Paper 5 



other long-per 1 od/^ astronomically induced/^ harmonics observed in 

 tidal data CLisitzin 197A), iJe did notr however* remove very 

 Long-period fluctuations such as those caused by isostatic 

 glacial responses (as at Yakutat* AK) or fluctuations related to 

 land subsidence or uplift (such as at Balboa* CZ). 



Our objective is to compare temporal fluctuations of sea level 

 along much of the eastern Pacific coast for eventual comparison 

 with fishery fluctuations. In order to allow comparison between 

 stations and to flag unusual events* the data are presented as 

 monthly mean anomalies or departures of a given month from its 

 long-term mean- The long-term means used in this report were for 

 the 19-yr period* 1949-67, The tidal reference datum differs 

 from station to station. Computation of anomalies at each 

 station allows comparison in time between stations having 

 different oatum Levels. 



PattulLo et al. (1935) found that in temperate and tropic 

 latitudes (between about 40N and 40S) changes in the specific 

 volume of the water column were responsible for most of the 

 nontidal variation in recorded sea Level. Atmospheric pressure 

 effects were found to account for only a small part of the 

 recorded changes in sea Level. This situation is not true* 

 however* in higher Latitudes. Lisitzin and PattulLo (1961) found 

 that north of 40N much of the variation in sea Level results from 

 changes in distribution of atmospheric pressure over the ocean. 

 This "inverted barometer" effect can be removed from the data in 

 high Latitudes by adjusting sea levels for departures of 

 atmospheric pressure from a long-term mean. 



There 

 qu i ck L 

 total 

 This 

 severa 

 T hu s* 

 equi L i 

 more . 

 const a 

 ch ange 

 differ 

 d i St ri 

 Saur 1 



IS evi 

 y foil 

 pr essu 

 isost a 

 I thou 



t he 

 br i urn 



ASSU 



nt * i 

 s* the 

 en ce 

 but i on 

 972). 



den c 

 ow ed 

 re o 

 ti c 

 sand 



o c 

 with 

 mi ng 

 f t 

 sea 

 so 



of 



e th 



by 

 n th 



ad j 



mil 

 ean 



atm 

 th 

 he 



su r 

 that 



pre 



at f 

 comp 

 e se 

 ustm 

 es a 

 can 

 osph 

 e a 

 pr es 

 face 

 th 

 ssur 



Lu c tu 

 ensat 

 a flo 

 ent 

 nd w i 



be 

 eric 

 ve rag 

 su re 



s lop 

 ere 

 e on 



a t i ons 

 i ng ch 

 or re 

 i s th 

 thin a 



consi 

 pres su 

 e pre 



diffe 

 e will 

 will 

 the se 



1 n 

 ange 

 main 

 ough 



ti m 

 der e 

 re f 

 ssur 

 ren c 



cha 

 be 

 a fl 



at mo 

 s in 



s 



t 



e 



d 



or 



e 



e 



V 



to 



sp 



t 



P 







b 



nge 



no 



oor 



sphe 

 sea 



e ry 

 occ 



an 



o a 



e r i o 



ve r 



e twe 



toe 



net 



(Fat 



n c 



leve 

 near 

 u r ov 

 of s 

 pp roa 

 ds of 

 the o 

 en t 

 ompen 

 ch an 

 tuL Lo 



pres 

 L so 



Ly 



era 

 ever 

 ch 

 a 

 cean 

 wo 

 sate 



ge 



et 



sure 

 tha 



cons 

 ran 



al 



i SOS 



mont 



s re 

 sta 

 for 

 i n 



al . 



are 

 t t he 

 t ant . 

 ge of 

 days . 

 t at i c 

 h or 

 mains 

 t i ons 

 this 



the 

 19 5 5; 



Pressure effe£ts were removed from the data by correcting sea 

 Levels to a long-term mean atmospheric pressure in the vicinity 

 of the tide gage. This compensates for both the normal seasonal 

 cycle and the monthly pressure anomaly- Monthly mean sea Level 

 pressure data were obtained from the »Jorld Weather Record series* 



53 



