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methyl bromide loss rate constants in the north Pacific Ocean
Author(s) -
Tokarczyk Ryszard,
Goodwin Kelly D.,
Saltzman Eric S.
Publication year - 2001
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 - 10.1029/2001gl013812
Subject(s) - seawater , reaction rate constant , bromide , subtropics , degradation (telecommunications) , environmental chemistry , surface water , chemistry , oceanography , environmental science , geology , kinetics , ecology , biology , inorganic chemistry , environmental engineering , physics , quantum mechanics , telecommunications , computer science
The degradation rate constant of CH 3 Br in the North Pacific Ocean was measured in surface seawater between September and October 1999, using a stable isotope ( 13 CH 3 Br) incubation technique. Total degradation rate constants ranged from 0.02 to 0.43 d −1 , decreasing in colder waters as a result of the temperature‐dependence of chemical losses. Biological rate constants ranged from 0.01 to 0.20 d −1 . In subtropical waters (13‐20°N), biological loss rate constants were small compared to chemical loss rate constants. North of Hawaii, biological processes played an increasingly significant role in CH 3 Br degradation. In subpolar waters (40‐58°N), biological losses dominated the removal of methyl bromide. Comparison of the measured loss rate constants with surface water CH 3 Br concentrations suggest that the CH 3 Br production rate is higher in warm, low latitude waters than in cold subpolar waters at this time of year. Diel studies revealed a midday maximum in biological degradation of methyl bromide.