Limitations of the streamtube model

A common feature of one-dimensional streamtube models is that the pressure gradient includes only the effect of the density difference between the plu me and the ambient water on a sloping bottom. Variations of the streamtube height and density along the flow path are thus neglected. In the present p aper a streamtube model is used to highlight the assumptions underlying the simplification and to obtain the limitations this prerequisite presents. T he results indicate that the parameter range for which the simplification i s applicable is largest when the initial outflow is parallel to the isobath s. More specific limits are given for three major outflows - the Mediterran ean, the Faroe Bank Channel and the Denmark Strait outflow. (C) 2000 Elsevi er Science Ltd. All rights reserved.