3-54 



and the spring of 1974. April-August and October-November were dry 

 periods; September rains had no detectable effect on salinity regimes, 

 although November salinities were reduced in the inner harbor (possibly 

 because sampling coincided with a neap tide) . December 1974- January 

 1975 precipitation caused reduced salinity from January through April. 

 Despite a wet July and September, no fall salinity low occurred in 1975. 

 Above average precipitation in January 1976 led to reduced salinities 

 January-March; much of the rest of the spring and sxommer was suffi- 

 ciently dry to preclude fall salinity minima. Rainy March and September 

 1977 were reflected in March- April and October salinity minima. 



A salinity minimum period reflecting runoff conditions has 

 occurred consistently between December and June; the duration, timing 

 and extent of the period is dependent on climatology and hydrology of 

 the drainage basin. Fall minima were apparent in 1971, 1972, 1974 and 

 1977, 



Water temperatures were not similar to air temperatures in 

 absolute terms, because conductive heat transfer across the air-water 

 interface is small compared to radiational transfer processes. However, 

 since the same radiational effects govern air and water heat transfer, 

 variation in patterns of air and water temperature are grossly similar. 



In 1971, there was no atmospheric correspondence with unusu- 

 ally low May and high August water temperatures. In turn, unusually 

 warm September and October air temperatures had no apparent effect on 

 water temperature. A relatively mild winter 1971-1972 saw normal water 

 temperatures; siimmer and fall 1972 waters were colder than in other 

 years, while air temperatures were normal for those seasons until 

 November, when they were below average. In January and February 1973, 

 the harbor was unusually warm, though no comparable climatological 

 pattern occurred. Despite a climatologically warm period that persisted 

 from March 1973 through August 1974, no departure from normal water 

 temperature was observed during this period. An unusually cold October 

 1974 was comparable for air and water. December 1974 was also cold in 



