Isoprene emission variability through the twentieth century

Unger, Nadine

doi:10.1002/2013jd020978

Cited by 43 publications

(37 citation statements)

References 60 publications

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“…The trend analysis performed within this 527 study is in accordance with isoprene emission trends calculated by means of biochemical 528 emissions global models (Unger, 2013). However, the long term variability in isoprene could 529 be related to the climate oscillation.…”

Section: Isoprene 518supporting

confidence: 70%

Multi-year levels and trends of non-methane hydrocarbon concentrations observed in ambient air in France

Waked

Sauvage

Borbon

et al. 2016

Atmospheric Environment

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Section: Isoprene 518supporting

confidence: 70%

Multi-year levels and trends of non-methane hydrocarbon concentrations observed in ambient air in France

Waked

Sauvage

Borbon

et al. 2016

Atmospheric Environment

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“…The larger reduction is comparable to results from previous studies that have estimated a 20-26 % reduction in biogenic VOC emissions from the late 19th century to the present day (Lathiere et al, 2010;Pacifico et al, 2012;Unger, 2013). Consistent with our study, Lathiere et al (2010) determined that the CO 2 sensitivity effect is the dominant driver of the change in isoprene emissions between 1901 and 2002, with the impact of land-use change about half that of CO 2 sensitivity.…”

Section: P Achakulwisut Et Al: Uncertainties In Isoprene Photochemisupporting

confidence: 87%

“…Consistent with our study, Lathiere et al (2010) determined that the CO 2 sensitivity effect is the dominant driver of the change in isoprene emissions between 1901 and 2002, with the impact of land-use change about half that of CO 2 sensitivity. In contrast, Pacifico et al (2012) and Unger (2013) found cropland expansion to be the dominant driver of the reduction. This discrepancy likely arises for two reasons.…”

Section: P Achakulwisut Et Al: Uncertainties In Isoprene Photochemimentioning

confidence: 81%

“…This discrepancy likely arises for two reasons. First, our study applied an increase of approximately 10 % in global cropland expansion (Guenther et al, 2012), which is smaller than the 22 % change estimated by Unger (2013). Second, we apply a CO 2 sensitivity algorithm that most likely provides an upper limit of this effect for past climates (Possell and Hewitt, 2011).…”

Section: P Achakulwisut Et Al: Uncertainties In Isoprene Photochemimentioning

confidence: 99%

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Uncertainties in isoprene photochemistry and emissions: implications for the oxidative capacity of past and present atmospheres and for climate forcing agents

et al. 2015

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Abstract. Isoprene and its oxidation products are major players in the oxidative chemistry of the troposphere. Current understanding of the factors controlling biogenic isoprene emissions and of the fate of isoprene oxidation products in the atmosphere has been evolving rapidly. We use a climate-biosphere-chemistry modeling framework to evaluate the sensitivity of estimates of the tropospheric oxidative capacity to uncertainties in isoprene emissions and photochemistry. Our work focuses on two climate transitions: from the Last Glacial Maximum (LGM, 19 000-23 000 years BP) to the preindustrial (1770s) and from the preindustrial to the present day (1990s). We find that different oxidants have different sensitivities to the uncertainties tested in this study. Ozone is relatively insensitive, whereas OH is the most sensitive: changes in the global mean OH levels for the LGM-to-preindustrial transition range between −29 and +7 % and those for the preindustrial-to-present-day transition range between −8 and +17 % across our simulations. We find little variability in the implied relative LGMpreindustrial difference in methane emissions with respect to the uncertainties tested in this study. Conversely, estimates of the preindustrial-to-present-day and LGM-to-preindustrial changes in the global burden of secondary organic aerosol (SOA) are highly sensitive. We show that the linear relationship between tropospheric mean OH and tropospheric mean ozone photolysis rates, water vapor, and total emissions of NO x and reactive carbon -first reported in Murray et al. (2014) -does not hold across all periods with the new isoprene photochemistry mechanism. This study demonstrates how inadequacies in our current understanding of isoprene emissions and photochemistry impede our ability to constrain the oxidative capacities of the present and past atmospheres, its controlling factors, and the radiative forcing of some short-lived species such as SOA over time.

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“…BVOCs are also important precursors for O 3 (Chameides et al, 1998) and secondary organic aerosol (SOA) formation (Kanakidou et al, 2005). Recent studies on historical emissions of BVOCs have shown that BVOC emissions have been affected by anthropogenic influences over the past millennium (Kaplan et al, 2011;Tanaka et al, 2012;Pacifico et al, 2012;Unger, Published by Copernicus Publications on behalf of the European Geosciences Union.…”

Section: Introductionmentioning

confidence: 99%

Aerosol size distribution and radiative forcing response to anthropogenically driven historical changes in biogenic secondary organic aerosol formation

et al. 2015

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Abstract. Emissions of biogenic volatile organic compounds (BVOCs) have changed in the past millennium due to changes in land use, temperature, and CO 2 concentrations. Recent reconstructions of BVOC emissions have predicted that global isoprene emissions have decreased, while monoterpene and sesquiterpene emissions have increased; however, all three show regional variability due to competition between the various influencing factors.In this work, we use two modeled estimates of BVOC emissions from the years 1000 to 2000 to test the effect of anthropogenic changes to BVOC emissions on secondary organic aerosol (SOA) formation, global aerosol size distributions, and radiative effects using the GEOS-Chem-TOMAS (Goddard Earth Observing System; TwO-Moment Aerosol Sectional) global aerosol microphysics model. With anthropogenic emissions (e.g., SO 2 , NO x , primary aerosols) turned off and BVOC emissions changed from year 1000 to year 2000 values, decreases in the number concentration of particles of size D p > 80 nm (N80) of > 25 % in year 2000 relative to year 1000 were predicted in regions with extensive landuse changes since year 1000 which led to regional increases in the combined aerosol radiative effect (direct and indirect) of > 0.5 W m −2 in these regions. We test the sensitivity of our results to BVOC emissions inventory, SOA yields, and the presence of anthropogenic emissions; however, the qualitative response of the model to historic BVOC changes remains the same in all cases. Accounting for these uncertainties, we estimate millennial changes in BVOC emissions cause a global mean direct effect of between +0.022 and +0.163 W m −2 and the global mean cloud-albedo aerosol indirect effect of between −0.008 and −0.056 W m −2 . This change in aerosols, and the associated radiative forcing, could be a largely overlooked and important anthropogenic aerosol effect on regional climates.

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Isoprene emission variability through the twentieth century

Cited by 43 publications

References 60 publications

Multi-year levels and trends of non-methane hydrocarbon concentrations observed in ambient air in France

Multi-year levels and trends of non-methane hydrocarbon concentrations observed in ambient air in France

Uncertainties in isoprene photochemistry and emissions: implications for the oxidative capacity of past and present atmospheres and for climate forcing agents

Aerosol size distribution and radiative forcing response to anthropogenically driven historical changes in biogenic secondary organic aerosol formation

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