海水的物理性质

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1、Review The shape and size of the earthPear-shaped; average radius(6371km);rotation rate (7.310-5s-1); L(1) 111.13km; L(1) 1.852km; 1 nautical mile(海里)=1.852km; 1kts(节）=1nautical mile/hour=0.51m/s Distribution of Ocean and LandLand and water are not uniformly distributed on the surface of the earth O

2、cean and Sea Four Principle Ocean Hydrological features of ocean, sea, fjord(bay), strait(channel)2 海水的物理性质Physical Properties of Sea Water2.1 Water Most common substance on the earths surface Ocean water makes up 98% of water inventory 96.5% is water, 3.5% is salt and dissolved minerals Accumulated

3、 on the surface from mass degassing of earths interior still happening, but much less Only substance that exists naturally in all three states in the normal temperature range of earth Solid, Liquid, and GasHydrogenHydrogenOxygen105 deg分子结构分子结构(Molecular structure)：极性，分子缔合力：极性，分子缔合力 Hydrogen Bondspol

4、ar molecules give water a structure that is responsible for a number of unique and important properties 溶解力强：水分子有很强的极性 密度变化异常密度变化异常不遵从不遵从“热胀冷缩热胀冷缩”。最大密度时温度是。最大密度时温度是4摄氏度摄氏度 温度4，有利于水分子的缔合；冻结为冰时，全部缔合成一个巨大的分子缔合体（分子晶体）由于晶体结构排列松散，故密度减小当温度从04度以前，主要过程是较大的缔合分子逐渐分解成为较小的分子，所以体积收缩，密度增大4度时，热运动加强，导致体积膨胀，密度所温度增高而

5、减小密度变化异常是由水分子的缔合造成的密度变化异常是由水分子的缔合造成的沸点(boiling point)和融点(melting point)、比热(specific heat)、蒸发潜热(latent heat of vaporization)等热性质比氧的同族化合物高 热性质特殊热性质特殊2.2 温度、盐度和密度的概念及关系Temperature, Salinity and DensityLehodey,P. et al., 2000. El Nino Southern Oscillation and tuna in the western Pacific. ScienceTemperat

6、ure distribution in California coastal area长江水的扩展2.2.1 Temperature Measurement Absolute Temperature T Unit: Kelvin (K) t = T K-273.15 The practical temperature scale (1887, 1927, 1948, 1968, and 1990) ITS-90: the International Temperature Scale of 1990 ITS-68: the International Temperature Scale of

7、1968 At 0they are the same, and above its-90 is slightly cooler. t90t68 = -0.002 at 10 ; -0.005 at 20 , -0.007 at 30 and -0.010 at 40 . t90=0.99976 t68; t68=1.00024 t902.2.2 Salnity11种主要无机盐，占99.99%； 99% of all the salt ions in the sea are sodium (Na+), chlorine (Cl-), sulfate (SO4-2), Magnesium (Mg+

8、2), calcium (Ca+2) and potassium (K+). Definition of Salinity Principle of constant proportion states that the absolute amount of salt in sea water varies, but the relative proportions of the ions is constant. Because of this principle, it is necessary to test for only one salt ion, usually chlorine

9、, to determine the total amount of salt present.海水组成恒定性原理 1) 传统的盐度定义(1902)： 1kg海水中将(Br-,I-)以氯置换，碳酸盐分解为氧化物,有机物全部氧化,所余固体物质的总克数。(480度加热48小时） 利用海水组成恒定性，测定出其中某一主要成分的含量，便可推算出海水盐度。2) 氯度: 1kg海水中将(Br-,I-)以氯代替，所含氯的总克数。 转换为盐度的关系式为：S=0.030+1.8050Cl Salinity Based on Chlorinitywhere chlorinity Cl is defined as “

10、the mass of silver required to precipitate completely the halogens in 0.328 523 4 kg of the sea-water sample.”(1969)(1902) 电导温度电导温度Salinity Based on Conductivity(1969) 实用盐标实用盐标Practical Salinity Scale of 1978The standard KCl solution contains a mass of 32.435 6 grams of KCl in a mass of 1.000 000 kg

11、 of solution.Salinity is presented as numbers (dimensionless) but may find different terms: lpsu (practical salinity units)lgram/kilogramlgram/literl o/ooMeasuring Salinity Evaporate Easy to do, but residue is complex Titration Traditional method prior to mid-60s Determine chlorinity and use empiric