A simple modeling approach to study the regional impact of a Mediterranean forest isoprene emission on anthropogenic plumes

Abstract. Research during the past decades has outlined the importance of biogenic isoprene emission in tropospheric chemistry and regional ozone photo-oxidant pollution. The first part of this article focuses on the development and validation of a simple biogenic emission scheme designed for regional studies. Experimental data sets relative to Boreal, Tropical, Temperate and Mediterranean ecosystems are used to estimate the robustness of the scheme at the canopy scale, and over contrasted climatic and ecological conditions. A good agreement is generally found when comparing field measurements and simulated emission fluxes, encouraging us to consider the model suitable for regional application. Limitations of the scheme are nevertheless outlined as well as further on-going improvements. In the second part of the article, the emission scheme is used on line in the broader context of a meso-scale atmospheric chemistry model. Dynamically idealized simulations are carried out to study the chemical interactions of pollutant plumes with realistic isoprene emissions coming from a Mediterranean oak forest. Two types of anthropogenic sources, respectively representative of the Marseille (urban) and Martigues (industrial) French Mediterranean sites, and both characterized by different VOC/NOx are considered. For the Marseille scenario, the impact of biogenic emission on ozone production is larger when the forest is situated in a sub-urban configuration (i.e. downwind distance TOWN-FOREST <30km, considering an advection velocity of 4.2 m.s-1). In this case the enhancement of ozone production due to isoprene can reach +37% in term of maximum surface concentrations and +11% in term of total ozone production. The impact of biogenic emission decreases quite rapidly when the TOWN-FOREST distance increases. For the Martigues scenario, the biogenic impact on the plume is significant up to TOWN-FOREST distance of 90km where the ozone maximum surface concentration enhancement can still reach +30%. For both cases, the importance of the VOC/NOx ratio in the anthropogenic plume and its evolution when interacting with the forest emission are outlined. In complement to real case studies, this idealized approach can be particularly useful for process and sensitivity studies and constitutes a valuable tool to build regional ozone control strategies.

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A simple modeling approach to study the regional impact of a Mediterranean forest isoprene emission on anthropogenic plumes

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-4-7691-2004 ◽

2004 ◽

Vol 4 (6) ◽

pp. 7691-7724 ◽

Cited By ~ 2

Author(s):

J. Cortinovis ◽

F. Solmon ◽

D. Serça ◽

C. Sarrat ◽

R. Rosset

Keyword(s):

Atmospheric Chemistry ◽

Field Measurements ◽

Mediterranean Ecosystems ◽

Tropospheric Chemistry ◽

Ozone Production ◽

Transfer Model ◽

Data Sets ◽

Isoprene Emission ◽

On Line ◽

The Impact

Abstract. Research over the past year has outlined the importance of biogenic isoprene emission in tropospheric chemistry, and notably in the context of regional ozone photo-oxidant pollution. The first part of this article deals with the development of a simple isoprene emission scheme based upon the classical Guenther's algorithm coupled with a soil-vegetation-atmosphere transfer model. The resulting emission scheme is tested in a "stand-alone" version at the canopy scale. Experimental data sets coming from Boreal, Tropical, Temperate and Mediterranean ecosystems are used to estimate the robustness of the scheme over contrasted climatic and ecological conditions. Considering the simple hypothesis used, simulated isoprene fluxes are generally consistent with field measurements and the emission scheme is thus deemed suitable for regional application. Limitations of the model are outlined as well as further improvements. In the second part of the article, the emission scheme is used on line in the broader context of a meso-scale atmospheric chemistry scheme. Dynamically idealized simulations are carried out to study the chemical interactions of pollutant plumes with realistic isoprene emissions coming from a Mediterranean oak forest. Two chemical scenarios are considered with anthropogenic emissions, respectively representative of the Marseille (urban) and Martigues (industrial) French Mediterranean areas. For the Marseille scenario, the impact of biogenic emission on ozone production is larger when the forest is situated in a sub-urban configuration (i.e. downwind distance TOWN-FOREST <30 km) and decrease quite rapidly as the distance increases. For the Martigues scenario, the biogenic impact on the plume is detectable even at a longer TOWN-FOREST distance of 100 km. For both cases, the importance of the VOC/NOx ratio, which characterizes the aging of advected pollutant plumes over the day, is outlined. Finally, possible applications of this work for real-case studies are discussed.

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Evaluation of two isoprene emission models for use in a long-range air pollution model

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-7399-2012 ◽

2012 ◽

Vol 12 (16) ◽

pp. 7399-7412 ◽

Cited By ~ 23

Author(s):

A. Zare ◽

J. H. Christensen ◽

P. Irannejad ◽

J. Brandt

Keyword(s):

North America ◽

Life Time ◽

Ozone Production ◽

Daily Maximum ◽

Direct Evaluation ◽

Biogenic Emission ◽

Isoprene Emission ◽

Ozone Concentrations ◽

Emission Models ◽

The Impact

Abstract. Knowledge about isoprene emissions and concentration distribution is important for chemistry transport models (CTMs), because isoprene acts as a precursor for tropospheric ozone and subsequently affects the atmospheric concentrations of many other atmospheric compounds. Isoprene has a short lifetime, and hence it is very difficult to evaluate its emission estimates against measurements. For this reason, we coupled two isoprene emission models with the Danish Eulerian Hemispheric Model (DEHM), and evaluated the simulated background ozone concentrations based on different models for isoprene emissions. In this research, results of using the two global biogenic emission models; GEIA (Global Emissions Inventory Activity) and MEGAN (the global Model of Emissions of Gases and Aerosols from Nature) are compared and evaluated. The total annual emissions of isoprene for the year 2006 estimated by using MEGAN is 592 Tg yr−1 for an extended area of the Northern Hemisphere, which is 21% higher than that estimated by using GEIA. The overall feature of the emissions from the two models is quite similar, but differences are found mainly in Africa's savannah and in the southern part of North America. Differences in spatial distribution of emission factors are found to be a key source of these discrepancies. In spite of the short life-time of isoprene, a direct evaluation of isoprene concentrations using the two biogenic emission models in DEHM has been made against available measurements in Europe. Results show an agreement between two models simulations and the measurements in general and that the CTM is able to simulate isoprene concentrations. Additionally, investigation of ozone concentrations resulting from the two biogenic emission models show that isoprene simulated by MEGAN strongly affects the ozone production in the African savannah; the effect is up to 10% more than that obtained using GEIA. In contrast, the impact of using GEIA is higher in the Amazon region with more than 8% higher ozone concentrations compared to that of using MEGAN. Comparing the ozone concentrations obtained by DEHM using the two different isoprene models with measurements from Europe and North America, show an agreement on the hourly, mean daily and daily maximum values. However, the average of ozone daily maximum value simulated by using MEGAN is slightly closer to the measured value for the average of all measuring sites in Europe.

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Evaluation of a high resolution regional atmospheric chemistry model using MAX-DOAS and in situ NO2 measurements

10.5194/egusphere-egu21-4989 ◽

2021 ◽

Author(s):

Vinod Kumar ◽

Julia Remmers ◽

Steffen Beirle ◽

Astrid Kerkweg ◽

Jos Lelieveld ◽

...

Keyword(s):

Spatial Distribution ◽

High Resolution ◽

Vertical Distribution ◽

Atmospheric Chemistry ◽

Pearson Correlation ◽

Surface Concentration ◽

Ozone Production ◽

Vertical Column ◽

The Impact ◽

The Vertical Distribution

Regional atmospheric chemistry models are adopted for simulating concentrations of atmospheric components at high resolution and quantifying the impact of localized emissions (e.g. industrial and urban clusters) on the non-linear chemical processes, e.g. ozone production. However, their evaluation is challenging due to the limited availability of high spatiotemporally resolved reference datasets. For the same reason, the vertical distribution of pollutants simulated by the model is especially arduous to assess.Here, we present regional atmospheric chemistry model studies with spatial resolution up to 2.2 &#215; 2.2 km2 focused around Germany for May 2018 using the MECO(n) model system. Using a network of surface concentration measurements at background, near traffic and industrial locations, we evaluate the spatial distribution of NO2 simulated by the model. The highly resolved model together with a comparable resolution and up-to-date input emissions inventory, was found to perform best in reproducing the spatial distribution of NO2 surface volume mixing ratios (VMRs). We propose a computationally efficient approach to account for the diurnal and day of the week variability of input anthropogenic emissions (e.g. from road transport), which proved to be crucial for resolving the temporal variability of NO2 surface VMRs.The simulated NO2 tropospheric vertical column densities were evaluated by employing the measurements of a 4-azimuth MAX-DOAS instrument in Mainz. Generally, such comparisons do not account for the spatial sensitivity volume of the MAX-DOAS measurements, the change of sensitivity within this volume and the spatial heterogeneity of NO2. We therefore apply a consistent approach of comparison of the differential slant column densities (dSCDs), which overcomes these limitations. Moreover, the dSCDs are obtained for several elevation and azimuth angles, which are characterized by distinctive sensitivity for different vertical levels within the boundary layer and different horizontal representativeness. Hence, also an evaluation of the model in simulating the vertical distribution of NO2 can be performed with this approach using continuous MAX-DOAS measurements spanning long time periods. We found that the model performs well with respect to the measured dSCDs at low elevation angles (< 8&#176;) with an overall bias between +14 and -9%, and Pearson correlation coefficients between 0.5 and 0.8 for the different azimuth viewing directions.

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Evaluation of two isoprene emission models for use in a long-range air pollution model

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-9247-2012 ◽

2012 ◽

Vol 12 (4) ◽

pp. 9247-9281 ◽

Cited By ~ 2

Author(s):

A. Zare ◽

J. Brandt ◽

J. H. Christensen ◽

P. Irannejad

Keyword(s):

Model Performance ◽

Life Time ◽

Ozone Production ◽

Emission Model ◽

Direct Evaluation ◽

Biogenic Emission ◽

Isoprene Emission ◽

Ozone Concentrations ◽

Emission Models ◽

The Impact

Abstract. Knowledge about isoprene emissions and concentration distribution is important for chemistry transport models (CTMs), because isoprene acts as a precursor for tropospheric ozone and subsequently affects the atmospheric concentrations of many other atmospheric compounds. Isoprene has a short lifetime, and hence it is very difficult to evaluate its emission estimates against measurements. For this reason, we coupled two isoprene emission models with the Danish Eulerian Hemispheric Model (DEHM), and evaluated the simulated background ozone concentrations based on different models for isoprene emissions. In this research, results of using the two global biogenic emission models; GEIA (Global Emissions Inventory Activity) and MEGAN (the global Model of Emissions of Gases and Aerosols from Nature) are compared and evaluated. The total annual emissions of isoprene for the year 2006 estimated by using MEGAN is 732 Tg yr−1 for an extended area of the Northern Hemisphere, which is 50% higher than that estimated by using GEIA. The overall feature of the emissions from the two models are quite similar, but significant differences are found mainly in Africa's savannah and the rain forests of South America, and in some subtropical regions, such as the Middle East, India and the southern part of North America. Differences in spatial distribution of emission factors are found to be a key source of these discrepancies. In spite of the short life-time of isoprene, a direct evaluation of isoprene concentrations using the two biogenic emission models has been made against available measurements in Europe. Results show that the two models in general represent the measurements well and that the CTM is able to simulate isoprene concentrations. Additionally, investigation of ozone concentrations resulting from the two biogenic emission models show that isoprene simulated by MEGAN strongly affects the ozone production in the African savannah; the effect is up to 20% more than that obtained using GEIA. In contrast, the impact of using GEIA is higher in the Amazon region with more than 15% higher ozone concentrations compared to that of using MEGAN. Comparing the results for ozone concentrations for Europe obtained by using the two different models with measurements, show that the MEGAN emission model improves the model performance significantly in the Mediterranean area.

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First year of real-time VOC measurements at the SIRTA facility (Paris region, France): diurnal and seasonal variabilities, impact of lockdowns on air quality

10.5194/egusphere-egu21-8643 ◽

2021 ◽

Author(s):

Leïla Simon ◽

Valérie Gros ◽

Jean-Eudes Petit ◽

François Truong ◽

Roland Sarda-Esteve ◽

...

Keyword(s):

Air Quality ◽

Atmospheric Chemistry ◽

Seasonal Variability ◽

Anthropogenic Sources ◽

First Year ◽

Good Representation ◽

Atmospheric Measurements ◽

Paris Region ◽

The Impact

Volatile Organic Compounds (VOCs) have direct influences on air quality and climate. They also play a key role in atmospheric chemistry, as they are precursors of secondary pollutants, such as ozone (O3) and secondary organic aerosols (SOA).Long-term datasets of in-situ atmospheric measurements are crucial to characterize the variability of atmospheric chemical composition. Online and continuous measurements of O3, NOx and aerosols have been achieved at the SIRTA-ACTRIS facility (Paris region, France), since 2012. Regarding VOCs, they have been measured there for several years thanks to bi-weekly samplings followed by offline Gas Chromatography analysis. However, this method doesn&#8217;t provide a good representation of the temporal variability of VOC concentrations. To tackle this issue, online VOC measurements using a Proton-Transfer-Reaction Quadrupole Mass-Spectrometer (PTR-Q-MS) have been started in January 2020.The dataset acquired during the first year of online VOC measurements is analyzed, which gives insights on VOC seasonal variability. The additional long-term datasets obtained from co-located measurements (O3, NOx, aerosol physical and chemical properties, meteorological parameters) are also used for the sake of this study.Due to Covid-19 pandemic, the year 2020 notably comprised a total lockdown in France in Spring, and a lighter one in Autumn. Therefore, a focus can be made on the impact of these lockdowns on the VOC variability and sources. To this end, the diurnal cycles of VOCs considered markers for anthropogenic sources are carefully investigated. Results notably indicate that markers for traffic and wood burning sources behave quite differently during the Spring lockdown in comparison to the other periods. A source apportionment analysis using positive matrix factorization allows to further document the seasonal variability of VOC sources and the impacts on air quality associated with the lockdown measures.

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Implications of potential future grand solar minimum for ozone layer and climate

10.5194/acp-2017-818 ◽

2017 ◽

Author(s):

Pavle Arsenovic ◽

Eugene Rozanov ◽

Julien Anet ◽

Andrea Stenke ◽

Thomas Peter

Keyword(s):

Solar Activity ◽

Greenhouse Gas ◽

21St Century ◽

Atmospheric Chemistry ◽

Solar Minimum ◽

Climate Model ◽

Ghg Emissions ◽

Ozone Production ◽

22Nd Century ◽

The Impact

Abstract. Continued anthropogenic greenhouse gas (GHG) emissions are expected to cause further global warming throughout the 21st century. Understanding potential interferences with natural forcings is thus of great interest. Here we investigate the impact of a recently proposed 21st century grand solar minimum on atmospheric chemistry and climate using the SOCOL3-MPIOM chemistry-climate model with interactive ocean. We examine several model simulations for the period 2000–2199, following the greenhouse gas scenario RCP4.5, but with different solar forcings: the reference simulation is forced by perpetual repetition of solar cycle 23 until the year 2199, whereas the grand solar minimum simulations assume strong declines in solar activity of 3.5 and 6.5 W m−2 with different durations. Decreased solar activity is found to yield up to a doubling of the GHG induced stratospheric and mesospheric cooling. Under the grand solar minimum scenario tropospheric temperatures are also projected to decrease. On the global scale the reduced solar forcing compensates at most 15 % of the expected greenhouse warming at the end of 21st and around 25 % at the end of 22nd century. The regional effects are predicted to be stronger, in particular in northern high latitude winter. In the stratosphere, the reduced incoming ultraviolet radiation leads to less ozone production by up to 8 %, which overcompensates the anticipated ozone increase due to reduced stratospheric temperatures and an acceleration of the Brewer-Dobson circulation. This, in turn, leads to a delay in total ozone column recovery from anthropogenic chlorine-induced depletion, with a global ozone recovery to the pre-ozone hole values happening only upon completion of the grand solar minimum in the 22nd century or later.

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Land cover change dominates decadal trends of biogenic volatile organic compound (BVOC) emission in China

10.5194/acp-2020-28 ◽

2020 ◽

Author(s):

Hui Wang ◽

Qizhong Wu ◽

Alex B. Guenther ◽

Xiaochun Yang ◽

Lanning Wang ◽

...

Keyword(s):

Land Cover ◽

Land Cover Change ◽

Correlation Coefficients ◽

Anthropogenic Sources ◽

The South ◽

High Positive Correlation ◽

Positive Correlation ◽

Isoprene Emission ◽

Increasing Trends ◽

The Impact

Abstract. Satellite observations reveal that China has been leading the global greening trend in the past two decades. We assessed the impact of land cover change on total BVOC emission in China during 2001–2016 and found a significant increasing trend of 1.09 % yr−1 with increases of 1.35, 1.25 and 1.43 % yr−1 for isoprene, monoterpenes and sesquiterpenes, respectively. Comparison of different scenarios showed that vegetation change is the main driver of BVOC emission change in China. Considerable heterogeneity was observed on regional scales, with the highest increasing trends of BVOC emission found in the Qinling Mountains and in the south of China. The BVOC emission for the year 2016 in these two regions was enhanced by 61.89 and 67.64 % compared to that of 2001, respectively. We compared the long-term HCHO vertical columns (VC) from the satellite-based Ozone Monitoring Instrument (OMI) with the estimation of isoprene emission in summer. The results showed statistically significant positive correlation coefficients over the regions with high vegetation cover fractions. In addition, the isoprene emission and HCHO VC both showed statistically significant increasing trends in the south of China where these two variables have high positive correlation coefficients. This result supports our estimation of the variability and trends of BVOC emission in China. Although anthropogenic sources comprise ∼63 % NMVOC emissions in China, the continued increase of BVOC will enhance the importance of considering BVOC when making policies for controlling ozone pollution in China along with ongoing efforts to reduce anthropogenic emissions.

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Investigation of strongly enhanced methane Part I: Chemical feedbacks and rapid adjustments.

10.5194/egusphere-egu2020-9786 ◽

2020 ◽

Author(s):

Franziska Winterstein ◽

Patrick Jöckel ◽

Martin Dameris ◽

Michael Ponater ◽

Fabian Tanalski ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Radiative Forcing ◽

Climate Model ◽

Numerical Study ◽

Stratospheric Ozone ◽

Lower Boundary ◽

Tropospheric Chemistry ◽

Substantial Part ◽

Mixing Ratios ◽

The Impact

Methane (CH4) is the second most important greenhouse gas, which atmospheric concentration is influenced by human activities and currently on a sharp rise. We present a study with numerical simulations using a Chemistry-Climate-Model (CCM), which are performed to assess possible consequences of strongly enhanced CH4 concentrations in the Earth's atmosphere for the climate.Our analysis includes experiments with 2xCH4 and 5xCH4 present day (2010) lower boundary mixing ratios using the CCM EMAC. The simulations are conducted with prescribed oceanic conditions, mimicking present day tropospheric temperatures as its changes are largely suppressed. By doing so we are able to investigate the quasi-instantaneous chemical impact on the atmosphere. We find that the massive increase in CH4 strongly influences the tropospheric chemistry by reducing the OH abundance and thereby extending the tropospheric CH4 lifetime as well as the residence time of other chemical pollutants. The region above the tropopause is impacted by a substantial rise in stratospheric water vapor (SWV). The stratospheric ozone (O3) column increases overall, but SWV induced stratospheric cooling also leads to enhanced ozone depletion in the Antarctic lower stratosphere. Regional&#160; patterns of ozone change are affected by modification of stratospheric dynamics, i.e. increased tropical up-welling and stronger meridional transport&#160; towards the polar regions. We calculate the net radiative impact (RI) of the 2xCH4 experiment to be 0.69 W m-2 and for the 5xCH4 experiment to be 1.79 W m-2. A substantial part of the RI is contributed by chemically induced O3 and SWV changes, in line with previous radiative forcing estimates and is for the first time splitted and spatially asigned to its chemical contributors.This numerical study using a CCM with prescibed oceanic conditions shows the rapid responses to significantly enhanced CH4 mixing ratios, which is the first step towards investigating the impact of possible strong future CH4 emissions on atmospheric chemistry and its feedback on climate.

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Isoprene emission response to drought and the impact on global atmospheric chemistry

Atmospheric Environment ◽

10.1016/j.atmosenv.2018.01.026 ◽

2018 ◽

Vol 183 ◽

pp. 69-83 ◽

Cited By ~ 13

Author(s):

Xiaoyan Jiang ◽

Alex Guenther ◽

Mark Potosnak ◽

Chris Geron ◽

Roger Seco ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Isoprene Emission ◽

The Impact

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Implication of extreme atmospheric methane concentrations for chemistry-climate connections

10.5194/acp-2019-41 ◽

2019 ◽

Author(s):

Franziska Winterstein ◽

Fabian Tanalski ◽

Patrick Jöckel ◽

Martin Dameris ◽

Michael Ponater

Keyword(s):

Atmospheric Chemistry ◽

Radiative Forcing ◽

Climate Model ◽

Numerical Study ◽

Stratospheric Ozone ◽

Tropospheric Chemistry ◽

Substantial Part ◽

Atmospheric Concentration ◽

Regional Patterns ◽

The Impact

Abstract. Methane (CH4) is the second most important greenhouse gas, which atmospheric concentration is influenced by human activities. In this study, numerical simulations with a chemistry-climate model (CCM) are performed aiming to assess possible consequences of significantly enhanced CH4 concentrations in the Earth's atmosphere for the climate. We analyze experiments with 2xCH4 and 5xCH4 present day (2010) mixing ratio and its quasi-instantaneous chemical impact on the atmosphere. The massive increase in CH4 strongly influences the tropospheric chemistry by reducing the hydroxyl radical (OH) abundance and thereby extending the CH4 lifetime as well as the residence time of other chemical pollutants. The region above the tropopause is impacted by a substantial rise in stratospheric water vapor (SWV). The stratospheric ozone (O3) column increases overall, but SWV induced stratospheric cooling also leads to a enhanced ozone depletion in the Antarctic lower stratosphere. Regional patterns of ozone change are affected by modification of stratospheric dynamics, i.e. increased tropical up-welling and stronger meridional transport towards the polar regions. We calculate the net radiative impact (RI) of the 2xCH4 experiment to be 0.69 W/m2 and for the 5xCH4 experiment to be 1.79 W/m2. A substantial part of the RI is contributed by chemically induced O3 and SWV changes, in line with previous radiative forcing estimates. To our knowledge this is the first numerical study using a CCM with respect to two/fivefold CH4 concentrations and it is therefore an overdue analysis as it emphasizes the impact of possible strong future CH4 emissions on atmospheric chemistry and its feedback on climate.

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