One of the geographical problems in high school is the sign of a weather system somewhere in the northern hemisphere.

According to the frontal direction of frontal cyclone, it can be judged that it is a frontal cyclone map in the northern hemisphere.

C is the center of the high-pressure cyclone, and D is the center of the low-pressure cyclone when the airflow sinks, and the airflow rises.

A is located on the ridge of high pressure, behind the cold front, and B is located in front of the cold front and behind the warm front, which is the warm air mass.

A is located on the high-pressure ridge of the high-pressure cyclone. The high-pressure cyclone in the northern hemisphere is clockwise, so you can see that it blows northward when you draw it. B Behind the warm front, the low-pressure cyclone in the northern hemisphere is counterclockwise. You can see it blowing south when you draw it.

The rain area of the cold front is behind the front, and the rain area of the warm front is before the front.