How does man-made affect storms?

Storm generally refers to the weather process that occurs when a strong weather system transits, especially the weather system accompanied by strong wind or heavy precipitation, such as thunderstorm, squall line, tornado (called dragon sucking water at sea), typhoon, tropical cyclone and tropical storm.

Lake Erie is located in the northeast of the United States, with Lake Huron in the northwest and Lake Ontario in the northeast. Millions of people in this area drink the fresh water from the lake basin directly. During the period of 1966~ 1969, heavy rain occurred in Lake Erie, and the rainfall reached 1 100 m3, which was equivalent to the water supply of this area 16 days. Therefore, people attach great importance to the water resources in this lake area.

Why does the storm here have so much precipitation in winter? According to the analysis of meteorologists, when the cold air of the polar air mass in the northern mainland moves to the southeast in winter, a large amount of water vapor is transported into the air when passing through the warmer lakes here. Because of their interaction, atmospheric instability often occurs in the lake area, forming convective stratocumulus clouds, that is, storms. Most of the rainfall of these storms occurred downwind of Lake Erie and along the eastern coast. Due to the heavy snow in winter, the expressway from Buffalo to Pennsylvania in northern new york often stops, causing economic losses to local industries and other departments. During the period of 1960~ 1970, the parking time of expressway is the longest, which is 27~36 hours.

What kind of clouds are the storms over Lake Erie? In order to develop the water resources in the lake area, cloud physics experts used airplanes and radars to detect the cloud conditions in this area. After some resource analysis, the rainstorm cloud system in Yili Lake area can be divided into three types:

(1) The first one is over the lake area, and there are often faint cumulus clouds. Light cumulus clouds further develop into medium cumulus clouds, and the temperature at the bottom of the clouds is mostly -6.5℃, and that in cloud top temperature is-17℃. Water vapor is continuously transported from the warmer lake to the cumulus, and the cloud body develops to form the cumulus stratocumulus. The concentration of frozen nuclei in these clouds is relatively low and will not cause natural snowfall. However, this cumulus stratocumulus is very suitable for artificial snowfall.

(2) The cloud base and cloud top temperature of the second kind of cumulus stratocumulus are low, and there are a lot of ice crystal nuclei in the cloud, which can make the cloud produce natural snowfall and is also suitable for artificial snowfall.

(3) The third is the severe winter. Convective stratocumulus in the lake area develops vigorously and the clouds are thick, which is the best condition for artificial snowfall.

During the period of 1968~ 1969, cloud physics experts carried out artificial catalytic snowfall on the above cumulus stratocumulus in the lake area, and snowfall and showers occurred, and then the clouds gradually dissipated.

In recent years, cloud physics experts have carried out a large number of experiments and operations to artificially influence rainfall and snowfall, and used radar detection and ground precipitation to monitor the effect of artificial catalysis.

In Lake Erie, dry ice was sown by plane, and cumulonimbus stratocumulus was artificially catalyzed for 26~35 minutes, and then showers were observed falling from the clouds.

A large number of artificial ice cores are spread in the clouds by projecting silver iodide flares into the clouds by airplanes or using silver iodide fumers on airplanes. After ten minutes, moderate or strong showers can fall from the clouds, and the rainfall falls on the lake.

Therefore, in order to increase the industrial and domestic water demand and water resources in the lake area, the above two methods are used to artificially catalyze the convective cumulus in the lake area in winter to increase the water resources.

In order to suppress excessive snowfall on the east bank of Lake Erie and adjust the distribution of snowfall areas, artificial catalysis can be carried out on the windward side of the lake in the early stage to make snowfall fall on the lake area and reduce the economic losses of industry and transportation caused by snowfall.