加分作業 翻譯 5-1.2 Global Air Circulation and Ocean Current Distribute Hete and Precipitation Unevenly

Three major factors determine how air circulates in the atmosphere and helps distribute heat and moisture from the tropics to other parts of the world. First is the uneven heating of the earth's surface by the sun. Air isheated much moreat the equator, where the sun's rays strike directly, than at the poles, where sunlight strikes at a slanted angle and spreads out over a much greater area. These differences in the distribution of incoming solar energy help exlain why tropical regions in between generally have intermediate average temperature (figure 5-2). Temperature also generally becomes progressively colder as elevation above sea level increases in the low atmosphere.

A second factor is the rotation of the earth on its axis. As the earth rotates around its axis, its equator spins faster then its polar regions. As a result, heated air masses rising above the equator and moving north and south to cooler areas are deflected to the west or east over different parts of the planets surface (figure 5-3).

The direction of air movement in the resulting huge regions in the atmosphere called cells sets up belts of prevailing winds-major surface winds that bloe almost continuously and distribute air, heat, moisture, and dust over the earth"s surface.
A third factor affecting global air circulation is properties of air, water, and land.Heat from the sun evaporates ocean water and transfers heat from the oceans to the atmosphere, especially near the hot equator. This evaporation of water creates giant cyclical convection cells that circulate air, heat, and moisture both vertical and from place to place in the atmosphere, as shown in figure 5-4.
The earth"s air circulation patterns, prevailing winds, and mixture continents and oceans result in six giant convection cells - three north of the equator and three south of equator - in which warm, moist and rises and cools, and the cool, dry air sinks. This leads to an irregular distribution of climates and patterns of vegetation, as shown in figure 5-5.

三個主要因素決定空氣在大氣中主要如何循環和分散熱及水分並且使其擴散到全世界。第一是來自於太陽這些熱不平均的分布在地球表面上，太陽直射赤道、兩極，將熱傳導至空氣，太陽光斜角射擴散至其他地區，分散滴吸入不同的太陽能量此可解釋赤道熱帶地區為什麼比較熱，還有為何極地區比較冷，以及為何溫帶地區的溫度較為平均。溫度隨海拔增高逐漸的降低。

第二個原因是地球隨著軸轉動。當地球隨著軸轉動，赤道地區轉動的速度會大於極地。因此，熱空氣在赤道上升移動向南北較冷的地方在地球表面轉向東西不同區域。空氣在大氣中流動的方向建立在環繞的行星風，表面的風主的要流動使得空氣、熱、水氣、灰塵分散到世界各地。

第三個影響地球空氣循環的是所有的空氣、水、陸地。熱來自太陽蒸發海洋和轉變熱從海洋到大氣，特別是赤道附近，水蒸發創造大量的水蒸氣循環在空氣、熱和水氣兩個垂直和在大氣中從一地到另一地，顯示在圖5-4。

地球空氣循環圖、行星風、及大陸和海洋的混合導致六大對流 - 其中三個指向赤道北邊和三個指向赤道南邊溫暖的空氣上升和乾冷的空氣下沉，使得會出現一個不一定的分散天氣和對流圖顯示在圖5-5。