What Is Advection?

The stratosphere, also known as the stratosphere, is located above the troposphere and below the middle layer. Its lower boundary is located at a distance of 10 km from the surface in the mid-latitude region, and about 8 km in the polar region, and its upper boundary is at a height of about 50 km from the ground. The temperature of the stratosphere rises and falls, and as the altitude increases, the temperature of the stratosphere is basically unchanged at first, and then rises rapidly. In the stratosphere, the atmosphere mainly flows in the horizontal direction, and the vertical movement is weak, so the air flow is stable, and there is almost no up and down convection. [1]

Advection is the horizontal movement of air. The temperature rises

Atmospheric wind field transfer of atmospheric physical properties. This is a major physical process in the atmosphere. Temperature advection, water vapor advection, and vorticity advection are often calculated. When the horizontal distribution of physical attributes in the atmosphere is uneven, advection often causes changes in these attributes in local areas. This change is called advection change (see

The strength of advection depends on three factors: The magnitude of the horizontal distribution gradient of this element (temperature, humidity, vorticity, etc.). The larger the gradient, the stronger the advection. The magnitude of wind speed. The higher the wind speed, the stronger the advection. Wind direction and the element

The stratosphere is sandwiched

Calculation of velocity parallel movement

Push stream or pan. All water masses (or water particles) move in parallel at the same flow rate. During the process of pushing flow, the pollutants do not diffuse along the direction of the water flow, and only move and sequentially pass along the water particles. The particles do not interfere with each other and do not mix with each other. The flux of pollutants caused by push flow can be expressed as

F _x =

, F _y =

, F _z = vc

In the formula: F _x , F _y , F _z are the pushing fluxes of pollutants in three coordinate directions of x, y, and z:,, are the time-averaged flow velocity components of a point in the water in the x, y, and z directions; Time-averaged concentration of pollutants at a point in the water body. Advection is an ideal flow state. Actual water bodies also change due to diffusion, mixing, and attenuation (or degradation). The process of changing the physical properties of local air due to the horizontal air movement. The process of reducing the local temperature due to the movement of cold air is called "cold advection". The process of increasing the local temperature due to the movement of warm air is called "warm advection". The fog formed when the turbulent heat exchange between air and the underlying surface reduces the temperature, or the fog formed when the air on the warm sea surface moves to the cold sea or land surface is called "advection fog". If the advection process, the fog formed by the warm air cooling process due to the underlying cooling is called "advection radiation fog".