Regional atmospheric composition modeling with CHIMERE

Abstract. Tropospheric trace gas and aerosol pollutants have adverse effects on health, environment and climate. In order to quantify and mitigate such effects, a wide range of processes leading to the formation and transport of pollutants must be considered, understood and represented in numerical models. Regional scale pollution episodes result from the combination of several factors: high emissions (from anthropogenic or natural sources), stagnant meteorological conditions, velocity and efficiency of the chemistry and the deposition. All these processes are highly variable in time and space, and their relative importance to the pollutants budgets can be quantified within a chemistry-transport models (CTM). The offline CTM CHIMERE model uses meteorological model fields and emissions fluxes and calculates deterministically their behavior in the troposphere. The calculated three-dimensional fields of chemical concentrations can be compared to measurements to analyze past periods or used to make air quality forecasts and CHIMERE has enabled a fine understanding of pollutants transport during numerous measurements campaigns. It is a part of the PREVAIR french national forecast platform, delivering pollutant concentrations up to three days in advance. The model also allows scenario studies and long term simulations for pollution trends. The modelling of photochemical air pollution has reached a good level of maturity, and the latest projects involving CHIMERE now aim at increasing our understanding of pollution impact on health at the urban scale or at the other end of the spectrum for long term air quality and climate change interlinkage studies, quantifying the emissions and transport of pollen, but also, at a larger scale, analyzing the transport of pollutants plumes emitted by volcanic eruptions and forest fires.

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CHIMERE 2013: a model for regional atmospheric composition modelling

Geoscientific Model Development ◽

10.5194/gmd-6-981-2013 ◽

2013 ◽

Vol 6 (4) ◽

pp. 981-1028 ◽

Cited By ~ 265

Author(s):

L. Menut ◽

B. Bessagnet ◽

D. Khvorostyanov ◽

M. Beekmann ◽

N. Blond ◽

...

Keyword(s):

Transport Model ◽

Reference Model ◽

Numerical Models ◽

Regional Scale ◽

Atmospheric Composition ◽

Trace Gas ◽

Transport Models ◽

Relative Contribution ◽

Wide Range ◽

Pollution Event

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Evolution of the CAMS global air quality forecasting system

10.5194/egusphere-egu2020-17941 ◽

2020 ◽

Author(s):

Zak Kipling ◽

Melanie Ades ◽

Anna Agusti-Panareda ◽

Jérôme Barré ◽

Nicolas Bousserez ◽

...

Keyword(s):

Air Quality ◽

Atmospheric Composition ◽

Additional Species ◽

Meteorological Model ◽

Forecasting System ◽

Long Term Trends ◽

Phase Chemistry ◽

Monitoring Service ◽

The Impact

As part of the Copernicus Atmosphere Monitoring Service (CAMS), operated by ECMWF on behalf of the European Commission, global analyses and forecasts of atmospheric composition have been produced operationally since 2015. These were built on many years of previous work under the GEMS and MACC projects, which began producing regular forecasts in 2007.Since the transition to an operational service, there have continued to be many new developments and improvements to the system in five major upgrades, including increased horizontal and vertical resolution, updated emissions and paramterisations, additional species such as nitrate aerosol, as well as updates to the underlying meteorological model and data assimilation. The components of this system (aerosols, gas-phase chemistry, meteorology and the ocean) are also now coupled more tightly via active feedbacks then ever before.In this interactive presentation, we will demonstrate the impact of a number of these developments on the performance of the resulting global air quality forecasts, alongside the continuing evolution of our approaches to assessing model improvement against independent in-situ and remote-sensing observations from a variety of platforms.Because the continuing evolution of an operational system can make the analysis of long-term trends problematic, we will also contrast this with the CAMS global reanalysis product, which (while not using the very latest version of the model) do provide a consistent long-term dataset from 2003 onwards.

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Long-term thermal two- and three-dimensional analysis of roller compacted concrete dams supported by monitoring verification

Canadian Journal of Civil Engineering ◽

10.1139/l10-004 ◽

2010 ◽

Vol 37 (4) ◽

pp. 600-610 ◽

Cited By ~ 5

Author(s):

Vladan Kuzmanovic ◽

Ljubodrag Savic ◽

John Stefanakos

Keyword(s):

Thermal Analysis ◽

Boundary Conditions ◽

Thermal Field ◽

Numerical Models ◽

Three Dimensional ◽

Roller Compacted Concrete ◽

Rcc Dam ◽

Field Investigations ◽

Good Agreement

This paper presents two-dimensional (2D) and three-dimensional (3D) numerical models for unsteady phased thermal analysis of RCC dams. The time evolution of a thermal field has been modeled using the actual dam shape, RCC technology and the adequate description of material properties. Model calibration and verification has been done based on the field investigations of the Platanovryssi dam, the highest RCC dam in Europe. The results of a long-term thermal analysis, with actual initial and boundary conditions, have shown a good agreement with the observed temperatures. The influence of relevant parameters on the thermal field of RCC dams has been analyzed. It is concluded that the 2D model is appropriate for the thermal phased analysis, and that the boundary conditions and the mixture properties are the most influential on the RCC dam thermal behavior.

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Changes to the chemical state of the northern hemisphere atmosphere during the second half of the twentieth century

10.5194/acp-2016-927 ◽

2016 ◽

Author(s):

Mike J. Newland ◽

Patricia Martinerie ◽

Emmanuel Witrant ◽

Detlev Helmig ◽

David R. Worton ◽

...

Keyword(s):

Northern Hemisphere ◽

Large Scale ◽

Atmospheric Composition ◽

The Arctic ◽

Major Influence ◽

Secondary Products ◽

Alkyl Nitrates ◽

Mixing Ratios ◽

Wide Range

Abstract. The NOX (NO and NO2) and HOX (OH and HO2) budgets of the atmosphere exert a major influence on atmospheric composition, controlling removal of primary pollutants and formation of a wide range of secondary products, including ozone, that can influence human health and climate. However, there remain large uncertainties in the changes to these budgets over recent decades. Due to their short atmospheric lifetimes, NOX and HOX are highly variable in space and time, and so the measurements of these species are of very limited value for examining long term, large scale changes to their budgets. Here, we take an alternative approach by examining long-term atmospheric trends of alkyl nitrates, the formation of which is dependent on the atmospheric NO / HO2 ratio. We derive long term trends in the alkyl nitrates from measurements in firn air from the NEEM site, Greenland. Their mixing ratios increased by a factor of 4–5 between the 1970s and 1990s. This was followed by a steep decline to the sampling date of 2008. Moreover, we examine how the trends in the alkyl nitrates compare to similarly derived trends in their parent alkanes (i.e. the alkanes which, when oxidised in the presence of NOX, lead to the formation of the alkyl nitrates). The ratios of the alkyl nitrates to their parent alkanes increase from around 1970 to the late 1990's consistent with large changes to the [NO] / [HO2] ratio in the northern hemisphere atmosphere during this period. These could represent historic changes to NOX sources and sinks. Alternatively, they could represent changes to concentrations of the hydroxyl radical, OH, or to the transport time of the air masses from source regions to the Arctic.

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Near real-time air quality forecasts using the NASA GEOS model

10.5194/egusphere-egu21-13587 ◽

2021 ◽

Author(s):

K. Emma Knowland ◽

Christoph Keller ◽

Krzysztof Wargan ◽

Brad Weir ◽

Pamela Wales ◽

...

Keyword(s):

Machine Learning ◽

Air Quality ◽

Real Time ◽

Weather Forecasting ◽

Atmospheric Composition ◽

Machine Learning Techniques ◽

Learning Techniques ◽

Wide Range ◽

Reactive Trace Gases ◽

Assimilation System

NASA's Global Modeling and Assimilation Office (GMAO) produces high-resolution global forecasts for weather, aerosols, and air quality. The NASA Global Earth Observing System (GEOS) model has been expanded to provide global near-real-time 5-day forecasts of atmospheric composition at unprecedented horizontal resolution of 0.25 degrees (~25 km). This composition forecast system (GEOS-CF) combines the operational GEOS weather forecasting model with the state-of-the-science GEOS-Chem chemistry module (version 12) to provide detailed analysis of a wide range of air pollutants such as ozone, carbon monoxide, nitrogen oxides, and fine particulate matter (PM2.5). Satellite observations are assimilated into the system for improved representation of weather and smoke. The assimilation system is being expanded to include chemically reactive trace gases. We discuss current capabilities of the GEOS Constituent Data Assimilation System (CoDAS) to improve atmospheric composition modeling and possible future directions, notably incorporating new observations (TROPOMI, geostationary satellites) and machine learning techniques. We show how machine learning techniques can be used to correct for sub-grid-scale variability, which further improves model estimates at a given observation site.

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Impact of the Christmas 2018 Mount Etna Eruption on the Regional Air Quality

10.5194/egusphere-egu21-2167 ◽

2021 ◽

Author(s):

Claire Lamotte ◽

Jonathan Guth ◽

Virginie Marécal ◽

Giuseppe Salerno ◽

Nicolas Theys ◽

...

Keyword(s):

Air Quality ◽

Regional Scale ◽

Volcanic Eruptions ◽

Mount Etna ◽

Surface Measurement ◽

Volcanic Plume ◽

Observation Data ◽

Sulfate Aerosols ◽

Lower Altitude ◽

The Impact

Volcanic eruptions are events that can eject several tons of material into the atmosphere. Among these emissions, sulfur dioxide is the main sulfurous volcanic gas. It can form sulfate aerosols that are harmful to health or, being highly soluble, it can condense in water particles and form acid rain. Thus, volcanic eruptions can have an environmental impact on a regional scale.The Mediterranean region is very interesting from this point of view because it is a densely populated region with a strong anthropogenic activity, therefore polluted, in which Mount Etna is also located. Mount Etna is the largest passive SO2 emitter in Europe, but it can also sporadically produce strong eruptive events. It is then likely that the additional input of sulfur compounds into the atmosphere by volcanic emissions may have effects on the regional atmospheric sulfur composition.We are particularly investigating the eruption of Mount Etna on December 24, 2018 [Corradini et al, 2020]. This eruption took place along a 2 km long breach on the side of the volcano, thus at a lower altitude than its main crater. About 100 kt of SO2 and 35 kt of ash were released in total, between December 24 and 30. With the exception of the 24th, the quantities of ash were always lower than the SO2.The availability of the TROPOMI SO2column estimates, at fine spatial resolution (7 km x 3.5 km at nadir) and associated averaging kernels, during this eruptive period made it also an excellent case study. It allows us to follow the evolution of SO2 in the volcanic plume over several days.Using the CNRM MOCAGE chemistry-transport model (CTM), we aim to quantify the impact of this volcanic eruption on atmospheric composition, sulfur deposition and air quality at the regional scale. The comparison of the model with the TROPOMI observation data allows us to assess the ability of the model to properly represent the plume. In spite of a particular meteorological situation, leading to a complex plume transport, MOCAGE shows a good agreement with TROPOMI observations. Thus, from the MOCAGE simulation, we can evaluate the impact of the eruption on the regional concentrations of SO2 and sulfate aerosols, but also analyse the quantities of dry and wet deposition, and compare it to surface measurement stations.

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Uncertainty in limb aerosol measurements following the Raikoke eruption

10.5194/egusphere-egu21-10523 ◽

2021 ◽

Author(s):

Landon Rieger ◽

Adam Bourassa ◽

Daniel Zawada ◽

Doug Degenstein ◽

Sergey Khaykin ◽

...

Keyword(s):

Forest Fires ◽

Climate Models ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Measurement Systems ◽

Error Characterization ◽

Systematic Biases ◽

Climatic Impacts ◽

The University

The eruption of Raikoke on June 22nd, 2019 was one of the largest in recent decades, spewing approximately 1.5 Tg of sulfur up to 17 km altitude. This eruption has been widely studied using a combination of climate models and measurement systems, including ground based lidars, in situ particle counters, and a variety of satellite platforms. The early plume has been well categorized by high-resolution measurements from CALIPSO, MODIS, VIIRS, IASI and other nadir viewing instruments, but as the plume ages investigation often shifts to limb sounding instruments that provide greater sensitivity to lower aerosol levels. These instruments have proven critical in understanding the long-term radiative and climatic impacts of stratospheric aerosol burdens after these explosive events, but the complexity of the measurements, sampling, and retrievals has made error characterization in high-loading conditions difficult.This work explores systematic biases in limb measurements after the Raikoke eruption due to a variety of factors often implicit in the retrievals and analysis. Near-coincident CALIPSO, SAGE III and OMPS-LP measurements are used to investigate saturation of limb-sounding measurement in the early plume. The recent OMPS-LP v2 stratospheric aerosol product is compared with the University of Saskatchewan product to investigate benefits and drawbacks of the tomographic approach. SAGE III measurements are used as a validation when available although coverage limitations preclude comparisons in the thickest parts of the plume. &#160;This work highlights the subtleties in comparing limb observations, with implications for model comparisons after large events such as volcanic eruptions and forest fires. Not only in the early plume, where sampling can be sparse, but also in the weeks and months following the eruption.

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An integrated numerical system to estimate air quality effects of forest fires

International Journal of Wildland Fire ◽

10.1071/wf02047 ◽

2004 ◽

Vol 13 (2) ◽

pp. 217 ◽

Cited By ~ 39

Author(s):

A. I. Miranda

Keyword(s):

Air Quality ◽

Forest Fires ◽

World Health ◽

Plume Dispersion ◽

Photochemical Pollution ◽

Meteorological Model ◽

Atmospheric Flow ◽

Fire Emissions ◽

Spread Model ◽

Smoke Dispersion

Forest fires are an important source of various gases and particles emitted into the atmosphere that may affect the air quality on a local and/or larger scale. Currently, there is a growing awareness that smoke from wildland fires exposes individuals and populations to hazardous air pollutants. In order to understand and to simulate forest fire effects on air quality, several issues should be analysed and integrated: fire progression, fire emissions, atmospheric flow, smoke dispersion and chemical reactions. In spite of the available models to simulate smoke dispersion and the existence of some systems already covering the main questions, there still remains a lack of integration concerning fire progression. Photochemical pollution is also not included in these modelling systems. AIRFIRE is a numerical system, developed to estimate the effects of forest fires on air quality, integrating several components of the problem through the inclusion of different modules, namely the mesoscale meteorological model MEMO, the photochemical model MARS, and the Rothermel fire spread model. The system was applied to simulate plume dispersion from a wildfire that occurred in a coastal area, close to Lisbon city, at the end of September 1991. Results, namely the obtained pollutants concentration fields, point to a significant impact on the local air quality. Obtained wind fields and concentration patterns revealed the presence of sea breezes and also the influence of the fire in the atmospheric flow. Estimated carbon monoxide concentration levels were very high, exceeding the recommended hourly limit value of the World Health Organization, and ozone concentration values pointed to photochemical production.

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Air Quality Impacts of Smoke from Hazard Reduction Burns and Domestic Wood Heating in Western Sydney

Atmosphere ◽

10.3390/atmos10090557 ◽

2019 ◽

Vol 10 (9) ◽

pp. 557 ◽

Cited By ~ 3

Author(s):

Maximilien Desservettaz ◽

Frances Phillips ◽

Travis Naylor ◽

Owen Price ◽

Stephanie Samson ◽

...

Keyword(s):

Air Quality ◽

Forest Fires ◽

Total Duration ◽

Atmospheric Composition ◽

Gaseous Species ◽

Hazard Reduction ◽

Pollution Levels ◽

Smoke Pollution ◽

Pm 10 ◽

Wood Heating

Air quality was measured in Auburn, a western suburb of Sydney, Australia, for approximately eighteen months during 2016 and 2017. A long open-path infrared spectrometer sampled path-averaged concentrations of several gaseous species, while other pollutants such as PM 2.5 and PM 10 were sampled by a mobile air quality station. The measurement site was impacted by a number of indoor wood-heating smoke events during cold winter nights as well as some major smoke events from hazard reduction burning in the spring of 2017. In this paper we compare the atmospheric composition during these different smoke pollution events and assess the relative overall impact on air quality from domestic wood-heaters and prescribed forest fires during the campaign. No significant differences in the composition of smoke from these two sources were identified in this study. Despite the hazard reduction burning events causing worse peak pollution levels, we find that the overall exposure to air toxins was greater from domestic wood-heaters due to their higher frequency and total duration. Our results suggest that policy-makers should place a greater focus on reducing wood-smoke pollution in Sydney and on communicating the issue to the public.

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Impacts of near-future cultivation of biofuel feedstocks on atmospheric composition and local air quality

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-24857-2011 ◽

2011 ◽

Vol 11 (9) ◽

pp. 24857-24881 ◽

Cited By ~ 1

Author(s):

K. Ashworth ◽

G. Folberth ◽

C. N. Hewitt ◽

O. Wild

Keyword(s):

Land Use ◽

Air Quality ◽

Oil Palm ◽

Large Scale ◽

Global Climate ◽

Land Use Changes ◽

Regional Scale ◽

Atmospheric Composition ◽

Scale Production ◽

Reactive Trace Gases

Abstract. Large-scale production of feedstock crops for biofuels will lead to land-use changes. We quantify the effects of realistic land use change scenarios for biofuel feedstock production on isoprene emissions and hence atmospheric composition and chemistry using the HadGEM2 model. Two feedstocks are considered: oil palm for biodiesel in the tropics and short rotation coppice (SRC) in the mid-latitudes. In total, 69 Mha of oil palm and 92 Mha of SRC are planted, each sufficient to replace just over 1 % of projected global fossil fuel demand in 2020. Both planting scenarios result in increases in total global annual isoprene emissions of about 1 %. In each case, changes in surface concentrations of ozone and biogenic secondary organic aerosol (bSOA) are significant at the regional scale and are detectable even at a global scale with implications for air quality standards. However, the changes in tropospheric burden of ozone and the OH radical, and hence effects on global climate, are negligible. The oil palm plantations and processing plants result in global average annual mean increases in ozone and bSOA of 38 pptv and 2 ng m−3 respectively. Over SE Asia, one region of planting, increases reach over 2 ppbv and 300 ng m−3 for large parts of Borneo. Planting of SRC causes global annual mean changes of 46 pptv and 3 ng m−3. Europe experiences peak monthly mean changes of almost 0.6 ppbv and 90 ng m−3 in June and July. Large areas of Central and Eastern Europe see changes of over 1.5 ppbv and 200 ng m−3 in the summer. That such significant atmospheric impacts from low level planting scenarios are discernible globally clearly demonstrates the need to include changes in emissions of reactive trace gases such as isoprene in life cycle assessments performed on potential biofuel feedstocks.

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