(海洋科学概论课件）第四章 节 海洋中的热收支和水平衡.ppt

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海洋科学概论 海洋中的热收支和水平衡
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海水中的热收支和水平衡---纲要
第一节海洋中的热收支
(一)海面热收支
一、太阳辐射Qs
二、海面有效回辐射Qb
三、蒸发潜热Qe
四、感热交换Qh
五、世界大洋海面年平均热收支随纬度变化
(二)海洋内部热交换
一、铅直方向上的热输运Qz
二、水平方向热输送QA
三、海洋中全热量平衡
第二节海洋中的水平衡
一、影响因子
二、水平衡方程
三、水平衡对盐度的影响
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第一节海洋热收支(Heat Budget in the Ocean)
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About half the sunlight reaching Earth is absorbed by the ocean and land, where it is temporarily stored near the surface. Only about a fifth of the available sunlight is directly absorbed by the atmosphere. Of the heat stored by the ocean, most is released locally to the atmosphere, mostly by evaporation and infrared radiation. The remainder is transported by currents to other areas especially mid latitudes. Heat lost by the tropical ocean is the major source of heat needed to drive the atmospheric circulation. And, solar radiation stored in the ocean from summer to winter helps ameliorate Earth’s climate. The heat transported by ocean currents is not steady, and significant changes in heat transport, particularly in the Atlantic, may have been important for the development of the ice ages. For these reasons, oceanic heat budgets and transports are important for understanding Earth’s climate and its short and long
term variability.
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(一)海面热收支(Heat budget of the sea surface)
太阳辐射
海面有效回辐射
蒸发潜热
感热交换
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2 辐射定律(law of radiation):
1)斯蒂芬—波尔兹曼定律:
任何温度高于绝对零度的物体都能以辐射的形式向外释放能量,它与绝对温度Tk的4次方成正比。
F为辐射体的透明系数,
F=0,绝对透明体,F=1,绝对黑体。
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2 辐射定律(law of radiation):
2)维恩定律:
辐射能量的最大波长与辐射体表面的绝对温度成反比。
C=2898(µm·k)
太阳辐射能量最强的波长为???
µm, 称为短波辐射,
对应于可见光中的青光波段
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3、影响因素( influencing factors):
A、太阳高度h:
B、大气透明度
C、天空中的云量、云状、不同纬度和季节
D、真正进入海洋的太阳辐射