Climate and climate resources of Uzbekistan Plan

Climate and climate resources of Uzbekistan

Plan:

1. Climate of Uzbekistan

2. Water resources of Uzbekistan
3. Temperature distribution
4. Seasons in Uzbekistan
Uzbekistan is a continental climate due to its remoteness from the oceans and seas and the interior of the Eurasian continent. In Uzbekistan, there are large differences between the annual changes in all elements of the climate, which depend primarily on the characteristics of climate-forming factors.
The climate of Uzbekistan is formed as a result of its geographical location and, in connection with it, solar radiation, atmospheric circulation, relief, the condition of the earth's surface, the impact of human activities on the climate (anthropogenic).
One of the most important factors in shaping the climate of Uzbekistan is its geographical location and associated solar radiation. Solar radiation is the energy base of all natural processes. Solar radiation, in turn, depends on the latitude of the place, the openness of the air and the period of the Sun's radiance.
It is known that Uzbekistan is located in the desert zone, mainly in subtropical latitudes, inside the oceans. This plays an important role in the formation of some features of its climate, such as the fact that the Sun is above the horizon, illuminating and heating for a long time, and less cloudy. Due to the fact that Uzbekistan is located in the far southern latitudes (about 37 ° and 45 ° -36 northern latitudes), it is summer. The sun shines more steeply (71-72 ° in the north and 760 ° in the south in June) and shines for a long time. In winter, the sun has an angle of 21 ° in the north and 29 ° in the south of Uzbekistan. Due to the fact that the territory of our republic stretches from north to south by 8 ° 25, the period of solar radiation and, in connection with it, the amount of total solar radiation also changes. Therefore, in Tashkent, the Sun shines an average of 2,889 hours a year, while in the southernmost Termez, the figure is 3,095 hours. The weather in Uzbekistan is clear all year round, especially in summer. Cloudy days are rare. Due to this, in May-October, which is the period of ripening of agricultural crops in the country, the sun shines in Tashkent 1749 hours, in Termez - 2012 hours. However, this figure reaches Cairo (located at about 30 ° N) (see Table 1), because Cairo is close to the Mediterranean Sea, so there are more cloudy days than in Tashkent and Termez. Therefore, it is no coincidence that Uzbekistan is a sunny country. In Uzbekistan, the period of sunshine in summer (June-August) is 84-95% of the period of radiance, and in winter (December-February) is 40-50%.
In the mountainous part of Uzbekistan, the period of solar radiation is 600-700 hours less than in the plains: at an altitude of 2,000 m in the mountains, the Sun shines an average of 2,300-2,500 hours a year. The main reason for this is the increase of cloudy days along the mountain slope, the position of the mountain slope relative to the sun (exposure).
Due to the fact that the sun is higher than the horizon in Uzbekistan, there are many cloudless days (90 days a year in Tashkent and 57 days in Termez), the sun shines for a long time, so a lot of light energy (heat) ) falls. In the northern part of the country, 136-140 kilocalories of heat per cm2 per year, ie in the southern part, 160 kilocalories of heat. The amount of total solar radiation is not evenly distributed throughout the year. The highest solar radiation is in the summer months (5 times more than in the winter months). Even in the south of Uzbekistan in July the radiation balance reaches 20 kcal / cm2. This is because in summer the sun rises above the horizon and shines and warms for a long time. On the contrary, in winter the sunlight falls flat, the cloudy days shed less light than they used to, and the albedo becomes larger due to the snow cover. As a result, in winter, especially in January, the total amount of radiation is positive in the central and southern parts of Uzbekistan, amounting to 0.1-1.0 kcal per cm2. However, in the north-western part of the republic (Ustyurt) in some years in winter the balance of radiation can be negative.
Atmospheric circulation (change of air masses) also plays an important role in the formation of the climate of Uzbekistan. The territory of the republic is affected by the following three main air masses throughout the year. Arctic, temperate and tropical.
In order to get a good idea of ​​the changing characteristics of the atmospheric circulation in the territory of Uzbekistan, we describe the hot (summer) and cold (winter) seasons of the year. In winter, the territory of Uzbekistan is more arctic and temperate (qu tbiy) under the influence of air masses, which enter from the northwest, north and northeast.
It is known that Turkestan, including Uzbekistan, is located south of the high-pressure barometric axis formed by the Siberian anticyclone in winter. As a result, air mass entered the territory of Uzbekistan from the same high-pressure barometric axis, ie from the north-east. Due to the anti-cyclone nature of this air mass, when it enters Uzbekistan, the air is clear, but at night it is dry and cold, and during the day it is slightly warm under the influence of sunlight, and there is almost no precipitation. This weather can last for three days, sometimes up to five days. Such weather is 28% of winter days. As a result, weak air masses from other regions of Uzbekistan also changed their properties under the influence of the same Siberian anticyclone (temperate Siberian-polar) air mass, and Turan (local continental) air forms a mass.
In winter, warm tropical air masses sometimes enter the territory of Uzbekistan from Iran-Afghanistan. As a result, in the southern part of Turkestan there is a polar front, which separates the temperate zone from the cold tropical air from Iran and Afghanistan. The weather around the front line is unstable, the movement of cyclones intensifies, and the south of the Caspian Sea and through the Tajang and Murgab valleys between Kopetdag and Parapamiz Mountains enters Turkestan and moves to the north-east. As a result, it will be weakened on the territory of Kazakhstan.
Due to the fact that the Oiklons bring with them a mass of warm tropical air, the air in the areas covered by them hangs (the temperature rises to 15-20), the clouds increase and it rains. Such weather is 25% of winter days. forms.
Mild and Arctic cold air masses blow through the south-eastern part of the Russian Plain to the territory of Uzbekistan from the north-west and north. These air masses make up 24% of winter wool. The air mass invading from the north-west will significantly cool the territory of Uzbekistan and reduce the daily temperature by -10-20 °. In addition, sometimes in winter, the Arctic cold air mass infiltrates and stagnates, and in January the temperature can drop to -35 °. Such colds were observed in December 1930, December 1948, January 1949, and January 1969. Similar cold days in the winter of 1948/49 occurred in southern Uzbekistan and even in Iran, where many fruit trees were frozen and dried up.
As mentioned above, as a result of the eastward movement of the oceans, the sea air mass of the temperate zone enters the territory of Uzbekistan from the west. As this air mass passes through the Mediterranean and Black Seas, it becomes humid, causing rain and sometimes snow. Such weather is 11% of the winter days.
In hot weather, air circulation in Uzbekistan differs sharply from winter. Since May, due to the rapid warming of the air of the Turan plain, a low-pressure center - thermal depression - has been formed. As a result, the air becomes very hot and the local continental Turan tropical air is formed. During this period, the temperature in Uzbekistan rose and reached 50 ° in Termez. Such weather (days of thermal depression) makes up 15% of the summer period.
In summer, in the north of the Turan plain, there is a moderate (polar) front line, one network is in Kazakhstan, and the other network is located in the north of the Black Sea and the middle reaches of the Volga River, where air pressure is high. As a result of thermal depression, the same high-pressure air mass is drawn in like a suction pump, and a mass of cool air blows from the north, northwest and west to the Turanian plane. According to the data, in summer the northern and north-western (38% of summer days) and western (29% of summer days) cool air masses are repeated in the Turan plain 1.5-2.0 times more than in winter. . However, due to overheating of the Turan plain, it does not change its climate, only lowers the temperature by 3-10 °, so the air is still clear, dry, low relative humidity, and condensation is difficult. Due to this, in the Turan plain, the northern, northwestern and western air masses are abundant in summer, but there is no precipitation. These air masses cool in the mountains of Uzbekistan (due to the cooling of the air as they rise) and form clouds.precipitation, sometimes in the form of snow.
Air currents blowing in Uzbekistan in summer.
The composition of the climate of Uzbekistan is also influenced by its surface structure - relief. The eastern and southern parts of Uzbekistan are surrounded by mountains, and the western and northern parts are open. Therefore, cold air masses from the north, northwest and west can easily enter its territory. The presence of mountains such as Paropamiz in the southern part of our country prevents the inflow of warm tropical air masses. The effect of relief on the climate of the republic can also be seen in the distribution of precipitation. It is known that the humid western and northwestern air masses blow more in summer than in winter, but the plains do not produce precipitation due to the extreme heat in summer, and in the mountainous part due to low temperatures condensation. rain or snow. In addition, the western and south-western slopes of the mountains of the same height receive more precipitation, while the humid air masses receive less precipitation on the opposite slopes. The impact of relief on the climate can be seen in the example of the Surkhan-Sherabad valley. Due to the fact that the valley is surrounded by mountains from the east, north and west, it blocks the flow of cold air, as a result of which the winter is warmer than in other parts of Uzbekistan. and 3.6 °. Relief affects not only the distribution of temperature and precipitation in the country, but also the formation of winds, especially local winds - Fyon, Garmsel, Afghan wind, Bekabad wind.
The climate of Uzbekistan is also affected by its surface condition, ie snow cover, soils and vegetation. Because the ability of the snow cover to reflect solar radiation (alhbedo) is very large (80-90% of the radiation falling on the snow surface is returned). This causes the air on the surface to become much colder. As a result, the air cools down further, causing severe winters. However, in Uzbekistan, the snow cover is unstable and may not melt for 30 days in the north and 1-3 days in the south. In the mountainous part, the snow cover is stable, and in the highest parts it is preserved in summer. This, in turn, partially affects the cooling of the air.
The plains of Uzbekistan are mostly covered with sand, there is brown and gray soil, vegetation is sparse. This absorbs most of the sun's radiation and reflects back a small portion, causing the air to heat up.
Anthropogenic factors also influence the formation of the climate of Uzbekistan. This is due to population growth and urbanization, increase in urban and industrial enterprises and cars, pollution of the air due to the release of dust, harmful gases, dry matter, smoke and solid particles due to various constructions, accelerating the process of condensation. . As a result, foggy days are increasing over the industrialized cities of the republic, the amount of precipitation is increasing: in Samarkand it is foggy for 14 days a year and 328 mm of precipitation, in the surrounding villages it is foggy for 31 days for 317 mm. `adi. In addition, in densely populated, industrialized cities, the air is polluted and the average annual temperature is 0.5-1.5 ° higher. Due to air pollution in 28 cities and settlements of Uzbekistan, various harmful compounds are much higher than the sanitary level. Among them are Andijan, Almalyk, Angren, Bekabad, Fergana, Chirchik, Navoi, Tashkent, Samarkand.
In Uzbekistan, more than 40,000 km2 have been irrigated and turned into oases. As a result, the microclimate changed, the air temperature in summer decreased by 1.5-3.5 ° C compared to the surrounding non-irrigated lands, the relative humidity increased by 10-15%, and the climate of the oasis was formed. Such places include Karshi and Mirzachul, Fergana, Chirchik-Ahangaron, Zarafshan, Surkhan-Sherabad and Lower Amudarya oases.
Due to the decrease in the water level of the Aral Sea, the average January temperature decreases in the surrounding areas, July increases and the spring frosts are extended to 12 days, while the autumn frosts begin 12 days earlier.
Temperature distribution. Temperature distribution in Uzbekistan depends on factors such as radiation, horizontal air exchange (advetic) and surface structure. It is known that the sun plays an important role in the distribution of summer temperatures, and the heat from it does not change from year to year, so the summer temperature in our country is stable and not as variable as in winter. Therefore, the temperature difference in Uzbekistan in summer (July-August) is around 3 °. However, in winter, the difference between December and February can exceed 8 ° due to the influx of cold air from the north and hot tropical air from the south.
To get an idea of ​​the distribution of heat in the territory of Uzbekistan, it is first necessary to know the location of the average annual temperature. In the plains of Uzbekistan, the average annual temperature rises from northwest to southeast. If the average annual temperature in Karakalpakstan (Churuk - 8.6 °, Nukus - 11.0 °, Turtkul - 12.4 °) is around 8.6-12.4 °, Bukhara-Karako l voh (in Shafirkan — 14.2 °, in Karakol — 14.8 °) 14.2—14.8 °, in the Surkhandarya valley of our republic (Denau — 15.9 °, Termez — 17.8 °, Sherabad — 18.0 °) is 15.9-18 °. This means that the coldest place in Uzbekistan is on the Ustyurt Plateau, and the hottest place is in the Surkhan-Sherabad oasis. This phenomenon is disrupted in the mountainous part of our republic. Because as it rises, the temperature decreases. Therefore, the average annual temperature at the height of 2300 m of the Ahangaron plateau is 4.0 °, at the height of 3200 m of the Turkestan ridge - 0.1 °, and at the height of 3700 m of the Western Tianshan mountains - 6.5 °. dir.
The winter weather in Uzbekistan is changeable, with the coldest temperature in January. The average temperature in January also fluctuates from northwest to south in the plains of the republic: in Churuk - 11.1 °, in Nukus - 6.9 °, in Urgench - 5.1 °, in Shafirkan - 1 , 5 °, in Karakol — 0.4 °, in Karshi —0.2 °, in Sherabad —3.6 °. These data show that the average January temperature is below zero in the plains of Uzbekistan, except for Surkhan-Sherabad, the valley and the rest of the Kashkadarya region, such as Kitab, Guzar, as well as in the mountains.
In winter, sometimes due to the inflow of cold air from the Arctic and Siberia, the temperature in the territory of Uzbekistan drops sharply, reaching the lowest temperature in the north-east (Churuk - 37 °, Nukus - 32 °, Tomdi - 31) - 29 ° -37 ° falls. At the same time, the lowest temperature in the Surkhandarya-Sherabad valley, which is the warmest region of Uzbekistan (-20 ° in Sherabad, -21 ° in Termez, -23 ° in Denau, -25 ° in Kumkurgan) dropped to -20-25 °. , causes damage to subtropical plants.
In some years, the winter in Uzbekistan is warm, and the plants do not stop growing. This winter is called "vegetative winter" and is more common in the south of Uzbekistan (80-100% of the total winter), while in the north, "vegetative winter" is 0-5% of the total winter. just
Summers in Uzbekistan are open, dry, hot and influenced by the local tropical air mass. In addition, sunlight: falls steeply and shines for a long time, as a result of which in July the earth's surface becomes very hot, and the sands in the deserts can heat up to 80 °. At this time, the plains and foothills of Uzbekistan are warm, and the average July temperature rises to 27.3 ° -32 °. The hottest places in the country in summer are in the central part of the Kyzylkum (average July temperature in Tomdi is 30 °) and the Surkhan-Sherabad valley (in Termez - 31.4, in Sherabad - 32.1 °), with an isotherm of July 30-32 °. passes. The cooler summer in the country is in the Lower Amudarya and Ustyurt Plateau, where the average July temperature (Churuk - 27.3 °, Nukus - 27.1 °, Urgench - 27.3 °) is 27.1-27. However, due to a decrease of 0.6 ° per 100 m ascending to the mountains, the average July temperature was 16.2 at an altitude of 2,300 m on the Ahangaron plateau and 10.3 at 3,200 m on the Turkestan ridge. , At an altitude of 3700 m in western Tianshan falls to 4.2 °.
In some years, the summer is extremely hot, with the highest temperature in the plains of Uzbekistan in July in the northwest (+ 43 ° in Churuk, + 44 ° in Nukus) to 43-44 °, in the central part (45 in Shafirkan and Karakol). °) reaches 45 ° and 48 ° in the southeast. The hottest place in Uzbekistan was observed in Termez, where on June 21, 1914 the maximum temperature reached 49.6 °.
Humidity and cloudiness. Humidity and cloudiness of the air in Uzbekistan depend primarily on the nature and variability of air masses, air temperature, surface condition and the rate of evaporation of precipitation. Due to the high temperature in the plains of Uzbekistan, especially in the hot part of the year, the possible evaporation is 15-20 times higher than the amount of oil. The annual amount of possible evaporation in our country ranges from 900 mm (around the Aral Sea) to 2000-2500 mm (in the Kyzylkum and Termez) and is not evenly distributed by month. If we say that the annual evaporation is 100%, 80-85% of it falls on the warm period of the year (May-October). Even the amount of evaporation in July is 8-10 times higher than in January.
Humidity is one of the most important climatic elements in the arid plains of Uzbekistan. Humidity, in particular the absolute humidity, which is the amount of water in the air, is not evenly distributed throughout the country. Absolute humidity varies from north to south, depending on air temperature and the condition of the earth's surface. In winter, especially in January, the average temperature in the north of the plains of Uzbekistan is Z-4 mm, and in the south - 5-6 mm. However, due to the low temperature in the mountains, the absolute humidity is less than 1-2 mm. The average absolute humidity in summer is higher than in winter, reaching 19-25 mm on the Aral Sea, in the Lower Amudarya, and 9-10 mm in the Kyzylkum. Hence, the distribution of absolute humidity in summer is y in addition to temperature It also depends on the availability of irrigated lands and water bodies (rivers, canals, reservoirs, lakes).
The relative humidity in the territory of Uzbekistan changes throughout the year, decreases in summer and increases in winter due to lower temperatures and increased precipitation. In winter (January) in the country, the relative humidity in the plains varies from 70-80% from north to south, in the mountains it can decrease to 55-59% and below, in Tashkent - 79%, in Termez - 79%. in Chimgan, which has a height of 1438 m, by 59%, the absolute height is 1545 m. in Shahimardon, which is 55%.
Due to high temperatures and almost no precipitation in Uzbekistan in summer (July), the average relative humidity is lowest in the Kyzylkum, Karshi and Sherabad deserts, at 30-35%. In the rest, the average relative humidity varies around 40-50% (40% in Tashkent, 46% in Andijan, 48% in Chimgan). It is of practical importance to know the number of dry days in the agriculture of Uzbekistan (days with a relative humidity of less than 30% are called "dry days"). Such days vary around 155-202 days in the plains of the republic: in Turtkul - 155 days, in Kogan - 202 days.
Another peculiarity of Uzbekistan's climate is that it is far from the oceans, inside the Eurasian continent, so there are few cloudy days and the weather is clear for most of the year. There are many open days in the territory of Uzbekistan, 143-168 days a year, while cloudy days are only 52-94 days: in Mirzachol 143 days are open, 83 days are cloudy, in Samarkand 155 days are open, It will be 77 days cloudy, 168 days clear in Kogan and 54 days cloudy. The most open and the least cloudy days in both plains and mountains of the republic are August-September. During this period, open days in the plains are 19-27 days, and cloudy days are 0-4 days; in the mountains the open days are 12-15 days. The most cloudy days of the year are in January-March. During this period, there will be 26-40 cloudy days in the plains of Uzbekistan: 26 days in Khiva, 29 days in Kogan, 39 days in Fergana, 40 days in Kitab.
Precipitation and snow cover. In Uzbekistan, where there is enough light and heat, on the contrary, the amount of precipitation is very low and very unevenly distributed throughout the region. This is due to the fact that it is located in the mainland of our republic, far from the oceans, the properties of air masses and relief. Turkestan, including Uzbekistan, is affected by a dry, cold air mass from the northeast in winter - the Siberian anticyclone. In summer, the western and north-western air masses heat up due to the extreme heat of the Turan plain, the formation of "thermal depression", the decrease in relative humidity, the difficulty of condensation and the absence of precipitation. As a result, very little precipitation falls on the plains of Uzbekistan, especially in the north-west. The lowest precipitation areas in the country are the Lower Amudarya, the western part of the Kyzylkum and the western part of the Fergana Valley, with an average annual precipitation of 80-100 mm: Khiva - 79 mm, Nukus - 82 mm, Qo In the blood — 89 mm, in the roof — 108 mm. In the rest of the plains of Uzbekistan the annual precipitation is about 300 mm: in Churuk - 122 mm, in Shafirkan - 120 mm, in Karakol - 114 mm, in Termez - 133 mm, in Navoi - 177 mm, in Karshi - 225 mm, Kattako 100-252 mm in diameter.
Annual precipitation is increasing in the foothills and mountains of Uzbekistan. This is due to the fact that as the temperature rises, condensation occurs and precipitation occurs. In addition, due to the fact that the precipitation is mainly brought by the western air masses, the western and south-western slopes of the mountains of the republic receive more precipitation than the northern and eastern slopes.
Precipitation in the foothills of Uzbekistan averages 300-550 mm per year (Denau - 360 mm, Kamashi - 327 mm, Samarkand - 328 mm, Tashkent - 359 mm, Jizzakh - 425 mm, Kitab - 545 mm). falls. The highest precipitation in the republic falls on its mountainous part, in particular, on the western and south-western slopes of the Western Tianshan, Zarafshan and Gissar mountains, with an average annual precipitation of 550— Precipitation is 900 mm, and in some places more than 900 mm: in Hazrati Bashir - 550 mm, in the East - 625 mm, in Chimgan - 787 mm, in Khumson - 879 mm, in Omonkoton - 881 mm.
In addition to the uneven distribution of precipitation in the territory of Uzbekistan, it does not fall evenly in the seasons. 30-50% of the total precipitation falls in spring, 25-40% in winter, 10-12% in autumn and 1-10% in summer. It is obvious that the highest amount of precipitation in the country falls in the spring and winter months. The main reason for this is the formation of a middle zone front zone in the territory of Uzbekistan, which separates the cold air masses from the warm tropical air masses in winter and spring, and the movement of cyclones intensifies and precipitation occurs.
In the plains of Uzbekistan, in particular, Ustyurt, Kuy i Amudarya, Kyzylkum, Lower Zarafshan, Karshi and Sherabad deserts have the highest precipitation in the spring, during which 35-50% of the total precipitation falls: in Ustyurt 35%, Lower In the Amudarya 42-45%, in the Kyzylkum 48%, in the Lower Zarafshan 44-45%, and in the Karshi and Sherabad deserts 44-45% of precipitation falls in the spring.
Our republic is mountainous and has the highest precipitation in the mountainous region
In spring, it makes up 41-49% of the annual rainfall
reaches 41% in Tashkent, 43% in Kosonsoy and 47% in Gallaorol
percent, in Samarkand 49 percent, in Boysun 45 percent, in Omonkoton
45%, in Hazrat Bashir 45%, in the East 46% in spring
corresponds to.
The highest annual rainfall in the country is in March, which is 14-24% of the annual rainfall. 14% in Andijan, 17% in Tashkent, 20% in Shafirkan, 21% in Karshi, 24% in Urgench, 20% in Omankotan and Kitob in March.
The lowest rainfall in Uzbekistan is in the summer months. In this season in the deserts of the Lower Amudarya, Kyzylkum, Mirzachul, Karshi and Sherabad 1-7% of annual precipitation (in Termez and Sherabad - 1%, in Karshi and Karakol - 2%, in Tomdi - 3%, in Gallaaral —4%, in Urgench 7%). In summer, due to the fall of the mountains and the decrease in temperature towards the mountains, the precipitation increases to 13-26% of the annual amount (in Chatkal - 13%, in Kuva - .14%). The lowest precipitation in summer is in August, with no precipitation at all in Surkhan-Sherabad oasis, Karshi desert, Lower Zarafshan and Kyzylkum; Tashkent, 1 mm in the Mirzachul oasis, 1-3 mm in the Lower Amudarya, 1-10 mm in the Fergana Valley. It's raining. However, in the summer months in some regions of Uzbekistan, including the Zarafshan, Fergana, Chirchik valleys, Nurata nets. 50 mm of rain was recorded in Tashkent, 37 mm in Bukhara, 75 mm in Jizzakh and 82 mm in Samarkand.
In winter, most of the precipitation in Uzbekistan is in the form of heavy snow. Although it snows in all parts of the republic, the snow cover in the plains remains unstable for an average of 5-20 days. Such places include Ustyurt, Lower Amudarya, Kyzylkum, Lower Zarafshan, Karshi and Surkhan-Sherabad oasis. Snow lasts for 50 days in Karakol, 15 days in Sherabad and Termez, 17 days in Turtkul, 11 days in Karshi and 20 days in Tomdi. In other parts of the plain and foothills, the average snowfall is 20-45 days (29 days in Guzar, 21 days in Kattakurgan, 35 days in Mirzachol, 39 days in Samarkand and Kitab, 43 days in Tashkent. day) is preserved. In the mountains of the republic the snow cover does not melt for a long time (up to 2-6 months), and in the highest parts there is a permanent snow cover.
In the plains of Uzbekistan the snow cover is very thin, reaching 3-7 cm, and in some cases 10-20 cm, and in the narrow zone 20-30 cm. However, the snow cover in the nets is thick, about 50-100 cm, and may even exceed 1-1.5 meters in some parts of the Chatkal valley.
Air pressure and winds. Air pressure and winds in the territory of Uzbekistan are not uniform in terms of region and seasons, depending on its surface structure, solar heating. The average annual air pressure in our republic varies from southeast to north and northwest. Air pressure varies with the seasons. In winter, the lowest pressure in Uzbekistan in January is observed in the south of the Kyzylkum, in the west of the Qosh Zarafshan and Karshi deserts, at 1024 mm. From here the air pressure increases to the north, northwest and east, in Kashkadarya and Surkhandarya regions, in the center of Kyzylkum to 1026 mm, in the northwest of Kyzylkum, Ustyurt, Lower Amudarya, Mirzachul, Zarafshan and Chirchik and Chirchik. 1027 mm. In January, the highest air pressure in Uzbekistan was in the eastern part of the Fergana Valley, reaching 1029 mm. The main reason for this is the orographic structure of the valley, which is surrounded by high mountains, and only in the west there is a narrow Khojand corridor. As a result, the cold air blowing from the mountains around the valley accumulated in it, leading to high pressure.
In the summer of July in Uzbekistan, the change in air pressure varies from southeast to northwest. If in the Surkhan-Sherabad valley 1001 mm. 1003 mm in the Karshi desert, 1004 mm in the Lower Zarafshan and Fergana valleys, 1006 mm in the center of the Kyzylkum, 1007 mm in the northwest, and 1008 mm in the north of the Lower Amudarya and Ustyurt. .
The direction and characteristics of winds in Uzbekistan are inextricably linked to changes in atmospheric circulation and pressure, temperature and orographic structure. In Uzbekistan, winds blow from the north-west, north and northeast throughout the year. However, in the eastern part of the republic, the direction of the winds changed due to the relief of the foothills and mountains, and more winds, such as mountains, valleys and fyon. r esadi.
In winter, the direction of winds in Uzbekistan is influenced by the Siberian anti-cyclone and the southern cyclone of the Turan plain. Therefore, in the north of the plains of our republic there are winds blowing more from the north-east, in the south their direction changes, and from the north and then from the south-east.
In summer, the Turan thermal depression occurs, pumping cold air masses from the northwest, north and northeast as a "pump". Therefore, in summer, 36% of the year-round winds in the plains of Uzbekistan are northeast, 15% in the north, 33% in the north-west and 32% in the north. esadi. In summer, the direction of winds changes due to the relief in the narrow and mountainous parts of Uzbekistan, more mountain valley winds blow: in the Surkhan-Sherabad valley (Termez) 26% of the year-round winds blow from the south. In the Zarafshan valley (Samarkand) 34% of the winds are from the south-east and 19% from the east.
Due to the fact that the Fergana Valley is surrounded by high barbed wire, in the winter there is a local anticyclone in the east, and in summer the central part of the valley heats up and a local low-pressure center is formed. Therefore, in winter the winds blow more from east to west, and in summer from west to east: in Andijan, located in the eastern part of the Fergana Valley, from October to June, the winds from the east, northeast and southeast are 43-45%. From June to October, more winds blow from the west, south-west and north-west, 38-44%.
The Chirchik-Ahangaroi valley is mostly influenced by mountain valleys, with wind blowing from the mountains at night from the northeast and from the southwest during the day. Therefore, 36% of year-round winds in Tashkent come from the north-east and east, and 31% from the south-west and west.
The average annual wind speed in Uzbekistan is not very high. In the plains it is about 3-4.6 m per second (2.8 m in Kogan, 3.7 m in Tomdi, 3.4 m in Urgench, 4.6 m in Churuk), and 1.5 m / s in the foothills. - not more than 3 m (in Tashkent - 1.4 m, in Samarkand - 1.4 m, in Termez - 2.6 m). In Uzbekistan, strong winds (more than 15 m / s) are rare in the plains and last for 3-11 days a year (3 days in Khiva, 5 days in Bukhara and Kogan, 10 days in Tomdi, 3 days in Chimmay). . However, in the narrow part of Uzbekistan, in the narrowed areas of the valleys and in the adjacent areas (Mirzachol, around the "Khojand Gate" of the Fergana Valley, at the exit of the Sangzor Valley to Mirzachol and other places) strong winds with a speed of 15 km The days from 15 to 64 days a year (in Termez - 15 days, in Jizzakh - 24 days, in Kokand - 39 days, in Ursatevsky - 47 days, in Zaporozhye - 64 days).
In Uzbekistan, especially around the "Khojand Gate" in the Fergana Valley, the east and south-east winds blowing towards Mirzachol are called Bekabad (Havos) winds, which sometimes reach 30-40 m / s in winter. This wind is strong when there is high pressure in the east of the Fergana valley, and in the west of the "Khojand Gate" when there are oysters, the cold air collected from the mountains in the valley moves to the west and compresses when it reaches the gate speed increases. On the contrary, in spring and autumn, the wind "Kokand" blows from the west to the Fergana Valley, reaching a speed of 15-25 m per second. The formation of the Kokand wind depends on the cold fronts coming from the west.
In addition to Bekabad and Kokand winds, there are also local winds in Uzbekistan, such as "Afghan", Fyon, Garmsel. Afghan wind is typical for Surkhandarya valley. This wind is due to the inflow of cold air from the north and northwest. This cold air accumulates in the Kopetdag and Parapoliz mountains and flows through the territory of Afghanistan to the low-pressure, hot Surkhan-Vakhsh valley. The wind speed in Afghanistan is sometimes 15-20 m / s. The dusty mixture enters the Surkhandarya valley and lasts for 1-2 days, in some cases 3-4 days. As a result, dusty weather is formed, sometimes 100-200 m. It is difficult to see things in the distance. When the Afghan wind blows in the spring, it creates dust, dries up agricultural crops, dries the leaves and causes great damage.
In the foothills of Uzbekistan, especially in the valleys such as Chirchik-Ahangaron, Fergana, in winter and spring, the wind blows frequently. Fyons cause cold air to flow down from the mountains when oiklons (low pressure) enter the plains of our republic in winter and spring. The air descending along the mountain slope is condensed every 100 m. As a result, reach the foothills of our republic The temperature may rise to 24 ° C. Fyon wind is hot and dry, sometimes 5-10 m per second. As a result, the relative humidity of the area affected by the wind decreases, the temperature rises and the melting of snow accelerates.
Another local wind in Uzbekistan is Garmsel. It is a hot and dry wind that blows in spring and summer. When Garmsel blows, the temperature rises and exceeds 40 °, on the contrary, the relative humidity decreases and falls by 5-10%. Sometimes the speed of garmsel is 15-20 m per second. Dark dust rises into the air, the sky becomes cloudy, dim and the temperature rises. As a result, crops and even fruit trees are damaged, their leaves turn yellow and dry out.
Garmsels are often found in Bukhara, Samarkand, Navoi, Jizzakh, Syrdarya regions of Uzbekistan, in the Fergana Valley. It is less in Khorezm region and Karakalpakstan.
There are different opinions about the formation of Garmsel. Some say that it is caused by hot air blowing in the Kyzylkum and Karakum deserts, while others say that it is caused by a mass of high-pressure air entering the air above the desert and driving it around. According to others, the air flow from Iran to the Turan plain is caused by the compression and heating of the Turkmen-Khurasan Mountains. According to another group of scientists, when a cold current approaches the mountains from the west, northwest, the pressure in front of the current decreases, resulting in a garmsel caused by winds from the east or south-east.
Seasons. In the Turan plain, including Uzbekistan, the seasons differ from those in the central part of Eurasia. Because in Uzbekistan the temperature rises from north to south, the beginning and duration of the seasons change, and the difference is up to 20-25 days. Therefore, local climatologists divide the climate of Uzbekistan into two periods - hot and cold. Days with an average daily temperature above 5 ° are included in the hot period, and days below 5 ° are included in the cold period.
There are many days in Uzbekistan with an average daily temperature above 5 °, 206 days in Ustyurt (Churuk), 272 days in the south of Kyzylkum (Karakol), 320 days in the Surkhan-Sherabad valley (Sherabad). However, in the mountainous part of the republic, the days with an average daily temperature above 5 ° are reduced to 3000 m. at an altitude of 100-105 days.
The hot season in Uzbekistan is divided into three seasons - early spring (March, April, May), mid-summer (June, July, August) and late autumn (September, October, November). linadi. The cold period corresponds to winter (December, January, February).
Q i sh. In Uzbekistan, winters are colder than in the Mediterranean region, and the weather is changeable. In winter, clear but cold days are sometimes replaced by continuous warm cloudy and rainy days. This is due to the anti-cyclone and cyclone air currents entering the territory of the republic in winter. If a mass of cold air enters the territory of Uzbekistan from the north and northeast, the air will be clear, the temperature will drop, and sometimes the temperature will drop to 37 ° (in Ustyurt) and rainy days will begin. The coldest days occur in the "winter chill" and last from December 25 to February 5. During the winter in Uzbekistan, when cyclones enter from the west and south, clouds appear in the air, the temperature rises and hangs (in some years the temperature rises to 10-29 °), it rains. Then it turns to snow.
It rains more in Uzbekistan in winter. If in the plains 20-40% of the annual precipitation falls in winter, in the foothills it falls to 30-37%. Although most of the precipitation falls in the snow, in the plains of Uzbekistan it is thin and does not last long: in the north of the plains of the republic the snow cover is 10-15 cm thick, does not melt for 28-30 days, in the south 4— It is 5 cm long and does not melt for 6-7 days. However, in the foothills the snow cover is 20-40 cm thick and does not melt for 35-45 days. At the height of 1500-3000 m in the mountains the thickness of snow is 70-90 cm, 45-65 days, 3500-4000 m. above 100 cm. does not dissolve throughout the year. Climatologist yye. According to N. Balasheva, in some parts of the Pskom Mountains the thickness of snow reaches 3-4 m.
In Uzbekistan, in some years, the winter is warm and there is little snow, and the plants continue to grow throughout the year (vegetative period). LN Babushkin calls such a winter "vegetative" winter. The "vegetative" winter is not the same in all parts of Uzbekistan. In its north-west 0-5% of winter days correspond to "vegetative winter", this figure is 50-60% in the central part of the republic, and in the southern part of the Surkhan-Sherabad valley - 80-100%. Some subtropical plants also grow to 100%.
Spring. Spring in Uzbekistan begins when the average daily temperature exceeds 5 ° sernam is the season. Therefore, spring does not begin at the same time in all parts of the republic: in the southern part of Uzbekistan (Surkhan-Sherabad valley) from mid-February, in the middle part (Bukhara-Karakum oasis) from late February, in the northwestern part (Lower Amudarya and Ustyurt). ) starts in the second half of March. Therefore, in the Surkhan-Sherabad valley, spring begins 1.5-2.0 weeks before the Bukhara-Karakol oasis, and 20-25 days before the Lower Amudarya. In the foothills of Uzbekistan, spring begins later, in early April, and in the mountains in late April.
Spring is the warmest season in the republic, with 40-43% of annual precipitation in the plains and 40-50% in the foothills.
In spring, the days in the territory of the republic are warm, in the southern part (Sherabad and Termez) the average temperature in March reaches 11.5 °, in the northern part it is relatively cool (in Nukus - 4.1 °, in Urgench - 5.0 °) 4 -5 °. On some days in March, the temperature rises to 35 ° in Sherabad and 34 ° in Nukus. It is obvious that since March in Uzbekistan the temperature has risen, there is frequent precipitation, the snow melts and the growth of plants accelerates. Almond, apricot, peach, cherry and cherry trees bloom in the south of the republic from the first ten days of March, and in the north from the end of March to the beginning of April. From the end of April to May, the temperature rose even more (average April temperature in Urgench - 13.8 ° in Kogan - 16.2, in Sherabad - 18.2 °, in May in Urgench - 21.0 °, in Kogan - 23.2 °. , In Sherabad -24.5 °) 1 The weather is clear, precipitation gradually decreases, and by the end of May the real summer begins.
YO z. In Uzbekistan, especially in its plains and foothills, summer differs from other seasons in that the weather is clear, hot and dry. Summer begins in the plains of Uzbekistan when the average daily temperature exceeds 20 ° and ends below 20 °, and in the mountains begins when the average daily temperature is 10-15 °.
In summer, the weather does not change much, the weather is clear, and in the plains of Uzbekistan in June-August there is an 80-95% chance of clear days. From June, hot days begin, the average monthly temperature is around 24-29.5 °. The hottest days of summer take place in the middle of the "summer chill", which lasts from June 25 to August 5, ie in July, the average temperature in the plains of the republic is around 26-32 °, and the maximum temperature is 41-48 °. Extremely high temperatures were observed on July 21, 1914 in Termez, reaching 49.6 °.
In summer, when the temperature in the plains of the republic is very high and the rainfall is very low, in some years it does not rain at all. The lowest precipitation in summer is 0 mm in the plains and foothills of Uzbekistan in August. from (Surkhandarya valley, plains of Kashkadarya and Samarkand regions, Kyzylkum) 3 mm. (Chirchik-Ahangaron valley, Fergana valley, Ustyurt, Lower Amudarya). In summer, there are occasional thunderstorms, heavy rains and passing quickly.
The plains of Uzbekistan become very hot in summer, there is a drought due to lack of precipitation, and the plants turn yellow and dry out. As a result, due to the hot wind - garmsel, the dust rises and the air becomes cloudy. Such dusty days occur in Bukhara-Karakol oasis and Chirchik-Ahangaron valley for 3-4 days, in Lower Amudarya and Ustyurt for 3-5 days, in Fergana valley for 6-7 days.
Autumn. In Uzbekistan, autumn begins when the average daily temperature drops below 20 ° and ends when it drops below 5 °. From this point of view, autumn begins in September in the northern and central parts of the republic (Ustyurt, Lower Amudarya, Kyzylkum, Mirzachul, Chirchik-Ahangaron, Fergana valleys and the middle parts of the Zarafshan valley), and in the south in early October.
From the second half of September, the weather in Uzbekistan will change, the temperature will gradually decrease and clouds will appear. From October onwards, as a result of cold air currents, the temperature may drop, sometimes dropping to 0 ° at night. Cold snaps are rare in the first ten days of October, but recur frequently in late October (with the exception of the Surkhandarya Valley). The cold snap in the Surkhandarya valley will begin in late October. In autumn, sometimes clouds appear, it gets cold, then the weather warms up again, the clouds dissipate and open days begin.
Rainfall in autumn is higher than in summer (15-25% of annual precipitation). Precipitation accelerates in the foothills of the republic from October, and in the plains from November.
The first half of autumn is the best season in Uzbekistan. Because during this period the days are hot and dry, the evening crops and fruits are fully ripe, and the leaves of the trees have not yet turned yellow.
Iq lim resources. Climatic resources include heat source, solar energy, wind energy, and their role in treatment.
One of the most important factors for the economy of Uzbekistan, especially agriculture, is heat resources. Because a certain level of heat is required for the ripening of agricultural crops, the sweetness of fruits. From this point of view, Uzbekistan has a very favorable heat resource.
In Uzbekistan, the last spring frosts occur in Ustyurt on March 12-14, in the Lower Amudarya in late March and early April, and in the Surkhan-Sherabad valley on March 2-15. The first frost in autumn falls on October 5-10 in Ustyurt, on October 20-25 in the Lower Amudarya, and on November 24 in Sherabad. Therefore, there are many cold days in the republic, from 153 to 210 days in the northern part of Ustyurt, Lower Amudarya and Kyzylkum, in the south of Kyzylkum, Mirzachul, Chirchik-Ahangaron, Fergana and Zarafshan, Kashkadarya valleys. It lasts 210-230 days, and in the southernmost Surkhan-Sherabad valley - 225-266 days. In addition, the sum of days with an average daily temperature above + 10 ° is 4000-4500 ° in the northwest of Uzbekistan, 4500-5100 ° in the Bukhara-Karakol oasis, 5100-5900 ° in the south (in Sherabad). 5900 °). In such climatic conditions it is possible to grow rice, ordinary and fine-fiber cotton, sweet melons, watermelons, various fruits rich in sugar, and in the Surkhan-Sherabad valley - subtropical plants. In Uzbekistan, heat resources allow to harvest twice a year, and in the Surkhan-Sherabad oasis up to three times.
In the plains of Uzbekistan, it is cloudless all year round, especially in summer, and the sun shines for a long time. In the plains and foothills of the republic, the sun shines from 2,500 hours (north) to 3,000 hours (south) a year. Therefore. Uzbekistan is a country rich in solar resources, with an average annual solar energy consumption of 4.861014 kWh, which is 30 billion kWh. t. is equivalent to coal.
However, the level of use of these solar resources in our country is still very low. Currently, solar resources are used for heating greenhouses and hothouses, groundwater abstraction with the help of special solar-powered pumps, desalination of brackish water with the help of special equipment, water heating in public utilities. In addition, solar resources can be used to heat buildings using special photocells and to generate energy for other purposes. Such experiments are used in the heating of the building of the recreation center "Mothers and Children" in Zaamin district of Jizzakh region.
Great work is being done in the field of solar energy at the experimental field in Parkent of the "Solar Production Association" of the Academy of Sciences of Uzbekistan. In special laboratories, it converts solar energy into electrical and mechanical energy, creating a very large temperature (4 million degrees). In the near future, our scientists will be looking for advanced ways to use solar resources, which will open the way for the conversion of solar energy into heat and electricity.
Groundwater can be used to supply water to desert pastures in Uzbekistan and to irrigate small areas with wind-powered pumps. In addition, wind-powered units can be used to supply electricity to farms and livestock houses, geological prospecting, research staff, and desalination of salt water. It is known that the average annual wind speed is 2.5-3.5 m per second. The wind power unit with a capacity of 10-12 kilowatts works smoothly and produces 26-35 thousand kilowatt-hours of energy per year. In this regard, Uzbekistan has a good opportunity. Because in most parts of it (Mirzachol, Dalvarzin desert, Ustyurt and Lower Amudarya, Kyzylkum) the average annual wind speed is 2.5-4.6 m per second. ga yetedi. With the help of wind units such as VB-3, VM-3, up to 4000-4300 liters of groundwater per hour can be extracted from wind power with this speed.
The hot, dry and sunny climate of Uzbekistan is important in the treatment of many diseases, especially nephritis. Because people with kidney flu need to keep their kidneys very calm. In this case, the skin should act as a kidney. The skin can perform such a function only in hot, dry and sunny climates. However, such climatic conditions exist in the plains of Uzbekistan. That is why there is a sanatorium in Bukhara for the treatment of kidney disease.
Uzbekistan The air in the mountainous part of the country is relatively dry and moderately dry, and plays an important role in the treatment of lung, cardiovascular, asthma, bronchitis and other diseases. In addition, sanatoriums and rest homes, which are necessary for recreation, are located in clean areas, especially in the mountains surrounding the Western Tianshan, Gissar and Fergana valleys. Examples of this are Chimgan, Aktash in the Bostash district, Shohimardon in the Fergana Valley.
References:

1. Yermakov Y.G. and dr. Physical geography of continents and oceans. M: Vqsshaya school, 1988.

2. Ryabchikov A.M. Physical geography of continents and oceans. M: Vqsshaya school, 1988.
3. Physical geography of the world ocean. M: Izdatelpstvo Moskovskogo Universiteta, 1988.
4. Ryabchikov A.M. Natural geography of the continents of the world, Tashkent, 1968.
5. Vlasova T.M. Physical geography of continents and oceans. Volume I-II, M: Prosveo`yeniye, 1976.
6. Vlasova T.M. Natural geography of continents and oceans. Volumes I-II. Tashkent, 1985.
7. Leontpev O.K. Physical geography of the world ocean. M: 1982.
Encyclopedic dictionary of geographical terms. M.1968.
8. http://ziyonet.uz