The Effect of Thermohaline Variability on the Exchange Through Mediterranean Straits
Abstract
A simple method is presented for estimating the thermohaline driven exchanges through straits. The primary assumption is that the exchange is determined by the pressure force created by the differing weights of the water columns on either side of the sill and by the continuity of mass required by the internal basin. This renders the exchanges insensitive to the particular bathymetry or dynamical complications within the strait and computable from density profiles on either side of the strait. The method is applicable at time scales greater than days, and thus facilitates the resolution of seasonal variability in thermohaline circulations and the monitoring of interannual trends. Application to the Strait of Gibraltar gave summer and winter outflows of 1.7 and 2.3 Sv, respectively. The seasonal balance of exchanges for the Tyrrhenian Sea was computed to provide an example of the interdependence of exchanges in basins with multiple openings. The flow through the Strait of Sicily is driven by the steric-height differences between the Ionian and both the Tyrrllenian and Balearic Seas. Eastward upper layer flow was calculated to be 0.6 and 2.0 Sv for summer and winter, respectively. A cursory example is also given of the consequences of atmospheric warming on the Mediterranean circulation. It is shown that the vigor of the thermohaline circulation would decline in proportion to a decline in deep-water production.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1989
- Accession Number
- AD1114332
Entities
People
- T. S. Hopkins
Organizations
- SACLANT ASW Research Centre