Methyl chloride and isoprene emissions from tropical rain forest in Southeast Asia

Saito, Takuya; Yokouchi, Yoko; Kosugi, Yukio; Tani, Makoto; Philip, Elizabeth; Okuda, Toshinori

doi:10.1029/2008gl035241

Cited by 37 publications

(43 citation statements)

References 32 publications

(43 reference statements)

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“…Table 3 summarises the isoprene and monoterpene fluxes measured during the OP3 campaigns relative to previous findings from Amazonia, Africa and South East Asia. Our measurements of isoprene compared very closely to leaflevel estimates made from a dipterocarp forest on mainland Malaysia (Saito et al, 2008) and to observations above regions of the Congo, but were at the extreme lower end of observations from Amazonia. In contrast, our measurements of total monoterpene fluxes are somewhat larger than those previously reported for other tropical forests.…”

Section: Isoprene and Monoterpene Surface-layer Fluxesmentioning

confidence: 50%

Fluxes and concentrations of volatile organic compounds from a South-East Asian tropical rainforest

et al. 2010

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Abstract. As part of the OP3 field study of rainforest atmospheric chemistry, above-canopy fluxes of isoprene, monoterpenes and oxygenated volatile organic compounds were made by virtual disjunct eddy covariance from a SouthEast Asian tropical rainforest in Malaysia. Approximately 500 hours of flux data were collected over 48 days in AprilMay and June-July 2008. Isoprene was the dominant nonmethane hydrocarbon emitted from the forest, accounting for 80% (as carbon) of the measured emission of reactive carbon fluxes. Total monoterpene emissions accounted for 18% of the measured reactive carbon flux. There was no evidence for nocturnal monoterpene emissions and during the day their flux rate was dependent on both light and temperature. The oxygenated compounds, including methanol, acetone and acetaldehyde, contributed less than 2% of the total measured reactive carbon flux. The sum of the VOC fluxes measured represents a 0.4% loss of daytime assimilated carbon by the canopy, but atmospheric chemistry box modelling suggests that most (90%) of this reactive carbon is returned back to the canopy by wet and dry deposition following chemical transformation. The emission rates of isoprene and monoterpenes, normalised to 30 • C and 1000 µmol m −2 s −1 PAR, were 1.6 mg m −2 h −1 and 0.46 mg m −2 h −1 respectively, which was 4 and 1.8 times lower respectively than the default value for tropical forests in the widely-used MEGAN Correspondence to: B. Langford (b.langford1@lancaster.ac.uk) model of biogenic VOC emissions. This highlights the need for more direct canopy-scale flux measurements of VOCs from the world's tropical forests.

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Section: Isoprene and Monoterpene Surface-layer Fluxesmentioning

confidence: 50%

Fluxes and concentrations of volatile organic compounds from a South-East Asian tropical rainforest

et al. 2010

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“…The latest studies, however, suggest that the gap is narrowing [World Meteorological Organization, 2011]. The bulk of atmospheric CH 3 Cl originates from biogenic production by/in vegetation, particularly in the tropics and subtropics [e.g., Yokouchi et al, 2000Yokouchi et al, , 2002Rhew et al, 2001;Saito et al, 2008;Blei et al, 2010]. A recent three-dimensional inverse modeling study constrained by observations from surface networks estimated that tropical plants account for 54% of total global CH 3 Cl emissions [Xiao et al, 2010].…”

Section: Introductionmentioning

confidence: 99%

Methyl chloride from the Aura Microwave Limb Sounder: First global climatology and assessment of variability in the upper troposphere and stratosphere

et al. 2013

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[1] Methyl chloride (CH 3 Cl) is by far the largest natural carrier of chlorine to the stratosphere. Its importance in stratospheric ozone chemistry is expected to increase in the coming decades as emission controls alter the relative contributions from natural and anthropogenic halogen sources. The Microwave Limb Sounder (MLS) on NASA's Aura satellite provides the first daily global observations of CH 3 Cl. Here we quantify the quality of the MLS version 3 CH 3 Cl data (single-profile precision of˙100 pptv; accuracy of 30-45%; vertical and horizontal resolution of 4-5 km and 450-600 km, respectively) and demonstrate their utility for scientific studies over the vertical range from 147 to 4.6 hPa. We exploit the unmatched scope of the 8 year MLS data set to investigate the spatial, seasonal, and interannual variations in the distribution of CH 3 Cl in the upper troposphere/lower stratosphere (UTLS). Like carbon monoxide, CH 3 Cl is a marker of pollution from biomass burning that can be lofted to the UTLS very rapidly by deep convection. The climatological seasonal cycle in CH 3 Cl reflects variability in regional fire activity and other surface sources as well as convection, and anomalous CH 3 Cl enhancements in the tropical upper troposphere are linked to specific episodes of intense burning. Methyl chloride is shown to be very useful as a tracer of large-scale dynamical processes, such as diabatic descent inside the stratospheric winter polar vortices, quasi-isentropic cross-tropopause transport associated with the summer monsoon circulations, and effects related to the quasi-biennial oscillation and the tropical "tape recorder".

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“…Secondly, there is some evidence that the rainforest might be a direct source of some halocarbons. A number of studies have looked at possible biogenic sources of halocarbons (principally CH 3 Cl, but including other chloro-and bromocarbons), with the sources including plants, leaf litter, wood-rotting fungi and insects (Harper,et al, 2008;Mead et al, 2008;Saito et al, 2008). Thirdly, there is increasing interest in the role of natural, short-lived halogen species, which could potentially be lifted rapidly to the low stratosphere in deep convection where they could play a role in stratospheric ozone destruction (see, for example, Law et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Bromoform in the tropical boundary layer of the Maritime Continent during OP3

et al. 2011

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Abstract. We report measurements of bromoform made by gas chromatography during the OP3 campaign in 2008. Measurements were made simultaneously for a few days at the World Meteorological Organization (WMO) Global Atmospheric Watch (GAW) site in the Danum Valley, a rainforest location in Sabah, Borneo, and at a nearby coastal site at Kunak. Background values at Kunak were higher than those measured in the rainforest (2-5 ppt compared with 1 ppt) and excursions away from the background were very much higher, reaching 10 s of ppt. Measurements of C 2 Cl 4 , an industrial tracer, showed no significant difference in background at the two sites. Modelling using two different models can reproduce a number of the observed features. The data are consistent with a strong, local coastal source of bromoform in eastern Sabah and can be used to infer the strength of the source of bromoform in South East Asia. However, they provide only a very weak constraint on global emissions. The global model results highlight the difficulty for short-lived species of extrapolating limited duration, local measurements to a global source.

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Methyl chloride and isoprene emissions from tropical rain forest in Southeast Asia

Cited by 37 publications

References 32 publications

Fluxes and concentrations of volatile organic compounds from a South-East Asian tropical rainforest

Fluxes and concentrations of volatile organic compounds from a South-East Asian tropical rainforest

Methyl chloride from the Aura Microwave Limb Sounder: First global climatology and assessment of variability in the upper troposphere and stratosphere

Bromoform in the tropical boundary layer of the Maritime Continent during OP3

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