Convection in bottom sediments and its role in material exchange between water and sediments
Convection in bottom sediments and its role in material exchange between water and sediments
复制标题
底部沉积物中的对流及其在水与沉积物之间物质交换中的作用
作者：
K. Lappalainen
在芬兰的两个湖泊中，在冬季和夏季，沉积物中的恒定温度直到1.5-2米的深度才达到。沉积物中的热分层模式与水体中的热分层模式相似。然而，在沉积物中缺乏湍流混合导致了薄的“沉积物”。这种分层是由对流引起的。沉积物中的对流在春季和秋季翻转时，上覆水的密度大于间隙水的密度最普遍。冬季也有对流。对流的持续时间和强度取决于升温和降温速率。这种对流在沉积物和水之间的物质交换中可能是重要的，因为间隙水中的物质浓度比上覆水中的物质浓度高5-100倍。
In two Finnish lakes, in winter and summer, a constant temperature in the sediment was not reached until a depth of 1.5–2 m. The thermal stratification pattern in the sediment was similar to that in water. However, the lack of turbulent mixing in the sediment resulted in a thin ‘episediment’. This stratification was caused by convection. Convection currents in the sediment were most prevalent during spring and autumn overturn when the density of overlying water was greater than that of the interstitial water. Convection was also possible in winter. The duration and magnitude of convection was dependent on warming and cooling rates. Such convection currents may be important in material exchange between sediment and water since material concentrations in interstitial water are 5–100 times greater than in overlying water.