Five years of water property variations on the southern flank of Georges Bank

J. Irish, R. Beardsley and K. Brink

The long-term moored effort maintained a mooring on the southern flank of Georges Bank in 76 meters of water to obtain a time history of the water property fluctuations. Preliminary results are shown in the plot of the "eyeball" water-column averaged values of temperature and salinity at 20 day intervals below. The strong intrusive signals were removed to view the lower frequency trends. The temperature shows the annual cycle of cooling to about 4° C in winter and warming to about 13 to 14° in summer, except for 1995, when the warm core ring intrusion warmed the water column another degree or 2. 1996 had the lowest temperature maximum (smallest water column warming) which was associated with the 1 PSU freshening of the water column. The salinity shows the more interesting longer variations. The salinity varies about a value of 33 PSU with a 6-month cycle until the end of 1995. During the first half of 1996, the salinity decreases to 32. Then from mid-1996 to mid 1997 the salinity increases to 32. Then from mid 1997 to mid 1998 it decreases to below 32 again. From mid-1998 until recovery, the salinity increases to nearly 33 PSU.

Figure 1

Southern Flank Moored Water Property Summary.