A heavy snow in Kiev, Ukraine, buried the car deeply. What factors are related to snowfall?

The snowfall is related to the environment and precipitation.

The snow in mountainous areas is stable, independent of winter temperature and not concentrated in the coldest months. However, the snow in the lowlands is extremely unstable, short in duration and highly dependent on negative temperature for survival. Snow is concentrated in the coldest month, which is very sensitive to temperature changes and easy to heat up. Secondly, the snowfall in winter in China is mainly caused by the infiltration of cold air from Siberia. Water vapor comes from the warm and humid air flow in the south or southeast, and the air humidity in this area also has a great influence on snowfall. Therefore, climate warming will lead to the strengthening of air flow exchange and water circulation between north and south, and increase snowfall in the Yangtze River basin.

Therefore, the regional differences between arid areas with less snow and humid areas with more snow are further aggravated. In addition, low temperature has an opposite effect on the formation of snow and snow. Extremely low negative temperature is not conducive to the formation of snow, but it is beneficial to the maintenance of snow. Therefore, the snowfall season in China is concentrated in early winter and early spring, and the glaciation area of ultra-high mountains is even concentrated in summer. On the contrary, the snowfall decreases in the coldest month, and the decrease in colder areas is more significant. Therefore, warming may lead to an increase in snowfall in the northernmost and mountainous areas of China.

With the global warming since the mid-1960s, the snowfall and snow cover on the Qinghai-Tibet Plateau, especially in the surrounding mountainous areas and the middle and lower reaches of the Yangtze River, have increased significantly. The snowfall and monthly snowfall in the central and western parts of the Northeast Plain tend to decrease. Therefore, it is reasonable to infer that the future warming of CO2 will further aggravate the regional differences of snow cover and snow cover between mountainous areas and lowlands, humid areas and arid areas in China. The drought in Tucheng may be caused by the decrease of snowfall days in the north, which should be paid attention to. Strengthen the prediction and prevention of freezing rain and snow disasters in the Qinghai-Tibet Plateau, the middle and lower reaches of the Yangtze River and mountainous areas.

Climate change, in the final analysis, is the change of water and heat balance in the climate system. So the large-scale snowfall fluctuation must be the result of climate change. Climatologists estimate that the decrease of global ice and snow reserves should be the response of ice and snow to climate warming. In fact, this change process and spatial pattern may be tortuous and complicated. Because climate is a nonlinear system, it is full of complex disaster cooperation and feedback cycle. Ice core analysis shows that during the heyday of the last ice age (20,000 years ago), the temperature of Antarctic ice sheet dropped by 10℃, and the snowfall was reduced by half. At present, the results of material balance observation and radar altimetry show that the snow cover rate in the central area of continental ice sheet is increasing. Although the snowfall in other areas increases with the increase of temperature, it is difficult to determine whether the total snowfall in the world is increasing or decreasing. From the time series of global snow area observed by NOAA satellite in recent 20 years, no change trend has been found.

The change trend of snow cover in China is positively correlated with the global average temperature, and its interannual fluctuation is contrary to volcanic activity. Rainy winter is in phase with binomial southward fluctuation. The warming of CO2 will aggravate the regional differences of snow distribution, leading to the decrease of snow days in northern plains and basins, and the increase of snow days in Qinghai-Tibet Plateau, alpine regions and the middle and lower reaches of the Yangtze River.