20 things you don’t know about the season

Thanks to the rickety planet, we have brought us all seasons, from bees to lungfish, all kinds of animals have adapted to the seasonal changes, and also have different growth and dormancy seasons.

1. The reason why the earth has four seasons is because the axis of rotation of the earth is not perpendicular to the plane of its orbital orbit, and the angle of deviation is 23.5 degrees. This makes the north and south hemispheres receive unequal solar illumination at different times and periodically change. More hemispheres in the sun are in summer and the other half in winter. Spring and autumn are transition seasons.

2. The orbit of the earth orbiting the sun is elliptical, and the distance from the earth to the sun varies with the elliptical orbit. Due to the rotation of the earth, the angle of each point on the earth and the sun’s rays change at any time. When the sun shines directly on the surface of the earth, the surface temperature of the ground is high, and when the angle of inclination is large, the temperature of the surface of the ground is low. (However, Earth’s orbit has a cycle of about 100,000 years, and in its most extreme cases, solar radiation can increase by as much as 30%, affecting the overall climate.)

3. Most astronomers believe that about 4.5 billion years ago, a Martian-sized celestial body hit our young planet, causing axial tilt. Incidentally, this inclination, or inclination, varies from 22.1 degrees to 24.5 degrees in about 40,000 years.

4. A larger angle of inclination means that the summer is hotter and the winter is colder; the decrease in inclination results in less temperature fluctuations. The range of extremes and polar nights on Earth will also decrease. Generally, this angle of inclination will not be too large from 23.5 degrees.

5. Stanley of the University of California, Santa Barbara, in 1986, concluded that by combining the growth curve of stromatolite (a biodeposited structure) with the latitude of the growth site, the earth’s axis inclination can be calculated. The calculation results show that the inclination of the earth’s axis 800 million years ago is almost the same as it is now. However, in 2007, some people thought that the method of using the stromatolite to calculate the tilt angle of the earth to the optical machine is not reliable, and the debate is still going on.

6. A paper published in the 2018 Astrophysics Journal News said that scientists don’t know how common planets like us are, but the seasonality of the Earth may help them find signs of life elsewhere. Current exoplanet analysis looks for oxygen, methane, and other gases that are necessary or produced by living organisms in the atmosphere.

7. When the Earth orbits the Sun, its tilting axis means that different regions receive more rays at different times of the year. The most obvious signs of this phenomenon are weather changes and the length of the day, but the atmospheric composition is also affected. For example, in the northern hemisphere, which contains most of the world’s vegetation, summer plant growth significantly reduces the amount of carbon dioxide in the atmosphere, and oxygen is just the opposite.

8. A study suggests that a more reliable exoplanet biometric may be a seasonal change in atmospheric composition, meaning that seasonal changes in the atmosphere of exoplanets may indicate the existence of extraterrestrial life. Scientists at the University of California, Riverside’s Alternative Earth Astrobiology Center are developing the first quantitative framework for dynamic biometrics based on seasonal changes in the Earth’s atmosphere.

9. The lead author of the study stated that the seasonality of the atmosphere is a highly desirable biological feature, because on Earth it is biologically regulated and it is likely that other livable worlds will also occur. Inferring life based on seasonality does not require a detailed understanding of alien biochemistry. Because it is a biological response to seasonal changes in the environment, not the result of specific biological activities specific to the Earth.

10. In this paper, the researchers also simulated fluctuations in atmospheric oxygen on a living planet with low oxygen content, just like the Earth billions of years ago. The researchers said that observing seasonal changes in oxygen or methane would give more information. A potentially effective way to assess the suitability of exoplanets is to look at their atmosphere in their orbit to see if we can detect changes in these biometric gases within a year.

11. In some cases, such changes are difficult to explain without life, and may even allow us to make progress to describe life, rather than simply recognizing the existence of life on an exoplanet. However, it has also been suggested that it is inaccurate to look for these so-called biogases, assuming that the exoplanet life forms have similar metabolism to the Earth’s biology.

12. On Earth, carbon dioxide levels are lower in summer than in winter, as most plants actively absorb carbon dioxide, while winter plants die or go to sleep.

13. At the same time, animals have many seasonal adaptation strategies, such as migration, which may mean altitude, latitude or hemisphere changes. Birds are probably the most famous migrators, including Arctic terns, which fly from the far north breeding grounds to Antarctica every year and then fly back.

14. Many marine animals also migrate, even if they do not migrate geographically. Seasonal changes in oxygen levels have forced many fish, crustaceans, and molluscs to migrate to higher or lower levels in water.

15. However, all four African lungfish stay in place, even though their freshwater habitat may disappear during the dry season. Their survival is due to summer sleep. Just as hibernation is a long-term cold adaptation strategy, summer sleep is also a state of reducing metabolism and reducing activity, often in the dry season.

16. Some African lungfish will have a summer sleep after digging holes into the soil to find permanent moisture, even after secreting their own mucus. In the dry season of lack of water, African lungfish are deeply buried in the mud hole for summer sleep, do not eat or move, through the sputum to complete the weak breathing, until the rainy season is coming, the hole is broken.

17. Some insects have evolved seasonal changes in a population. Take the Western Italian bee as an example. In mild climates, worker bees are born in spring and summer and can survive for a few weeks to raise young bees for nectar and pollen. However, in the same ant colony, worker bees in winter – workers who appear when the chances of eating in the fall are reduced – may survive for 6 months or longer. Most of these winter bees gather around the queen to warm themselves.

18. Seasonal differences in life span are related to vitellogenin, a protein found in the blood that is equivalent to the blood of a bee. Winter bees have significantly higher protein content, which may sustain their survival.

19. Seasonal foods can alter microbial communities, and larger organisms, including humans, are their harbors. In 2017, a scientific study of hunter-gatherers in Tanzania found that the entire bacterial family entered and exited the participants’ intestines, reflecting seasonal changes in diet. The study focused on changes in microbial populations in both tropical and wet seasons.

20. The fourth national climate assessment report released in November 2018 pointed out that the wildfire season in the United States has been extended, in part because of prolonged drought. With global warming, the risk period in many other countries is also expanding, largely due to human activities. At the same time, the global cyclone season has become more intense in the Atlantic and shows signs of increased activity in the Pacific.