The warm sun has a cold day,

The North has just undergone a warm sunny day and it was cold again on February 2. Why does the winter weather have such happenings?

Warm sunshine occurs only one day before it becomes cold again due to the increase in cold air.

After a warm sunny day, the North continued to sink in cold weather from February 2.

According to the forecast of the Central Hydrometeorological Forecast Center, on February 2 morning, the intensified cold air has affected some places in the Northern mountainous region and the Eastern North region, causing the heat background to decline. down.

This rapid weather change has affected many people and many cases of respiratory diseases such as bronchitis, rhinitis, .

The explanation of the phenomenon of hot sunny days in the winter, interwoven between cold air waves, Jeff Haby, meteorologist at the University of Mississippi (USA), said, because the Sun heats the left surface. Land.

However, the sun's angle plays an important role in the amount of sunlight that can heat the air. In winter, the lowest sun angle should limit the increase in energy and heat the Earth's surface.

In fact, hot or cold weather mainly depends on the amount of heat that the Earth receives from the Sun more or less.

The Earth usually rotates around the Sun at an angle of 23.5 degrees. Therefore, this angle causes some areas to be far or near the Sun and this also affects the different heat gain in each region on Earth.

Moreover, the temperature and weather conditions in winter depend very much on the movement speed of cold air flows. Therefore, the phenomenon of a warm sunny day but then cold again is not too much surprise.

The temperature in a winter day is also different.(Illustration).

Even the difference in temperature in a winter day can be markedly different (higher in the afternoon than in the early morning and late evening).

The fluctuations and changes in weather are also influenced by factors such as wind direction, location near the ocean, impacts of phenomena such as La Nina, El Nino climate change, . In the world, There are many cases of weather that are quite unusual.

Specifically, Daniel Swain, climate scientist at UCLA (USA), said the Southern California region rarely occurs wildfire around December in the wet conditions of winter.

However, in December 2017, at least 6 forest fires are active in Southern California, setting a record for many serious forest fires in California state.

Many large wildfires occurred in Southern California in December 2017.(Photo: Mercury News).