< p >南极最明显的原因是比北极寒冷的高度。北极主要是由海洋和低洼土地而南极大陆是非常高,平均约2400米的高度。对流层中的环境直减率约为6.5°C /公里,这对应于一个15°C之间的温差北极和南极仅根据高度。显然实际温差大于这样一定有别的东西在起作用。南极洲的大部分是只有这么高,因为它有几公里的冰坐在上面,所以这并不能解释为什么有一个巨大的,永久的(至少过去~ 3500万年)冰盖坐在那里放在第一位。< / p > < p >有两个主要原因在南极冰原会持续下去。首先,南部极地地区目前由一个大型块大陆(南极洲)。土地比水热容低得多,因此在北极,海洋作为一个大型水库的热量,主要运输从低纬度地区,这限制了海冰厚度。相反,在南极雪可以在土地和积累,如果没有在夏季融化,就会埋下一个冬天,导致冰的积累。< / p > < p >的第二个原因是寒冷的南极绕极流的存在,从西到东流,是世界上最大的洋流,平均100 - 150 sv的运输。这寒流,运送大量的水,用于热使南极洲从温暖的亚热带海域,冷却的大陆。 The openings of the Drake Passage and the Tasman Gateway, the exact timings of which are debated but are generally thought to have both happened by about 30 million years ago, allowed the formation of the ACC and are roughly coincident with the onset of permanent glaciation in Antarctica. An additional factor in the present day, as mentioned @winwaed, is that southern hemisphere winter solstice currently coincides with aphelion (roughly), which produces colder winters in the southern hemisphere, allowing extreme temperatures of -94.7°C to be reached. The flip side of this is that summer solstice coincides with perihelion, which produces higher summer temperatures.