What occurs when dry, cold winter air causes plants to dry out?

The phenomenon you're referring to is accurately described as winter desiccation, which occurs when dry, cold air leads to moisture loss in plants. This is particularly common in evergreen species, which are more susceptible because they retain their leaves throughout winter.

During the winter months, when temperatures drop and humidity levels fall, plants can lose water faster than they can absorb it from the soil, especially if the ground may be frozen and not readily providing moisture. As a result, this excessive drying can cause significant damage to the plant tissues, leading to browning and dieback of the foliage.

This term directly captures the essence of the process—'desiccation' refers to extreme dryness, which clearly aligns with the symptoms observed in plants affected by this cold, dry air. The use of specific terminology helps in understanding and communicating the conditions affecting plant health in winter.