Topic 7. Climatic conditions and Resources
§ 19. Klimatotvirni factors
1. Recall that the factors shaping the climate area.
2. What climate zone is Ukraine?
Overview of the climate. The territory of Ukraine is in the temperate zone in temperate continental climate. And only on a narrow band formed the southern coast climate, similar to subtropical Mediterranean type. At the same time has a temperate continental climate significant differences between the basic parameters (temperature and amount precipitation) in different parts of Ukraine. Above the flat part of the country from north west to south-east continental climate is growing: in this direction summer mean temperatures rise and winter - are falling, declining annual rainfall. In the Ukrainian Carpathians and Crimean mountains are formed their special climatic conditions, associated with significant elevation. Since lifting up the average monthly temperature decrease at any time of year, and total rainfall increases.
As you know, the climate of any territory forming following factors: 1) the number of solar radiation received at Earth's surface; 2) circulation of the atmosphere, 3) the nature of the laying surface. Consider the impact the climate in Ukraine.
Number of solar radiation. Solar radiation (Heat and light emitted by the Sun) is the main energy source of atmospheric processes. Number of solar radiation reaching the earth surface, expressed in kilokaloriyah 1 cm2 (Kcal / cm2) Or megajoules 1 m2 (MJ / m2) per unit time. It changes throughout the day and year, which is associated with changes height of the Sun above the horizon and the length of the day.
As you know, height or angle of the Sun sunlight depends on geographic latitude and the Earth of the Sun at a specific point in its annual and daily rotation. Ukraine located in the middle latitudes in temperate light, where midday height of the sun is always less than 90 ° and every day there is a change of day and night. Together so the Sun and height, and length of day change significantly during the year, so in Ukraine distinct seasons.
South of the country receives more sun per year radiation than the north because the height of midday sun in the south each day higher than in the north. Main of solar radiation comes from May to September, when increasing the duration of the solar Lights. Until the earth's surface comes direct solar radiation in a direct rays of the Sun and part dissipated solar radiation - One that is dispersed by water present in the atmosphere steam, dust, gases and clouds. Direct and scattered radiation coming on the Earth's surface, called total solar radiation. The total radiation is distributed in the earth's surface is not strictly zonal, because its revenue is also dependent on cloudiness and atmospheric transparency. Therefore Western Ukraine, where there is more cloudy days will be during the year less total solar radiation than those in eastern region most latitudes. The annual amount of total solar radiation in Ukraine varies from 3500 mJ / m2 (In the north-western areas) and 4000 MJ / m2 (In the north-east) to 5200 MJ / m2 the south Crimea. Part of solar radiation reflected from Earth's surface, and part absorbed by it. Absorbed radiation characterizing arrivals heat on the Earth's surface.
Fig. Formation of a total solar radiation
Fig. Solar radiation. Sun radiance
Work with map
1. What areas of Ukraine received the largest number of total solar radiation, and that - the smallest?
2. What is the value of total solar radiation in the central regions of Ukraine?
3. How many total solar radiation received your area?
The circulation of air masses. The distribution and redistribution of heat and moisture affects atmospheric circulation - movement of air masses of different types.
Air masses that determine the climate in Ukraine, have a "local" origin and come from afar - from the regions thousands of kilometers distant. Overall during the year over the territory of Ukraine dominate moderatePrimarily marine air masses with Atlantic. They come from the west and northwest through constant westerly winds. Winter air masses coming from Atlantic accompanied by warming in the summer - some cooling. In addition, This air is always damp. His influence is particularly felt in the west and north-west of Ukraine. With promotion to the east and southeast, it gradually converted (transformed) to the continental. This factor climate in Ukraine is changing from north to south, and west to the east. Moderate continental air massComing in Ukraine, formed over the central regions of Eurasia. They are always dry and bring cold weather in winter and hot summer. The most tangible impact of their the east and south.
From time to time to penetrate the borders of Ukraine and dry cold Arctic air massesWhich give rise to a sharp decline air temperature in winter, late spring and early autumn frosts. Dry and hot tropical air mass, coming from the desert regions of Africa or Southwest Asia, bring the hot weather in summer, warm and serene fall.
Change air masses with different properties (primarily temperature) causes passing through Ukraine atmospheric fronts. Atmospheric Front- A transition zone between warm and cold air masses, which under slight angle to the ground surface is inclined toward cold air. Depending on which active air - warm or cold - and this front. Warm atmospheric front formed when warm air offensive. This warm air as easily naplyvaye the cold, gradually displacing it. Cold atmospheric front moves toward the warm air. Cold air it is replacing warm, pidplyvayuchy under it. And in the heat, and cold front created clouds from which precipitation falls.
Atmospheric circulation in Ukraine has also frequent cyclones and anticyclones change - huge atmospheric vortex diameter several thousand kilometers and a height of several thousand meters. As you know, center Cyclone formed area of low atmospheric pressure, which rising flow of circulating air. She closed the ring around the increased pressure, and therefore the winds blow in cyclones from the edges to the center, veering in Northern Hemisphere counterclockwise. Most cyclones occur over North Atlantic, the Mediterranean or the Barents Sea. They quickly moved over the territory of Ukraine for several days to form an unstable cloudy and windy weather with lots of rain. In anticyclone in center formed a closed area of high atmospheric pressure from the descending air flow. Winds blowing from center to edges clockwise. On territory of Ukraine anticyclone coming from the east, north and tropical parts Atlantic. They are sedentary, over the territory of Ukraine delayed long time, causing cloudy dry weather, hot in summer and winter cold. Total per year over the territory of the country is nearly 45 cyclones and over 35 anticyclones. However, the number of days antytsyklonalna sharply prevailing weather.
In the warm season there is a local circulation: breezeson the shores of the Black and Azov seas, reservoirs, lakes, estuaries, large rivers; mountain-valley winds in the Carpathians and Crimean mountains.
On the influence of atmospheric circulation in winter stripe high atmospheric pressure that goes along the lines of Lugansk - Dnipropetrovsk - Balta. It is part of the so-called axis Voyeykova, that stretches nearly across Eurasia from Spain to Mongolia. North of this band is dominated by Western and relatively warm moist winds of the south - east and south-eastern cold and dry winds. In the warm season, this axis is weakened, warming due to land because almost the entire territory of Ukraine falls in area of low pressure, but because west winds blow. Only in the South continue Eastern winds prevail.
Fig. Atmospheric fronts: a) warm and b) cold
Fig. Atmospheric Vortices: a) cyclone b) anticyclone (for the Northern Hemisphere)
Laying surface. Laying surface affects climate are primarily due to absorption and conversion solar radiation. Soils, vegetation, snow, water and absorb differently reflect solar radiation. For example, covered with fresh snow surface reflects over 90% of the total solar radiation received by it, and absorbs only 10%. The ratio of reflected radiation to total call albedo. The lowest albedo with water and wet black earth (10%), the largest - Snow. Summer in the areas of forests and forest albedo is to 19% in the plains - to 17%.
In the climate affects the surface topography and remoteness of the area from the ocean. Contributes to the plainness of the territory of Ukraine free penetration and spread it over a moderate sea and continental masses, as well as Arctic. However, a significant length of Ukraine in meridional direction causes the transformation of maritime air masses from continental promotion to the east. Barriers to movement of air masses are the Ukrainian Carpathians and Crimean mountains. They stop cold arctic or temperate continental air Transcarpathia and South Crimean coast. Therefore, winter temperature in the steppe Crimea may be 20 ° C lower than on the southern coast. In the mountains temperatures lower than on the adjacent plains. Moist air trapped on the windward slopes of mountains. Mountains strengthen ascending motion of air over them and formed a more sunny more rain falls than in the plain. Even at low Donetskand Azov Upland annual amount of precipitation, the number of thunderstorms Mists and compared with the surrounding areas.
The climate of the whole territory of Ukraine is moderate continental and the southern coast of Crimea - close to the subtropical Mediterranean type.
The annual amount of solar radiation may cause changes thermal conditions in the territory of Ukraine from north to south.
For year rule over the territory of Ukraine moderate air masses: the sea (from the Atlantic Ocean) і Continental; to penetrate its borders Arctic and tropical continental air mass.
Atmospheric circulation in Ukraine has frequent passage of hot and cold atmospheric fronts, cyclones and anticyclones.
Through influence of western continental air transfer of climate on the flat part of Ukraine is increasing from northwest to southeast.
Questions and Tasks
1. In what direction and why growing continental climate in Ukraine?
2. What are the main klimatotvirni factors influenced which formed the climate in Ukraine.
3. Air mass types penetrate into the territory of Ukraine? How do they affect the climate?
4. What is the weather in Ukraine and anticyclone cyclones form?
5. As laying surface affect climate?
7 *. Midday Sun height above the horizon (the angle of sunlight at noon) in some point the earth's surface is calculated by the formula:
h = 90º – φ + δ,
where φ - Geographic location, δ - Declination of the Sun, which varies from 0