摘要:
以中国首次北极科学考察采用国内外海冰、大气和海洋的先进观测设备,获得海、陆、空的同步或准同步观测资料为基础,重点研究北冰洋的海雾.发现在北冰洋大范围被海冰覆盖或冰水相间的洋面上,能够形成平流雾、辐射雾和蒸汽雾.每种海雾的特点和形成的物理机制不同.在北冰洋的南部,由于暖湿气流充分,易形成持续时间长、浓度大的平流雾;在冰盖和大浮冰块上,由于冰雪面的强辐射冷却,容易形成稳定的辐射雾;在浮冰区能够形成像开锅的蒸汽一样的蒸汽雾.指出在北冰洋形成多种海雾原因是海冰的分布及独特的物理特性造成下垫面性质的复杂化,产生的海气相互作用复杂化的结果,特别是冰雪面的反照率高,不能吸收极昼期充足的太阳辐射.冰又是热的不良导体,成为海气热交换的屏障,在浮冰区由于冰屏障的破碎,海气交换活跃.海洋以潜热的形式向大气输送热量,以蒸汽雾的形式反映出海气热交换的程度和对气候影响的一种表现形式.提出在蒸汽雾发生的过程中,海洋以感热的形式向大气输送热量.
Abstract:
Synchronous or quasi-synchronous sea-land-air observations were conducted using advanced sea ice,atmospheric and marine instruments during China's First Arctic Expedition.Based on the precious data from the expedition,it is found that in the Arctic Ocean,most part of which is covered with ice or is mixed with ice,various kinds of sea fog formed such as advection fog,radiation fog and vapor fog.Each kind has its own characteristic and mechanics of creation.In the southern part of the Arctic Ocean,due to the sufficient warm and wet flow there,it is favor able for advection fog to form,which is dense and lasts a long time.On ice cap or vast floatingice,due to the strong radiation cooling effect,stable radiating fog is likely to form.In floating ice area there forms vapor fog with the appearance of masses of vapor from a boiling pot,which is different from shor-tlasting land fog.The study indicates that the reason why there are many kinds of sea fog form in the Arctic Ocean is the complicated cushion and the consequent sea-air interaction caused by the sea ice distribution and its unique physical character istics.Sea fog is the atmospheric phenomenon of sea-air heat exchange.Especially,due to the high albedo of ice and snow surface,it is difficult to absorb great amount of solar radiation during the polar days.Besides,ice is a poor conductor of heat; it blocks the sea-air heat exchange.The sea-air exchange is active in floating ice area where the ice is broken.The sea sends heat to the atmosphere in form of latent heat;vapor fog is a way of sea-air heat exchange influencing the climate and an indicator of the extent of the exchange.The study also indicates that the sea also transports heat to the atmosphere in form of sensible heat when vapor fog occurs.
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