scholarly journals Seasonal cycles of isoprene concentrations in the Amazonian rainforest

2004 ◽  
Vol 4 (2) ◽  
pp. 1291-1310 ◽  
Author(s):  
C. R. Trostdorf ◽  
L. V. Gatti ◽  
A. Yamazaki ◽  
M. J. Potosnak ◽  
A. Guenther ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Large Scale ◽  
Forest Canopy ◽  
Primary Forest ◽  
Mixing Ratio ◽  
Mixing Ratios ◽  
Physiological Capacity ◽  
Volatile Organic ◽  
Leaf Level ◽  
Boundary Layer Dynamics

Abstract. Tropical forests are an important global source of volatile organic compounds (VOCs) and other atmospheric trace gases. The high biodiversity in tropical rainforests complicates the extrapolation of biogenic volatile organic compound (BVOC) emissions from leaf-level measurements to landscape and regional or global scales. In Amazônia, a significant fraction of the carbon emitted from the biosphere to the atmosphere is emitted in the form of BVOCs, and the knowledge of these emissions is important to our understanding of tropical and global atmospheric chemistry and carbon cycling. As part of the Large scale Biosphere-atmosphere experiment in Amazônia (LBA). VOC concentrations were measured at two sites near Santarém, Para State, Brazil. The two sites are located in the National Forest of Tapajós, the first corresponding to primary forest and the second to a forest, that was selectively logged. The samples were collected simultaneously at heights of 65 and 55 m (20 and 10 m above forest canopy, respectively). The average isoprene mixing ratio was 2.2–2.5 ppb at the two sites and the standard deviations within a site ranged from 1 to 1.2 ppb. A strong seasonality of isoprene mixing ratio was observed and associated with the wet and dry seasons. The lowest mixing ratios were found during the transition between the wet to dry season, while at the start of the biomass burning season the mixing ratios increase. A qualitative analysis of a one dimensional model demonstrates that the seasonal cycle in concentrations reflects changes in isoprene production by the ecosystem, not changes in boundary layer dynamics or chemistry. The magnitude of the cycle indicates that the physiological capacity of the ecosystem to emit isoprene may depend on water availability although phenological changes could also contribute to the observed variations. A simple 1-D model that assumes mean daytime isoprene fluxes of 1.5 mg m−2h−1 and 0.9 mg m−2h−1 scaled by an algorithm depending on precipitation at the primary forest and selectively logged sites, respectively, is able to reproduce the observed vertical gradients.

scholarly journals Seasonal and diurnal variations of biogenic volatile organic compounds in highland and lowland ecosystems in southern Kenya

2021 ◽  
Author(s):  
Yang Liu ◽  
Simon Schallhart ◽  
Ditte Taipale ◽  
Toni Tykkä ◽  
Matti Räsänen ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Daily Maximum ◽  
Mixing Ratio ◽  
Biogenic Volatile Organic Compounds ◽  
Mixing Ratios ◽  
Seasonal And Diurnal Variations ◽  
Volatile Organic ◽  
Dry Seasons

Abstract. The East African lowland and highland areas consist of water-limited and humid ecosystems. The magnitude and seasonality of biogenic volatile organic compounds (BVOCs) emissions from these functionally contrasting ecosystems are limited due to a scarcity of direct observations. We measured mixing ratios of BVOCs from two contrasting ecosystems, humid highlands with agroforestry and dry lowlands with bushland, grassland, and agriculture mosaics, during both the rainy and dry seasons of 2019 in southern Kenya. We present the diurnal and seasonal characteristics of BVOC mixing ratios and their reactivity, and estimated emission factors (EFs) for certain BVOCs from the African lowland ecosystem based on field measurements. The most abundant BVOCs were isoprene and monoterpenoids (MTs), with isoprene contributing > 70 % of the total BVOC mixing ratio during daytime, while MTs accounted for > 50 % of the total BVOC mixing ratio during nighttime at both sites. The contributions of BVOCs to the local atmospheric chemistry were estimated by calculating the reactivity towards the hydroxyl radical (OH), ozone (O3), and the nitrate radical (NO3). Isoprene and MTs contributed the most to the reactivity of OH and NO3, while sesquiterpenes dominated the contribution of organic compounds to the reactivity of O3. The mixing ratio of isoprene measured in this study was lower to that measured in the relevant ecosystems in west and south Africa, while that of monoterpenoids was similar. Isoprene mixing ratios peaked daily between 16:00 and 20:00 with a maximum mixing ratio of 809 parts per trillion by volume (pptv) and 156 pptv in the highlands, and 115 pptv and 25 pptv in the lowlands, during the rainy and dry seasons, respectively. MT mixing ratios reached their daily maximum between midnight and early morning (usually 04:00 to 08:00) with mixing ratios of 254 pptv and 56 pptv in the highlands, and 89 pptv and 7 pptv in the lowlands, in the rainy and dry seasons, respectively. The dominant species within the MT group were limonene, α-pinene, and β-pinene. EFs for isoprene, MTs, and 2-methyl-3-buten-2-ol (MBO) were estimated using an inverse modeling approach. The estimated EFs for isoprene and β-pinene agreed very well with what is currently assumed in the world’s most extensively used biogenic emissions model, the Model of Emissions of Gases and Aerosols from Nature (MEGAN), for warm C4 grass, but the estimated EFs for MBO, α-pinene, and especially limonene, were significantly higher than that assumed in MEGAN for the relevant plant functional type. Additionally, our results indicate that the EF for limonene might be seasonally dependent in savanna ecosystems.

scholarly journals Seasonal and diurnal variations in biogenic volatile organic compounds in highland and lowland ecosystems in southern Kenya

2021 ◽  
Vol 21 (19) ◽  
pp. 14761-14787
Author(s):  
Yang Liu ◽  
Simon Schallhart ◽  
Ditte Taipale ◽  
Toni Tykkä ◽  
Matti Räsänen ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Daily Maximum ◽  
Mixing Ratio ◽  
Biogenic Volatile Organic Compounds ◽  
Mixing Ratios ◽  
Seasonal And Diurnal Variations ◽  
Volatile Organic ◽  
Dry Seasons

Abstract. The East African lowland and highland areas consist of water-limited and humid ecosystems. The magnitude and seasonality of biogenic volatile organic compounds (BVOCs) emissions and concentrations from these functionally contrasting ecosystems are limited due to a scarcity of direct observations. We measured mixing ratios of BVOCs from two contrasting ecosystems, humid highlands with agroforestry and dry lowlands with bushland, grassland, and agriculture mosaics, during both the rainy and dry seasons of 2019 in southern Kenya. We present the diurnal and seasonal characteristics of BVOC mixing ratios and their reactivity and estimated emission factors (EFs) for certain BVOCs from the African lowland ecosystem based on field measurements. The most abundant BVOCs were isoprene and monoterpenoids (MTs), with isoprene contributing > 70 % of the total BVOC mixing ratio during daytime, while MTs accounted for > 50 % of the total BVOC mixing ratio during nighttime at both sites. The contributions of BVOCs to the local atmospheric chemistry were estimated by calculating the reactivity towards the hydroxyl radical (OH), ozone (O3), and the nitrate radical (NO3). Isoprene and MTs contributed the most to the reactivity of OH and NO3, while sesquiterpenes dominated the contribution of organic compounds to the reactivity of O3. The mixing ratio of isoprene measured in this study was lower than that measured in the relevant ecosystems in western and southern Africa, while that of monoterpenoids was similar. Isoprene mixing ratios peaked daily between 16:00 and 20:00 (all times are given as East Africa Time, UTC+3),​​​​​​​ with a maximum mixing ratio of 809 pptv (parts per trillion by volume) and 156 pptv in the highlands and 115 and 25 pptv in the lowlands during the rainy and dry seasons, respectively. MT mixing ratios reached their daily maximum between midnight and early morning (usually 04:00 to 08:00), with mixing ratios of 254 and 56 pptv in the highlands and 89 and 7 pptv in the lowlands in the rainy and dry seasons, respectively. The dominant species within the MT group were limonene, α-pinene, and β-pinene. EFs for isoprene, MTs, and 2-Methyl-3-buten-2-ol (MBO) were estimated using an inverse modeling approach. The estimated EFs for isoprene and β-pinene agreed very well with what is currently assumed in the world's most extensively used biogenic emissions model, the Model of Emissions of Gases and Aerosols from Nature (MEGAN), for warm C4 grass, but the estimated EFs for MBO, α-pinene, and especially limonene were significantly higher than that assumed in MEGAN for the relevant plant functional type. Additionally, our results indicate that the EF for limonene might be seasonally dependent in savanna ecosystems.

scholarly journals Modelling bi-directional fluxes of methanol and acetaldehyde with the FORCAsT canopy exchange model

2016 ◽  
Author(s):  
Kirsti Ashworth ◽  
Serena H. Chung ◽  
Karena A. McKinney ◽  
Ying Liu ◽  
Bill J. Munger ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Atmospheric Chemistry ◽  
Forest Canopy ◽  
Global Scale ◽  
Exchange Model ◽  
Forest Site ◽  
Canopy Exchange ◽  
Harvard Forest ◽  
Leaf Level ◽  
Underlying Mechanisms

Abstract. The FORCAsT canopy exchange model was used to investigate the underlying mechanisms governing foliage emissions of methanol and acetaldehyde, two short chain oxygenated volatile organic compounds ubiquitous in the troposphere and known to have strong biogenic sources, at a northern mid-latitude forest site. The explicit representation of the vegetation canopy within the model allowed us to test the hypothesis that stomatal conductance regulates emissions of these compounds to an extent that its influence is observable at the ecosystem-scale, a process not currently considered in regional or global scale atmospheric chemistry models. We found that FORCAsT could only reproduce the magnitude and diurnal profiles of methanol and acetaldehyde fluxes measured at the top of the forest canopy at Harvard Forest if light-dependent emissions were introduced to the model. With the inclusion of such emissions FORCAsT was able to successfully simulate the observed bi-directional exchange of methanol and acetaldehyde. Although we found evidence that stomatal conductance influences methanol fluxes and concentrations at scales beyond the leaf-level, particularly at dawn and dusk, we were able to adequately capture ecosystem exchange without the addition of stomatal control to the standard parameterisations of foliage emissions, suggesting that ecosystem fluxes can be well enough represented by the emissions models currently used.

scholarly journals Revision of the convective transport module CVTRANS 2.4 in the EMAC atmospheric chemistry–climate model

2015 ◽  
Vol 8 (8) ◽  
pp. 2435-2445 ◽  
Author(s):  
H. G. Ouwersloot ◽  
A. Pozzer ◽  
B. Steil ◽  
H. Tost ◽  
J. Lelieveld
Keyword(s):  
Atmospheric Chemistry ◽  
Climate Model ◽  
Convective Transport ◽  
Computational Time ◽  
Cloud Base ◽  
Mixing Ratio ◽  
Time Step ◽  
Mixing Ratios ◽  
Time Stepping ◽  
Intermediate Time

Abstract. The convective transport module, CVTRANS, of the ECHAM/MESSy Atmospheric Chemistry (EMAC) model has been revised to better represent the physical flows and incorporate recent findings on the properties of the convective plumes. The modifications involve (i) applying intermediate time stepping based on a settable criterion, (ii) using an analytic expression to account for the intra-time-step mixing ratio evolution below cloud base, and (iii) implementing a novel expression for the mixing ratios of atmospheric compounds at the base of an updraft. Even when averaged over a year, the predicted mixing ratios of atmospheric compounds are affected considerably by the intermediate time stepping. For example, for an exponentially decaying atmospheric tracer with a lifetime of 1 day, the zonal averages can locally differ by more than a factor of 6 and the induced root mean square deviation from the original code is, weighted by the air mass, higher than 40 % of the average mixing ratio. The other modifications result in smaller differences. However, since they do not require additional computational time, their application is also recommended.

scholarly journals Measurement report: Variability in the composition of biogenic volatile organic compounds in a Southeastern US forest and their role in atmospheric reactivity

2021 ◽  
Vol 21 (20) ◽  
pp. 15755-15770
Author(s):  
Deborah F. McGlynn ◽  
Laura E. R. Barry ◽  
Manuel T. Lerdau ◽  
Sally E. Pusede ◽  
Gabriel Isaacman-VanWertz
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Growing Season ◽  
Mixing Ratio ◽  
Biogenic Volatile Organic Compounds ◽  
Mixing Ratios ◽  
Southeastern Us ◽  
Atmospheric Reactivity ◽  
Volatile Organic ◽  
The Impact

Abstract. Despite the significant contribution of biogenic volatile organic compounds (BVOCs) to organic aerosol formation and ozone production and loss, there are few long-term, year-round, ongoing measurements of their volume mixing ratios and quantification of their impacts on atmospheric reactivity. To address this gap, we present 1 year of hourly measurements of chemically resolved BVOCs between 15 September 2019 and 15 September 2020, collected at a research tower in Central Virginia in a mixed forest representative of ecosystems in the Southeastern US. Mixing ratios of isoprene, isoprene oxidation products, monoterpenes, and sesquiterpenes are described and examined for their impact on the hydroxy radical (OH), ozone, and nitrate reactivity. Mixing ratios of isoprene range from negligible in the winter to typical summertime 24 h averages of 4–6 ppb, while monoterpenes have more stable mixing ratios in the range of tenths of a part per billion up to ∼2 ppb year-round. Sesquiterpenes are typically observed at mixing ratios of <10 ppt, but this represents a lower bound in their abundance. In the growing season, isoprene dominates OH reactivity but is less important for ozone and nitrate reactivity. Monoterpenes are the most important BVOCs for ozone and nitrate reactivity throughout the year and for OH reactivity outside of the growing season. To better understand the impact of this compound class on OH, ozone, and nitrate reactivity, the role of individual monoterpenes is examined. Despite the dominant contribution of α-pinene to total monoterpene mass, the average reaction rate of the monoterpene mixture with atmospheric oxidants is between 25 % and 30 % faster than α-pinene due to the contribution of more reactive but less abundant compounds. A majority of reactivity comes from α-pinene and limonene (the most significant low-mixing-ratio, high-reactivity isomer), highlighting the importance of both mixing ratio and structure in assessing atmospheric impacts of emissions.

scholarly journals From emissions to ambient mixing ratios: on-line seasonal field measurements of volatile organic compounds over a Norway spruce dominated forest in central Germany

2013 ◽  
Vol 13 (11) ◽  
pp. 30187-30232 ◽  
Author(s):  
E. Bourtsoukidis ◽  
J. Williams ◽  
J. Kesselmeier ◽  
S. Jacobi ◽  
B. Bonn
Keyword(s):  
Volatile Organic Compounds ◽  
Norway Spruce ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Temperature Dependency ◽  
Emission Rates ◽  
Temperature Dependent ◽  
Central Germany ◽  
Mixing Ratios ◽  
Volatile Organic

Abstract. Biogenic volatile organic compounds (BVOC) are substantial contributors to atmospheric chemistry and physics and demonstrate the close relationship between biosphere and atmosphere. Their emission rates are highly sensitive to meteorological and environmental changes with concomitant impacts on atmospheric chemistry. We have investigated seasonal isoprenoid and oxygenated VOC (oxVOC) fluxes from a Norway spruce (Picea abies) tree in Central Germany and explored the emission responses under various atmospheric conditions. Emission rates were quantified by using dynamic branch enclosure and Proton Transfer Reaction–Mass Spectrometry (PTR-MS) techniques. Additionally, ambient mixing ratios were derived through application of a new box model treatment on the dynamic chamber measurements. These are compared in terms of abundance and origin with the corresponding emissions. Isoprenoids govern the BVOC emissions from Norway spruce, with monoterpenes and sesquiterpenes accounting for 50.8 ± 7.2% and 19.8 ± 8.1% respectively of the total emissions. Normalizing the VOC emission rates, we have observed a trend of reduction of carbon containing emissions from April to November, with an enhancement of oxVOC. Highest emission rates were observed in June for all measured species, with the exception of sesquiterpenes that were emitted most strongly in April. We exploit the wide range of conditions experienced at the site to filter the dataset with a combination of temperature, ozone and absolute humidity values in order to derive the emission potential and temperature dependency development for the major chemical species investigated. A profound reduction of monoterpene emission potential (E30) and temperature dependency (β) was found under low temperature regimes, combined with low ozone levels (E30MT, LTLO3=56 ± 9.1 ng g(dw)−1 h−1, βMT,LTLO3=0.03±0.01 K−1) while a combination of both stresses was found to alter their emissions responses with respect to temperature substantially (E30MT,HTHO3=1420.1 ± 191.4 ng g(dw)−1 h−1, βMT,HTHO3=0.15 ± 0.02 K−1). Moreover, we have explored compound relationships under different atmospheric condition sets, addressing possible co-occurrence of emissions under specific conditions. Finally, we evaluate the temperature dependent algorithm that seems to describe the temperature dependent emissions. Highest emission deviations were observed for monoterpenes and these emission fluctuations were attributed to a fraction which is triggered by an additional light dependency.

scholarly journals Friagem Event in Central Amazon and its Influence on Micrometeorological Variables and Atmospheric Chemistry

2020 ◽  
Author(s):  
Guilherme F. Camarinha-Neto ◽  
Julia C. P. Cohen ◽  
Cléo Q. Dias-Júnior ◽  
Matthias Sörgel ◽  
José Henrique Cattanio ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Temperature Drop ◽  
Atmospheric Modeling ◽  
Amazon Region ◽  
Cold Pool ◽  
Large Temperature ◽  
Mixing Ratio ◽  
Air Masses ◽  
Central Amazon ◽  
Mixing Ratios

Abstract. In the period between July 9th and 11th, 2014 a Friagem event reached the central Amazon region causing significant changes in microclimate and atmospheric chemistry. On July 11th, the southwest flow related to the Friagem converged with the easterly winds in the central Amazon region. The interaction between these two distinct air masses formed a convection band, which intensified over the Manaus region and the Amazon Tall Tower Observatory (ATTO) site. The satellite images show the evolution of convective activity on July 11th, which lead to 21 mm of precipitation in the ATTO site. Moreover, the arrival of the Friagem caused a sudden drop in temperature and a predominance of southerly winds, which could be seen in Porto Velho between July 7th and 8th and in Manaus and ATTO site from July 9th to 11th. The results of ERA reanalysis and Brazilian developments on the Regional Atmospheric Modeling System (BRAMS) simulations show that this Friagem event coming from the southwest, carries a mass of air with higher O3 and NO2 mixing ratios and lower CO mixing ratio compared to the air masses present at the central Amazon. At lake Balbina the Friagem intensifies the local circulations, such as the breeze phenomena. At the Manaus region and ATTO site, the main effects of the Friagem event are: a decrease in the incoming solar radiation (due to intense cloud formation), a large temperature drop and a distinct change in surface O3 and CO2 mixing ratios. As the cold air of the Friagem was just in the lower 500 m the most probable cause of this change is that a cold pool above the forest prevented vertical mixing causing accumulation of CO2 from respiration and very low O3 mixing ratio due to photochemistry reduction and limited mixing within the boundary layer.

scholarly journals Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

2016 ◽  
Vol 16 (11) ◽  
pp. 7149-7170 ◽  
Author(s):  
W. Joe F. Acton ◽  
Simon Schallhart ◽  
Ben Langford ◽  
Amy Valach ◽  
Pekka Rantala ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Northern Italy ◽  
Top Down ◽  
Bottom Up ◽  
Mixing Ratios ◽  
Volatile Organic ◽  
Leaf Level ◽  
Tof Ms

Abstract. This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs) 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton-transfer-reaction mass spectrometer (PTR-MS) and a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) together with the methods of virtual disjunct eddy covariance (using PTR-MS) and eddy covariance (using PTR-ToF-MS). Isoprene was the dominant emitted compound with a mean daytime flux of 1.9 mg m−2 h−1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28-day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m−2 h−1 was calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN) isoprene emission algorithms (Guenther et al., 2006). A detailed tree-species distribution map for the site enabled the leaf-level emission of isoprene and monoterpenes recorded using gas-chromatography mass spectrometry (GC–MS) to be scaled up to produce a bottom-up canopy-scale flux. This was compared with the top-down canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant-species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

scholarly journals Pollution trace gas distributions and their transport in the Asian monsoon upper troposphere and lowermost stratosphere during the StratoClim campaign 2017

2020 ◽  
Vol 20 (23) ◽  
pp. 14695-14715
Author(s):  
Sören Johansson ◽  
Michael Höpfner ◽  
Oliver Kirner ◽  
Ingo Wohltmann ◽  
Silvia Bucci ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Large Scale ◽  
Trajectory Analysis ◽  
Asian Summer Monsoon ◽  
Trace Gas ◽  
Ozone Monitoring Instrument ◽  
Air Masses ◽  
Upper Troposphere ◽  
Mixing Ratios ◽  
Monitoring Service

Abstract. We present the first high-resolution measurements of pollutant trace gases in the Asian summer monsoon upper troposphere and lowermost stratosphere (UTLS) from the Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) during the StratoClim (Stratospheric and upper tropospheric processes for better climate predictions) campaign based in Kathmandu, Nepal, 2017. Measurements of peroxyacetyl nitrate (PAN), acetylene (C2H2), and formic acid (HCOOH) show strong local enhancements up to altitudes of 16 km. More than 500 pptv of PAN, more than 200 pptv of C2H2, and more than 200 pptv of HCOOH are observed. Air masses with increased volume mixing ratios of PAN and C2H2 at altitudes up to 18 km, reaching to the lowermost stratosphere, were present at these altitudes for more than 10 d, as indicated by trajectory analysis. A local minimum of HCOOH is correlated with a previously reported maximum of ammonia (NH3), which suggests different washout efficiencies of these species in the same air masses. A backward trajectory analysis based on the models Alfred Wegener InsTitute LAgrangian Chemistry/Transport System (ATLAS) and TRACZILLA, using advanced techniques for detection of convective events, and starting at geolocations of GLORIA measurements with enhanced pollution trace gas concentrations, has been performed. The analysis shows that convective events along trajectories leading to GLORIA measurements with enhanced pollutants are located close to regions where satellite measurements by the Ozone Monitoring Instrument (OMI) indicate enhanced tropospheric columns of nitrogen dioxide (NO2) in the days prior to the observation. A comparison to the global atmospheric models Copernicus Atmosphere Monitoring Service (CAMS) and ECHAM/MESSy Atmospheric Chemistry (EMAC) has been performed. It is shown that these models are able to reproduce large-scale structures of the pollution trace gas distributions for one part of the flight, while the other part of the flight reveals large discrepancies between models and measurement. These discrepancies possibly result from convective events that are not resolved or parameterized in the models, uncertainties in the emissions of source gases, and uncertainties in the rate constants of chemical reactions.

scholarly journals Cryptogamic organisms are a substantial source and sink for volatile organic compounds in the Amazon region

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Achim Edtbauer ◽  
Eva Y. Pfannerstill ◽  
Ana Paula Pires Florentino ◽  
Cybelli G. G. Barbosa ◽  
Emilio Rodriguez-Caballero ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Forest Canopy ◽  
Oxidation Products ◽  
Atmospheric Oxidation ◽  
Tropical Rainforests ◽  
Volatile Organic ◽  
Flux Measurements ◽  
Made In

AbstractCryptogamic organisms such as bryophytes and lichens cover most surfaces within tropical forests, yet their impact on the emission of biogenic volatile organic compounds is unknown. These compounds can strongly influence atmospheric oxidant levels as well as secondary organic aerosol concentrations, and forest canopy leaves have been considered the dominant source of these emissions. Here we present cuvette flux measurements, made in the Amazon rainforest between 2016–2018, and show that common bryophytes emit large quantities of highly reactive sesquiterpenoids and that widespread lichens strongly uptake atmospheric oxidation products. A spatial upscaling approach revealed that cryptogamic organisms emit sesquiterpenoids in quantities comparable to current canopy attributed estimates, and take up atmospheric oxidation products at rates comparable to hydroxyl radical chemistry. We conclude that cryptogamic organisms play an important and hitherto overlooked role in atmospheric chemistry above and within tropical rainforests.

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