Open AccessOn temperate sources of bromoform and other reactive organic bromine gases
Author(s) -
Carpenter L. J.,
Liss P. S.
Publication year - 2000
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jd900242
Subject(s) - bromoform , environmental science , bromine , troposphere , atmospheric sciences , temperate climate , ozone , environmental chemistry , biomass (ecology) , atmosphere (unit) , oceanography , ozone depletion , chemistry , ecology , meteorology , stratosphere , geology , biology , geography , organic chemistry , chromatography , chloroform
Current estimates of annual bromoform production by temperate marine algae underestimate, by at least an order of magnitude, the flux required to sustain atmospheric concentrations. In the light of recent evidence of the potential of bromoform to deplete upper‐tropospheric/lower‐stratospheric ozone, such a substantial discrepancy in global emission rates is of considerable concern. Here we present new information on air and seawater CHBr 3 , CH 2 Br 2 , and CHBr 2 Cl concentrations in the coastal east Atlantic and review previous data from widespread locations which suggest that concentrations and ratios of reactive organobromines are consistent with marine macroalgal emissions. Detailed reviews of algal halocarbon emissions and biomass estimates imply that macroalgae produce around 70% of the world's bromoform, rather than only ∼20% as previously thought, and that the underestimation was most likely caused by over conservative biomass estimates. Our total global source strength estimate of 2.2×10 11 g CHBr 3 yr −1 agrees well with recent calculations derived from atmospheric data. Given the dominant role of macroalgae in producing bromoform, the effect of changing climate and environment on seaweed populations and consequent effect on biogenic bromine emissions should be investigated.