What does it mean to go back to Nantian? go back to Nantian
It is very necessary to understand when it will appear in the southern sky. This advantage is to be able to take precautions in advance, reduce the harm of the meteorological environment to us, and take effective protective measures. It is also urgent
What is Huinantian?
Cantonese people are no strangers to "Huinan Tian". Every year, the temperature fluctuates greatly between winter and spring, resulting in significant changes in the temperature difference between indoor and outdoor. When the temperature of indoor objects is less than or equal to the "air dew point", water vapor condenses on the surface of the object to form a "water outlet" phenomenon, which is what citizens call "Huinan Tian".
A very important concept here is the "dew point". The "dew point" is the temperature at which the air humidity reaches saturation. It is not a fixed value, but is related to the air temperature and humidity. Generally speaking, the "dew point" is less than the atmospheric temperature, and the temperature of daily objects is greater than the "dew point".
The phenomenon of returning to the south is the phenomenon of the weather returning to moisture, which usually occurs in February and March in spring. The main reason is that after the cold air leaves, the warm and humid air quickly counterattacks, causing the temperature to rise and the air humidity to increase. When the surface of some cold objects encounters the warm and humid air, it is easy to produce water droplets. The phenomenon of returning to the south is more serious in the south, which is related to the fact that the south is close to the sea and the air is humid. When "returning to the south" appears, the air humidity is close to saturation, and the walls and even the ground will be "water". There are wet scenes everywhere, and the air seems to be able to wring out water. And thick fog is the most characteristic appearance of "returning to
Before the arrival of "Return to the South", there were signs: first of all, there must be a continuous cold process, at least three days or more, in order to make the temperature of indoor objects drop to the same level as the outdoor, which is called "cold through". At this time, the weather came to a sudden change, the warm and humid air in the south strengthened, and the outdoor temperature rose rapidly (the "dew point" of the air also rose rapidly at the same time). At this time, although the temperature of indoor objects also rose, it was far from catching up with the speed of outdoor temperature rise. The increase in the temperature difference between indoor and outdoor caused the temperature of indoor objects to be smaller than the "dew point" of the air, resulting in the phenomenon
According to the introduction, the low-temperature and rainy weather with an average daily temperature below 12 ° C lasted for more than three days, and it suddenly turned into a warm and humid airflow with a rapid rise in temperature, which is a harbinger of the "return to the south".
According to statistics, when the phenomenon of Huinan is serious, the visibility can be reduced to 50 meters. In Huinan weather, some items or food are prone to moisture, and then mildew and rot. Therefore, appropriate moisture-proof measures should be taken.
The main reason for the formation of Huinantian
Everyone knows that winter comes to spring, and it is warm and cold. When people wake up, they find that the world outside the window is mired in a vast sea of fog. This kind of weather is called "Huinan Tian" by people in Guangdong and Guangdong. So what are the reasons for the formation of Huinan Tian?
In spring, water will come out of the walls and floors of Huinan, which is actually very similar to the principle of sea fog. The warm and humid ocean air flow from the warmer sea surface to the cooler sea surface, and the water vapor in the air condenses into fog droplets when cold, and accumulates in the air to form fog. If the temperature difference between the sea surface where the air flow passes is large, the chance of fog is also greater.
Similarly, due to the cold weather in winter, the walls and floors are cold on the outside. If warm and humid air flows through the walls and floors at this time, the water in the air condenses into droplets when it cools and adheres to the walls and floors, as if water seeps out of the walls and floors. In summer, even though there is humid ocean air flow, the walls and floors are not cold enough on the outside, and the walls and floors will not come out of the water.
The back to the south usually appears in February and March in spring. The main reason is that after the cold air leaves, the warm and humid air rises rapidly, causing the temperature to rise. As a result, the humidity in the air increases. After encountering the warm and humid air on the surface of some originally cold objects, these cold objects absorb heat, which reduces the surrounding temperature and causes water droplets to condense. The phenomenon of back to the south is more serious in the south, which is related to the fact that the south is close to the sea and the air is humid. When "back to the south" appears, the air humidity is close to saturation, and the walls and even the ground will be "watery". There are wet scenes everywhere, and the air seems to be able to wring out water. And thick fog is the most characteristic appearance of "back to the south".
Obviously, there must be at least two conditions for the formation of "Huinan": first, there must be a long period of low temperature, and the daily average weather must be lower than 12 ° C for at least 3 days. For example, before the "Huinan" appeared in February 2010, the daily average temperature was lower than 12 ° C for 9 consecutive days; secondly, there must be a sudden change in the weather. After a long period of low temperature, it will suddenly become warm and humid. When "Huinan" occurs, the humidity sometimes reaches 100%.
Although Huinan weather is a very uncomfortable climate, the arrival of Huinan weather does not also prove that all things wake up in spring, the climate will slowly warm up, and the temperature will rise. In Huinan weather, some items or food are prone to moisture, and then mildew and rot, so pay attention to moisture and mildew prevention in Huinan climate.
When will Huinantian appear?
Returning to Nantian, the thing that southerners are most afraid of mentioning, mastering the law of when returning to Nantian will take precautions, which will play a good role in protecting everyone's living environment. Don't you want to know about it?
Returning to the South is a phenomenon of returning tide in the weather. So, when will it appear in the South? Generally, it occurs in February and March in spring.
After understanding when Return to Nantian will appear, let's take a look at the relevant knowledge.
The formation principle of Hui Nantian is the same as the formation principle of'dew ', that is, dew is knotted in the home, on the walls, floors and furniture.
The formation of Huinan Heaven requires at least two conditions:
First of all, there must be a long period of low temperature, and the daily average weather below 12 ° C will last for at least 3 days. For example, before the return to the south in February 2010, the daily average temperature was below 12 ° C for 9 consecutive days.
Secondly, there must be a sudden change in the weather. After a long period of low temperature, it will suddenly become warm and humid. When it occurs back to the south, the humidity can sometimes reach 100%.
The weather process of'going back to the south 'is also the process of the warm and humid southerly airflow repulsing the northern system. After studying the "going back to the south" in the past 10 years, it was found that before and after "going back to the south", the temperature rose rapidly and the air pressure dropped sharply. From the north wind to the south wind, the wind speed suddenly increased, the visibility dropped sharply, and the humidity tended to be saturated.
According to reports, after exploration and research, Guangdong's forecasting scientific research and business personnel have summarized several experiences in forecasting back to the southern sky.
One is that after a long cold, when the ground and building base temperature are low, if there is fog with visibility less than 1km, and the temperature is expected to continue to rise and the air pressure will drop, you should pay close attention to the possibility of "returning to the south" in the future.
Second, the probability of "Huinan Tian" appearing from late February to early March exceeded 60%, and 50% of "Huinan Tian" with a serious degree appeared.
Knowing when to return to the south is very necessary. This advantage is to be able to take precautions in advance, reduce the harm of the meteorological environment to us, and take effective protective measures.
