Lebmung, it seems you don't know what is "inversion" nor "infrared radiation". You are always speaking of cold winds but inversion occurs only when there is no wind but clear sky. There are two ways to get colds. You speak of one way and Ilya speaks of the other.
The best would be to read few things about it.
> The soil is hotter than the air
yes, this is usually true. The frost damages are very rare in the first 5 cm (2inc). But when in the 'inversion conditions' the temperature at 10 cm are much lower than at 1 meter.
This effect is often called inverse greenhouse effect.
Cold continental climate is the perfect place for inversion conditions. Romania cannot be an exception...