摘要
利用中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG)发展的全球耦合气候系统模式(FGCM-1·0)100年数值模拟结果,分析了模式模拟的印度尼西亚贯穿流(ITF)的平均态、季节变化和年际变化,并且利用这些资料对ITF季节变化和年际变化的成因做了初步分析。模式模拟的ITF平均态、季节变化和年际变化同已有的观测结果相比是合理的,经作者分析认为ITF的季节变化主要是因为印度尼西亚海域地处亚澳季风区,海流对于季风的响应使得ITF发生季节变化;ITF的年际变化主要是因为热带环流的年际变化及其所导致的洋流调整造成的,太平洋和印度洋都有影响。
The Indonesian Throughflow （ITF） is analyzed in a numerical simulation with a coupled ocean-atmosphere model （FGCM-1. 0）. The model, developed by the LASG/IAP/CAS （State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences）, has been integrated for 300 years. The 100 （101 - 200） years result is used to simulate and analyze the change of ITF flux The simulated features of annual mean, seasonal cycle, and interannual cycle of ITF flux agree well with the observations and other simulations. The annual mean ITF flux simulated by FGCM-1.0 is 17 Sv （1 Sv=10^6m^3·s^-1 ）. The primary bias in the annual mean ITF simulated by FGCM-1.0 is that the ITF route is not the same as the observed route. Comparing the simulated route with FGCM-1.0 with the observed route, there is less flux through the Makassar Strait, more flux through the Maluku Strait and the Halmahera Strait, more flux through the Lombok Strait, less flux through the Timor Strait. The simulated ITF crosses mainly the Makassar Strait, the Maluku Strait and the Hamahera Strait, then crosses the Lombok Strait and the Ombai Strait and enters the Indian Ocean straightway. The observed ITF crosses the Makassar Strait, the Maluku Strait and the Hamahera Strait, then turns eastward and crosses the Timor Strait, finally enters the Indian Ocean. The seasonal ITF flux change simulated by FGCM-1.0 is from 7 Sv in January to 22 Sv in August. The seasonal ITF flux change has obvious semi-year period. The interannual cycle of ITF flux agrees well with the observed. Compared to the average ITF flux simulated by FGCM-1.0, the ITF flux is less during El Nifio period and the flux is more during La Nina period. The ENSO cycle period simulated by FGCM-1.0 is 2 - 4 years, and the interannual change of ITF flux simulated by FGCM-1.0 has the same cycle period. There is a remarkable negative correlation between the ENSO cycle period and the interannual change of ITF flux, and the correlation coefficient is-0. 92. The reasons of ITF change are also simply analyzed. The seasonal cycle of ITF is decided by the top layer current which is driven by the monsoon. The intemannual change of ITF transport is connected with ENSO event in the tropic ocean. The correlation between the interannual cycle of ITF and the ENSO cycle can be explained by the island rule of Godfrey. It is said in the theory that the ITF intensity mainly lies on the integral of wind stress vorticity around Australia. During E1 Nifio period, atmosphere is heated up abnormally in the middle and eastern tropical Pacific, which results in abnormal cyclonic atmospheric circulation in the southwestern Pacific. The less ITF flux can be calculated by the Godfrey island rule. The more ITF transport can be calculated during the corresponding La Nina period. The signal of interannual ITF flux change mainly comes from the Pacific ENSO. By analysis, the interannual ITF flux change also has some relations with the Indian Ocean current change. In brief, the interannual cycle of ITF is mainly caused by the interannual variation of tropical circulation, but it is affected by both the Pacific Ocean and the Indian Ocean.
出处
《大气科学》
CSCD
北大核心
2005年第5期697-708,共12页
Chinese Journal of Atmospheric Sciences
基金
"十五"国家重点科技攻关项目"全球环境变化对策与支撑技术研究"
国家重点基础研究发展规划项目G2000078502
国家自然科学基金资助项目40231004
40221503
