Although this fall's "opening show"
It's one miserable storm after another,
But the beauty of autumn is not absent,
Since last Thursday, with the good weather blooming,
It perfectly interprets "chrysanthemum crab fat osmanthus flower is clean, the most beautiful in the world is autumn".
Especially the last weekend,
When we look up,
There are romantic "fish scale clouds" all over the sky,
And through the city, there is a refreshing fragrance of osmanthus flowers circulating in the air
Unfortunately, the autumn in Hangzhou is too "stingy",
It's ten days less than spring.
And it's in the midst of "shrinking.",
According to statistics,
From the 1990s to the present, autumn in Hangzhou has been reduced by 7 to 9 days.
Therefore, such an autumn high is more worthy of our cherishing!
Good news again:
Recently, the two air forces of cold and warm, the overall are relatively "stopped", until the end of the month, our province will maintain a sunny and rainy weather pattern, the temperature is relatively stable, except for Wednesday affected by the spread of weak cold air, the temperature dropped slightly.
This is really an "autumn welfare" big delivery, but in the autumn high and refreshing, it also implies the side effect of "large temperature difference between day and night"
Why is it easier to have a large temperature difference between day and night when autumn is sunny?
The result of the "autumn high and cool" is the increase in "clear sky radiation" in autumn. During the day, the ground and its vicinity air heat up by absorbing the sun's short-wave radiation; at night, the ground and its vicinity air cool down due to long-wave outward radiation. On cloudy nights, this long-wave radiation is absorbed by clouds, which in turn emit long-wave radiation upwards and downwards, respectively. The downward radiation part returns to the ground to compensate for the heat lost on the ground, so that it is like covering the air near the ground with a quilt, so that the temperature will not drop too much; on a clear night without this layer of "quilt", the long wave radiated out of the ground will rarely "return", and this radiation cooling is especially obvious in the clear night, and the temperature also drops badly.
For example, this morning, the minimum temperature in most parts of our province is only 10-12 °C, of which 6 areas such as Pan'an, Haining and Anji are less than 10 °C, but during the day with the help of sunlight, the maximum temperature can rise to 2 characters, and the temperature difference is more than 10 °C.
At this time, the "onion-style dressing method" comes in handy, adding clothes in the morning and evening, undressing at noon, and following the footsteps of the temperature to increase or decrease clothes in a timely manner, and the cold will not find the door!
In addition, the weather is still, easy to breed fog, this morning in the northern Zhejiang region of the local fog, visibility is reduced, you need to pay attention to driving safety.
Editor| First Instance: Lan ShuoQun
Second instance: Wang Ying
Final Judge: Li Ruimin
(Zhejiang Meteorological Service Center)