ESTIMATION AND ANALYSIS OF THE RADIO REFRACTIVITY, ITS GRADIENT AND THE GEOCLIMATIC FACTOR IN ARCTIC REGIONS

In this paper, local meteorological data of one year have been used to calculate the surface atmospheric radio refractivity (N) and estimate the vertical refractivity gradient (dN(1)) as well as the geoclimatic factor (K) in the lowest atmospheric layer above the ground surface in the station Kuujjuaq (Quebec, Canada). In this region, the climate is arctic, characterized by very long and very cold winters (on average the temperature is below -20 degrees C for almost 240 days per year). The precipitations are almost nonexistent, and the vegetation is scarce. Average daily, monthly, seasonal, and yearly variations of N, dN(1), and K are estimated and analysed. The obtained values of these indices are compared to the corresponding values provided by the ITU. The results show that the more negative values of dN(1) lie in the summer season. This is mainly due to the important variations of the temperature and humidity during this season. However, the estimated values lie in the limits mostly corresponding to standard refraction.