Figure 12-4 is the frontal cyclone map of the northern hemisphere. Look at the map and answer the following questions: (1)P _ 1, P _ 2, P _ 3 In the map, the values of the three isobars are from large to small. ( 1)P 3？ P 2？ P 1？ (2) a? Ding? (3) B？ Ding? (4) Southwest wind

Because this is a frontal cyclone map in the northern hemisphere, the closed isobar distribution must be that the surrounding air pressure is higher and the central air pressure is the lowest. Cyclone is a convergent and ascending system of airflow, especially on the front, which often produces clouds, rain and even heavy rain, thunderstorms and windy weather. In this picture, in front of the cyclone is a wide warm front cloud system and the accompanying continuous precipitation weather; Behind the cyclone is a relatively narrow cold front cloud system and precipitation weather; The central part of the cyclone is controlled by the warm air mass. Because the warm front precipitation is mainly in front of the front, and the cold front precipitation is mainly behind the front, it is raining at four points A, B, C and D. Compared with A and B, because A is behind the cold front, it is a cold air mass and B is a warm air mass, so the temperature of B is higher than that of A; Compared with D, C is on the side of heating air mass, so the temperature of C is higher than that of Adjudicator, and the pressure of D is higher than that of C. ..