Brief introduction of low pressure storage tank

The trough of low pressure refers to the connecting line between the points with the highest cyclone curvature and the lowest pressure (or potential height) on the medium pressure (high) line. It is the area with the strongest horizontal convergence of airflow in the low pressure trough. Usually, the weather changes obviously near the trough line. For example, in the westerly belt, the southerly wind often blows in front of the trough line, and there is an upward movement. A large amount of water vapor can form clouds and precipitation. There is a northerly wind with sinking movement at the back of the trough line, and the weather is mostly cloudy and sunny. In the westerly belt, the distribution pattern and movement of various trough lines are often different. The trough lines near the meridian on the south side of the low pressure are called vertical trough lines, which often move eastward; The trough line on the west side of the low pressure is close to parallel to the weft circle, which is called transverse trough line and often moves to the southeast; The trough line extending from south to north on the north side of the low pressure or the back of the high pressure is called the inverted trough line (such as the southwest inverted trough) that slowly moves eastward or even westward. There is also a north-south easterly trough line moving from east to west in the easterly belt. A weather system with high air pressure on three sides and low air pressure on one side is called a trough for short. The trough with low pressure is often accompanied by convergence and upward movement, which is easy to produce clouds and precipitation.

The part of the weather map where the center of low pressure extends outward, and the low pressure area with a slightly "U" shape or "λ" shape (like a water tank, the air pressure in the middle is low and the air pressure on both sides is high) is called the low pressure trough.