The E region at 69°N, 19°E: Trends, significances, and detectability

摘要: [1] Earlier, it has been demonstrated that ionospheric parameters such as critical frequencies and layer heights exhibit long-term trends. These trends have reported to be both positive negative depending on parameter geographic location, forming a picture is difficult explain in terms of physics combined with the widely accepted climatic cooling underlying middle atmosphere. Here we present updated results from Tromso (69°N, 19°E) confirming previously identified trend E region frequency (and therefore electron density) altitude (commensurable shrinking atmosphere). We note data sets are not necessarily best described by Gaussian distributions. quantify uncertainties required time series lengths for detectability basis true probability density functions, giving high credibility climate change lower thermosphere.