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Internal wave weather in a stratified lake
Author(s) -
Saggio Angelo,
Imberger Jörg
Publication year - 1998
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1998.43.8.1780
Subject(s) - internal wave , geology , stratification (seeds) , thermistor , seiche , dissipation , water column , structural basin , typhoon , meteorology , climatology , geophysics , atmospheric sciences , oceanography , physics , geomorphology , seed dormancy , botany , germination , quantum mechanics , dormancy , biology , thermodynamics
Thermistor chain data collected in Lake Biwa (Japan) during a period of strong stratification were used to determine the nature of the water column response to wind forcing. The evolution of the basin‐scale waves in the lake were reproduced in three‐dimensional numerical simulations and the time variability of the internal wave spectrum is discussed based on spectral analysis of the thermistor chain records. Severe winds associated with the passage of three typhoons during the sampling period excited basin‐scale Kelvin and Poincaré waves, which, by interaction with the topography of the lake and non‐linear effects, generate trains of high‐frequency internal waves. Time‐frequency analysis of the temperature signals suggests that the ω −2 slope of the internal wave spectrum is probably the result of the composition of groups of waves with high intermittence travelling through the wave guide. The observed rapid decay of internal wave energy after severe wind events seemed to be due mostly to high dissipation at the sloping boundaries of the lake.