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本文在考虑水上湍流交换系数随高度和离岸距离变化而变化并与大气稳定度有关的情况下,从运动方程和连续方程出发推导当气流从陆上流入水上时,由于下垫面粗糙度改变所引起的水上风速定常变化的理论模式。根据这个模式计算结果,当气流由陆上流入水上时,水上风速的变化主要是发生在最初几公里(在陆上大气中性平衡和层结不稳定时)到十几公里(在陆上大气层结稳定时)距离以内,且随着离水面距离增大水域对风速的影响迅速减小。在大气层结稳定时,水上1米高度的风速可比陆上增大2—3倍,中性平衡时可比陆上增14％(强风时)到50％(小风时)。在大气层结不稳定时,水上风速变化最小,且强风时反比陆上风速减小,弱风时则仍比陆上风速有些增大。
Based on the equations of motion and continuous equations, when the air turbulence exchange coefficient changes with altitude and offshore distance and is related to the atmospheric stability, when the airflow flows from the land into the water, the roughness of the underlying surface changes Caused by the constant changes in wind speed on the theoretical model. According to the results of this model, when the airflow flows from land to water, the change of the wind speed over the water mainly occurs in the first few kilometers (when the onshore atmospheric neutral balance and instability of stratification) to more than ten kilometers (in the onshore atmosphere The stability of the junction) within the distance, and as the distance from the water increases the impact on the wind speed rapidly decreases. At stable atmospheric storms, the wind speed at 1 meter above sea level can be 2-3 times greater than that on land, and can be increased by 14% (strong winds) to 50% (light winds) over the land surface at neutral balance. At instability of the atmosphere, the change of water wind speed is the smallest, and the wind speed of reverse wind on the contrary decreases when the strong wind blows, while the wind speed is still slightly higher than that of the onshore wind in the weak wind.