Halocarbon emissions by selected tropical seaweeds: species-specific and compound-specific responses under changing pH

Mithoo-Singh, Paramjeet Kaur; Keng, Fiona Seh-Lin; Phang, Siew‐Moi; Elvidge, Emma Leedham; Sturges, William T.; Malin, Gill; Rahman, Noorsaadah Abd.

doi:10.7717/peerj.2918

Cited by 24 publications

(40 citation statements)

References 68 publications

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“…Laut merupakan sumber untuk bromokarbon jangka hayat pendek seperti dibromometana (CH 2 Br 2 ), bromodiklorometana (CHBrCl 2 ) dan bromoform (CHBr 3 ) melalui organisma marin seperti makroalga dan fitoplankton yang membantu di dalam proses pertukaran dari permukaan laut ke atmosfera (Raimund et al 2011). Di dalam kajian Mithoo-Singh et al (2017), majoriti sumber pelepasan halokarbon dihasilkan oleh makroalga yang menyumbang kepada kira-kira 70% daripada bromoform dunia, dan ia memberi kesan kepada fenomena perubahan iklim.…”

Section: Pendahuluanunclassified

“…Di negara tropika seperti Malaysia, pelepasan gas jangka hayat pendek (VSL) diangkut cepat oleh perolakan lapisan tropika dalam kepada lapisan bawah stratosfera tropika dan memberi kesan signifikan pada ozon stratosferik dunia (Carpenter et al 2014). Pada masa kini, terdapat banyak kajian mengenai halokarbon jangka hayat pendek yang dihasilkan secara biologi oleh rumpai laut di habitat semula jadi dan rumpai laut di kawasan pengkulturan telah dijalankan di Malaysia Mithoo-Singh et al 2017;Phang et al 2015). Meskipun bromokarbon telah dikaji secara meluas dalam bidang marin, dalam kajian ini kami mensasarkan untuk mengkaji faktor seperti keamatan cahaya dan kepekatan klorofil a (chl-a) yang mempengaruhi pengeluaran bromokarbon CHBr 3 , CH 2 Br 2 , dan CHBrCl 2 oleh rumpai laut di kawasan perairan yang terpilih di Malaysia.…”

Section: Pendahuluanunclassified

“…Berdasarkan Jadual 2, kepekatan yang tertinggi CH 2 Br 2 dilepaskan oleh Gracilaria changii dan diikuti oleh CHBr 3 dan CHBr 2 Cl pada waktu tengahari dengan nilai 1738 pmolL -1 , 712 pmolL -1 dan 319 pmolL -1 untuk CH 2 Br 2 , CHBr 3 dan CHBr 2 Cl. Hasil kajian ini juga dikaji di dalam kajian terdahulu dengan pelepasan sebatian bromin tinggi datangnya daripada makroalga perang dan merah berbanding makroalga hijau (Carpenter et al 2000;Ekdahlet al 1998;Leedham et al 2013;Mithoo-Singh et al 2017;Nightingale et al 1995).…”

Section: Hasil Dan Perbincangan Pelepasan Bromokarbon Daripada Rumpaiunclassified

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Kadar Pelepasan Bromokarbon Jangka Hayat Pendek oleh Rumpai Laut Tropika menggunakan Simulasi Laut Tropika

Raynusha¹,

Rozaimi²,

Hidayah³

et al. 2019

JSM

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Macroalgae (seaweeds) are a major contributor in emitting very short-lived (VSL) bromocarbons into the atmosphere especially in tropical countries with high primary productivity such as Malaysia. Abiotic factors such as light intensities and chlorophyll a concentrations can influence the production of bromocarbons emitted by seaweeds, however, not many studies have systematically quantified their influence on the release rates of VSL bromocarbons. Hence, to measure this, we used a seaweed culture system mimicking a natural environment to study the release rate of VSL bromocarbons (CH 2 Br 2 , CHBr 3 and CHBr 2 Cl) for several red, brown and green seaweeds (Gracilaria changii, Ulva reticulata, Caulerpa racemosa var. macrophysa, Kappaphycus alvarezii, Sargassum binderi, Sargassum siliquosum, and Padina australis. The production of VSL bromocarbons showed a diurnal cycle with halocarbon concentrations increasing to a maximum level at mid-day (1738 pmolL -1 ) and decreasing when light intensity and SST decreased. The production of VSL bromocarbons of seaweeds kept in the sunlight is five times higher than the production of aquaculture tanks placed in dark environments indicating the occurrence of photochemical production. The average photochemical rate for VSL bromocarbons from aquaculture tank experiments ranges from 1 to 137 pmol per g -1 FW -1 h -1 . This makes the red seaweeds (Gracilaria changii) as the highest. Likewise, bromoperoxide (BPO) extracted from all seaweeds also showed the highest activity in red seaweed followed by brown and green seaweed.

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Section: Pendahuluanunclassified

Section: Hasil Dan Perbincangan Pelepasan Bromokarbon Daripada Rumpaiunclassified

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Kadar Pelepasan Bromokarbon Jangka Hayat Pendek oleh Rumpai Laut Tropika menggunakan Simulasi Laut Tropika

Raynusha¹,

Rozaimi²,

Hidayah³

et al. 2019

JSM

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“…Of the six remaining molecules, the atmospheric lifetimes range from a few minutes to a few months: (CH 3 ) 2 S has a lifetime between 11 min and 46 h (Marandino et al, 2013); CH 3 I has a lifetime of ∼ 4 days and CHBr 3 a lifetime of ∼ 15 days (Carpenter et al, 2014); that of CHBr 2 Cl is about 3 months, while CH 2 Br 2 and CH 2 BrCl have lifetimes of the order of 6 months (Montzka et al, 2010;Mellouki et al, 1992;Leedham Elvidge et al, 2015;Khalil and Rasmussen, 1999).…”

Section: Very Short-lived Substancesmentioning

confidence: 99%

Observations of ozone-poor air in the tropical tropopause layer

Newton

Vaughan

Hintsa³

et al. 2018

Atmos. Chem. Phys.

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Abstract. Ozonesondes reaching the tropical tropopause layer (TTL) over the west Pacific have occasionally measured layers of very low ozone concentrations – less than 15 ppbv – raising the question of how prevalent such layers are and how they are formed. In this paper, we examine aircraft measurements from the Airborne Tropical Tropopause Experiment (ATTREX), the Coordinated Airborne Studies in the Tropics (CAST) and the Convective Transport of Active Species in the Tropics (CONTRAST) experiment campaigns based in Guam in January–March 2014 for evidence of very low ozone concentrations and their relation to deep convection. The study builds on results from the ozonesonde campaign conducted from Manus Island, Papua New Guinea, as part of CAST, where ozone concentrations as low as 12 ppbv were observed between 100 and 150 hPa downwind of a deep convective complex. TTL measurements from the Global Hawk unmanned aircraft show a marked contrast between the hemispheres, with mean ozone concentrations in profiles in the Southern Hemisphere between 100 and 150 hPa of between 10.7 and 15.2 ppbv. By contrast, the mean ozone concentrations in profiles in the Northern Hemisphere were always above 15.4 ppbv and normally above 20 ppbv at these altitudes. The CAST and CONTRAST aircraft sampled the atmosphere between the surface and 120 hPa, finding very low ozone concentrations only between the surface and 700 hPa; mixing ratios as low as 7 ppbv were regularly measured in the boundary layer, whereas in the free troposphere above 200 hPa concentrations were generally well in excess of 15 ppbv. These results are consistent with uplift of almost-unmixed boundary-layer air to the TTL in deep convection. An interhemispheric difference was found in the TTL ozone concentrations, with values < 15 ppbv measured extensively in the Southern Hemisphere but seldom in the Northern Hemisphere. This is consistent with a similar contrast in the low-level ozone between the two hemispheres found by previous measurement campaigns. Further evidence of a boundary-layer origin for the uplifted air is provided by the anticorrelation between ozone and halogenated hydrocarbons of marine origin observed by the three aircraft.

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“…(CH 3 ) 2 S, CHBr 3 and CH 2 Br 2 are produced by phytoplankton (Dacey 30 & Wakeham, 1986;Quack et al, 2007;Stemmler et al, 2015). CH 3 I is produced by cyanobacteria and picoplankton (SmytheWright et al, 2006) and large concentrations of CH 3 I are present in the marine boundary layer is produced naturally by various marine macroalgae (Gschwend et al, 1985), and CH 2 BrCl is emitted by tropical seaweed (Mithoo-Singh et al, 2017).…”

mentioning

confidence: 99%

Observations of ozone-poor air in the Tropical Tropopause Layer

Newton¹,

Vaughan²,

Hintsa³

et al. 2017

Preprint

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Abstract. Ozonesondes reaching the tropical tropopause layer (TTL) over the West Pacific have occasionally measured layers of very low ozone concentrations-less than 15 ppbv-raising the question of how prevalent such layers are and how they are formed. In this paper we examine aircraft measurements from the ATTREX, CAST and CONTRAST campaigns based in By contrast, the mean ozone concentrations in profiles in the Northern Hemisphere were always above 15 ppbv and normally above 20 ppbv at these altitudes. The CAST and CONTRAST aircraft sampled the atmosphere between the surface and 120 hPa, 10 finding very low ozone concentrations only between the surface and 700 hPa; mixing ratios as low as 7 ppbv were regularly measured in the boundary layer, whereas in the free troposphere above 200 hPa concentrations were generally well in excess of 15 ppbv. These results are consistent with uplift of almost-unmixed boundary layer air to the TTL in deep convection. An interhemispheric difference was found in the TTL ozone concentrations, with values <15 ppbv measured extensively in the Southern Hemisphere but seldom in the Northern Hemisphere. This is consistent with a similar contrast in the low-level ozone 15 between the two hemispheres found by previous measurement campaigns. Further evidence of a boundary layer origin for the uplifted air is provided by the anti-correlation between ozone and halogenated hydrocarbons of marine origin observed by the three aircraft.

show abstract

Halocarbon emissions by selected tropical seaweeds: species-specific and compound-specific responses under changing pH

Cited by 24 publications

References 68 publications

Kadar Pelepasan Bromokarbon Jangka Hayat Pendek oleh Rumpai Laut Tropika menggunakan Simulasi Laut Tropika

Kadar Pelepasan Bromokarbon Jangka Hayat Pendek oleh Rumpai Laut Tropika menggunakan Simulasi Laut Tropika

Observations of ozone-poor air in the tropical tropopause layer

Observations of ozone-poor air in the Tropical Tropopause Layer

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