According to a recent report on time and date, the global time and time zone management website, the fastest 28 days since the beginning of the record will take place in 2020. Researchers from the national time service center of the Chinese Academy of Sciences and the time and frequency group of the National Physics Laboratory in the UK said that since mid-2020, the earth's rotation rate has been accelerating. The report predicts that 2021 will be the shortest year in decades.

The earth is accelerating its rotation

The report points out that from the second half of 2020, the earth will rotate faster than at any time in the past 50 years, and the average time of a day will be 0.2 millisecond faster than before. It can be seen that the 24-hour natural day will gradually shorten.

In fact, the earth itself is an excellent timer, with an average rotation of 86400 seconds, equivalent to 24 hours. But the earth doesn't always rotate at this speed. Since its birth, the speed of the earth's rotation has gradually slowed down. About every 250 million years, the rotation cycle will be extended by one hour.

This is because the tidal action of the moon causes internal friction between the sea water and the earth's solid surface, then consumes the earth's rotational kinetic energy and slows down the earth's rotational speed.

However, the observation results of the National Institute of standards and Technology (NIST) show that the earth rotation speed, which has been slowing down for a long time, has been accelerating since 1999.

By 2020, the earth's rotation will be faster than ever. The time of the earth's rotation began to be slightly shorter than 24 hours. According to the data recorded in the past 60 years, the shortest 28 days since the beginning of the record are all in the middle of 2020, and the shortest day occurs on July 19, 2020, which is 1.4602 milliseconds shorter than the average 24 hours. Yes, the earth is spinning faster.

The impact of global warming?

What changes the speed of the earth's rotation? According to the report, it is human activities, especially global warming, that may affect the speed of the earth's rotation.

Global warming leads to the melting of ice and snow in high latitudes, which has an impact on the distribution of the earth's mass.

Take the melting of glaciers and ice sheets. When the ice sheet melts into the ocean, the mass of the earth is redistributed. The material is closer to the center than before, and the earth will rotate faster. Just like skaters, if they contract their arms when they are spinning, they will rotate faster.

Another explanation is that due to climate warming, more extreme weather and frequent atmospheric movements such as typhoons and hurricanes, matter is transferred from one part of the earth to another, which is enough to affect the earth's center of gravity.

Wei Ke, associate researcher of Institute of Atmospheric Physics, Chinese Academy of Sciences, told reporters: "the earth's rotation speed is mainly affected by the earth's internal mantle convection, earthquake and other activities, while the influence of atmospheric motion, ocean tide and lunar gravity is relatively small. Although the melting of ice and snow at high altitude may also affect the earth's rotation speed, the specific impact needs to be further studied."

"Accelerated" earth will produce

What are the impacts?

Some scientists believe that if the earth's rotation speed accelerates, it will produce more powerful hurricanes, and even strengthen the Coriolis effect of atmospheric ocean current movement, forming more distant cyclones. As a result, the corresponding extreme climate phenomena will appear more frequently than in the past 100 years.

German climate scientists once initiated a research topic. They have been using computer models to study and analyze the relationship between global warming and global water distribution since 2007. After 10 years of data research and analysis, they concluded that in the case of increasing global warming, the earth's rotation speed has also been affected, further aggravating the process of climate warming.

In order to ensure the time accuracy of all countries, an international earth rotation service (IERS) has been set up in Paris, France, which is specially responsible for global time adjustment and tells the world six months in advance when leap seconds must be added or subtracted from clocks.

"If the earth spins faster, it's likely to need a negative leap second." "This may push the decision to abolish leap seconds," Peter whibberley, a physicist at the National Physics Laboratory, told the Daily Telegraph

Source: China Environment News