基于WOA09温盐数据的TEOS-10方程在南海的验证

采用TEOS-10方程建立计算南海密度场的数值模型,分析南海的密度特征,并对模型计算精度进行分析.研究表明,南海冬季的表面等密线主要沿东北-西南方向分布,等密线分布密集,密度最大和最小处分别位于北部湾和南沙群岛北部海域,其值分别是1 023.5和1 021.5 kg/m3;夏季表层等密线呈区域涡旋式分布,各海域密度差异小,在1 021 kg/m3左右;垂向浅水层密度和表层密度在数值上相差不大;密跃层在50 ～ 150 m,密度为1 022～1 025 kg/m3;水深在700 m时密度约为1 027 kg/m3,再往下密度变化缓慢,从700 ～1 000 m变化不超过0.5 kg/m3.选取两个特定地点验证模型计算结果的精度,计算所得密度与参考密度的最大误差为0.04％,平均误差约为0.02％,研究表明基于TEOS-10方程建立南海密度数值模型的准确性.

Validation on the Applicability of TEOS-10 Equation in the SCS Based on WOA09 Thermohaline Data

The thermodynamic Equation of Seawater 2010 published in 2009 is the new equations to calculate the density of sea water, but few applications has been done in China at present. TEOS - 10 equation was adopted to establish the numerical model of calculating the density field of the south China sea, and the density characteristics of the SCS were analyzed. After that, the calculation preci- sion were aslo studied. The result shows that the surface isodenses of the SCS in winter mainly dis- tribute close along the northeast -southwest direction; the maximum and minimum densities are 1 023.5 kg/m3 and 1 021.5 kg/m3, respectively in the Beibu Gulf and the north of Nansha Islands. In summer the surface isodenses of the SCS distribute like vortexes, and the value are small, mostly being 1 021 kg/m3. In the vertical direction, the densities in shallow layer have few difference from surface; the depth of the pycnocline are always in the range of 50 -150 m, and the densitiy changes very quickly from 1 022 kg/m3 to 1 025 kg/m3 ; in the deep layer, the density is 1 027 kg/m3 at thedepth of 700 m, and there is no more increase in deeper position. In order to compare the results ob- tained from the model with the reference, two specific location were selected, and the maximum error were 0.04%, the average error were 0. 02%. The result demonstrates that the model established based on TEOS - 10 equation are accurate on calculating the density of the South China Sea.