Impact of Ganges–Brahmaputra interannual discharge variations on Bay of Bengal salinity and temperature during 1992–1999 period
Impact of Ganges–Brahmaputra interannual discharge variations on Bay of Bengal salinity and temperature during 1992–1999 period
复制标题
1992-1999年恒河-雅鲁藏布江流量年际变化对孟加拉湾盐度和温度的影响
DOI：
10.1007/s12040-011-0118-x
复制
发表时间：
2011
影响因子：
1.9
通讯作者：
S. Bala
中科院分区：
文献类型：
--
作者：
F. Durand;F. Papa;Atiqur Rahman;S. Bala
本研究探讨了1992-1999年期间，每月恒河雅鲁藏布江流量变化对孟加拉湾盐度和温度的影响。恒河-雅鲁藏布江流量具有明显的季节性周期和强烈的年际变化。年最大/最小洪峰流量出现在1998年夏季/1992年夏季，1998年为1992年的2倍。这条河流流量，然后用来迫使海洋环流模式。我们的主要结果是，这些河流对孟加拉湾海面盐度的变化的影响是强烈的北方的一部分，与过量的径流迫使新鲜的异常，反之亦然。在大多数年份，河流流量年际变化对海湾盐度的影响并不延伸到~10°N以南。这与现有的观测结果形成鲜明对比，可能与我们模型的相对粗糙的分辨率有关。然而，1998年的极端流量异常是通过海湾南部边界输出的，并在流量高峰后几个月渗透到阿拉伯海东南部。在响应放电异常，模式模拟显着的混合层温度异常在孟加拉湾北方。这有可能影响该地区的气候。从我们的结论来看，似乎有必要使用一个数值模式与更高的分辨率（无论是在水平和垂直），以定量研究孟加拉湾的盐度结构。
This study investigates the impact of monthly Ganges–Brahmaputra river discharge variations on Bay of Bengal salinity and temperature during the period 1992–1999. The Ganges–Brahmaputra river discharge is characterized by a well-defined seasonal cycle with strong interannual variations. The highest/lowest yearly peak discharge occurs in summer 1998/summer 1992, with 1998 value amounting to twice that of 1992. This river discharge is then used to force an ocean general circulation model. Our main result is that the impact of these rivers on the variability of Bay of Bengal sea surface salinity is strong in the northern part, with excess run-off forcing fresh anomalies, and vice versa. Most of the years, the influence of the interannual variability of river discharge on the Bay salinity does not extend south of ~10°N. This stands in contrast with the available observations and is probably linked to the relatively coarse resolution of our model. However, the extreme discharge anomaly of 1998 is exported through the southern boundary of the Bay and penetrates the south-eastern Arabian Sea a few months after the discharge peak. In response to the discharge anomalies, the model simulates significant mixed-layer temperature anomalies in the northern Bay of Bengal. This has the potential to influence the climate of the area. From our conclusions, it appears necessary to use a numerical model with higher resolution (both on the horizontal and vertical) to quantitatively investigate the upper Bay of Bengal salinity structure.