Theoretical study on occlusal front

Meteorologists' theoretical research on frontier matured in the early 20th century. They believe that the most intense weather in the atmosphere does not occur in the cold and warm air mass, but on the interface of the cold and warm air mass. Meteorologists define the front as: cold and warm air masses meet in space, and the narrow transition zone with discontinuous meteorological elements between them is called the front. The interface is called the front, and the intersection of the front and the ground is called the front. In practical work, front and front are collectively referred to as front. The front is always inclined in space, and it is inclined to the side of the cold air mass. Warm air is above the front and cold air is below the front. The length of the front line is several hundred to several Qian Qian meters, the horizontal width near the ground is about several tens of kilometers, the altitude can reach more than 200 to 400 kilometers, and the vertical thickness is several hundred meters to one or two kilometers.

There are three main conditions for the formation of occlusion front:

(1) The terrain in front is blocked by mountains;

(2) Two cold fronts meet head-on;

(3) The cold front in the extratropical cyclone catches up with the warm front.

In these cases, the warm air in front of the cold front is lifted off the ground and trapped in the air. Therefore, the interface between the cold air mass behind the cold front and the cold air mass in front of the warm front is called the blocking front.