日气温变化下杭州湾水温的数值模拟

Numerical simulation of water temperature under diurnal variation of air temperature in the Hangzhou Bay

杭州湾内水温在不同时间尺度下均存在变化,这对河口生态等会产生影响。由于昼夜气温变化大,空气和海水的热量交换较为频繁。另外,随着气温的逐日下降,水温也随之降低。为研究日气温变化下杭州湾内的水温变化,建立了三维数学模型,通过考虑水面和空气的热交换通量,复演了日气温变化下湾内水温特征。经过和实测潮流数据比较,本文模型很好地模拟出了杭州湾内大、中和小潮期间水流的变化。在综合考虑太阳辐射、长波辐射和水气感热交换下,模型成功再现了日气温变化下水温的变化过程。研究结果一方面有助于认识强潮河口湾内水温变化特征,另一方面将为研究温度对泥沙运动的影响提供前期基础。

There are changes of water temperature in the Hangzhou Bay at different time scales, which will impact on the estuarine ecosystem. Due to the diurnal change of air temperature, the heat exchange between air and water is frequently occurred. In addition, water temperature is dropped with the decrease of the diurnal air temperature. A three-dimensional model is established to determine the change of water temperature in the Hangzhou Bay. The heat exchange between water and air is taken into account and thus the feature of water temperature under the diurnal variation of air temperature is reproduced. On the basis of comparison between the observation data and the simulation, tidal currents are accurately reproduced by this model in the Hangzhou Bay. Under the comprehensive consideration of solar radiation, long wave radiation and heat exchange between water and air, it is successful to simulate the diurnal variation of water temperature in the bay. It is not only helpful to understand the feature of water temperature in the macro-tidal estuary, but also provide the basis for investigating the influence of water temperature on suspended sediments.