北半球东半部对流层夏季平均环流形成物理机制的流体模拟实验

在旋转流体盘中做物理实验 ,模拟研究北半球东半部对流层夏季平均大气环流的形成物理机制。用镍铬电阻丝通电加热实验盘底作为热源 ,用冷水循环的铜管对实验盘底制冷作为冷源。将热源及冷源分布在绘有北半球极赤射面投影地图的底面上。人工地制造出中高纬西风带及越赤道气流模型。用流体物理模拟实验方法研究北半球东半部对流层夏季平均大气环流物理机制。逐个地试验了海陆温差、青藏高原地形及其高空热源、中高纬西风带 ,及来自南半球的越赤道气流的作用

FLUID MODELING EXPERIMENTS ON PHYSICAL MECHANISM OF ATMOSPHERIC CIRCULATION OVER THE EAST PART OF NORTHERN HEMISPHERE

Physical modeling experiments have been performed in a rotating fluid dishpan to study the physical mechanism of the formation of the mean atmospheric circulation over the east part of summer Northern Hemisphere. As the heat source the charged nickel chromium alloy wire is used to head the bottom surface of the dishpan, and the circulating cold water in a thin brass pipe paved under the fluid container is used as the cold source, to refrigerate the dishpan bottom. The heat and cold sources are distributed at the stereographic projection map of Northern Hemisphere on the dishpan bottom. The influence of westerlies of middle and high latitudes, and the temperature difference between sea and land, the mechanical obstruction of Tibetan Plateau terrain on the westerly current, the elevated heating of the plateau and the influence of cross equatorial currents that affect the formation of the mean summer atmospheric circulation over Asia have been tested. The experiments show that the atmospheric circulation over the east part of the summer Northern Hemisphere is produced by a compound influence of the above mentioned factors, and each of them possesses its unique and non substitution role. The mechanical obstruction of Tibetan Plateau terrain on the westerly current of middle latitudes causes the formation of a huge and deep trough on the east and southeast sides of the terrain. The combination of this dynamically produced trough with the thermally produced low pressure at low level forms the domination of huge low or trough over Southern Asia. The experiments show that if there were no cross equatorial currents at low levels from the southern hemisphere, the Asian summer monsoon circulation system would not be formed. All the same, if there were no land sea temperature difference effects, the cross equatorial currents from the Southern Hemisphere could not be maintained, and after crossing Equator the current would be turned to east and then to south back to the Equator. Due to the elevated heating of the Tibetan Plateau, a huge anticyclone circulation is formed over the Plateau, and a strong westerly current on its north and a strong easterly current on its south both formed over the South Asia in the upper troposphere.