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摘要: 利用涡扩散法、海面高度资料和气候水文资料, 对孟加拉湾海域海盆尺度涡(湍流)致热盐输运进行了估算. 结果发现, 在孟加拉湾大量的涡致输运主要存在于4个区域: 孟加拉湾北部的西部边界(NB)、孟加拉湾西部(WB)、斯里兰卡南部和东部(SWB)以及孟加拉湾东南部靠近马六甲海峡区域(SEB). 根据涡输运的气候态分布, 涡致热输运主要存在于NB和SWB海域, 而涡致盐输运主要存在于NB、SWB和SEB海域. 基于季节平均的涡致输运估计, NB和SWB海域涡致热输运较为显著的季节为初夏和夏季季风季节, 而在WB和SEB海域为后夏季风季节. 此外, 季节性涡流动能(EKE)调制通过季节性强化的东印度洋沿岸流(EICC)和西南/东北季风电流(SMC/NMC), 被确定为影响季节性涡流的主要因素之一, 在 NB、WB 和 SWB 区域分别进行运输.
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Key words:
- Eddy diffusivity /
- eddy heat transport /
- eddy salt transport
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Fig. 1 Spatial distribution of mean eddy heat (106 W/m) and salt transport (kg/ms) in the BOB averaged over the period from 2005 to 2012 a) Meridional component, b) zonal component, and c) magnitude of eddy heat transport (shading) along with the respective direction (arrows); e)-f) are the same as a)-c) but for eddy salt transport
Fig. 2 a)-(d) Seasonal climatology of surface geostrophic currents (ms–1; vectors) and seasonal mean surface EKE (m–2s–2; shading); e) monthly mean surface EKE for the four regions NB, WB, SWB, and SEB (see Figure 1)
Tab. 1 Seasonal values of spatial mean eddy heat and salt transport for four sub-regions NB, WB, SWB and SEB
Sub-regions Winter Monsoon Pre-summer Monsoon Summer Monsoon Post-summer Monsoon 106· W·m–1 kg/ms 106· W·m–1 kg/ms 106· W·m–1 kg/ms 106 W·m–1 kg/ms NB 5.73 11.11 18.94 23.25 8.66 10.11 8.00 14.14 WB 7.82 11.73 7.28 11.88 7.35 6.95 19.31 15.30 SWB 8.87 16.27 4.34 6.86 16.80 9.87 10.58 12.43 SEB 5.31 17.24 6.91 13.31 3.88 10.36 9.22 14.93 -
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