Weather principle of forward tilting trough

The synoptic principle of forward tilting trough is that the trough line inclines forward with the height, and the upper trough line is located in front of the ground front.

Forward-leaning trough means that the trough line inclines forward with height, and the upper trough line is located in front of the ground front. Generally, it is a short-wave westerly trough with a short duration and a weakening trend. In summer, the forward tilt trough is one of the important weather systems to stimulate strong convective weather in eastern China. In winter, the weather behind the trough is sunny and cloudy, but it is often accompanied by strong winds and dust.

The westerly trough refers to the trough in the wavy westerly airflow around the polar regions in the middle and high latitudes, which corresponds to the trough on the contour line. The forward tilt trough is generally characterized by short-wave westerly trough and tends to weaken. The short-wave westerly trough has a wavelength less than 5000km, an amplitude less than 10 latitude, and an average eastward moving speed of 10- 15 latitude/day, which is also called a small trough.

The westerly trough is a heat and energy transport mechanism between different areas in the north and south. Because there are generally convergent ascending motion and precipitation areas in front of the trough, and divergent sinking motion behind the trough, the weather is fine. Therefore, the absorption and release of latent heat in the process of water evaporation and condensation enhance the heat transport in the westerly trough. ?

The short-wave westerly trough is a moderate disturbance in the westerly belt, which makes the cold and warm airflow in the big disturbance spread to a wider range. The dry and cold air behind the high-altitude trough is superimposed on the warm and humid air in front of the low-altitude trough, which increases the convective instability of the air column.

course content

The study of this course aims to make students systematically understand the basic state and main influencing factors of atmospheric motion in middle and high latitudes; The structure, fluctuation, movement law of main weather systems and the weather changes they bring; Large-scale weather processes affecting China; The basic principles and methods of weather forecast will lay the most important professional foundation for future atmospheric science research and weather forecast.

This course requires students to firmly grasp the basic concepts, facts and principles related to weather change; Master the conceptual models and evolution laws of major weather systems and weather processes; Understand the basic principles and methods of weather forecasting, and can be applied to actual weather analysis and forecasting.