南沙群岛海域近海面粗糙度、中性曳力系数及总体交换系数研究

STUDIES ON ROUGHNESS LENGTHS,NEUTRAL DRAG COEFFICIENTS AND BULK TRANSFER COEFFICIENTS OVER NANSHA ISLANDS SEA AREA

根据 1 994年 9月 1 8— 30日南沙群岛海域渚碧礁的近海面大气湍流观测实验资料 ,分别计算了该海域光滑海面和粗糙海面上的空气动力粗糙度 (z0 )、中性曳力系数 (CDN)。利用Brutsaert的假定 ,推导了一组求取标量粗糙度 (zT,zQ)、整体输送系数 (感热交换系数CHN、水汽交换系数CEN)的公式。在此基础上分别计算和分析了该海域近海面光滑海面和粗糙海面上z0 ,zT,zQ,CDN,CHN,CEN 及它们关于水平风速u分量的分布 ,并得到了一些有意义的结论。

Based on the data of atmospheric turbulence observed over Nansha Islands sea area,aerodynamic roughness length ( z 0) and neutral drag coefficient ( C DN ) are calculated. By use of Brutsaert's hypothesis,formulas are given to get bulk exchange coefficients (heat transfer coefficient C HN ,water vapor exchange coefficient C EN ) both over smooth surface and over rough surface. On this basis, the distributions of aerodynamic roughness lengths,drag coefficients and bulk exchange coefficients with wind speed ( u ) at the height of 9.4m are discussed and some interesting results are obtained.