Determining and recording the total amount of clouds. Determining and recording the total amount of clouds What cloudiness can be completely 10 points

Cloudiness is determined visually using a 10-point system. If the sky is cloudless or there are one or more small clouds occupying less than one tenth of the entire sky, then the cloudiness is considered equal to 0 points. When cloudiness is 10 points, the entire sky is covered with clouds. If 1/10, 2/10, or 3/10 parts of the sky are covered with clouds, then the cloudiness is considered equal to 1, 2, or 3 points, respectively.

Determination of light intensity and background radiation level*

Photometers are used to measure illumination. The deflection of the galvanometer needle determines the illumination in lux. You can use photo exposure meters.

To measure the level of background radiation and radioactive contamination, dosimeters-radiometers (Bella, ECO, IRD-02B1, etc.) are used. Typically, these devices have two operating modes:

1) assessment of background radiation based on the equivalent dose rate of gamma radiation (μSv/h), as well as contamination by gamma radiation of samples of water, soil, food, crop products, livestock, etc.;

* Units of measurement of radioactivity

Radionuclide activity (A)- reduction in the number of radionuclide nuclei over a certain

long time interval:

[A] = 1 Ci = 3.7 · 1010 disp./s = 3.7 · 1010 Bq.

Absorbed radiation dose (D) is the energy of ionizing radiation transferred to a certain mass of the irradiated substance:

[D] = 1 Gy = 1 J/kg = 100 rad.

Equivalent radiation dose (N) equal to the product of the absorbed dose by

average quality factor of ionizing radiation (K), taking into account biological

gical effect of various radiations on biological tissue:

[H] = 1 Sv = 100 rem.

Exposure dose (X) is a measure of the ionizing effect of radiation, united

the value of which is 1 Ku/kg or 1 R:

1 P = 2.58 · 10-4 Ku/kg = 0.88 rad.

Dose rate (exposure, absorbed or equivalent) is the ratio of the dose increment over a certain time interval to the value of this time interval:

1 Sv/s = 100 R/s = 100 rem/s.

2) assessment of the degree of contamination of surfaces and samples of soil, food, etc. with beta-, gamma-emitting radionuclides (particles/min. cm2 or kBq/kg).

The maximum permissible radiation dose is 5 mSv/year.

Determination of the radiation safety level

The level of radiation safety is determined using the example of using a household dosimeter-radiometer (IRD-02B1):

1. Set the operating mode switch to the “μSv/h” position.

2. Turn on the device by setting the “off-on” switch.

V "on" position. Approximately 60 s after switching on the device is ready

to work.

3. Place the device in the place where the equivalent dose rate is determined gamma radiation. After 25-30 s, the digital display will display a value that corresponds to the dose rate of gamma radiation in a given location, expressed in microsieverts per hour (µSv/h).

4. For a more accurate assessment, it is necessary to take the average of 3-5 consecutive readings.

A reading on the digital display of the device of 0.14 means that the dose rate is 0.14 μSv/h or 14 μR/h (1 Sv = 100 R).

25-30 seconds after the device starts operating, it is necessary to take three consecutive readings and find the average value. Present the results in the form of a table. 2.

Table 2. Determination of radiation level

		Instrument readings		Average value
				dose rate

Registration of the results of microclimatic observations

Data from all microclimatic observations are recorded in a notebook, and then processed and presented in the form of a table. 3.

Table 3. Results of microclimate processing

observations

Temperature

ra air

Temperature

Humidity

on high,

ra of air,

air on

height, %

The concept of “cloudiness” refers to the number of clouds observed in one place. Clouds, in turn, are atmospheric phenomena formed by a suspension of water vapor. The classification of clouds includes many types, divided by size, shape, nature of formation and height of location.

In everyday life, special terms are used to measure cloudiness. Expanded scales for measuring this indicator are used in meteorology, maritime affairs and aviation.

Meteorologists use a cloudiness scale of ten, which is sometimes expressed as a percentage of the visible sky (1 point = 10% coverage). In addition, the height of cloud formation is divided into upper and lower tiers. The same system is used in maritime affairs. Aviation meteorologists use a system of eight octants (parts of the visible sky) with a more detailed indication of the height of the clouds.

A special device is used to determine the lower boundary of the clouds. But only aviation weather stations have an urgent need for it. In other cases, a visual assessment of the height is made.

Cloud types

Cloudiness plays an important role in shaping weather conditions. Cloud cover prevents heating of the Earth's surface and prolongs its cooling process. Cloud cover significantly reduces daily temperature fluctuations. Depending on the amount of clouds at a certain time, several types of cloudiness are distinguished:

1. “Clear or partly cloudy” corresponds to cloudiness of 3 points in the lower (up to 2 km) and middle tier (2 - 6 km) or any amount of clouds in the upper (above 6 km).
2. “Variable or variable” - 1-3/4-7 points in the lower or middle tier.
3. “With clearing” - up to 7 points of total cloudiness of the lower and middle tier.
4. “Cloudy, cloudy” - 8-10 points in the lower tier or non-transparent clouds in the middle, as well as with precipitation in the form of rain or snow.

Types of clouds

The World Classification of Clouds identifies many types, each of which has its own Latin name. It takes into account the shape, origin, height of formation and a number of other factors. The classification is based on several types of clouds:

• Cirrus clouds are thin filaments of white color. They are located at an altitude of 3 to 18 km depending on latitude. They consist of falling ice crystals, which give them their appearance. Among cirrus clouds at an altitude of over 7 km, clouds are divided into cirrocumulus, altostratus, which have a low density. Below, at an altitude of about 5 km, there are altocumulus clouds.
• Cumulus clouds are dense formations of white color and considerable height (sometimes reaching more than 5 km). They are most often located in the lower tier with vertical development into the middle. Cumulus clouds at the top of the middle layer are called altocumulus.
• Cumulonimbus, shower and thunderclouds, as a rule, are located low above the Earth's surface, 500-2000 meters, and are characterized by precipitation in the form of rain and snow.
• Stratus clouds are a layer of low-density suspension. They transmit light from the sun and moon and are located at an altitude of between 30 and 400 meters.

Cirrus, cumulus and stratus types mix to form other types: cirrocumulus, stratocumulus, cirrostratus. In addition to the main types of clouds, there are other, less common ones: silvery and pearlescent, lenticular and moth-like. And clouds formed by fires or volcanoes are called pyrocumulative.

Thanks to the shielding effect, it prevents both the cooling of the Earth's surface due to its own thermal radiation and its heating by solar radiation, thereby reducing seasonal and daily fluctuations in air temperature.

Cloud characteristics

Number of clouds

The amount of clouds is the degree of cloud coverage of the sky (at a certain moment or on average over a certain period of time), expressed on a 10-point scale or as a percentage of coverage. The modern 10-point cloudiness scale was adopted at the first Marine International Meteorological Conference (Brussels,).

When observed at meteorological stations, the total number of clouds and the number of lower clouds are determined; these numbers are recorded in weather diaries separated by fractional slashes, for example 10/4 .

In aviation meteorology, an 8-octant scale is used, which is simpler for visual observation: the sky is divided into 8 parts (that is, in half, then in half and again), cloudiness is indicated in octants (eighths of the sky). In aviation meteorological weather reports (METAR, SPECI, TAF), the amount of clouds and the height of the lower boundary are indicated by layers (from the lowest to the highest), and gradations of quantity are used:

• FEW - minor (scattered) - 1-2 octants (1-3 points);
• SCT - scattered (separate) - 3-4 octants (4-5 points);
• BKN - significant (broken) - 5-7 octants (6-9 points);
• OVC - solid - 8 octants (10 points);
• SKC - clear - 0 points (0 octants);
• NSC - no significant cloudiness (any amount of clouds with a base height of 1500 m and above, in the absence of cumulonimbus and powerful cumulus clouds);
• CLR - no clouds below 3000 m (the abbreviation is used in reports generated by automatic weather stations).

Cloud shapes

Observed cloud forms are indicated (Latin notations) in accordance with the international cloud classification.

Cloud Base Height (BCL)

The VNGO of the lower tier is determined in meters. At a number of weather stations (especially aviation ones), this parameter is measured by a device (10-15% error), at others - visually, approximately (in this case, the error can reach 50-100%; visual VNGO is the most unreliably determined weather element). Depending on the VNGO, cloudiness can be divided into 3 tiers (Lower, Middle and Upper). The lower tier includes (approximately up to a height of 2 km): stratus (precipitation may fall in the form of drizzle), nimbostratus (overlying precipitation), stratocumulus (in aviation meteorology, ruptured-stratus and ruptured-nimbus are also noted). Middle layer (from approximately 2 km to 4-6 km): altostratus and altocumulus. Upper level: cirrus, cirrocumulus, cirrostratus clouds.

Cloud top height

Can be determined from aircraft and radar sounding of the atmosphere. It is usually not measured at weather stations, but in aviation weather forecasts for flight routes and areas, the expected (predicted) height of the cloud top is indicated.

see also

Sources

Seasons Tropical seasons Weather conditions Precipitation Weather forecast and diary

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Excerpt describing Cloudiness

Finally, the elder Dron entered the room and, bowing low to the princess, stopped at the lintel.
Princess Marya walked around the room and stopped opposite him.
“Dronushka,” said Princess Marya, who saw in him an undoubted friend, the same Dronushka who, from his annual trip to the fair in Vyazma, brought her his special gingerbread every time and served her with a smile. “Dronushka, now, after our misfortune,” she began and fell silent, unable to speak further.
“We all walk under God,” he said with a sigh. They were silent.
- Dronushka, Alpatych has gone somewhere, I have no one to turn to. Is it true that they tell me that I can’t leave?
“Why don’t you go, your Excellency, you can go,” said Dron.
“They told me it was dangerous from the enemy.” Darling, I can’t do anything, I don’t understand anything, there’s no one with me. I definitely want to go at night or early tomorrow morning. – The drone was silent. He glanced at Princess Marya from under his brows.
“There are no horses,” he said, “I told Yakov Alpatych too.”
- Why not? - said the princess.
“It’s all from God’s punishment,” said Dron. “Which horses there were were dismantled for use by the troops, and which ones died, what year it is today.” It’s not like feeding the horses, but making sure we don’t die of hunger ourselves! And they sit like that for three days without eating. There is nothing, they are completely ruined.
Princess Marya listened carefully to what he told her.
- Are the men ruined? Do they have no bread? – she asked.
“They’re dying of starvation,” said Dron, “not like the carts...”
- Why didn’t you tell me, Dronushka? Can't you help? I will do everything I can... - It was strange for Princess Marya to think that now, at such a moment, when such grief filled her soul, there could be rich and poor people and that the rich could not help the poor. She vaguely knew and heard that there was master's bread and that it was given to the peasants. She also knew that neither her brother nor her father would refuse the needs of the peasants; she was only afraid of somehow making a mistake in her words about this distribution of bread to the peasants, which she wanted to dispose of. She was glad that she had been presented with an excuse for concern, one for which she was not ashamed to forget her grief. She began asking Dronushka for details about the needs of the men and about what was lordly in Bogucharovo.
– After all, we have the master’s bread, brother? – she asked.
“The master’s bread is all intact,” Dron said proudly, “our prince did not order it to be sold.”
“Give him to the peasants, give him everything they need: I give you permission in the name of my brother,” said Princess Marya.
The drone said nothing and took a deep breath.
- Give them this bread if it is enough for them. Give everything away. I command you in the name of my brother, and tell them: what is ours is also theirs. We will spare nothing for them. So tell me.
The drone looked intently at the princess while she spoke.
“Dismiss me, mother, for God’s sake, tell me to accept the keys,” he said. “I served for twenty-three years, I didn’t do anything bad; leave me alone, for God's sake.
Princess Marya did not understand what he wanted from her and why he asked to dismiss himself. She answered him that she never doubted his devotion and that she was ready to do everything for him and for the men.

An hour after this, Dunyasha came to the princess with the news that Dron had arrived and all the men, by order of the princess, gathered at the barn, wanting to talk with the mistress.
“Yes, I never called them,” said Princess Marya, “I only told Dronushka to give them bread.”
“Only for God’s sake, Princess Mother, order them away and don’t go to them.” It’s all just a lie,” Dunyasha said, “and Yakov Alpatych will come and we’ll go... and if you please...

Purpose of the lesson: study the classification of clouds and master the skills of determining the type of clouds using the “Cloud Atlas”

General provisions

The processes of formation of a separate cloud occur under the influence of many factors. Clouds and the precipitation that falls from them play a vital role in the formation of various types of weather. Therefore, cloud classification provides specialists with the opportunity to monitor the spatiotemporal variability of cloud formations, which is a powerful tool for studying and predicting processes occurring in the atmosphere.

The first attempt to divide clouds into different groups according to their appearance was made in 1776 by J. B. Lamarck. However, the classification he proposed, due to its imperfection, did not find wide application.

changes. The first classification of clouds included in science was developed by the English amateur meteorologist L. Howard in 1803. In 1887, scientists Hildebrandson in Sweden and Abercrombie in England, having revised the classification of L. Howard, proposed a draft of a new classification, which formed the basis for all subsequent classifications . The idea of ​​​​creating the first unified cloud atlas was supported at the International Conference of Directors of Meteorological Services in Munich in 1891. The committee created by it prepared and published in 1896 the first International Cloud Atlas with 30 color lithographs. The first Russian edition of this Atlas was published in 1898. The further development of meteorology and the introduction into practice of synoptic analysis of the concepts of atmospheric fronts and air masses required a much more detailed study of clouds and their systems. This predetermined the need for a significant revision of the classification used at that time, which resulted in the publication in 1930 of a new International Cloud Atlas. This Atlas was published in Russian in 1933 in a slightly abbreviated version.

Clouds and precipitation falling from them are among the most important meteorological (atmospheric) phenomena and play a decisive role in the formation of weather and climate, in the distribution of flora and fauna on Earth. By changing the radiation regime of the atmosphere and the earth's surface, clouds have a noticeable impact on the temperature and humidity regime of the troposphere and ground layer of air, where human life and activity takes place.

A cloud is a visible collection of droplets and/or crystals suspended in the atmosphere and in the process of continuous evolution, which are products of condensation and/or sublimation of water vapor at altitudes from several tens of meters to several kilometers.

Changes in the phase structure of the cloud - the ratio of droplets and crystals by mass, number of particles and other parameters per unit volume of air - occur under the influence of temperature, humidity and vertical movements both inside and outside the cloud. In turn, the release and absorption of heat as a result of phase transitions of water and the presence of particles themselves in the air flow have a reverse effect on the parameters of the cloud environment.

Based on their phase structure, clouds are divided into three groups.

1. Water, consisting only of droplets with a radius of 1-2 microns or more. Drops can exist not only at positive, but also at negative temperatures. The purely droplet structure of the cloud is maintained, as a rule, to temperatures of the order of –10...–15 °C (sometimes lower).

2. Mixed, consisting of a mixture of supercooled drops and ice crystals at temperatures of –20...–30 °C.

3. Ice, consisting only of ice crystals at fairly low temperatures (about –30...–40 °C).

Cloud cover during the day reduces the influx of solar radiation to the earth's surface, and at night it noticeably weakens its radiation and, consequently, cooling, very significantly reduces the daily amplitude of air and soil temperatures, which entails a corresponding change in other meteorological quantities and atmospheric phenomena.

Regular and reliable observations of cloud forms and their transformation contribute to the timely detection of dangerous and unfavorable hydrometeorological phenomena accompanying a particular type of cloud.

The meteorological observation program includes monitoring the dynamics of cloud development and determining the following cloud characteristics:

a) the total number of clouds,

b) the number of low-level clouds,

c) the shape of the clouds,

d) the height of the lower boundary of the lower or middle level clouds (in the absence of lower level clouds).

The results of observations of cloudiness from meteorological observation units in real time using code KN-01 (national version of the international code FM 12-IX SYNOP) are regularly transmitted to local forecasting authorities (organizations and divisions of UGMS) and the Hydrometeorological Research Center of the Russian Federation (Hydrometcenter Russia) for synoptic analysis and preparation of weather forecasts at various lead times. In addition, these data are calculated over different time intervals and are used for climate assessments and generalizations.

The amount of clouds is defined as the total proportion of the sky covered by clouds from the entire visible surface of the sky and is estimated in points: 1 point is 0.1 share (part) of the entire sky, 6 points is 0.6 sky, 10 points is the entire sky is covered by clouds .

Long-term observations of clouds have shown that they can be located at different heights, both in the troposphere and in the stratosphere and even in the mesosphere. Tropospheric clouds are usually observed as isolated, isolated cloud masses or as a continuous cloud cover. Depending on their structure, clouds are divided by appearance into shapes, types and varieties. Noctilucent and nacreous clouds, in contrast to tropospheric clouds, are observed quite rarely and are characterized by relatively little diversity. The classification of tropospheric clouds by appearance currently used is called the international morphological classification.

Along with the morphological classification of clouds, genetic classification is also used, i.e. classification according to the conditions (reasons) for the formation of clouds. In addition, clouds are classified according to their microphysical structure, i.e., by their state of aggregation, type and size of cloud particles, as well as by their distribution within the cloud. According to the genetic classification, clouds are divided into three groups: stratus, wavy and cumuliform (convective).

The main distinguishing features when determining the shape of clouds are their appearance and structure. Clouds can be located at different heights in the form of separate isolated masses or a continuous cover, their structure can be different (homogeneous, fibrous, etc.), and the lower surface can be smooth or dissected (and even torn). In addition, clouds can be dense and opaque or thin - the blue sky, moon or sun shines through them.

The height of clouds of the same shape is not constant and may vary somewhat depending on the nature of the process and local conditions. On average, cloud heights are greater in the south than in the north, and greater in summer than in winter. Clouds are lower over mountainous regions than over plains.

An important characteristic of clouds is the precipitation that falls from them. Clouds of some forms almost always produce precipitation, while others either do not produce precipitation at all, or precipitation from them does not reach the surface of the earth. The fact of precipitation, as well as its type and nature of precipitation, serve as additional signs for determining the shapes, types and varieties of clouds. The following types of precipitation fall from clouds of certain shapes:

– showers – from cumulonimbus clouds (Cb);

– covered – from nimbostratus (Ns) in all seasons, from altostratus (As) – in winter and sometimes weak – from stratocumulus (Sc);

– drizzling – from stratus clouds (St).

In the process of development and decay of a cloud, its appearance and structure change and it can transform from one form to another.

When determining the number and shape of clouds, only clouds visible from the earth's surface are taken into account. If the entire sky or part of it is covered with clouds of the lower (middle) tier, and clouds of the middle (upper) tier are not visible, this does not mean that they are absent. They may be above underlying cloud layers, but this is not taken into account in cloud observations.

Cloudiness- a complex of clouds that appear in a certain place on the planet (local point or territory) at a certain moment or period of time.

Types of clouds

This or that type of cloudiness corresponds to certain processes occurring in the atmosphere, and therefore foreshadows this or that weather. Knowing the types of clouds from a navigator's point of view is important for predicting weather based on local conditions. For practical purposes, clouds are divided into 10 main forms, which in turn are divided by height and vertical extent into 4 types:

Clouds of large vertical development. These include:

Cumulus. Latin name: Cumulus(indicated as Cu on weather maps)– isolated thick vertically developed clouds. The upper part of the cloud is dome-shaped, with prominences, the lower part is almost horizontal. The average vertical extent of the cloud is 0.5 -2 km. The average height of the lower base from the earth's surface is 1.2 km.

– heavy masses of clouds of large vertical development in the form of towers and mountains. The upper part is a fibrous structure, often with anvil-shaped projections to the sides. The average vertical length is 2-3 km. The average height of the lower base is 1 km. They often produce showers accompanied by thunderstorms.

Low level clouds. These include:

– low, amorphous, layered, almost uniform rain clouds of a dark gray color. The lower base is 1-1.5 km. The average vertical extent of the cloud is 2 km. Precipitation falls from such clouds.

– a homogeneous light gray foggy veil of continuous low clouds. Often form from rising fog or develop into fog. The height of the lower base is 0.4 - 0.6 km. The average vertical length is 0.7 km.

- Low cloud cover, consisting of individual ridges, waves, plates or flakes, separated by gaps or translucent areas (translucent) or without clearly visible gaps, the fibrous structure of such clouds is more clearly visible at the horizon.

Mid-level clouds. These include:

– a fibrous veil of gray or bluish color. The lower base is located at an altitude of 3 – 5 km. Vertical length - 04 - 0.8 km).

– layers or spots consisting of highly flattened rounded masses. The lower base is located at an altitude of 2 – 5 km. The average vertical extent of the cloud is 0.5 km.

Upper level clouds. They are all white and provide almost no shadow during the day. These include:

Cirrostratus (Cs) - a thin whitish translucent veil, gradually covering the entire sky. They do not obscure the outer contours of the Sun and Moon, causing a halo to appear around them. The lower boundary of the cloud is at an altitude of about 7 km.