Let's talk about the peculiarities of the climate in the Aral Sea before it dries up. In winter, the area of the Aral Sea is under the influence of the western spur of the Siberian anticyclone, and above the sea itself there is a weakly expressed depression of low pressure.
Hence the prevalence of north-westerly winds. The air above the surrounding sea space in January cools down to an average of -12 °, -14 °, and above the sea the air temperature is kept at about 0 °.
Unstable weather in winter is created by the invasions of cold arctic air masses and cyclones of the polar front. Arctic invasions entail a sharp cooling (the air temperature drops to -35 °, -40 °). On the other hand, warm sectors of incoming cyclones create thaws in the middle of winter.
Spring in the Aral Sea region is characterized by a rapid rise in air temperature. In March, its monthly average values are + 5 °, + 10 °, and in April they already reach + 19 °, + 20 °. Above the sea, the temperature is 3-5 ° lower than in the adjacent areas.
Colder air leads to the formation of a weakly expressed spur of increased pressure over the sea. While the spur of the Siberian anticyclone collapses, a baric minimum appears over Iran, so northeastern winds prevail.
Due to increased cyclonic activity, the amount of precipitation increases (up to 20-30 mm per month). Over the sea itself, they fall less. Summer is characterized by high levels of solar radiation, exceptional dryness and very stable weather.
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The South Asian baric minimum continues to deepen; therefore, the northeastern winds remain dominant. A local anticyclone forms over the sea, and the air spreads from the center to the shores.
The air temperature is characterized by high average monthly values (in July + 27 °, + 28 °), and the daily average reaches + 35 °; daily differences are large (10-12 °). Rains are extremely rare. In July-August there are only one or two days with rains, which fall in the form of short-term showers.
The stable hot and dry weather in summer is due to weak cyclonic activity. Transformed arctic air passes to the rear of rare cyclones, then the heat and dryness soften somewhat. However, very soon this air warms up without moistening, and as a result, a hot and dry air mass is created.
Autumn is characterized by a rapid and sharp drop in air temperature and an increase in precipitation. Already in November, the air temperature above the surrounding spaces becomes below 0 °, while over the sea it keeps about + 2 °, + 4 °.
Above the warmer sea, there is a local area of low pressure. To the north of the Aral, a spur of the Siberian anticyclone is formed, thus maintaining the prevalence of northeastern winds.
Cold air penetrating to the south comes into contact with warm air, exacerbates the fronts and intensifies cyclopean activity, which is associated with an increase in precipitation, heat returns and a transition to unstable winter weather. The connections between the river runoff and the sea are complex and varied.
The Amu Darya annually brings into the Aral Sea 41 km of water, 17.74 million tons of dissolved salts, 100.0 million tons of suspended and 5.0 million tons of sediments carried along the bottom. During the same time, the Syr Darya releases 18 km3 of water, 6.05 million tons of dissolved salts, 8 million tons of suspended matter and 0.5 million tons of entrained sediment.
Once in the sea, each of these components affects its appearance in its own way. Liquid runoff and dissolved salts change the salt composition and affect the level and magnitude of the sea salinity and its distribution over the water area.
Runoff influences the formation of shores and depths in delta areas. For example, from the sands deposited on the coast of the Amu Darya, the waves build up on about. Tokmak-Ata sand spit, called Tiger's tail. Running a long distance across the deserts, the waters of the Amu Darya and Syr Darya heat up in about the same way as the sea water, and therefore do not significantly affect the thermal regime of the Aral Sea.