Paper 6 



CiES Bianco ta Point Conceetign (42Nr l^SW to 36N^ 

 patterns of positive anomalies during winter a 

 anomalies during summer noted above were not repea 

 along the coasts of southern Oregon and northern 

 This stretch uf coast encompasses the core of the 

 Current upwelLing region^ which is characterized^ in 

 a maximum in the alongshore component of surface 

 during July (Nelson in press). In 1976 the timing/^ d 

 intensity of the indicated up.jelling at Cape Blanco 

 Mendocino (39N)x and to a lesser extent Point Conce 

 were markedly different than the 1946-67 long 

 condi t ion s. 



122W). The 

 nd negative 

 ted exactly 

 California. 

 California 

 the mean* by 

 wind stress 

 urat ion* and 

 (42N)* Cape 

 ption (36 N)/ 

 -term mean 



Positive anomalies occurred in January and February* during a 

 part of the year ordinarily characterized by coastal convergence. 

 Although onshore transport was indicated at 42Nr upwelling 

 indices for 39N were positive and were clearly above the 50th 

 percentile. This feature continued a long trend of positive 

 anomalies which began in April 1975 (bakun 1978). 



The onset of anomalous upwelling appeared to occur rather 

 abruptly in March. The timing of this event was coherent at 

 three locations along the coast (Fig. 6.2). Near Cape Mendocino 

 (39N)* the March index was nearly a factor of three greater than 

 the long-term mean value for this month and location. A return 

 to near normal conditions occurred in April. 



Cond 

 May* 

 perc 

 Mend 

 larg 

 unus 

 year 

 i ndi 

 shif 

 c i re 

 t i mi 

 Inde 

 the 



i t ions f 



June* 

 entile a 

 oc i no ( 

 est in J 

 ually I 

 in w h i c 

 cated. 

 t in* or 

 u I at i on 

 ng of th 

 X va Lue 

 long-ter 



avo r 



and 



t bo 



39 N) 



une 



arge 



h St 



Such 



in 



inf 



e su 



s pe 



m me 



able 



Ju 



th 4 



we 



with 



pos 



rong 



Ion 



tens 



luen 



mmer 



aked 



an c 



to 



ly. 



2N a 

 re 



in t 

 i t iv 

 e r t 

 g-te 

 i f ic 

 cing 



upw 



in 

 yc le 



strong 



Month 

 nd 39N. 

 the se 

 he 31- 

 e anoma 

 han nor 

 rm pers 

 a t i o n 

 the 

 el I i ng 

 May* tw 

 s for t 



coas 



ly 



Th 

 cond 



yr 



lies 



mal 



iste 



of* 



west 



seas 



o mo 



hese 



tal 

 mean 

 e v 



hi g 

 seri 



ma r 

 coa s 

 nee 



the 



CO 



on w 



nths 

 loc 



upw 

 i nd 



a lue 



hest 



es . 



keo 



tal 



poss 

 la 



ast 



as a 

 ear 



at io 



e I Li ng 

 ices ex 

 s comp 



in May 

 This 

 the fou 



di verg 

 i bly su 

 rge-sca 

 of Nort 

 Lso som 

 I ier th 

 ns . 



reap 

 ceede 

 ut ed 

 * and 



recu 

 rt h c 

 en ce 

 ggest 

 le a 

 h Ame 

 ewh at 

 an th 



pear 



d th 



for 



the 



rren 



onse 



has 



s ei 



t mos 



r i ca 



un 



e pe 



ed in 



e 3Cth 



Cape 



thi rd 



ce of 



cut i ve 



been 



t he r a 



phe r i c 



. The 



usual. 



a ks in 



A rapid transition to below narmal upwelling (i.e.* negative 

 anomalies) during August was ifn mediately followed by a return to 

 large positive anomalies in September. The period of relaxed 

 upwelling in August was notable* since negative anomalies during 

 this month were evident along the entire stretch of coast froT 

 the northern Gulf of Alaska to the Southern California Bight. 



The pattern of positive anomalies oersisted through the last 

 quarter of 1976. While the upwelling indices at 42N approached 

 the 20-yr mean values (i.e.* downwe I li ng ) * inoices exceeding the 



68 



