Fahihil the range was 2.2°F. The February series is particularly 

 interesting in that it shows an appreciable diurnal range and the mixing 

 effect of a strong wind in midafternoon. In this series the highest 

 surface temperature was observed at 1300 LST (about the time of 

 maximum air temperature and maximum solar insolation). Soon after 

 1300 a "shamal" type wind began; wind speeds increased to Beaufort 

 force 4 by 1400 and remained so to the end of the observation period. 

 Within two hours after the maximum temperature was observed, mixing 

 had reduced the surface temperature by 3°F.,andby 1600 (3 hours after 

 the beginning of the "shamal") the entire water column was nearly 

 isothermal. 



It is possible then that diurnal heating could account entirely for the 

 total range of temperatures shown on the surface temperature chart, 

 Figure 2; the oceanographic station observations were taken in the 

 same week as the BT observations for the second time-depth section. 

 (This is the reason that local time also is given for the oceanographic 

 stations shown in Figure 1.) 



A comparison of the three diurnal warming sections illustrates well 

 the monthly increase in water temperature, particularly that in the 

 surface layer. It appears that as a general rule the maximum air 

 temperature and maximum surface water temperature are within 

 a few degrees of each other except, of course, when increased wind 

 speeds prevent formation of or destroy the warmer surface layer by 

 mixing. 



III. Salinity 



Salinity observations were taken on 23-24 February 1949 only, when 

 the series of oceanographic stations (Fig. 1) was occupied. Water 

 samples were collected at the surface and near the bottom, and only 

 at the surface where depths were less than 2 meters. Of the 32 samples 

 taken, eight were missing or the sample bottles broken in transit before 

 reaching the laboratory. Three of these, the surface samples for 

 Stations 2, 4, and 14, would have been helpful in adding detail to the 

 analysis in certain areas. 



Surface and bottom salinity charts, presented as Figures 7 and 

 8, respectively, are based on these data. Over the harbor area the 

 total salinity range at the surface is about 3.5 %o (parts per thousand); 

 maximum salinities are observed in the shoal waters near the head 

 of the embayment. The freshest water, which incidentally exceeds 

 the average salinity of water in the open ocean by more than 2 %o, was 

 observed in the very shallow water immediately west of Jazirat 



