What is low-altitude convergence and high-altitude divergence?

Divergence means that the air in the horizontal direction moves backward, and convergence means that the air in the horizontal direction moves in the opposite direction. The following figure reflects a low-pressure weather system on the ground. There is updraft in the vertical direction of the low-pressure center, ground convergence and high-altitude divergence in the horizontal direction. Generally speaking, this is a geographical term to describe cyclones. Cyclone: refers to the large vortex in which the horizontal airflow rotates counterclockwise (clockwise) in the northern (southern) hemisphere atmosphere. At the same height, the air pressure at the center of the cyclone is lower than that around it. In the northern hemisphere, the air moves counterclockwise, the central air pressure is the lowest, and it gradually increases outward. Air keeps flowing into the center, forming an upward airflow. At the same time, due to the influence of horizontal pressure gradient force, the airflow flows from high pressure to low pressure. Therefore, on the vertical plane of the cyclone, the airflow at low altitude converges to the center, and then the airflow begins to diverge after flowing to high altitude. In the northern hemisphere, the cyclone air flow moves counterclockwise from low altitude to high altitude, and in the southern hemisphere, the cyclone moves clockwise from low altitude to high altitude. Weather conditions of cyclone: rainy. In the northern hemisphere, the anticyclone airflow moves clockwise from high altitude to low altitude, and in the southern hemisphere, the anticyclone moves counterclockwise from high altitude to low altitude. Weather conditions of anticyclone: sunny.