What difficulties did Chen Yide encounter in the process of meteorological research?

Chen Yi must study hard his favorite astronomy and meteorology. Using his rich teaching knowledge, he calculated the time difference between Yunnan and Beijing with sundial observation, measured the standard time of Yunnan counties and the time when the sun appeared and disappeared in 24 seasons, and observed the sky on this basis. After years of observation, according to the latitude and longitude of Kunming, Chen Yide created the "sky-mending gauge" and drew the first "Kunming Star Map". By aiming at the direction and correcting the date with the sky-mending gauge, you can identify the stars that appeared in the sky in Kunming that night. If you are in other places, you can also adjust the viewing according to the latitude and longitude. Yuan Jiagu went to Chen Yide's residence to try out the "sky-mending gauge", and compared the observation results with astronomical books, which were consistent and could not help but admire. Because of the convenience of the "rule of mending the sky", people who study astronomy have come to ask for it. However, because Chen Yide couldn't raise a large sum of money, he couldn't make the "sky-mending rule" on a large scale, so the "sky-mending rule" was not popularized. 1934, Chen Yide successfully measured the scriptures in the gymnasium of Yunnan University. 194 1 year, the Chinese astronomical society was established and organized Chen Yi to go to Lintao, Gansu Province to watch the total solar eclipse.

weather prognosis

In addition to astronomical observations, Chen Yide also makes meteorological predictions. Starting from 1926, Chen Yi was able to teach for more than 10 years, and went to Nanjing Meteorological Observatory for further study at his own expense. Half a year later, Chen Yide traveled from Nanjing, Shanghai, Nantong, Wuhan, Beijing, Tianjin and Qingdao, around Yokohama, Tokyo, Japan, and passed through Haiphong and Hanoi, Vietnam, visited famous astronomical weather stations in East Asia, and returned to Kunming after purchasing meteorological observation instruments. 1in July, 927, Chen Yide set up a meteorological station on the roof of the dormitory, and the signboard of "a weather station" hung at the door of the house. Chen Yide observes and records the sunny and rainy weather, temperature, humidity, wind direction and cloud shape in Kunming on time every day, and makes statistics, collation and periodical publication. In addition to domestic exchanges, there are also international exchanges. This has made a certain contribution not only to the local area, but also to the national and international meteorological observation and forecast. 1936, the Yunnan provincial government built a brick-wood meteorological observatory at the top of Taihua Mountain in Xishan, named "Yunnan Meteorological Observatory", and asked Chen Yide to be the director.

Study earthquakes

Chen Yide thinks it is very necessary to study earthquakes. He found that earthquakes in Yunnan all occurred in the first or second quarter, so he thought that earthquakes were related to the movement of the moon. He visited various earthquake zones on the spot, from Jianshui and Shiping in the south, to Yongren and Lijiang in the west, and then to Lvliang and Maitreya in the east, copying trails, crossing rapids and climbing dangerous peaks to explore the source, and his analysis and research were recorded in detail. He also collected a large number of proverbs about people having a premonition about earthquakes, and the phenomenon that poultry, livestock or other animals were restless before earthquakes, thus enriching the means of earthquake prediction and improving the accuracy of earthquake prediction.

Chen Yide participated in the compilation of astronomical meteorology in the new edition of Yunnan Tongzhi, got rid of the old theory of superstitious annexes such as Chen Wei and Fu Rui, and re-edited it with a scientific attitude, creating a new pattern of local chronicles compilation. Chen Yide also compiled Yanjin County Records. In addition, he also compiled the astronomical and meteorological data of Qiaojia, Lunan and Jinning.

Chen Yide is usually very experienced in research. He has printed and distributed some research results such as floods and weather, rainfall distribution in Yunnan, and the results spread like wildfire in Japan. Austrian scientists came to Kunming with the American consul in Kunming to visit Chen Yide's weather station, and they were all surprised by its accurate records. As for domestic experts in the fields of agriculture, forestry, water conservancy and aviation architecture who come to Kunming, it is even more necessary to visit and listen to his report. Chen Yide works conscientiously and responsibly. When he was a member of the China Association for Science and Technology, he always went to meetings to listen to the exchange of experience, accepted the spirit of resolutions, and returned to Kunming to convey and promote his work. During his tenure as director of the branch of Yunnan Natural Science Federation, chairman of Yunnan Popular Science Association and curator of the museum, he worked hard.

195810 June 17, Chen Yide died in Kunming. Chen Yide's rigorous academic spirit, perseverance in studying science and simple style have won the admiration of the older generation of scientists such as Zhu Kezhen and Liang. Chen Yide's main works include: Meteorological Observation Records of Kunming in Recent 30 Years (Quarterly Report and Monthly Report), Distribution of Meteorological Elements in Yunnan, Changes of Water Level in Kunming, Dali Wind, Observation of Earthquake History in Yunnan, and West Yunnan Earthquake Belt.

Study on precipitation sources in Yunnan

By observing, recording and consulting a lot of data for many years, and applying modern meteorological science theory, Chen Yide made a regular analysis and summary of precipitation sources in Yunnan for the first time. Most of the land precipitation comes from the warm and humid air mass formed over the ocean, and the land precipitation finally sinks into the ocean to complete the water cycle on the earth. Southeast Yunnan borders Vietnam, overlooking the Beibu Gulf in the South China Sea, facing the Pacific Ocean and the Philippine Islands. The southwest is adjacent to Myanmar and near the Bay of Bengal. The Pacific Ocean and the Indian Ocean have a great influence on Yunnan's climate, absorbing land heat, transpiration water vapor and forming warm and humid air masses. Southern Yunnan has a low latitude and a tropical climate. The mountains in the northwest are connected with Sichuan and Tibet, and the Yunling trunk line runs through the whole province. The mountains in Yunnan are parallel and high in altitude, which is easy to form a barrier to warm and humid air masses from the Pacific Ocean and the Indian Ocean. The formation of precipitation in Yunnan is also easily influenced by topography, so the situation of precipitation in various parts of Yunnan is very complicated. After in-depth study, Chen Yide scientifically divided the precipitation in Yunnan into four types:

Topographic precipitation: Every time China's oceans, rivers and lakes absorb hot air, transpiration water vapor, and water vapor is blocked by mountains, it is forced to rise rapidly, suddenly condenses when it meets cold, and liquefaction drops with the wind, so rainfall can be formed. Chen Yide called it "topographic precipitation". He believes that most of the precipitation in Yunnan is "topographic precipitation". "The mountains and forests are deep, and the water vapor is more saturated, especially the topographic precipitation, but the rainfall area is not large."

Cyclone rain: The precipitation that widely affects Yunnan is called "cyclone rain". Because Yunnan is connected with Myanmar and India, in the tropical areas of south-central India, the radiation of the sun produces accumulated heat, and the evaporation of land water vapor produces warm and humid air masses, so the air pressure becomes lower. The center enters Yunnan from southwest to northeast. If you suddenly meet the cold air flow in the north, it will suddenly become "cyclone rain", which is characterized by slow first and then fast, long time and wide area.

Thermoelectric rain: Yunnan Province is characterized by high mountains and deep valleys, easy involvement of intense heat, long sunshine time and high ground temperature. Whenever the wind is weak, it plays the role of strong convection, steam rises and the difference between positive and negative charges in the air suddenly increases. At this time, "thermoelectric rain" will follow. In southern counties, there are many thunderstorms in summer and at night. At this time, thunder and lightning and heavy rain poured down, but the duration was short, the scope was not wide, and the duration from generation to stop was short.

Typhoon rainstorm: According to meteorological observation and records, the largest and most disaster-prone rainfall in Yunnan is typhoon rainstorm. 1936, a typhoon center landed in Wenzhou, passed through Jiangxi, Hunan and Guizhou, and finally reached eastern Yunnan, causing an "unprecedented disaster" in Yanjin and Zhaotong. All the counties along the Yanjin River were flooded, which was so destructive that these towns have not recovered their old appearance after more than ten years. The typhoon affecting Yunnan comes from the warm and humid air mass near the equator and occurs in the eastern Pacific Ocean of the Philippine Islands. Every summer and autumn, it often goes to China's coastal activities, and it is more powerful in July and August. It often lands in Guangdong, Fujian, Zhejiang and other provinces, and it is extremely destructive along the way.

There are not only various types of precipitation in Yunnan, but also different types of precipitation often occur at the same time. Tracing back to the source, it is an unprecedented work to clearly classify the rainfall in this province and reveal its characteristics, which has a great impact on industrial and agricultural production. This is a great achievement of Chen Yide's meteorological research in Yunnan.

Precipitation distribution in Yunnan

With regard to the distribution of precipitation in Yunnan, Chen Yide summed up six main laws with extremely precious scientific value from the perspective of regional distribution in this paper: First, the rainfall lines such as 1500mm surround the western and southern frontiers of Yunnan. Second, the rainfall in southwest Yunnan is often more than that in northeast Yunnan. 3. The rainfall in southern Yunnan is more than that in the border areas of western Yunnan, that is, the area near Tokyo Bay in southern Yunnan is slightly richer than that in southwestern Yunnan far from the Bay of Bengal. 4. The rainfall in the west of Hengduan Mountains is more than that in the east, that is, the Nujiang River basin is more than the Lancang River basin, and the Lancang River basin is more than the Jinsha River basin. 5. The isohyet of 1000 mm winds all over Yunnan from northwest to southeast. 6. There was a heavy rainfall near Kunming, with a period of more than 1 1 year. There were two rainy years and few rainy years, with a period of more than 5 to 6 years.

In addition, Chen Yide also observed and recorded the rainfall distribution from 1937 to 1943 in Yunnan, studied the rainfall in each month of each year, and drew regular conclusions. This research result is contained in "Continued Yunnan Tongzhi Long Text". Chen Yide believes that rainfall in various parts of Yunnan can be analyzed from seven aspects: First, the lunar calendar 1 month is the dry season, which is the month with the least rainfall, and the highest isorainfall line in southern Yunnan is less than 20 mm, only in Dali, western Yunnan. There are still special reasons for the rainfall exceeding in recent years. Second, the rainfall in the province increased in February in spring. Shunning (now Fengqing) and Dali have an average of 40 mm, which is caused by the contact zone between cold and warm air. In March and March, the rainfall in Dali increased, with an average of 80 mm, which is also the highest in the province. Precipitation is increasing in the southwest and east of the province. The advance of equatorial air mass is quite remarkable. In April and April, the air mass in the south was more abundant, the average rainfall in the estuary increased to more than 100 mm, and the isorainfall line of the whole province moved northward, slightly parallel to the latitude. Since the rainy season began in May and May, the rainfall in Yunnan has generally increased, with the humid and hot zone in the lower reaches of Yuanjiang reaching 250 mm, the rainfall in most places in June and June is 100 mm, and the rainfall in Shunningte in western Yunnan is as high as 350 mm, which is the peak of marine warm and humid air mass, especially in southwest China. In July and July, the rainfall in the whole province is at least 100 mm, Gejiu in southern Yunnan is very large, with an average of 400 mm, and Baoshan and Jingdong in western Yunnan are less than other places, which is caused by the mountain barrier. From September to1February, the precipitation in Yunnan plummeted, and by1February, the rain line in the rainy areas in southwest China was only 30 mm.