ReviewReview n n The shape and size of the earthThe shape and size of the earth Pear-shaped; average radius(6371km);rotation rate (Pear-shaped; average radius(6371km);rotation rate (7.3107.310-5 -5 s s- - 1 1 ); ); L(1L(1) ) 111.13km111.13km; ; L( L(1) 1) 1.852km; 1.852km; 1 nautical mile(1 nautical mile(海海 里里)=)=1.852km1.852km; 1kts(; 1kts(节）节）=1nautical mile/hour=1nautical mile/hour=0.51m/s0.51m/s n n Distribution of Ocean and LandDistribution of Ocean and Land Land and water are not uniformly distributed on the surface of the earthLand and water are not uniformly distributed on the surface of the earth n n Ocean and SeaOcean and Sea n n Four Principle OceanFour Principle Ocean n n HHydrologicalydrological features of ocean, sea, fjord(bay), features of ocean, sea, fjord(bay), strait(channel)strait(channel) 洋洋(Ocean)(Ocean)：；远离大陆，受陆地影响小；水文要：；远离大陆，受陆地影响小；水文要 素稳定；盐度平均素稳定；盐度平均3535，且年变化小；有独立的潮，且年变化小；有独立的潮 汐系统和强大的洋流系统汐系统和强大的洋流系统 海海(Sea)(Sea)：温、盐等水文要素受陆地影响大，季节：温、盐等水文要素受陆地影响大，季节 变化明显；透明度小；潮汐系统受大洋支配变化明显；透明度小；潮汐系统受大洋支配 海湾海湾(Gulf, Bay, Fjord)(Gulf, Bay, Fjord)：水文要素特征一般与其相：水文要素特征一般与其相 邻的海或大洋相似，在海湾中常有大潮差。邻的海或大洋相似，在海湾中常有大潮差。 海峡海峡(Strait, Channel)(Strait, Channel)：流速很大，尤其潮流流速：流速很大，尤其潮流流速 很大很大 n n Location SystemLocation System n n 海图海图: :墨卡托投影墨卡托投影等角投影等角投影 n n 两点之间距离的换算两点之间距离的换算( (适用小范围内适用小范围内) ) Point1(lon1,lat1) Point2(lon2,lat2)degree Y=(lat2-lat1)*111.13(km) X=(lon2-lon1)*cos(lat2+lat1)/2)*111.13(km) Distance=sqrt(x*x+y*y)(km) 密度变化异常 不遵从“热胀冷缩”。最大密度时温度是4摄氏度 2.2 2.2 温度、盐度和密度的概念及关系温度、盐度和密度的概念及关系 Temperature, Salinity and DensityTemperature, Salinity and Density Lehodey,P. et al., 2000. El Nino Southern Oscillation and tuna in the western Pacific. Science 2.2.1 Temperature2.2.1 Temperature n n MeasurementMeasurement n n Absolute Temperature TAbsolute Temperature T n n Unit: Kelvin (K)Unit: Kelvin (K) nt = T K-273.15 nThe practical temperature scale (1887, 1927, 1948, 1968, and 1990) nITS-90: the International Temperature Scale of 1990 nITS-68: the International Temperature Scale of 1968 nAt 0 they are the same, and above its-90 is slightly cooler. nt90t68 = -0.002 at 10 ; -0.005 at 20 , -0.007 at 30 and -0.010 at 40 . nt90=0.99976 t68; t68=1.00024 t90 2.2.2 Salnity2.2.2 Salnity 11种主要无机盐，占99.99%； At the simplest level, salinity is the total amount of dissolved material in grams in one kilogram of sea water. Measuring SalinityMeasuring Salinity n n EvaporateEvaporate n n Easy to do, but residue is complex Easy to do, but residue is complex n n TitrationTitration n n Traditional method prior to mid-Traditional method prior to mid- 6060 s s n n Determine Determine chlorinitychlorinity and use empirical formula and use empirical formula S = 1.80655 ClS = 1.80655 Cl n n ConductivityConductivity n n Uses a Uses a “ “resistance bridgeresistance bridge” ” n n Current - CTDCurrent - CTD s s n n 密度（密度（DensityDensity）：单位体积物体的质量）：单位体积物体的质量 Unit: kg/mUnit: kg/m 3 3 n n specific volume(specific volume(比容比容) )：单位质量物体的体积 =1/ (m =1/ (m 3 3 kg kg-1 -1 ) ) n n (S,t,p)(S,t,p)S,tS,t-1 -1,p ,p 2.2.3 Density2.2.3 Density n n s st (sigma-t)(t (sigma-t)(条件密度条件密度) ): : Shorthand methodShorthand method of of expressing the density of a sample of seawater at expressing the density of a sample of seawater at atmospheric pressure as determined by its atmospheric pressure as determined by its in situin situ temperature and salinitytemperature and salinity s s t t = ( = (r - 1000r - 1000) kg/m) kg/m 3 3 在海面（p=0)海水密度仅为盐度和温度的函数 n密度超量： kg/m3 The effect of PressureThe effect of Pressure n n Pressure has relatively little effect on density Pressure has relatively little effect on density compared to salinity and temperature, however, compared to salinity and temperature, however, the density will increase with increasing pressure the density will increase with increasing pressure (or depth) and becomes important in the deep (or depth) and becomes important in the deep sea where salinity and temperature remain nearly sea where salinity and temperature remain nearly constant. constant. The effect of TemperatureThe effect of Temperature The effect of Salinity The effect of Salinity S24.7, the density will continue to increase with decreasing temperature until the water freezes T，D T, D n n Table 4.4Table 4.4 n n When S is constant When S is constant and greater than 24.7, and greater than 24.7, the density decreases the density decreases as T increasesas T increases n n When T is constant, When T is constant, the density increases the density increases with increasing Swith increasing S T T No SaltNo SaltSalt 20Salt 20252530303535 -1-1Ice Ice 0.9170.917 1.016061.016061.020101.020101.024131.02413 0 0 0.999840.999841.016071.016071.020081.02008 1 1 0.999900.999901.016051.016051.020051.02005 2 2 0.999940.999941.016031.016031.020011.02001 3 3 0.999960.999961.015981.015981.019951.01995 4 4 0.999970.999971.015931.015931.01