Development of a High-Resolution Nested Air Pollution Model

Frohn, Lise M.; Christensen, J. H.; Brandt, Jørgen

doi:10.1006/jcph.2002.7036

Cited by 126 publications

(100 citation statements)

References 37 publications

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“…This subsystem is driven by global meteorological data from the European Centre for Medium-Range Weather Forecasts (ECMWF) or National Centers for Environmental Prediction (NCEP). The DEHM model includes two-way nesting capabilities (Frohn et al, 2002).…”

Section: The Danish Eulerian Hemispheric Model (Dehm)mentioning

confidence: 99%

Atmospheric black carbon and sulfate concentrations in Northeast Greenland

et al. 2015

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Abstract. Measurements of equivalent black carbon (EBC) in aerosols at the high Arctic field site Villum Research Station (VRS) at Station Nord in North Greenland showed a seasonal variation in EBC concentrations with a maximum in winter and spring at ground level. Average measured concentrations were about 0.067 ± 0.071 for the winter and 0.011 ± 0.009 for the summer period. These data were obtained using a multi-angle absorption photometer (MAAP). A similar seasonal pattern was found for sulfate concentrations with a maximum level during winter and spring analyzed by ion chromatography. Here, measured average concentrations were about 0.485 ± 0.397 for the winter and 0.112 ± 0.072 for the summer period. A correlation between EBC and sulfate concentrations was observed over the years 2011 to 2013 stating a correlation coefficient of R 2 = 0.72. This finding gives the hint that most likely transport of primary emitted BC particles to the Arctic was accompanied by aging of the aerosols through condensational processes. BC and sulfate are known to have only partly similar sources with respect to their transport pathways when reaching the high Arctic. Aging processes may have led to the formation of secondary inorganic matter and further transport of BC particles as cloud processing and further washout of particles is less likely based on the typically observed transport patterns of air masses arriving at VRS. Additionally, concentrations of EC (elemental carbon) based on a thermo-optical method were determined and compared to EBC measurements. EBC measurements were generally higher, but a correlation between EC and EBC resulted in a correlation coefficient of R 2 = 0.64. Model estimates of the climate forcing due to BC in the Arctic are based on contributions of long-range transported BC during spring and summer. The measured concentrations were here compared with model results obtained by the Danish Eulerian Hemispheric Model, DEHM. Good agreement between measured and modeled concentrations of both EBC/BC and sulfate was observed. Also, the correlation between BC and sulfate concentrations was confirmed based on the model results observed over the years 2011 to 2013 stating a correlation coefficient of R 2 = 0.74. The dominant source is found to be combustion of fossil fuel with biomass burning as a minor, albeit significant source.

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Section: The Danish Eulerian Hemispheric Model (Dehm)mentioning

confidence: 99%

Atmospheric black carbon and sulfate concentrations in Northeast Greenland

et al. 2015

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“…The chemical long-range transport model DEHM (Danish Eulerian Hemispheric Model) has been under development since the beginning of the 1990's at the National Environmental Research Institute (NERI), see (Christensen, 1997;Frohn et al, 2002bFrohn et al, , 2003Frohn, 2004 (Olivier et al, 1996) both with 1…”

Section: The Chemical Transport Model Dehmmentioning

confidence: 99%

“…The hemispheric Chemical long-range Transport Model (CTM) DEHM (Danish Eulerian Hemispheric Model) (Christensen, 1997;Frohn et al, 2002bFrohn et al, , 2003Frohn, 2004) is used in the current experiment to investigate the future air pollution levels and distribution in the Northern Hemisphere with special emphasis on Europe and the Arctic. The coupled Atmosphere-Ocean General Circulation Model ECHAM4-OPYC3 (Roeckner et al, 1999;Stendel et al, 2002) provides 21st century meteorology and part of the 20th century based on the IPCC SRES A2 scenario (Nakicenovic et al, 2000) every 6 h as input to DEHM.…”

Section: Introductionmentioning

confidence: 99%

Impacts of climate change on air pollution levels in the Northern Hemisphere with special focus on Europe and the Arctic

et al. 2008

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Abstract. The response of a selected number of chemical species is inspected with respect to climate change. The coupled Atmosphere-Ocean General Circulation Model ECHAM4-OPYC3 is providing meteorological fields for the Chemical long-range Transport Model DEHM. Three selected decades (1990s, 2040s and 2090s) are inspected. The 1990s are used as a reference and validation period. In this decade an evaluation of the output from the DEHM model with ECHAM4-OPYC3 meteorology input data is carried out. The model results are tested against similar model simulations with MM5 meteorology and against observations from the EMEP monitoring sites in Europe.The test results from the validation period show that the overall statistics (e.g. mean values and standard deviations) are similar for the two simulations. However, as one would expect the model setup with climate input data fails to predict correctly the timing of the variability in the observations. The overall performance of the ECHAM4-OPYC3 setup as meteorological input to the DEHM model is shown to be acceptable according to the applied ranking method. It is concluded that running a chemical long-range transport model on data from a "free run" climate model is scientifically sound. From the model runs of the three decades, it is found that the overall trend detected in the evolution of the chemical species, is the same between the 1990 decade and the 2040 decade and between the 2040 decade and the 2090 decade, respectively.The dominating impacts from climate change on a large number of the chemical species are related to the predicted temperature increase. Throughout the 21th century the ECHAM4-OPYC3 projects a global mean temperature increase of 3 K with local maxima up to 11 K in the Arctic winter based on the IPCC A2 emission scenario. As a consequence of this temperature increase, the temperature dependent biogenic emission of isoprene is predicted to increase Correspondence to: G. B. Hedegaard (gbh@dmu.dk) significantly over land by the DEHM model. This leads to an increase in the O 3 production and together with an increase in water vapor to an increase in the number of free OH radicals. Furthermore this increase in the number of OH radicals contributes to a significant change in the typical life time of many species, since OH are participating in a large number of chemical reactions. It is e.g. found that more SO 2− 4 will be present in the future over the already polluted areas and this increase can be explained by an enhanced conversion of SO 2 to SO 2− 4 .

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“…Section 4 highlights the concluding remarks and an outlook for future studies. Christensen, 1997;Hedegaard et al, 2011;Brandt et al, 2012), with a two-way nesting capability to obtain higher resolution over limited areas (Frohn et al, 2002). The model is defined on a polar stereographic projection true at 60°N and is here applied with two domains -a mother domain with a resolution of 150 km × 150 km and a nested domain covering Europe with a resolution of 50 km × 50 km.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2012

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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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Development of a High-Resolution Nested Air Pollution Model

Cited by 126 publications

References 37 publications

Atmospheric black carbon and sulfate concentrations in Northeast Greenland

Atmospheric black carbon and sulfate concentrations in Northeast Greenland

Impacts of climate change on air pollution levels in the Northern Hemisphere with special focus on Europe and the Arctic

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

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