Distribution of methyl iodide, ethyl iodide, bromoform, and dibromomethane over the ocean (east and southeast Asian seas and the western Pacific)

Yokouchi, Yoko; Mukai, Hitoshi; Yamamoto, Haruhisa; Otsuki, Akira; Saitoh, C.; Nojiri, Yukihiro

doi:10.1029/96jd03384

Cited by 89 publications

(82 citation statements)

References 25 publications

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“…4, Table 1), which was consistent with the previous measurements, 0.3-1.8 pptv at Mace Head (Carpenter et al, 1999); <0.004-2.12 pptv at Spitzbergen (Schall and Heumann, 1993); 0.24-2.0 over Asian Seas and 0.05-5.0 pptv over western Pacific (Yokouchi et al, 1997). Its highest concentration was observed in the tropics as CH 3 Cl and CH 3 Br in this study.…”

Section: Methyl Iodidesupporting

confidence: 81%

Distribution of methyl chloride, methyl bromide, and methyl iodide in the marine boundary air over the western Pacific and southeastern Indian Ocean.

Li¹,

Yokouchi²,

Akimoto³

et al. 2001

Geochem. J.

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Methyl chloride (CH 3 Cl), methyl bromide (CH 3 Br), and methyl iodide (CH 3 I) in marine boundary air were measured over the western Pacific and the southeastern Indian Ocean during the period of December 1996-February 1997. The mean concentrations of CH 3 Cl, CH 3 Br, and CH 3 I were 623, 10.3, and 1.1 pptv, respectively, and their highest concentrations were observed in the tropics. The enhancement of CH 3 Cl concentration in the tropics, particularly near islands, was consistent with the recently reported finding on its high emissions from tropical coastal lands. The enhancement of CH 3 Br in the tropics was not related to the closeness of the sampling sites to islands, suggesting that land sources were not so important for CH 3 Br as for CH 3 Cl. The atmospheric CH 3

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Section: Methyl Iodidesupporting

confidence: 81%

Distribution of methyl chloride, methyl bromide, and methyl iodide in the marine boundary air over the western Pacific and southeastern Indian Ocean.

Li¹,

Yokouchi²,

Akimoto³

et al. 2001

Geochem. J.

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“…However, the scarcity of observations to constrain the emissions, the impact of deep convection, and the effect of dehydration processes limit the prediction of short-lived source gases that reach the stratosphere (3). On the other hand, atmospheric observations of VSL org have been provided by ground measurements and cruise, balloon, and airborne campaigns (12)(13)(14), but the different instruments used between campaigns, and the low spatial and temporal coverage of each study, contribute to the uncertainties in the estimations of total bromine and its partitioning (15). In an attempt to reduce these limitations, we present unique measurements of organic bromine substances carried out with the same instrument, the Global Hawk Whole Air Sampler (GWAS), deployed during the NASA Airborne Tropical Tropopause Experiment (ATTREX), which covered the tropical Pacific region during 2013 and 2014 (see SI Text for details of the campaign).…”

mentioning

confidence: 99%

Airborne measurements of organic bromine compounds in the Pacific tropical tropopause layer

Navarro

Atlas

Saiz‐Lopez

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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Very short-lived brominated substances (VSLBr) are an important source of stratospheric bromine, an effective ozone destruction catalyst. However, the accurate estimation of the organic and inorganic partitioning of bromine and the input to the stratosphere remains uncertain. Here, we report near-tropopause measurements of organic brominated substances found over the tropical Pacific during the NASA Airborne Tropical Tropopause Experiment campaigns. We combine aircraft observations and a chemistry−climate model to quantify the total bromine loading injected to the stratosphere. Surprisingly, despite differences in vertical transport between the Eastern and Western Pacific, VSLBr (organic + inorganic) contribute approximately similar amounts of bromine [∼6 (4−9) parts per thousand] to the stratospheric input at the tropical tropopause. These levels of bromine cause substantial ozone depletion in the lower stratosphere, and any increases in future abundances (e.g., as a result of aquaculture) will lead to larger depletions.

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“…Therefore, this region has the potential to supply a portion of the "missing" ∼ 6 pmol mol −1 of bromine, thought to be related to VSLS, to the stratosphere. Yokouchi et al (1997) were the first to report atmospheric bromocarbon measurements in the Strait of Malacca and the South China Sea. During a cruise between Japan and the Bay of Bengal, they measured mean concentrations of 0.77 pmol mol −1 (max 1.42 pmol mol −1 ) and 1.2 pmol mol −1 (max 7.1 pmol mol −1 ) for CH 2 Br 2 and CHBr 3 respectively.…”

Section: Introductionmentioning

confidence: 99%

Bromocarbons in the tropical coastal and open ocean atmosphere during the 2009 Prime Expedition Scientific Cruise (PESC-09)

Nadzir

Phang²,

Abas³

et al. 2014

Atmos. Chem. Phys.

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Abstract. Atmospheric concentrations of very short-lived species (VSLS) bromocarbons, including CHBr 3 , CH 2 Br 2 , CHCl 2 Br, CHClBr 2 , and CH 2 BrCl, were measured in the Strait of Malacca and the South China and Sulu-Sulawesi seas during a two-month research cruise in June-July 2009. The highest bromocarbon concentrations were found in the Strait of Malacca, with smaller enhancements in coastal regions of northern Borneo. CHBr 3 was the most abundant bromocarbon, ranging from 5.2 pmol mol −1 in the Strait of Malacca to 0.94 pmol mol −1 over the open ocean. Other bromocarbons showed lower concentrations, in the range of 0.8-1.3 pmol mol −1 for CH 2 Br 2 , 0.1-0.5 pmol mol −1 for CHCl 2 Br, and 0.1-0.4 pmol mol −1 for CHClBr 2 . There was no significant correlation between bromocarbons and in situ chlorophyll a, but positive correlations with both MODIS and SeaWiFS satellite chlorophyll a. Together, the shortlived bromocarbons contribute an average of 8.9 pmol mol −1 (range 5.2-21.4 pmol mol −1 ) to tropospheric bromine loading, which is similar to that found in previous studies from global sampling networks (Montzka et al., 2011). Statistical tests showed strong Spearman correlations between brominated compounds, suggesting a common source. Log-log plots of CHBr 3 /CH 2 Br 2 versus CHBr 2 Cl/CH 2 Br 2 show that both chemical reactions and dilution into the background atmosphere contribute to the composition of these halocarbons at each sampling point. We have used the correlation to . Finally, we note that satellite-derived chlorophyll a (chl a) products do not always agree well with in situ measurements, particularly in coastal regions of high turbidity, meaning that satellite chl a may not always be a good proxy for marine productivity.

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Distribution of methyl iodide, ethyl iodide, bromoform, and dibromomethane over the ocean (east and southeast Asian seas and the western Pacific)

Cited by 89 publications

References 25 publications

Distribution of methyl chloride, methyl bromide, and methyl iodide in the marine boundary air over the western Pacific and southeastern Indian Ocean.

Distribution of methyl chloride, methyl bromide, and methyl iodide in the marine boundary air over the western Pacific and southeastern Indian Ocean.

Airborne measurements of organic bromine compounds in the Pacific tropical tropopause layer

Bromocarbons in the tropical coastal and open ocean atmosphere during the 2009 Prime Expedition Scientific Cruise (PESC-09)

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