On the search of sublimation regions in the interplanetary medium

In the nearest solar space, there is a specific region (up to ~ 20 Re), where intensive processes of sublimation of solid substance (interplanetary dust, meteoroid streams, etc.) take place. The resonance radiation of releasing atoms and low-charge ions is a reliable indicator of sublimation processes. Sublimation regions in ground-based observations can be detected only during total solar eclipses, because of extremely low intensity of such a radiation. These observations have been conducted during five solar eclipses since 1997. Here we present the main findings of the observations and discuss prospects of further investigations.