THE frost is a meteorological phenomenon characterized by the formation of a thin layer of ice on exposed surfaces, such as the ground and plants, resulting from the freezing of dew. It can also be described as a phenomenon that leads to the freezing and death of vegetation, which causes severe damage to farmers. In Brazil, its occurrence is common in the South and Southeast regions.
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frost summary
Frost is a meteorological phenomenon that consists of the formation of a layer of ice on surfaces exposed to the open, such as vegetation.
It is also characterized by the freezing of the internal structure of plants due to extreme cold, which can lead to their death.
It is formed by the freezing of dew and the deposition of a layer of ice on unprotected surfaces.
Frosts are classified as advective, radiative or mixed, according to their formation, and can be characterized as white frost or black frost, according to the appearance visual.
In Brazil, frosts occur mainly in the South and Southeast.
the frost and the snow consist of different phenomena, with different formation processes, and snow is a type of atmospheric precipitation.
What is frost?
frost is a phenomenon meteorological characterized by the formation of a layer slim of ice on surfaces exposed, as is the case with soil, plants and vehicles, for example. The occurrence of frost occurs in very cold periods and in places where there is the presence of water vapor (or humidity) in the layer of air closest to the earth's surface.
In Agronomy, frosts can also be understood as the very intense cold that leads to the death of plant tissues. In many cases, the occurrence of frosts results in the loss of entire crops and great damage to agriculture.
How does frost form?
the frosts form in the cold condition intense, when recorded temperatures are close to or lower than 0 °C. For this reason, they are more common in winter, but they are not restricted to that time of year. Frosts can be present, for example, during freezing nights and during the passage of a cold front.
With the sudden drop in temperatures, water on exposed surfaces in the form of dew (liquid state) reaches its freezing point, thus giving rise to the thin layer of ice that characterizes frost. The maintenance of cold weather causes the vapor present in the air to also change its physical state, thus causing its eventual deposition on leaves and vegetation in general, on cars, on windows, on the ground and on any other surfaces unprotected.
Also know: How does fog form?
types of frost
→ Classification according to the training process
Frost is classified according to its formation process into three types. See below.
◾ Advective frost
Advective frost is formed with the occurrence of very cold winds that cause a sudden drop in temperatures. These winds are produced by cold fronts, which mark the arrival of a mass of polar air in the region.
◾ Radiative or radiation frost
Radiative or radiating frost is formed during cold, dry nights with clear skies, without the presence of clouds and in the absence of winds. At these times, surfaces and air lose heat, which can result in frost.
◾ Mixed frost
Mixed frost is formed with the occurrence of processes characteristic of both advective and radiative frosts.
→ Classification according to visual appearance
The classification of frosts is also given according to their visual appearance. We thus have two types of frost. See below.
◾ White frost
White frost is characterized by the presence of a whitish layer of ice on the surfaces.
◾ Black Frost
Black frost is characterized by the death of vegetation in periods of intense cold without the deposition of a layer of ice on it, as if the vegetation were burned. Freezing, in this case, takes place in the interior systems of plants, leading to the loss of their functions.
frost in Brazil
The occurrence of frost is more common in the states of South regionfrom Brazil, which includes Rio Grande do Sul, Santa Catarina and Paraná, in parts of Southeast region, as in Sao Paulo, part of Rio de Janeiro and south of Minas Gerais, and also at the southern end of the Mato Grosso do Sul. The phenomenon is present especially during the autumn and winter months, when cold fronts are formed by the advance of the polar air mass.
The worst frost in Brazil happened in Paraná on July 18, 1975, causing many losses to farmers in the state. Reports carried out on the event indicate that almost all the coffee cultivars were lost due to extreme cold, in addition to other crops that were also decimated. Most of these losses were caused by the freezing of the plants themselves, even before the formation of the ice layer on them, and this frost is therefore characterized as black.|1|
Differences between frost and snow
Frost and snow are two distinct phenomena that form through different processes. See below.
Frost: characterized by a layer of ice that forms or is deposited on the exposed surface of plants and objects, and can be described as the freezing of the internal systems of plants due to extreme cold, without necessarily accumulating ice. It forms close to the ground.
Snow: consists of a type of atmospheric precipitation that originates within the clouds. It is formed by freezing water vapor in freezing conditions, giving rise to ice crystals and snowflakes. As with the rains, precipitation occurs when the weight of these structures overcomes the air resistance, thus causing snow.
Grades
|1| SAVIANI, Rodrigo. 'Black frost' that destroyed coffee trees in Paraná turns 40 years old. G1, 18 Jul. 2015. Available here.
By Paloma Guitarrara
Geography teacher
