Tropospheric chemistry in the Integrated Forecasting  System of ECMWF

Abstract. A representation of atmospheric chemistry has been included in the Integrated Forecasting System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF). The new chemistry modules complement the aerosol modules of the IFS for atmospheric composition, which is named C-IFS. C-IFS for chemistry supersedes a coupled system in which chemical transport model (CTM) Model for OZone and Related chemical Tracers 3 was two-way coupled to the IFS (IFS-MOZART). This paper contains a description of the new on-line implementation, an evaluation with observations and a comparison of the performance of C-IFS with MOZART and with a re-analysis of atmospheric composition produced by IFS-MOZART within the Monitoring Atmospheric Composition and Climate (MACC) project. The chemical mechanism of C-IFS is an extended version of the Carbon Bond 2005 (CB05) chemical mechanism as implemented in CTM Transport Model 5 (TM5). CB05 describes tropospheric chemistry with 54 species and 126 reactions. Wet deposition and lightning nitrogen monoxide (NO) emissions are modelled in C-IFS using the detailed input of the IFS physics package. A 1 year simulation by C-IFS, MOZART and the MACC re-analysis is evaluated against ozonesondes, carbon monoxide (CO) aircraft profiles, European surface observations of ozone (O3), CO, sulfur dioxide (SO2) and nitrogen dioxide (NO2) as well as satellite retrievals of CO, tropospheric NO2 and formaldehyde. Anthropogenic emissions from the MACC/CityZen (MACCity) inventory and biomass burning emissions from the Global Fire Assimilation System (GFAS) data set were used in the simulations by both C-IFS and MOZART. C-IFS (CB05) showed an improved performance with respect to MOZART for CO, upper tropospheric O3, and wintertime SO2, and was of a similar accuracy for other evaluated species. C-IFS (CB05) is about 10 times more computationally efficient than IFS-MOZART.

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Tropospheric chemistry in the integrated forecasting system of ECMWF

Geoscientific Model Development Discussions ◽

10.5194/gmdd-7-7733-2014 ◽

2014 ◽

Vol 7 (6) ◽

pp. 7733-7803 ◽

Cited By ~ 6

Author(s):

J. Flemming ◽

V. Huijnen ◽

J. Arteta ◽

P. Bechtold ◽

A. Beljaars ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Transport Model ◽

Nitrogen Monoxide ◽

Coupled System ◽

Tropospheric Chemistry ◽

Chemical Mechanism ◽

Atmospheric Composition ◽

Chemical Transport Model ◽

Data Set ◽

Forecasting System

Abstract. A representation of atmospheric chemistry has been included in the Integrated Forecasting System (IFS) of the European Centre for Medium-range Weather Forecasts (ECMWF). The new chemistry modules complement the aerosol modules of the IFS for atmospheric composition, which is named C-IFS. C-IFS for chemistry supersedes a coupled system, in which the Chemical Transport Model (CTM) Model for OZone and Related chemical Tracers 3 was two-way coupled to the IFS (IFS-MOZART). This paper contains a description of the new on-line implementation, an evaluation with observations and a comparison of the performance of C-IFS with MOZART and with a re-analysis of atmospheric composition produced by IFS-MOZART within the Monitoring Atmospheric Composition and Climate (MACC) project. The chemical mechanism of C-IFS is an extended version of the Carbon Bond 2005 (CB05) chemical mechanism as implemented in the CTM Transport Model 5 (TM5). CB05 describes tropospheric chemistry with 54 species and 126 reactions. Wet deposition and lightning nitrogen monoxide (NO) emissions are modelled in C-IFS using the detailed input of the IFS physics package. A one-year simulation by C-IFS, MOZART and the MACC re-analysis is evaluated against ozonesondes, carbon monoxide (CO) aircraft profiles, European surface observations of ozone (O3), CO, sulphur dioxide (SO2) and nitrogen dioxide (NO2) as well as satellite retrievals of CO, tropospheric NO2 and formaldehyde. Anthropogenic emissions from the MACC/CityZen (MACCity) inventory and biomass burning emissions from the Global Fire Assimilation System (GFAS) data set were used in the simulations by both C-IFS and MOZART. C-IFS (CB05) showed an improved performance with respect to MOZART for CO, upper tropospheric O3, winter time SO2 and was of a similar accuracy for other evaluated species. C-IFS (CB05) is about ten times more computationally efficient than IFS-MOZART.

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Extending methane profiles from aircraft into the stratosphere for satellite total column validation using the ECMWF C-IFS and TOMCAT/SLIMCAT 3-D model

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-6663-2017 ◽

2017 ◽

Vol 17 (11) ◽

pp. 6663-6678 ◽

Cited By ~ 2

Author(s):

Shreeya Verma ◽

Julia Marshall ◽

Mark Parrington ◽

Anna Agustí-Panareda ◽

Sebastien Massart ◽

...

Keyword(s):

Greenhouse Gases ◽

Transport Model ◽

A Priori ◽

Atmospheric Composition ◽

Random Errors ◽

Chemical Transport Model ◽

Spatial Coverage ◽

Forecasting System ◽

The Impact ◽

Total Column

Abstract. Airborne observations of greenhouse gases are a very useful reference for validation of satellite-based column-averaged dry air mole fraction data. However, since the aircraft data are available only up to about 9–13 km altitude, these profiles do not fully represent the depth of the atmosphere observed by satellites and therefore need to be extended synthetically into the stratosphere. In the near future, observations of CO2 and CH4 made from passenger aircraft are expected to be available through the In-Service Aircraft for a Global Observing System (IAGOS) project. In this study, we analyse three different data sources that are available for the stratospheric extension of aircraft profiles by comparing the error introduced by each of them into the total column and provide recommendations regarding the best approach. First, we analyse CH4 fields from two different models of atmospheric composition – the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System for Composition (C-IFS) and the TOMCAT/SLIMCAT 3-D chemical transport model. Secondly, we consider scenarios that simulate the effect of using CH4 climatologies such as those based on balloons or satellite limb soundings. Thirdly, we assess the impact of using a priori profiles used in the satellite retrievals for the stratospheric part of the total column. We find that the models considered in this study have a better estimation of the stratospheric CH4 as compared to the climatology-based data and the satellite a priori profiles. Both the C-IFS and TOMCAT models have a bias of about −9 ppb at the locations where tropospheric vertical profiles will be measured by IAGOS. The C-IFS model, however, has a lower random error (6.5 ppb) than TOMCAT (12.8 ppb). These values are well within the minimum desired accuracy and precision of satellite total column XCH4 retrievals (10 and 34 ppb, respectively). In comparison, the a priori profile from the University of Leicester Greenhouse Gases Observing Satellite (GOSAT) Proxy XCH4 retrieval and climatology-based data introduce larger random errors in the total column, being limited in spatial coverage and temporal variability. Furthermore, we find that the bias in the models varies with latitude and season. Therefore, applying appropriate bias correction to the model fields before using them for profile extension is expected to further decrease the error contributed by the stratospheric part of the profile to the total column.

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Ethane, ethyne and carbon monoxide concentrations in the upper troposphere and lower stratosphere from ACE and GEOS-Chem: a comparison study

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-13099-2011 ◽

2011 ◽

Vol 11 (4) ◽

pp. 13099-13139 ◽

Cited By ~ 1

Author(s):

G. González Abad ◽

N. D. C. Allen ◽

P. F. Bernath ◽

C. D. Boone ◽

S. D. McLeod ◽

...

Keyword(s):

Carbon Monoxide ◽

Atmospheric Chemistry ◽

Transport Model ◽

Chemical Mechanism ◽

Chemical Transport Model ◽

Spectrometer Data ◽

Chemistry Experiment ◽

Global Mean ◽

Tropospheric Concentrations ◽

Good Agreement

Abstract. Near global upper tropospheric concentrations of carbon monoxide (CO), ethane (C2H6) and ethyne (C2H2) from ACE (Atmospheric Chemistry Experiment) Fourier transform spectrometer on board the Canadian satellite SCISAT-1 are presented and compared with the output from the Chemical Transport Model (CTM) GEOS-Chem. The retrievals of ethane and ethyne from ACE have been improved for this paper by using new sets of microwindows compared with those for previous versions of ACE data. With the improved ethyne retrieval we have been able to produce a near global upper tropospheric distribution of C2H2 from space. Carbon monoxide, ethane and ethyne concentrations retrieved using ACE spectra show the expected seasonality linked to variations in the anthropogenic emissions and destruction rates as well as seasonal biomass burning activity. The GEOS-Chem model was run using the dicarbonyl chemistry suite, an extended chemical mechanism in which ethyne is treated explicitly. Seasonal cycles observed from satellite data are well reproduced by the model output, however the simulated CO concentrations are found to be systematically biased low over the Northern Hemisphere. An average negative global mean bias of 12% and 7% of the model relative to the satellite observations has been found for CO and C2H6 respectively and a positive global mean bias of 1% has been found for C2H2. ACE data are compared for validation purposes with MkIV spectrometer data and Global Tropospheric Experiment (GTE) TRACE-A campaign data showing good agreement with all of them.

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Ammonia in the summertime Arctic marine boundary layer: sources, sinks, and implications

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-1937-2016 ◽

2016 ◽

Vol 16 (4) ◽

pp. 1937-1953 ◽

Cited By ~ 36

Author(s):

Gregory R. Wentworth ◽

Jennifer G. Murphy ◽

Betty Croft ◽

Randall V. Martin ◽

Jeffrey R. Pierce ◽

...

Keyword(s):

Boundary Layer ◽

Transport Model ◽

Canadian Arctic ◽

Atmospheric Composition ◽

Chemical Transport Model ◽

Data Set ◽

Baffin Bay ◽

Melt Ponds ◽

Ambient Nh3 ◽

The Impact

Abstract. Continuous hourly measurements of gas-phase ammonia (NH3(g)) were taken from 13 July to 7 August 2014 on a research cruise throughout Baffin Bay and the eastern Canadian Arctic Archipelago. Concentrations ranged from 30 to 650 ng m−3 (40–870 pptv) with the highest values recorded in Lancaster Sound (74°13′ N, 84°00′ W). Simultaneous measurements of total ammonium ([NHx]), pH and temperature in the ocean and in melt ponds were used to compute the compensation point (χ), which is the ambient NH3(g) concentration at which surface–air fluxes change direction. Ambient NH3(g) was usually several orders of magnitude larger than both χocean and χMP (< 0.4–10 ng m3) indicating these surface pools are net sinks of NH3. Flux calculations estimate average net downward fluxes of 1.4 and 1.1 ng m−2 s−1 for the open ocean and melt ponds, respectively. Sufficient NH3(g) was present to neutralize non-sea-salt sulfate (nss-SO42−) in the boundary layer during most of the study. This finding was corroborated with a historical data set of PM2.5 composition from Alert, Nunavut (82°30′ N, 62°20′ W) wherein the median ratio of NH4+/nss-SO42− equivalents was greater than 0.75 in June, July and August. The GEOS-Chem chemical transport model was employed to examine the impact of NH3(g) emissions from seabird guano on boundary-layer composition and nss-SO42− neutralization. A GEOS-Chem simulation without seabird emissions underestimated boundary layer NH3(g) by several orders of magnitude and yielded highly acidic aerosol. A simulation that included seabird NH3 emissions was in better agreement with observations for both NH3(g) concentrations and nss-SO42− neutralization. This is strong evidence that seabird colonies are significant sources of NH3 in the summertime Arctic, and are ubiquitous enough to impact atmospheric composition across the entire Baffin Bay region. Large wildfires in the Northwest Territories were likely an important source of NH3, but their influence was probably limited to the Central Canadian Arctic. Implications of seabird-derived N-deposition to terrestrial and aquatic ecosystems are also discussed.

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Accounting for model error in air-quality forecasts: an application of 4DEnVar to the assimilation of atmospheric composition using QG-Chem 1.0

10.5194/gmd-2016-107 ◽

2016 ◽

Author(s):

Emanuele Emili ◽

Selime Gürol ◽

Daniel Cariolle

Keyword(s):

Air Quality ◽

Data Assimilation ◽

Atmospheric Chemistry ◽

Transport Model ◽

Model Error ◽

Tropospheric Chemistry ◽

Atmospheric Composition ◽

Forecast Errors ◽

Model Errors ◽

Ensemble Size

Abstract. Model errors play a significant role in air-quality forecasts. Accounting for them in the data assimilation (DA) procedures is decisive to obtain improved forecasts. We address this issue using a reduced-order chemical transport model based on quasi-geostrophic dynamics and a detailed tropospheric chemistry mechanism, which we name QG-Chem. This model has been coupled to a generic software library for data assimilation and used to assess the potential of the 4DEnVar algorithm for air-quality analyses and forecasts. Among the assets of 4DEnVar, we reckon the possibility to deal with multivariate aspects of atmospheric chemistry and to account for model errors of generic type. A simple diagnostic procedure for detecting model errors is proposed, based on the 4DEnVar analysis and one additional model forecast. A large number of idealized data assimilation experiments are shown for several chemical species of relevance for air-quality forecasts (O3, NOx, CO and CO2), with very different atmospheric life-times and chemical couplings. Experiments are done both under a perfect model hypothesis and including model error through perturbation of surface chemical emissions, for two meteorological and chemical regimes. Some key elements of the 4DEnVar algorithm such as the ensemble size and localization are also discussed. A comparison with results of 3D-Var, widely used in operational centers, shows that, for some species, analyses and next day forecast errors can be halved when model error is taken in account. This result was obtained using a small ensemble size, which remain affordable for most operational centers. We conclude that 4DEnVar has a promising potential for operational air-quality models. We finally highlight areas that deserve further research for applying 4DEnVar to large scale chemistry models, i.e. localization techniques, propagation of analysis covariance between DA cycles and treatment for chemical non-linearities. QG-Chem provides a useful tool in this regard.

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Updated tropospheric chemistry reanalysis and emission estimates, TCR-2, for 2005–2018

Earth System Science Data ◽

10.5194/essd-12-2223-2020 ◽

2020 ◽

Vol 12 (3) ◽

pp. 2223-2259 ◽

Cited By ~ 5

Author(s):

Kazuyuki Miyazaki ◽

Kevin Bowman ◽

Takashi Sekiya ◽

Henk Eskes ◽

Folkert Boersma ◽

...

Keyword(s):

Transport Model ◽

Horizontal Resolution ◽

Tropospheric Chemistry ◽

Atmospheric Composition ◽

Data Sets ◽

Vertical Profiles ◽

Chemical Transport Model ◽

Near Surface ◽

Key Species

Abstract. This study presents the results from the Tropospheric Chemistry Reanalysis version 2 (TCR-2) for the period 2005–2018 at 1.1∘ horizontal resolution obtained from the assimilation of multiple updated satellite measurements of ozone, CO, NO2, HNO3, and SO2 from the OMI, SCIAMACHY, GOME-2, TES, MLS, and MOPITT satellite instruments. The reanalysis calculation was conducted using a global chemical transport model MIROC-CHASER and an ensemble Kalman filter technique that optimizes both chemical concentrations of various species and emissions of several precursors, which was efficient for the correction of the entire tropospheric profile of various species and its year-to-year variations. Comparisons against independent aircraft, satellite, and ozonesonde observations demonstrate the quality of the reanalysis fields for numerous key species on regional and global scales, as well as for seasonal, yearly, and decadal scales, from the surface to the lower stratosphere. The multi-constituent data assimilation brought the model vertical profiles and interhemispheric gradient of OH closer to observational estimates, which was important in improving the description of the oxidation capacity of the atmosphere and thus vertical profiles of various species. The evaluation results demonstrate the capability of the chemical reanalysis to improve understanding of the processes controlling variations in atmospheric composition, including long-term changes in near-surface air quality and emissions. The estimated emissions can be employed for the elucidation of detailed distributions of the anthropogenic and biomass burning emissions of co-emitted species (NOx, CO, SO2) in all major regions, as well as their seasonal and decadal variabilities. The data sets are available at https://doi.org/10.25966/9qgv-fe81 (Miyazaki et al., 2019a).

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Exploring ice core sea ice proxies through process-based modelling

10.5194/egusphere-egu21-16037 ◽

2021 ◽

Author(s):

Rachael Rhodes ◽

Xin Yang ◽

Eric Wolff

Keyword(s):

Sea Ice ◽

Atmospheric Chemistry ◽

Transport Model ◽

Ice Core ◽

Ice Cores ◽

Internal Variability ◽

Atmospheric Composition ◽

Chemical Transport Model ◽

Aerosol Emission ◽

Abrupt Shifts

It is important to understand the magnitude and rate of past sea ice changes, as well as their timing relative to abrupt shifts in other components of Earth&#8217;s climate system. Furthermore, records of past sea ice over the last few centuries are urgently needed to assess the scale of natural (internal) variability over decadal timescales. By continuously recording past atmospheric composition, polar ice cores have the potential to document changing sea ice conditions if atmospheric chemistry is altered.&#160; Sea salt aerosol, specifically sodium (Na), and bromine enrichment (Brenr, Br/Na enriched relative to seawater ratio) are two ice core sea ice proxies suggested following this premise.Here we aim to move beyond a conceptual understanding of the controls on Na and Brenr in ice cores by using process-based modelling to test hypotheses. We present results of experiments using a 3D global chemical transport model (p-TOMCAT) that represents marine aerosol emission, transport and deposition. Critically, the complex atmospheric chemistry of bromine is also included allowing us to explore the partitioning of Br between gas and aerosol phases. &#160;

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The chemistry CATT–BRAMS model (CCATT–BRAMS 4.5): a regional atmospheric model system for integrated air quality and weather forecasting and research

Geoscientific Model Development Discussions ◽

10.5194/gmdd-6-1173-2013 ◽

2013 ◽

Vol 6 (1) ◽

pp. 1173-1222 ◽

Cited By ~ 9

Author(s):

K. M. Longo ◽

S. R. Freitas ◽

M. Pirre ◽

V. Marécal ◽

L. F. Rodrigues ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Amazon Basin ◽

Weather Forecasting ◽

Transport Model ◽

Atmospheric Model ◽

Atmospheric Modeling ◽

Chemical Mechanism ◽

Model Description ◽

Tracer Transport ◽

Chemical Transport Model

Abstract. The Coupled Chemistry Aerosol-Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CCATT–BRAMS, version 4.5) is an online regional chemical transport model designed for local and regional studies of atmospheric chemistry from surface to the lower stratosphere suitable both for operational and research purposes. It includes gaseous/aqueous chemistry, photochemistry, scavenging and dry deposition. The CCATT–BRAMS model takes advantages of the BRAMS specific development for the tropics/subtropics and of the recent availability of preprocessing tools for chemical mechanisms and of fast codes for photolysis rates. BRAMS includes state-of-the-art physical parameterizations and dynamic formulations to simulate atmospheric circulations of scales down to meters. The online coupling between meteorology and chemistry allows the system to be used for simultaneous atmospheric weather and chemical composition forecasts as well as potential feedbacks between them. The entire system comprises three preprocessing software tools for chemical mechanism (which are user defined), aerosol and trace gases emission fields and atmospheric and chemistry fields for initial and boundary conditions. In this paper, the model description is provided along evaluations performed using observational data obtained from ground-based stations, instruments aboard of aircrafts and retrieval from space remote sensing. The evaluation takes into account model application on different scales from megacities and Amazon Basin up to intercontinental region of the Southern Hemisphere.

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Ethane, ethyne and carbon monoxide concentrations in the upper troposphere and lower stratosphere from ACE and GEOS-Chem: a comparison study

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-9927-2011 ◽

2011 ◽

Vol 11 (18) ◽

pp. 9927-9941 ◽

Cited By ~ 22

Author(s):

G. González Abad ◽

N. D. C. Allen ◽

P. F. Bernath ◽

C. D. Boone ◽

S. D. McLeod ◽

...

Keyword(s):

Carbon Monoxide ◽

Atmospheric Chemistry ◽

Transport Model ◽

Chemical Mechanism ◽

Chemical Transport Model ◽

Spectrometer Data ◽

Chemistry Experiment ◽

Global Mean ◽

Tropospheric Concentrations ◽

Good Agreement

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Biomass burning at Cape Grim: exploring photochemistry using multi-scale modelling

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-11707-2017 ◽

2017 ◽

Vol 17 (19) ◽

pp. 11707-11726 ◽

Cited By ~ 4

Author(s):

Sarah J. Lawson ◽

Martin Cope ◽

Sunhee Lee ◽

Ian E. Galbally ◽

Zoran Ristovski ◽

...

Keyword(s):

Biomass Burning ◽

Atmospheric Chemistry ◽

Transport Model ◽

Near Field ◽

Atmospheric Composition ◽

Large Impact ◽

Chemical Transport Model ◽

Model Sensitivity ◽

Important Species ◽

Cape Grim

Abstract. We have tested the ability of a high-resolution chemical transport model (CTM) to reproduce biomass burning (BB) plume strikes and ozone (O3) enhancements observed at Cape Grim in Tasmania, Australia, from the Robbins Island fire. The CTM has also been used to explore the contribution of near-field BB emissions and background sources to O3 observations under conditions of complex meteorology. Using atmospheric observations, we have tested model sensitivity to meteorology, BB emission factors (EFs) corresponding to low, medium, and high modified combustion efficiency (MCE), and spatial variability. The use of two different meteorological models (TAPM–CTM and CCAM–CTM) varied the first (BB1) plume strike time by up to 15 h and the duration of impact between 12 and 36 h, and it varied the second (BB2) plume duration between 50 and 57 h. Meteorology also had a large impact on simulated O3, with one model (TAPM–CTM) simulating four periods of O3 enhancement, while the other model (CCAM) simulating only one period. Varying the BB EFs, which in turn varied the non-methane organic compound (NMOC) ∕ oxides of nitrogen (NOx) ratio, had a strongly non-linear impact on simulated O3 concentration, with either destruction or production of O3 predicted in different simulations. As shown in previous work (Lawson et al., 2015), minor rainfall events have the potential to significantly alter EF due to changes in combustion processes. Models that assume fixed EF for O3 precursor species in an environment with temporally or spatially variable EF may be unable to simulate the behaviour of important species such as O3. TAPM–CTM is used to further explore the contribution of the Robbins Island fire to the observed O3 enhancements during BB1 and BB2. Overall, TAPM–CTM suggests that the dominant source of O3 observed at Cape Grim was aged urban air (age  = 2 days), with a contribution of O3 formed from local BB emissions. This work shows the importance of assessing model sensitivity to meteorology and EF and the large impact these variables can have in particular on simulated destruction or production of O3 in regional atmospheric chemistry simulations. This work also shows the importance of using models to elucidate the contribution from different sources to atmospheric composition, where this is difficult using observations alone.

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