Mount Mangart and Mount Jalovec on a Typical Anticyclonic Day with Visible and Marked Valley Thermal Inversion; Upper "Rio del Lago" Valley; Julian Alps, Udine, FVG, Italia
15-November-2024
Sunny peaks with mild and dry air, shady valley with frosty, humid and cold air: it is a classic of some alpine valleys, plains and basins in conditions of high pressure and calm wind during the late autumn and winter period.
The valley hoar frost (produced by freezing fog that then dissolved) makes this air column reversal gradient evident.
The cold air, heavier, stagnates towards the bottom while the warm, lighter, air slides above it, so every long night with clear skies the air in the valley becomes colder and more humid.
It is an orographic/microclimatic self-produced cold, due to the loss of heat from soil towards space which occurs mainly during the late autumn (and winter) long clear nights but which also persists during the day, due to the weak and low sun on the horizon, with greater evidence in the shaded areas.
Mount Mangart and Mount Jalovec on a Typical Anticyclonic Day with Visible and Marked Valley Thermal Inversion; Upper "Rio del Lago" Valley; Julian Alps, Udine, FVG, Italia
15-November-2024
Sunny peaks with mild and dry air, shady valley with frosty, humid and cold air: it is a classic of some alpine valleys, plains and basins in conditions of high pressure and calm wind during the late autumn and winter period.
The valley hoar frost (produced by freezing fog that then dissolved) makes this air column reversal gradient evident.
The cold air, heavier, stagnates towards the bottom while the warm, lighter, air slides above it, so every long night with clear skies the air in the valley becomes colder and more humid.
It is an orographic/microclimatic self-produced cold, due to the loss of heat from soil towards space which occurs mainly during the late autumn (and winter) long clear nights but which also persists during the day, due to the weak and low sun on the horizon, with greater evidence in the shaded areas.