Saturday , October 16 2021

Weather of Arabia: The La Nina phenomenon is in remarkable development, and this is its impact on the Arab world | The time of Arabia



The time of Arabia The latest statistical forecasts for Arab weather still indicate an expected return to the La Niña phenomenon in the coming months again, God willing.

What is the La Niña phenomenon?

The La Niña phenomenon is initially defined as a decrease in the temperature of surface waters in the tropical region of the Pacific Ocean relative to its general average by more than 0.5 ° C and over a period of time exceeding 3 consecutive months.

Trade winds blow from east to west in the equatorial region of the Pacific Ocean as a result of the rotation of the Earth around it and from there begins the story of La Niña. Humidity forms a system of low atmospheric pressure and air travels. again along the upper part of the troposphere to the eastern Pacific Ocean, forming a ring, then this cold air converges up and down along the east coast of the Pacific Ocean forming a high pressure region and , then the wind moves from the high system to the low level to complete this cycle.

The end result is warmer surface water in the west and colder surface water in the east. Peru and South America, which suffer from adjacent cold waters.

So how does this affect the climate in the Arab world?

The effect of the La Niña phenomenon is not limited to the vertical movement of air at the equator, but its effect is evident in the horizontal movement, where the ascending air of the equatorial region of the Pacific Ocean branches from the equator to higher latitudes. north and south, shifting hot tropical air to the tropics Cancer and Capricorn to descend to the earth’s surface and back to the equator and this is called Hadley’s rotation.

The subtropical ray current is formed as a result of the confluence of the upper winds of the Hadley cycle with the Ferrel cycle, which means that the La Niña phenomenon indirectly affects the subtropical ray current and the air altitudes that arise. at latitudes close to 30 degrees. The La Niña phenomenon towards the Indian Ocean, as it indirectly leads to a decrease in the surface temperature of the water in the western part of the Indian Ocean and the Arabian Sea, which causes a decrease in the amount of steam. of water flowing into the atmosphere of the Arabian Peninsula after the will of God.

Statistically, the La Niña phenomenon

The La Niña phenomenon is mainly a statistical phenomenon, that is, it depends on temperature anomalies over a period of time (since the beginning of climate records, that is, since 1960 AD), and the La Niña phenomenon is statistically linked to below-average rainfall seasons in the Arabian Mashreq, in stark contrast to the Maghreb regions with increased rainfall, lower-than-normal temperatures and increased probabilities of floods and torrential rains in the Maghreb regions .

Misconceptions about El NinoMASTER) and the movement of air currents across the stratosphere (QBO), and many other meteorological factors, i.e. the meteorological condition is not exclusive and is the result of a particular meteorological phenomenon.


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