A multi-year study of radio-wave refractivity profiles above the Adriatic Sea up to an altitude of 40 km
Viher, Mladen; Prtenjak, Maja Teli Sman
Radio-wave refractivity conditions in the atmosphere are determined by the vertical gradient of the refractive index, which can be computed from regular aerological balloon probe measurements. This study is focused on the refractivity conditions over the Adriatic Sea using a multiannual series of data from four aerological stations. According to the refractive profiles computed from the aerological probes, two models are proposed: a polynomial model for both the troposphere and the stratosphere up to an altitude of 40 km and a much simpler linear model for the stratosphere alone. By confirming a discontinuity in the refractive conditions between the troposphere and stratosphere, both models exhibited a good fit and superior characteristics over a range of heights from the surface up to 40 km compared with the widely used simple exponential model. New recommended regular refractive profiles can be used as a guide for any type of long-range radio system design.