The climate of Irkutsk is sharply continental, a number of factors influence its features: location, topography, circulation of air masses, constructed hydroelectric power station.
Concepts and Definitions
Climate is a multi-year weather regime of a specific locality; it is relatively constant. The very concept of “climate” has its roots in the Greek word klima, which means “slope”, that is, the slope of the earth's surface to the rays of the sun. The climate features of the area are closely related to physical and geographical conditions (river valleys, mountain ranges, remoteness from the sea) and atmospheric circulation (anticyclones, cyclones, air mass movements).
Weather is defined as the state of the lower layers of the atmosphere at a certain time in a certain place, it is variable.
What is the climate in Irkutsk? Features of the climate of the city
The climate of Irkutsk is sharply continental with long (about 6 months) frosty winters and warm, wet, rainy summers. The climate of the city was significantly affected by the construction of the Irkutsk and other hydroelectric power plants on the Angara River: it became softer, but at the same time, the humidity in the region increased significantly. Summer temperatures have dropped significantly, and winter temperatures have risen slightly compared to the period before the construction of the hydroelectric station.
In winter, an anticyclone dominates the city, dry sunny frosty weather prevails, light winds (not more than 1 m / s), the process of cooling the earth's surface is intensively taking place.
In the warm season, anticyclones are replaced by cyclones (low atmospheric pressure), which are characterized by high clouds and heavy rainfall. About 85% of annual precipitation falls in the summer.
The main climatic indicators of the city of Irkutsk and its environs
The uniqueness of meteorological variables forms the location of the city of Irkutsk. It is located in the Angara River Valley, remote from the sea coast. A peculiarity of the climate of the city is a frosty long winter and a rainy short summer.
Residents call their city nothing more than “the city of permafrost” - because of the snowy winters and frequent winds, the surface of the earth is practically not covered by snow and is frozen. The coldest month in Irkutsk is January (-15-33 ° С), and the warmest is July (+ 18 + 20 ° С). In temperature conditions, the minimum air t is -50 ° С, the maximum - + 36 ° С. The average temperature in Irkutsk in January is -18 ° C (night), -15 ° C (day), in July + 20 ° C (night) and + 23 ° C (day). Daily amplitudes reach 20 ° C, annual amplitudes up to 50 ° C. The harsh temperature conditions in modern conditions can be transferred using ventilation equipment and air conditioning systems. Installation and sale of such equipment is carried out by Climate LLC (Irkutsk).
In precipitation, the maximum is typical for July, with an average of 500 mm falling per year. The average air humidity is about 70%, humidity increases in the summer.
The main directions of the winds prevailing in Irkutsk
In winter, westerly winds dominate over Irkutsk and its environs, and north-west winds dominate in summer. The Angara River valley within the city is oriented from the north-west to the southeast, the frequency of these wind directions in the city is greatest.
Table of wind direction in Irkutsk
|
Sb |
IN |
S-z |
WITH |
Southeast |
3 |
YU |
NW |
|
2% |
4.7% |
5.7% |
6.5% |
11.2% |
18.9% |
19.7% |
31.3% |
In the cold season, due to the influence of the anticyclone, periodic calmness is observed, its share is about 40%. In spring and autumn, wind speeds reach about 3 m / s.
Adverse weather events developing in the city of Irkutsk
Adverse weather events in settlements pose a serious threat to the life and health of people, causing substantial damage to property. According to the calculations of meteorological scientists, in the near future within the city and its environs, an increase in the frequency of floods, showers, blizzards, severe floods, tornadoes, hurricane winds, abnormal temperature fluctuations, droughts and fires is expected.
The main reason for the growth of such phenomena is an increase in the average temperature of the air and the underlying surface, which leads to an increase in evaporation from the earth's surface (with an increase in t by 1 ° C, evaporation increases by about 7%) and, as a result, an increase in precipitation. So, over the past few years, from January to October, there has been an increase in average monthly t ° С compared with the period 1963-2009. approximately 2.6 ° C.
Among the seasonal adverse weather phenomena of Irkutsk that affect the well-being of residents and their livelihoods include extremely high temperatures (maximum air t ° C + 35 ° C for 5 days) and extremely low temperatures (minimum air t ° C below -40 ° C for 5 days).
The causes of extreme temperature manifestations are the continental climate of Irkutsk and the circulation processes in the lower atmosphere (the invasion of cold air from arctic latitudes in the cold season and the long passage of anticyclones in the summer season).
One of the most adverse weather phenomena in the city is a strong wind. Meteorologists distinguish two annual maximums of strong and very strong winds - in May and November. In the middle of winter and summer, there is a minimal recurrence of cases with strong winds.
In winter, blizzards are associated with strong winds, a significant part of them is observed from November to March.
In the summer months, strong winds are associated with dust storms and squalls, usually in May-June.
In the middle of summer, there is a peak of such phenomena as continuous rain (more than 100 mm falls in 12 hours or about 120 mm per day), very heavy rain (50 mm falls in 12 hours) and large hail (gradients with a diameter of 20 mm).
Cyclones from the south increase the frequency of heavy showers (the amount of liquid precipitation is more than 30 mm for a period of less than 1 hour), showers fall in the second half of summer (peak occurs in August).
Strong fog (visibility is less than 50 m) in the warm season is observed 5 times more often than in the cold, in addition, in recent years the number of days in a year with fog has been increasing. The formation of fogs and increased cloudiness in summer, hoarfrost and low visibility in spring and autumn is influenced by hydroelectric power stations.
Strong fog (visibility is less than 50 m) is observed in the warm season 5 times more often than in the cold, in addition, in recent years the number of days in a year with strong fog has been increasing.
The effect of cyclones and anticyclones on the climate of the city
Long cold periods are associated with the invasion of polar cyclones on the territory, and long warm periods are associated with the passage of southern air masses from temperate latitudes. In recent years, the following pattern has been recorded: in the Irkutsk region, periods with extremely severe frost are observed much more often than with extremely intense heat.
Anticyclones make a significant contribution to the formation of haze and fog in Irkutsk, and cyclones influence the formation of showers and a strong squally wind.
