Biogenic isoprene emissions, dry deposition velocity, and surface ozone concentration during summer droughts, heatwaves, and normal conditions in southwestern Europe

At high concentrations, tropospheric ozone (O3) deteriorates air quality, inducing adverse effects on human and ecosystem health. Meteorological conditions are key to understanding the variability in O3 concentration, especially during extreme weather events. In addition to modifying photochemistry and atmospheric transport, droughts and heatwaves affect the state of vegetation and thus the biosphere–troposphere interactions that control atmospheric chemistry, namely biogenic emissions of precursors and gas dry deposition. A major source of uncertainty and inaccuracy in the simulation of surface O3 during droughts and heatwaves is the poor representation of such interactions. This publication aims at quantifying the isolated and combined impacts of both extremes on biogenic isoprene (C5H8) emissions, O3 dry deposition, and surface O3 in southwestern Europe. First, the sensitivity of biogenic C5H8 emissions, O3 dry deposition, and surface O3 to two specific effects of droughts, the decrease in soil moisture and in biomass, is analysed for the extremely dry summer 2012 using the biogenic emission model MEGANv2.1 and the chemistry transport model CHIMEREv2020r1. Despite a significant decrease in biogenic C5H8 emissions and O3 dry deposition velocity, characterized by a large spatial variability, the combined effect on surface O3 concentration remains limited (between +0.5 % and +3 % over the continent). The variations in simulated biogenic C5H8 emissions, O3 dry deposition, and surface O3 during the heatwaves and agricultural droughts are then analysed for summer 2012 (warm and dry), 2013 (warm), and 2014 (relatively wet and cool). We compare the results with large observational data sets, namely O3 concentrations from Air Quality (AQ) e-Reporting (2000–2016) and total columns of formaldehyde (HCHO, which is used as a proxy for biogenic emissions of volatile organic compounds) from the Ozone Monitoring Instrument (OMI) of the Aura satellite (2005–2016). Based on a cluster approach using the percentile limit anomalies indicator, we find that C5H8 emissions increase by +33 % during heatwaves compared to normal conditions, do not vary significantly during all droughts (either accompanied or not by a heatwave), and decrease by −16 % during isolated droughts. OMI data confirm an average increase in HCHO during heatwaves (between +15 % and +31 % depending on the product used) and decrease in HCHO (between −2 % and −6 %) during isolated droughts over the 2005–2016 summers. Simulated O3 dry deposition velocity decreases by −25 % during heatwaves and −35 % during all droughts. Simulated O3 concentrations increase by +7 % during heatwaves and by +3 % during all droughts. Compared to observations, CHIMERE tends to underestimate the daily maximum O3. However, similar sensitivity to droughts and heatwaves are obtained. The analysis of the AQ e-Reporting data set shows an average increase of +14 % during heatwaves and +7 % during all droughts over the 2000–2016 summers (for an average daily concentration value of 69 µg m−3 under normal conditions). This suggests that identifying the presence of combined heatwaves is fundamental to the study of droughts on surface–atmosphere interactions and O3 concentration.</p

Global ammonia emissions from CAMEO throughout the century for 3 scenarios (2000-2100)

&lt;p&gt;&lt;strong&gt;Global ammonia emissions from the CAMEO process-based model&nbsp;&lt;/strong&gt;(general model description can be found in Beaudor et al., 2023, GMD;&nbsp;https://doi.org/10.5194/gmd-16-1053-2023).&lt;/p&gt;&lt;p&gt;Monthly files containing global NH3&nbsp;emissions in gN.m2.yr-1&nbsp;(2.5° lon x 1.27° lat; IPSL-CM6A-LR Earth System Model resolution):&lt;/p&gt;&lt;p&gt;1) total agricultural emissions&nbsp; (TOT_AGRI; the sum of manure management and agricultural soil emissions)&lt;/p&gt;&lt;p&gt;2) manure management emissions (MANURE_MANAG.)&lt;/p&gt;&lt;p&gt;3) agricultural soil emissions (SOIL_AGRI)&lt;/p&gt;&lt;p&gt;4) natural soil emissions (SOIL_NAT) corrected for baresoil (excluding Sahara in this new version)&lt;/p&gt;&lt;p&gt;5) Fraction of continent (CONT_FRAC) from the model to use for CTM prescription or global budget calculation&lt;/p&gt;&lt;p&gt;The four files correspond to a specific simulation using input4MIPs forcing files :&lt;/p&gt;&lt;p&gt;- Present-day simulation from 2000 to 2014&nbsp;&lt;/p&gt;&lt;p&gt;- Future simulation from 2015 to 2100 under scenario SSP-2.45&lt;/p&gt;&lt;p&gt;- Future simulation from 2015 to 2100 under scenario SSP-4.34&lt;/p&gt;&lt;p&gt;-&nbsp;Future simulation from 2015 to 2100 under scenario SSP-5.85&lt;/p&gt;&lt;p&gt;Note that these datasets have been prepared in the scope of a publication to be submitted&nbsp;to the&nbsp;ERL journal.&lt;/p&gt;&lt;p&gt;&lt;i&gt;&lt;strong&gt;Beaudor, M., N. Vuichard, J. Lathière, D. Hauglustaine.,&nbsp;Historical and future ammonia emissions&nbsp;database (2000-2100) from the CAMEO process-based model, in preparation.&lt;/strong&gt;&lt;/i&gt;&lt;/p&gt

Modeling sensitivity of biogenic VOC emissions to environmental factors

International audienceGlobal inventory of biogenic VOC emissions MEGAN-MACC (REF) has been created using the model MEGANv2.1 (Guenther et al., 2012). Emissions of the main chemical species emitted by vegetation were estimated on monthly basis for the period of 1980 – 2010. The global BVOC emission total is dominated by isoprene (69% of global total). Further, we present three sensitivity isoprene emission inventories. Dataset SM accounts for impact of soil moisture deficiency on isoprene emission. In dataset titled SW a simplified calculation of PAR (Photosynthetically Active Radiation) input variable has been used assuming that PAR equals to ½ of incoming shortwave radiation. In dataset CRU, we replaced the MERRA meteorological fields (used for the reference as well as for SM and SW datasets) by the meteorological inputs from the CRU-NCEP reanalysis. These variations in driving environmental factors resulted in substantial changes of isoprene global total which decreased by 50% in SM, increased by 16% in SW and decreased by 27% in CRU sensitivity model runs when compared to the reference

Impact of O3 on terrestrial ecosystems : a more mechanistic parametrization in the global vegetation model ORCHIDEE

Impact of O3 on terrestrial ecosystems : a more mechanistic parametrization in the global vegetation model ORCHIDEE. 27. Task Force Meeting of the ICP Vegetatio

Incorporating a more mechanistic ozone impact parametrisation in the ORCHIDEE global vegetation model

Incorporating a more mechanistic ozone impact parametrisation in the ORCHIDEE global vegetation model. 27th Task Force Meeting of the ICP Vegetatio

Global agricultural ammonia emissions simulated with the ORCHIDEE land surface model

Abstract. Ammonia (NH3) is an important atmospheric constituent.It plays a role in air quality and climate through the formation of ammonium sulfate and ammonium nitrate particles.It has also an impact on ecosystems through deposition processes.About 85 % of NH3 global anthropogenic emissions are related to food and feed production and, in particular, to the use of mineral fertilizers and manure management.Most global chemistry transport models (CTMs) rely on bottom-up emission inventories, which are subject to significant uncertainties.In this study, we estimate emissions from livestock by developing a new module to calculate ammonia emissions from the whole agricultural sector (from housing and storage to grazing and fertilizer application) within the ORCHIDEE (Organising Carbon and Hydrology In Dynamic Ecosystems) global land surface model.We detail the approach used for quantifying livestock feed management, manure application, and indoor and soil emissions and subsequently evaluate the model performance.Our results reflect China, India, Africa, Latin America, the USA, and Europe as the main contributors to global NH3 emissions,accounting for 80 % of the total budget.The global calculated emissions reach 44 Tg N yr−1 over the 2005–2015 period, which is within the range estimated by previous work.Key parameters (e.g. the pH of the manure, timing of N application, and atmospheric NH3 surface concentration) that drive the soil emissions have also been tested in order to assess the sensitivity of ourmodel.Manure pH is the parameter to which modeled emissions are the most sensitive, with a 10 % change in emissions per percent change in pH.Even though we found an underestimation in our emissions over Europe (−26 %) and an overestimation in the USA (+56 %) compared with previous work, other hot spot regions are consistent.The calculated emission seasonality is in very good agreement with satellite-based emissions.These encouraging results prove the potential of coupling ORCHIDEE land-based emissions to CTMs, which are currently forced by bottom-up anthropogenic-centered inventories such as the CEDS (Community Emissions Data System).info:eu-repo/semantics/publishe

Global agricultural ammonia emissions simulated with the ORCHIDEE land surface model

International audienceAmmonia (NH3) is an important atmospheric constituent. It plays a role in air quality and climate through the formation of ammonium sulfate and ammonium nitrate particles. It has also an impact on ecosystems through deposition processes. About 85 % of NH3 global anthropogenic emissions are related to food and feed production and, in particular, to the use of mineral fertilizers and manure management. Most global chemistry transport models (CTMs) rely on bottom-up emission inventories, which are subject to significant uncertainties. In this study, we estimate emissions from livestock by developing a new module to calculate ammonia emissions from the whole agricultural sector (from housing and storage to grazing and fertilizer application) within the ORCHIDEE (Organising Carbon and Hydrology In Dynamic Ecosystems) global land surface model. We detail the approach used for quantifying livestock feed management, manure application, and indoor and soil emissions and subsequently evaluate the model performance. Our results reflect China, India, Africa, Latin America, the USA, and Europe as the main contributors to global NH3 emissions, accounting for 80 % of the total budget. The global calculated emissions reach 44 Tg N yr−1 over the 2005-2015 period, which is within the range estimated by previous work. Key parameters (e.g., the pH of the manure, timing of N application, and atmospheric NH3 surface concentration) that drive the soil emissions have also been tested in order to assess the sensitivity of our model. Manure pH is the parameter to which modeled emissions are the most sensitive, with a 10 % change in emissions per percent change in pH. Even though we found an underestimation in our emissions over Europe (−26 %) and an overestimation in the USA (+56 %) compared with previous work, other hot spot regions are consistent. The calculated emission seasonality is in very good agreement with satellite-based emissions. These encouraging results prove the potential of coupling ORCHIDEE land-based emissions to CTMs, which are currently forced by bottom-up anthropogenic-centered inventories such as the CEDS (Community Emissions Data System)

Necessary Integrative Approaches

International audienc

Global biogenic volatile organic compound emissions in the ORCHIDEE and MEGAN models and sensitivity to key parameters

International audienceA new version of the biogenic volatile organic compounds (BVOCs) emission scheme has been developed in the global vegetation model ORCHIDEE (Organizing Carbon and Hydrology in Dynamic EcosystEm), which includes an extended list of biogenic emitted compounds, updated emission factors (EFs), a dependency on light for almost all compounds and a multi-layer radiation scheme. Over the 2000–2009 period, using this model, we estimate mean global emissions of 465 Tg C yr−1 for isoprene, 107.5 Tg C yr−1 for monoterpenes, 38 Tg C yr−1 for methanol, 25 Tg C yr−1 for acetone and 24 Tg C yr−1 for sesquiterpenes. The model results are compared to state-of-the-art emission budgets, showing that the ORCHIDEE emissions are within the range of published estimates. ORCHIDEE BVOC emissions are compared to the estimates of the Model of Emissions of Gases and Aerosols from Nature (MEGAN), which is largely used throughout the biogenic emissions and atmospheric chemistry community. Our results show that global emission budgets of the two models are, in general, in good agreement. ORCHIDEE emissions are 8 % higher for isoprene, 8 % lower for methanol, 17 % higher for acetone, 18 % higher for monoterpenes and 39 % higher for sesquiterpenes, compared to the MEGAN estimates. At the regional scale, the largest differences between ORCHIDEE and MEGAN are highlighted for isoprene in northern temperate regions, where ORCHIDEE emissions are higher by 21 Tg C yr−1, and for monoterpenes, where they are higher by 4.4 and 10.2 Tg C yr−1 in northern and southern tropical regions compared to MEGAN. The geographical differences between the two models are mainly associated with different EF and plant functional type (PFT) distributions, while differences in the seasonal cycle are mostly driven by differences in the leaf area index (LAI). Sensitivity tests are carried out for both models to explore the response to key variables or parameters such as LAI and light-dependent fraction (LDF). The ORCHIDEE and MEGAN emissions are differently affected by LAI changes, with a response highly depending on the compound considered. Scaling the LAI by a factor of 0.5 and 1.5 changes the isoprene global emission by −21 and +8 % for ORCHIDEE and −15 and +7 % for MEGAN, and affects the global emissions of monoterpenes by −43 and +40 % for ORCHIDEE and −11 and +3 % for MEGAN. Performing a further sensitivity test, forcing ORCHIDEE with the MODIS LAI, confirms the high sensitivity of the ORCHIDEE emission module to LAI variation. We find that MEGAN is more sensitive to variation in the LDF parameter than ORCHIDEE. Our results highlight the importance and the need to further explore the BVOC emission estimate variability and the potential for using models to investigate the estimated uncertainties