arrived at the conclusion that it reflects the behavior of
the large-scale magnetic field. The Gnevyshev gap occurs at the polarity
reversal of the solar magnetic field at the photosphere level. The presence of
the Gnevyshev gap in sunspot data at the photosphere level is disguised by
non-global structures that retain dependence on both latitude and longitude
(the accepted mathematical term is tessaral, see below for more details).
However, it is clearly visible in the magnetic field data at the photosphere
level and is even more pronounced at the source surface (i.e., in the corona).
