The paper proposes a method for determining the level above which can be considered a slips in determining the time rate of total electron content (TEC). The method is based on a statistical estimation of the properties of the distribution for the studied parameter. The aim of the method is the experimental determination of the threshold values of TEC jumps, associated with the "tails" of the studied distributions for a given physically adequate level of significance defined by latitudinal properties of geo- and heliophysical conditions. It was found that the threshold value (from which the measured values can be considered as statistical noise) depends on the latitude of the observation region. The maximum of threshold is for the Arctic region, minimum - to the middle lattitude band stations. The method application performed for different sets of 400 IGS network stations located in the high (200 plants), middle (over 100) and equatorial latitudes (over 100 stations) respectively. The test methodics is conducted for the 2010 and 2014 in a variety of geo- and heliophysical conditions and phases of the solar cycle 24. As the level of significance we selected range "two dispersions".
94.20.Vv Ionospheric disturbances, irregularities, and storms
94.20.wh Ionosphere/magnetosphere interactions
94.80.+g Instrumentation for space plasma physics, ionosphere, and magnetosphere
$^1$1Department of Physics of atmosphere, Faculty of physics, Lomonosov Moscow State University\
$^2$Institute of Solar-Terrestrial Physics SB RAS