The caves with single entrance have a circulation "air bag style" really? The hygrothermal conditions of Andrassa (Ligury, Italy)

The study illustrates the hygrothermal conditions of a cave (Andrassa) that has the ideal morphology for a circulation "air bag style", where the winter temperature is determined by a convective circulation, which comes from the entrance. We examined the seasonal conditions. Indirectly, the temperature distribution in air and ground indicates the direction of air flow, even when the flows are too slow for direct measurements. The results show that the water in Andrassa cave influences the ground temperature more than air. So, in summer the cave air is colder than on the outside, but the air enters at least at 180 m from the entrance. This condition lasts from spring to autumn: the transitional seasons of the "air bag style", in which “air little circulates, with direction that varies, depending on the temperature variation of the outside air”, there are not. During winter, the cave air is a bit hotter (like in the model named "air bag style"), and the thermic gradient is actually negative upwards, but only as far as 60 m from the entrance. It is not there “a short transition zone” between a deep air (cold and homogeneous) and an entrance-zone air (at a temperature that reaches quickly the outside value). The water circulation definitely influences the temperatures of Andrassa. With its weak runoff, and its normal oozing, Andrassa represents the commonest type of cave developed downwards and with single entrance. It seems very probable that the "air bag" model of circulation is not the rule for all caves similar to Andrassa, but is limited to very dry caves.