FISHERY BULLETIN: VOL. 86, NO. 4 



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Figure 9.— Sea temperatures and wind off Mendocino during the 1980-81 downwelling season, 

 methods used in obtaining and plotting the data. 



See capture of Figure 4 and text for 



Event 1— Sea temperature fell to 8.5°C on 16 August after 9 consecutive days of 7-10 K northerlies, producing the last episode of 

 strong upwelling during the 1980 upwelling season. 



Event 2— Sea temperature rose to 10.4°C on 26 August after southerlies of 5-12 K on 9 of the preceding 11 days. Then began a 6-wk 

 transition to the downwelling season, during which 1-4 day periods of 2-10 K northerlies, with slightly lowered sea temperatures, alter- 

 nated with 1-4 day periods of southerlies, with slightly elevated temperatures. 



Event 3— The last bit of upwelling before the season's first major downwelling episode began on 1 4 October with 7 consecutive days 

 of northerlies— 20 K during the first 2, 4-8 K during the next 5. 



Event 4— Sea temperatures rose to 11.2°C on 7 November after 16 straight days of 2-12 K southerlies or weak (2-5 K) northerlies. 

 Event 5— Sea temperatures fell to 9.7°C during a major cooling that coincided with 8 days of 3-9 K northerlies (with gusts to 20 K) 

 from 8 to 15 November. 



Event 6— On 21 November the wind shifted to the south, with gusts to 20K, and sea temperatures began rising. 

 Event 7— A 3-day storm (1-3 December) with 20-30 K southerlies (and rain) briefly accelerated the rise in temperature. 

 Event 8— The warming trend was briefly interrupted by several 1-3 day periods of 4-10 K northerlies. 



Event 9— By 22 December sea temperatures had risen to levels above 12°C that characterized the 1980-81 dowmwelling season. Although 

 southerlies predominated over the next 3 weeks, on some days reaching 25 K (e.g., on 25 December), there were no further large in- 

 creases in temperature. 



Event 10— Sea temperatures anomalously fell during the first 2 weeks of January, even though winds during that period were mostly 

 southerlies of up to 10 K. 



Event 11— An 8-day storm (15-22 January) with 12-20 K southerlies (and rain) resulted in sea temperatures rising to 12.7°C— the warmest 

 of the year (equaled 3 weeks later). 



730 



