Radiocaesium and circulation patterns west of Scotland

The patterns of circulation to the west of Scotland can be traced with the aid of radiocaesium isotopes of Sellafield origin contained in the coastal current water. A survey in July 1981 has provided data of flow rates and dilution for comparison with two previous surveys and, in extending the area of interest to the entire shelf region between the North Channel and Cape Wrath, has allowed assessments to be made firstly of the volume transport to the east and west of the Outer Hebrides and secondly of the Atlantic water input to the coastal system. Transport through the Minches was about 4.5 times the volume of the coastal flow west of the Hebrides. The North Channel outflow of approx. 4.7 x 104 m3 s-1 of Irsih Sea/Clyde water had been supplemented in the coastal current by approx. 6.5 x 104 m3 s-1 of Atlantic water when the east and west branches reached 580N. (author)