What season does the grass grow and the warbler fly in February?

"The grass grows in February and the willows are drunk with spring smoke" describes the early spring season in February.

I. Introduction to Spring

Spring is one of the four seasons, between beginning of spring and Long Summer, including solar terms such as beginning of spring, rain, fright, vernal equinox, Qingming and Grain Rain. Spring represents warmth and growth. In spring, the qi of yin and yang begins to change, and everything germinates and grows with the rise of yang. ? Spring is a period of alternating winter and summer monsoon, with cold air and warm and humid air alternating.

As far as solar terms are concerned, spring in China begins in the beginning of spring (February 2-5) and ends in the long summer (May 5-7). In Europe and America, spring begins at the vernal equinox in China and ends at the summer solstice. In Ireland, February to April is designated as spring.

At present, the method of "waiting for average temperature" proposed by modern scholar Zhang Baokun is often used to divide the four seasons in China. Taking the five-day average temperature as the standard, the five-day average temperature after winter passes 10℃ and begins to enter spring. When the temperature is higher than 22℃, it means the end of spring and the beginning of summer.

Second, climate.

In spring, the northern hemisphere of the earth began to tilt towards the sun, receiving more and more direct sunlight, so the temperature began to rise. In spring, plants begin to sprout and grow, and many flowers bloom.

Hibernating animals wake up, many animals with eggs for the winter hatch, and birds begin to migrate, leaving the wintering ground for breeding grounds. Many animals are in estrus during this period, so China also calls spring the season of "the revival of everything".

Astronomy and solar terms beginning of spring

First of all, astronomy

The angle between the equator of the earth and the orbit of revolution is the fundamental reason for the seasonal change. In spring, the direct point of the sun gradually moves from the tropic of Capricorn to the north, crosses the equator after the vernal equinox, and the sun shines directly into the northern hemisphere. In spring, the distance between the earth and the sun is getting farther and farther. Every year around 65438+10.3, the earth is closest to the sun. Seen from the ecliptic plane, the sun is on the background of Aquarius, Pisces and Aries.

Second, the solar term beginning of spring

Beginning of spring, also known as the Spring Festival, the First Month Festival, the Lunar New Year Festival, the Lunar New Year Festival, the Lunar New Year Festival and the Lunar New Year Festival, is the first of the 24 solar terms, the beginning of the year of the dry calendar and the beginning of the end of everything, representing the beginning of everything and the meaning of self-improvement.

Twenty-four solar terms were originally formulated on the basis of "variable stars". When the bucket handle of the Big Dipper points to the shade, it is beginning of spring. At present, solar terms are determined according to the longitude of the sun. When the sun reaches the longitude of 3 15, it will be beginning of spring, which is celebrated on February 3-5 of the Gregorian calendar every year.