Thursday, August 29, 2019

Beijing

I’m going to look at how Beijing’s (while mentioning China) climate will be affected and change if the average temperature will rise, creating global warming around the world. An overview of how Beijing’s weather and climate is currently. Average temperature in January is -7o to -4o C, while average temperatures in July are at 25o to 26  °C. Highest temperature ever recorded is 42 °C and lowest recorded is -27 °C. Annual precipitation is over 600 mm, with 75% of that in summer. Beijing is located in a high pressure area. Under the scorching sun in summer, heavy rainstorms also sees to occur late in the season. The citys climate is a monsoon-influenced humid continental climate characterized by hot, humid summers due to the East Asian monsoons, and generally cold, windy winters that reflect the influence of the vast Siberian anticyclone. Frequent typhoons coming from the Pacific Ocean also influence the city but in a minor scale, most of the typhoons make their direction for Japan and never really reaches into Beijing. Springtime weather in Asia produces intense wind storm events that can pass over the Gobi Desert along the northern China / Mongolia. These prevailing westerly winds brings dust from the desert and trough suspension carries the sand dust via Beijing and further on. This threatens Beijing by a rolling tide of sand advancing on the capital from the Gobi Desert that is responsible for the massive dust storms every spring. If we then assume that the average temperature is rising, I think that the long term warming will cause a bit more spreading (in number) of natural hazards such as monsoons, (droughts), typhoons leading to more severe rainfall. Since the typhoons never really reaches the city but foremost Japan (due to the coriolis force/effect) the size and number may increase and then there will be more rain. Mostly this happens if the ocean currents are warm. The precipitation from both the monsoons and typhoons but also through convectional rainfall will eventually increase leading to e. g. floods (in coastal areas) and agricultural crops may die or grow (depending of what type of crops and its surrounding) more because of the intense rainfall. The temperature rises heating the land more which makes moist, warm air which becomes less dense and is forced to rise as strong convectional currents. In this picture below you can see were most of the precipitation occurs due to e. g. monsoons in the southern China, in the summer when there is strong solar radiation and the rain period is at its highest in Beijing. If we would see a similar picture but in present time or in about 10 years from now I would say that the color of amount precipitation in Beijing would be more in the blue scale. Because the winds bring more moist and rain clouds since the earth is moving. The climatic change may even change or disrupt the monsoonal pattern. In winter the temperature can be very low but if the global temperature rises I think so will the cold temperatures. It will not be as cold in the future as it is now. The Gobi Deserts sand dunes are already slowly expanding with winds blowing the sand towards the capital. In their wake, these massive dust storms have left entire towns abandoned and refugees left in a high number. The dust storms have probably also brought some weather effects due to the high altitude transportation of the sand. These winds are capable of generating huge yellow clouds of suspended dust which based on the direction of the prevailing wind can be sent out to sea to North America. And even have an impact on the visibility across different regions in the south western United States Part of the reason for why these dust storms are so severe, is maybe because the soil is so loose and fine. In addition to the fact that sandstorms cause such inconvenience in people’s lives, they also influence agricultural production, transportation and shipping, and other industries, and cause serious economic damage. The problem is overgrazing and deforestation which causes many land areas in China to become a desert. Due to this desert spreading that is getting closer to Beijing the government is planning to plant a â€Å"green wall† of millions of trees between Beijing and the sands. The plants should be planted to bind the soil more effectively. Some of the smaller rivers or lakes could even disappear due to the desert spreading cutting of water supply. And the larger rivers that transports some of the melting glaciers from the Himalayas could expand and lead to flooding in some cases. The air pollution from the city results in damage to air and water quality, agriculture and human health, with acid rain falling down. The climatic change will also have a great impact on the economy since they have to prevent some hazard from spreading far too much but the economy will also lose a lot of money if the agricultural farming is reduced every year. But if the rainfall changes the agricultural problem will give the economy a profit. Many people would have to leave their homes to try to find another place to grow their crops or move into the main city to try and find a job. Due to arable agriculture and overgrazing wind removes the soil so that soil erosion occurs. Then, during times of erosive rainfall or windstorms, soil may be detached, transported, and (possibly travelling a long distance) deposited. It has impacts which are both on-site (at the place where the soil is detached) and off-site (wherever the eroded soil ends up). As a conclusion Beijing will probably have more rainfall due to the monsoons and typhoons. The desert will increase or decrease (not expand as much) depending on how much it will rain and if the soil is nutrient enough to let vegetation grow. But if it increases Beijing will suffer from more dust storms as a thick layer of haze that can reduce direct solar radiation, it can have a dramatic impact on the visibility. It will also get warmer in the city since the air pollution is very high making a sort of cover over the area, thereby trapping the sun radiation from going back out into the atmosphere, making it more humid. The temperature will get higher during all seasons but in a slow process. The economic development may decrease because of manly the loss of agricultural land to soil erosion.

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