stationary front

From cloudy and cloudy rain, to Southern China before flood, to Meiyu in Japan, Meiyu in Jianghuai, and to Meiyu in Korea. East Asian countries in this series of rainfall in the immersion xixilili, sometimes the rain with vigour and vitality.

And the start of the rainwater is the usual guest in the middle latitude of the weather - the still front.

What is a front, and what is a static front?

Early in high school, even in junior high school geography teaching materials, has come into contact with the concept of front. There is a concept of the cold front, warm front, stationary front and occluded front.

I will from the higher level point of view it again ~ (if only to see the cold and warm fronts in the comments section said this is not the junior / Senior High School Geography buddy, I think it may need a lot of training the ability to accept new knowledge ~ after all nouns will not change, but the content may be more and more.)

In simple terms, front is actually the interface when several different gas masses move to each other.

1. Brief introduction

1.1. Leng Feng

The left side is the most typical front pressure field configuration, the place is located in the front trough the maximum curvature, southerly front, front northerly winds, cold after cold high pressure filled with cold air, high pressure and low pressure at the intersection of the isobars is more intensive, often accompanied by winds.

If we consider the vertical section (A---B dashed line), it is the fact that the cold air group is actively drilling below the heating group and forcing the heating group to lift. I believe you all have some understanding. The main driving cold air mass is the north wind component in the air mass, but in the west wind belt, the cold and warm air mass also contains the western wind component. Because the heating group is lifted, the height of the 850 hPa height around the cold front front area is about 1500m. There will be a warm area and a weak south wind area, which is caused by the heating group's lifting.

1.2. Warm front

Under the left is a typical frontal cyclone, cold air is composed of entanglement and the formation of cyclone. The red line is the warm front, is a map from the south to the north of the warm front movement.

Similar to the cold front, warm front is because warm air like active cold air movement and climb up the cold air formed, so the diagram is very similar to the cold front, and the cold front is different, Dongfeng component of cold air in front of the warm front, and because of the warm air wind forces is strong, easy to then the lower atmosphere formation of low-level jet, promote the formation of the warm region in the rain.

1.3, occluding front

The cold air is occluded front after the warm air, resulting in two before and after the cold air will warm air and surrounded by warm air out of the ground, and the formation of the front. Including warm occluded, cold occluded and neutral occluded, here is not to say.

1.4. Jing Zhifeng

At last it was the protagonist of this article - the still front.

We know, whether it is cold or warm, cold and warm air in front of two there is a strong one, and the stationary front is different, resulting in front of cold and warm air keep stable well-matched in strength.

This is the pressure field configuration of two typical stationary front, may be a little difficult to understand, also need to know that, even if the saw pressure field configuration, can not immediately say stationary existence, also needs the temperature, temperature, humidity and pseudo equivalent potential temperature, dew point temperature and so on. To determine whether the parameters of wet frontogenesis.

The left side of the picture is a typical stationary front configuration, stationary front located between high and low voltage (southerly), isobars in frontal and isobars parallel. The most typical example is Kunming quasi, actually this kind of configuration of the isobars is also closely related to the effect of topography.

The right side of this chart is more difficult to understand, here in the stationary front corner of the cyclonic fold isobar, known as reflux. In the corner office, due to friction, surface wind across the isobars, appeared in southerly wind component, resulting in wind weakened, behind the wind speed is large area air fixed here and slow accumulation, formation of ascending motion, thus forming a stationary front. The most typical front is the East Asian Meiyu front.

The picture is a typical East Asian Meiyu front, from the Yangtze River in China through the Pacific Ocean through Japan. The Pacific is located in the quasi implicit slot between the two high voltage in parallel with the isobars. The picture comes from the Japanese Meteorological Office (JMA)

It can be seen that the wind speed is smaller at the angle of the air flow, because the reflux effect causes air accumulation and lifting.

The front area of 2, middle latitude

In the previous geography class, if you have heard the word "polar front", what is the extreme forward? What role does the polar front play in the whole earth's atmospheric system?

The polar front is not a front, but it is called the polar front, or the pole front system.

One of the fronts, including the frontal cyclone, is included in the pole front system, including the middle latitudes.

Every year in different seasons, tropical air group will be very low and mid latitudes in fierce battle, and when the spring and summer, the subtropical high is the representative of the warm and cold vortex forces as the representative of the cold power in East Asia met, forming a long, continuous dissipation, but overall still continues Feng: Meiyu front. Because the fronts near the equator are difficult to exist, only middle latitudes are the most typical fronts.

Two, East Asian Meiyu front

When it comes to Meiyu, it always reminds me of the rainy weather in the Huaihe River Valley. In fact, it is a narrow sense of plum rain. In the broad sense, the East Asian plum rain is the pre flood season beginning in April, and the rainy season in South Korea and the central part of Japan all belong to the East Asian plum rain.