PART VI: WATER CHARACTERISTICS 
52. Monthly averages of daily measurements of surface water tempera— 
ture, visibility, and density at the seaward end of the FRF pier are given in 
Table 8. The summaries represent single observations made near 0700 EST and, 
therefore, may not reflect daily average conditions since such characteristics 
can change within a 24-hr period. Large temperature variations were common 
when there were large differences between the air and water temperatures and 
variations in wind direction. From past experience, persistent onshore winds 
move warmer surface water toward the shoreline, although offshore winds cause 
colder bottom water to circulate shoreward, resulting in lower temperatures. 
Table 8 
Mean Surface Water Characteristics 
Temperature Visibility Density 
deg C m g/cm? 
1980- 1980- 1980- 
Month 1991 1991 1991 _1991 1991 1991 
Jan 8.9 6.1 1.6 1.3 1.0223 1.0234 
Feb Oeil 5.6 2.2 1.8 1.0228 1.0232 
Mar 10.1 Derk 1.7 1.6 1.0225 1.0229 
Apr 12.5 balck 2.5 2.3 1.0219 1.0225 
May 17.6 15.5 2.5 2.4 1.0211 1.0221 
Jun 22.4 19.6 2.6 3.4 1.0202 1.0214 
Jul 23.6 22.1 4.8 3.8 1.0213 1.0214 
Aug 25 Zo89) 2.7 3.2 1.0206 1.0204 
Sep 23.9 23.1 2.7 2.3 1.0212 1.0209 
Oct Ao ale) a5) 1.8 1.6 1.0218 1.0217 
Nov 13.9 14.8 1.2 1.1 1.0237 1.0229 
Dec 11.7 10.1 1.3 atoal 1.0248 1.0235 
Annual 16.6 14.9 2.3 2.1 1.0220 1.0222 
Temperature 
53. Daily sea surface water temperatures (Figure 19) were measured with 
an NOS water sampler and thermometer. Monthly mean water temperatures 
(Table 8) varied with the air temperatures (see Table 2). 
46 
