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Unanticipated consequences of ocean acidification: A noisier ocean at lower pH
Author(s) -
Hester Keith C.,
Peltzer Edward T.,
Kirkwood William J.,
Brewer Peter G.
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl034913
Subject(s) - ocean acidification , environmental science , absorption (acoustics) , fossil fuel , range (aeronautics) , oceanography , seawater , noise (video) , climate change , atmospheric sciences , sound (geography) , environmental chemistry , flux (metallurgy) , atmosphere (unit) , effects of global warming on oceans , global warming , chemistry , geology , meteorology , materials science , physics , image (mathematics) , organic chemistry , artificial intelligence , computer science , composite material
We show that ocean acidification from fossil fuel CO 2 invasion and reduced ventilation will result in significant decreases in ocean sound absorption for frequencies lower than about 10 kHz. This effect is due to known pH‐dependent chemical relaxations in the B(OH) 3 /B(OH) 4 − and HCO 3 − /CO 3 2− systems. The scale of surface ocean pH change today from the +105 ppmv change in atmospheric CO 2 is about −0.12 pH units, resulting in frequency dependant decreases in sound absorption ( α = dB/km) exceeding 12%. Under reasonable projections of future fossil fuel CO 2 emissions and other sources a pH change of 0.3 units or more can be anticipated by mid‐century, resulting in a decrease in α by almost 40%. Ambient noise levels in the ocean within the auditory range critical for environmental, military, and economic interests are set to increase significantly due to the combined effects of decreased absorption and increasing sources from mankind's activities.