Temperatures in many places across the country have exceeded historical extremes. Why are the temperatures so high in the first month of this year?
Temperatures in many places across the country have exceeded historical extremes. Why are the temperatures so high in the first month of this year?
Even before the first lunar month, we already have the taste of summer.
At around 2 pm on the 20th, the highest temperature in Beijing exceeded 20℃. As the temperature rises, many Beijing residents have taken off their thick down jackets, cotton-padded jackets and other cold-proof clothing and put on lightweight clothing. However, starting from the 21st, the temperature in Beijing will drop step by step, with the highest temperature expected to drop to 6°C on the 23rd and 24th. In addition, from the night of the 22nd to the day of the 23rd, the northern part of Beijing is expected to experience light snow or sporadic light snow.
Hebei: The recovery is accelerating, with the highest temperature exceeding 20°C in most of central and southern Hebei Province
On the 20th, the temperature in most of central and southern Hebei Province stood firmly above 20°C, and the highest temperature in Handan on Sunday will soar to 27℃.
Tianjin: The temperature exceeded 20℃ for two consecutive days, setting a new record for the same period in history
At noon on the 20th, the temperature in many jurisdictions in Tianjin exceeded 20℃. The highest temperature occurred in urban Tianjin, reaching 23℃, setting a new record for the highest temperature on the same day in Tianjin’s history since 1951. This is also the second consecutive high temperature for the same day in history since the temperature of 21.3℃ appeared on the 19th. record.
As if in early summer, the temperature in Jiangsu exceeded 25°C
High temperature weather also occurs in the south. On the 20th, the highest temperatures in Jiangsu Province were generally above 20°C, with Yixing exceeding 25°C, which was significantly higher than the average temperature for the same period in previous years. However, according to the prediction of the local meteorological department, due to the influence of cold air, Jiangsu Province will usher in a round of cooling from the 22nd to the 23rd, with a cooling range of about 10°C.
Liu Mei, chief forecaster of the Jiangsu Provincial Meteorological Observatory: Judging from the maximum temperature, from the 20th to the 21st, the entire province was at 23°C to 24°C; from the 22nd to the 23rd, the maximum temperature in our province In some areas, the maximum temperature will be between 10℃ and 15℃, and the minimum temperature will be below 5℃.
Shanghai: The highest temperature today may reach 23℃
The temperature in Shanghai continues to warm up, and the long-awaited white magnolias are beginning to bloom. The trees are full of white, which means spring. The footsteps have arrived.
According to official news from the China Meteorological Administration, in Inner Mongolia, Northeast China, North China, Huanghuai, Jianghuai and other regions, the temperature has generally risen by 6 to 10 degrees Celsius, and in eastern Inner Mongolia, Hebei, Beijing and other places, the temperature has risen by 12 to 12 degrees Celsius. 18℃.
The weather monitoring on the 20th showed that the highest temperatures at 365 weather observation stations across the country exceeded the historical extreme value for the same period in February.
What is the reason for the rising temperatures in various places? Let’s see what meteorological experts from around the world have to say.
The reasons for the soaring temperatures in different places are actually different.
According to Zhang Ning, chief forecaster of the Henan Provincial Meteorological Observatory, the main reason for the recent continuous rise in temperature in Henan is due to the weak force of cold air at high latitudes in East Asia. Most areas in central and eastern my country are controlled by warm air masses, and the weather Sunny with prevailing westerly and southerly winds at ground level.
According to Zhang Jiangtao, chief forecaster of the Hebei Provincial Meteorological Observatory, the current temperature rise in Hebei is due to the influence of warm air masses. The warming areas, especially the central and southern parts of Hebei Province, have not had cold air or cold air forces for a long time. Caused by very weak.
In Shandong, Shi Qian, chief forecaster of the Provincial Meteorological Observatory, said that due to the cooperation between the warm ridge and the southwest warm advection, the southerly wind on the ground is the main cause of the warming.
Is this related to the Brahma Wind Effect?
It is generally believed that foehn wind is a hot and dry wind caused by the sinking of over-mountain airflow caused by topographic dynamic forcing. It may occur in any mountainous area with a relative height of no less than 800 to 1000 meters in mid-latitudes.
In fact, whether the water vapor phase change occurs during the rise and fall of the airflow only depends on whether different formulas are introduced in the estimation of foehn wind temperature, and does not shake the core element of its warming mechanism: when the air mass rises from the ground , although no heat is gained or lost under ideal conditions, the air block expands due to the decrease in pressure after rising, consuming internal energy and causing the temperature to drop; when the air block sinks, the external air pressure gradually increases, the volume of the air block is compressed, and the internal energy increases , the temperature also increases.
If it is really difficult to understand, you can also think about it this way: if you climb over a high mountain without replenishing water, your cheeks will be red and your whole body will be dehydrated with only your tongue hanging out and gasping for breath. Woolen cloth?
Of course, no matter how much the body temperature soars, it cannot compare to the temperature increase brought about by the influence of this terrain.
As for this warming, Zhang Jiangtao believes that the area along the Taihang Mountains is indeed affected by the foehn wind, and the warm air mass is concentrated in the front of the mountain, making the warm air mass even warmer.
According to the actual situation, the temperature on the north side of the Taishan Mountains is higher than that on the south side, the wind force in Jinan and Zibo is also significantly stronger, and there is also some Foehn effect.
What impact will it have on agricultural production?
This rising temperature will have both pros and cons on agricultural production.
For Shandong, the temperature in the province has risen rapidly in recent days, and most areas have sufficient sunlight, which has accelerated the process of winter wheat turning green, which is beneficial to the heat storage and warming in greenhouses and the improvement of the production and quality of facility vegetables.
In Hebei, Cao Chunli, an expert at the Shijiazhuang Ecological and Agricultural Meteorology Center, also believes that this warming will have little impact on agriculture. For the main crop of wheat, current wheat is still cold-tolerant, and warming will Promote rejuvenation.
With the continued high temperatures, sunshine and strong winds, the drought situation in Henan Province has further developed. At the same time, the risk of winter wheat being damaged by late frost is also increasing.
According to Li Tongxiao, a senior engineer at the Henan Provincial Agricultural Meteorological Service Center, since January, precipitation in Henan has been 60% less than the same period in normal years, and 78% of stations in the province have experienced mild or above meteorological drought. Distributed in most parts of the north of the Huaihe River. In addition, according to the 0-50cm data of the automatic soil moisture monitoring network on February 20, 49 (accounting for 21%) measuring stations in the province have insufficient moisture, mainly distributed in northern Henan, western Henan, southwestern Henan and some parts of central Henan.
At present, winter wheat in various parts of Henan has turned green one after another. A slight lack of moisture is beneficial to the root system of wheat and improves the water utilization rate of deep soil. However, continued drought will affect the normal jointing of wheat and have certain adverse effects on wheat fields that lack moisture and have no irrigation conditions.
Li Tongxiao reminded that the evaporation of winter wheat gradually increases after it turns green. Areas with insufficient moisture should pay close attention to the development of drought, make preparations for drought resistance and moisture conservation, and scientifically conduct spring management. Wheat fields with weak growth should be combined with watering. With good top dressing management, the wheat fields will grow vigorously, and water and fertilizer should be delayed appropriately to ensure the steady growth of wheat seedlings.