CHBr3, CH2Br2, and CHClBr2in U.S. coastal waters during the Gulf of Mexico and East Coast Carbon cruise

Liu, Yina; Yvon‐Lewis, S. A.; Hu, Lei; Salisbury, Joseph E.; O'Hern, Julia E.

doi:10.1029/2010jc006729

Cited by 39 publications

(43 citation statements)

References 55 publications

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“…Karlsson et al (2008) published production rates of 2.6-9.3 × 10 −2 pmol [µg Chl a] −1 h −1 for CHBr 3 (depending on the time of day) and 5 × 10 −4 -3.6 × 10 −3 pmol [µg Chl a] −1 h −1 for CH 2 Br 2 from an in situ study in the Baltic Sea during a cyanobacterial bloom. Liu et al (2011) calculated 417 (CHBr 3 ) and 258 pmol m −3 h −1 (CH 2 Br 2 ) for the subtropical and temperate eastern US coast, which are tenfold higher than the production rates determined from our study ( Table 7). The differences between these studies and ours may have several origins.…”

Section: Comparison To Previously Reported Rateschbr 3 and Ch 2 Brcontrasting

confidence: 73%

“…CHBr 3 and CH 2 Br 2 correlated significantly, but weakly with T Chl a, which is not an unusual feature (Abrahamsson et al, 2004a;Carpenter et al, 2009;Liu et al, 2011;Hepach et al, 2014). It has been suggested that CHBr 3 is not produced directly from phytoplankton, but rather from dissolved organic matter (DOM) present in sea water (Lin and Manley, 2012).…”

Section: Chbr 3 and Ch 2 Brmentioning

confidence: 92%

“…The half-life of CHBr 3 with respect to photolysis is 9 years assuming a mixed-layer depth of 100 m and is potentially longer for CH 2 Br 2 . Liu et al (2011) calculated the half-life of CHBr 3 due to photolysis in a coastal mixed layer of 5 m to be only 82 days. Mixed layers during MSM18/3 were from surface down to 49 m, photolysis of bromocarbons in the mixed layer will lead to half-lives of several months.…”

Section: Transport and Loss Processes In The Mixed Layermentioning

confidence: 99%

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Halocarbon emissions and sources in the equatorial Atlantic Cold Tongue

et al. 2015

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Abstract.Halocarbons from oceanic sources contribute to halogens in the troposphere, and can be transported into the stratosphere where they take part in ozone depletion. This paper presents distribution and sources in the equatorial Atlantic from June and July 2011 of the four compounds bromoform (CHBr 3 ), dibromomethane (CH 2 Br 2 ), methyl iodide (CH 3 I) and diiodomethane (CH 2 I 2 ). Enhanced biological production during the Atlantic Cold Tongue (ACT) season, indicated by phytoplankton pigment concentrations, led to elevated concentrations of CHBr 3 of up to 44.7 and up to 9.2 pmol L −1 for CH 2 Br 2 in surface water, which is comparable to other tropical upwelling systems. While both compounds correlated very well with each other in the surface water, CH 2 Br 2 was often more elevated in greater depth than CHBr 3 , which showed maxima in the vicinity of the deep chlorophyll maximum. The deeper maximum of CH 2 Br 2 indicates an additional source in comparison to CHBr 3 or a slower degradation of CH 2 Br 2 . Concentrations of CH 3 I of up to 12.8 pmol L −1 in the surface water were measured. In contrary to expectations of a predominantly photochemical source in the tropical ocean, its distribution was mostly in agreement with biological parameters, indicating a biological source. CH 2 I 2 was very low in the near surface water with maximum concentrations of only 3.7 pmol L −1 . CH 2 I 2 showed distinct maxima in deeper waters similar to CH 2 Br 2 . For the first time, diapycnal fluxes of the four halocarbons from the upper thermocline into and out of the mixed layer were determined. These fluxes were low in comparison to the halocarbon sea-to-air fluxes. This indicates that despite the observed maximum concentrations at depth, production in the surface mixed layer is the main oceanic source for all four compounds and one of the main driving factors of their emissions into the atmosphere in the ACTregion. The calculated production rates of the compounds in the mixed layer are 34 ± 65 pmol m −3 h −1 for CHBr 3 , 10 ± 12 pmol m −3 h −1 for CH 2 Br 2 , 21 ± 24 pmol m −3 h −1 for CH 3 I and 384 ± 318 pmol m −3 h −1 for CH 2 I 2 determined from 13 depth profiles.

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Section: Comparison To Previously Reported Rateschbr 3 and Ch 2 Brcontrasting

confidence: 73%

Section: Chbr 3 and Ch 2 Brmentioning

confidence: 92%

Section: Transport and Loss Processes In The Mixed Layermentioning

confidence: 99%

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Halocarbon emissions and sources in the equatorial Atlantic Cold Tongue

et al. 2015

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“…In the mixed layer, CHBr 3 , CH 2 Br 2 , CHClBr 2 , and CHBrCl 2 concentrations were in general higher in the coastal ocean (depth ≤ 200 m) and the tropics (∼20°S to 20°N; Table and Figure ). Such a general trend is consistent with that observed in other regions [ Butler et al ., ; Carpenter et al ., ; Class and Ballschmiter , ; Liu et al ., ; Quack and Wallace , ]. CHBr 3 and CH 2 Br 2 concentrations were higher below the mixed layer within the euphotic zone than those observed in the mixed layer and below euphotic zone (Table and Figures and ).…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, unlike outside the inland passage, the restricted water circulations in the inland passage may also allow CHBr 3 and CH 2 Br 2 to accumulate. Despite the fact that the CHBr 3 and CH 2 Br 2 mixed layer concentration maxima observed in this study were lower than other studies in macroalgal‐dominated regions, where extremely high concentrations of BrVSLS were observed in surface waters above macroalgal beds, the concentration patterns observed in the Chilean coast were consistent with other studies [ Carpenter and Liss , ; Fogelqvist and Krysell , ; Goodwin et al ., ; Gschwend and MacFarlane , 1986; Jones and Carpenter , ; Laturnus , ; Laturnus et al ., ; Liu et al ., ; Moore and Tokarczyk , ; Yokouchi et al ., ]. Lin and Manley [] found that CHBr 3 and CH 2 Br 2 production is a function of coastal DOM characteristics (i.e., size fraction and source).…”

Section: Resultsmentioning

confidence: 99%

Spatial distribution of brominated very short‐lived substances in the eastern Pacific

et al. 2013

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[1] Seawater concentrations and distributions of brominated very short-lived substances (BrVSLS), including bromoform (CHBr 3 ), dibromomethane (CH 2 Br 2 ), bromodichloromethane (CHBrCl 2 ), chlorodibromomethane (CHClBr 2 ), were measured in the upper water column (5-750 m) in the eastern Pacific. Inorganic nutrient, pigment concentrations, and picoplankton cell counts were measured to determine biogeochemical factors that affect the production and distribution of these BrVSLS. Elevated concentrations of BrVSLS were observed in coastal and tropical seawater. Concentration maxima for CHBr 3 , CH 2 Br 2 , and CHClBr 2 were observed below the mixed layer, near the subsurface chlorophyll a maxima, which suggest BrVSLS production may be related to photosynthetic biomass production. Our results also suggest that heterotrophic bacteria may also contribute to CH 2 Br 2 and CHBrCl 2 production in the water column. The maximum CHBrCl 2 concentration was observed at a depth much deeper than the euphotic zone, which suggests sources other than photosynthetic biomass. Elevated CHBrCl 2 concentrations in deeper waters were coincident with elevated CHCl 3 concentrations, which may be an evidence for successive chlorine substitution of CHBr 3 in deeper and older water masses.

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Spatial and temporal distributions of bromoform and dibromomethane in the Atlantic Ocean and their relationship with photosynthetic biomass

et al. 2013

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[1] Atmospheric mixing ratios and seawater concentrations of bromoform (CHBr 3 ), dibromomethane (CH 2 Br 2 ), and other brominated very short-lived substances (BrVSLS) were measured during five cruises from 1994 to 2010. These cruises were conducted over large latitudinal (62 N-60 S) and longitudinal transects (11 W-86 W) in the Atlantic Ocean. Elevated seawater concentrations of CHBr 3 and CH 2 Br 2 were often observed in regions where chlorophyll a concentrations were also elevated, which suggests biogeochemical processes associated with photosynthetic biomass may be related to CHBr 3 and CH 2 Br 2 production. Our results suggest that, at least in the open ocean, several phytoplankton taxa may contribute to the production of these trace gases. While observed correlations between CHBr 3 and CH 2 Br 2 in different regions are usually interpreted as common sources for these compounds, results in this study suggest different biogeochemical processes may contribute separately to the production of these trace gases. Heterotrophic bacterial abundance was significantly correlated with CH 2 Br 2 , but not with CHBr 3 , which suggests the biogeochemical processes associated with heterotrophic bacteria may be related to CH 2 Br 2 in seawater but probably not to CHBr 3 . In general, the Atlantic Ocean is a net source for CHBr 3 and CH 2 Br 2 , except for a few locations where these trace gases were undersaturated in seawater. Assuming fluxes measured in the Atlantic open ocean are globally representative, the resulting extrapolated, global open-ocean annual net sea-to-air fluxes calculated from data from the five cruises was estimated at 0.24-3.80 Gmol Br yr À1 for CHBr 3 and 0.11-0.77 Gmol Br yr À1 for CH 2 Br 2 .

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CHBr₃, CH₂Br₂, and CHClBr₂in U.S. coastal waters during the Gulf of Mexico and East Coast Carbon cruise

Cited by 39 publications

References 55 publications

Halocarbon emissions and sources in the equatorial Atlantic Cold Tongue

Halocarbon emissions and sources in the equatorial Atlantic Cold Tongue

Spatial distribution of brominated very short‐lived substances in the eastern Pacific

Spatial and temporal distributions of bromoform and dibromomethane in the Atlantic Ocean and their relationship with photosynthetic biomass

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