Open AccessExternal gravity oscillations in Lake Onega
Author(s) -
S. F. Rudnev,
G. Salvadè,
Kolumban Hutter,
F. Zamboni
Publication year - 1995
Publication title -
annales geophysicae
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.522
H-Index - 93
eISSN - 1432-0576
pISSN - 0992-7689
DOI - 10.1007/s00585-995-0893-2
Subject(s) - seiche , barotropic fluid , shallow water equations , geology , current (fluid) , forcing (mathematics) , eigenvalues and eigenvectors , current meter , mode (computer interface) , matrix (chemical analysis) , grid , quadratic equation , hydrology (agriculture) , geodesy , climatology , physics , seismology , mathematics , oceanography , geometry , geotechnical engineering , computer science , materials science , quantum mechanics , composite material , operating system
Lake Onega is located in the southern part ofKarelia, in the north-west of Russia. We report data taken by variouslimnigraphs and current meters and isolate, by spectral analysis, the mostconspicuous barotropic periods of these signals. The analysis that follows isbased on the linearized shallow-water equations, that are solved for the freeoscillations and thus identify the eigenperiods and corresponding modestructures for this lake. Computational results are presented for a finitedifference representation for these surface-seiche equations applied to theentire Lake Onega including its bays. The grid consists of quadratic elements of1000 m side length corresponding to 9344 active cells. The emerging matrixeigenvalue problem exceeds the storage and compuational capacity of standard PCsor workstations and thus requires use of the approximate Lanczos procedure toisolate the first ten eigenperiods and corresponding mode structures of thebarotropic seiches, lying between 12.1 and 2.2 h. Comparison of computationalresults and inferences from the water level and current-meter records, disclosesatisfactory agreement between theory and observation