DEHM

At the moment, this description is only in Danish. It will soon be translated to English.

 

DEHM – den Danske Eulerske Hemisfæriske Model – er en state-of-the-art luftforureningsmodel, som bl.a. anvendes indenfor overvågningsprogrammet NOVANA til beregning af kvælstofdepositioner, inden for AMAP til kvantificering af transporten af luftforurening til Arktis, samt i THOR systemet til beregning af luftforureningsprognoser på Europæisk skala.

DEHM indeholder en realistisk beskrivelse af de fysiske og kemiske processer i atmosfæren og kan bl.a. anvendes til at beregne transport, spredning og kemisk omdannelse i atmosfæren, samt afsætning af luftforurening på land- og vandoverflader.

Modellen indeholder mulighed for at dække forskellige områder med forskellig opløsning og er i øjeblikket sat op med 3 forskellige domæner, sådan at der opnås et stort modelområde samtidigt med at der er høj opløsning i modellen for udvalgte områder, som f.eks. Danmark (se figuren herunder). Når det er muligt at dække både hemisfære og national skala samtidigt skyldes det, at DEHM er en såkaldt nested model. Det vil sige, at den opererer på forskellige geografiske niveauer og at den udnytter beregningsresultaterne fra det første niveau med lav geografisk opløsning som input til de mere detaljerede beregninger på det følgende niveau osv.

De tre modeldomæner i DEHM: Nordlig hemisfære (sort), Europa (grøn) og Nordeuropa inkl. Danmark (rød) med geografisk opløsninger på henholdsvis 150 km x 150 km, 50 km x 50 km og 17 km x 17 km.

DEHM er fællesbetegnelsen for en hel familie af modeller, der er baseret på den samme atmosfærefysik. Den version af modellen, som anvendes til beregningerne i NOVANA kaldes DEHM-REGINA, og er den fulde kemiversion af modellen. Der er 63 kemiske stoffer i denne version (f.eks. ozon, kvælstof, organiske forbindelser, partikler, mm.) og 120 kemiske reaktioner. I denne version af modellen er der lagt vægt på beregning af koncentrationer og depositioner af kvælstof og svovl på national skala. De forskellige versioner af modellen er:

  • DEHM-SOx-Pb - som indeholder svovlforbindelser og bly.

  • DEHM-REGINA – som er kemiversionen af DEHM, inkl. 63 kemiske stoffer.

  • DEHM-CO2 - som er specielt udviklet til at beregne CO2 koncentrationer i atmosfæren og udveksling med overfladen

  • DEHM-POP – som er en version af modellen til studier af persistente organiske forbindelser (POP’er) i atmosfæren og udveksling med forskellige overfladetyper

  • DEHM-HG – som er en kviksølv version af modellen med 13 kviksølvkomponenter

  • DEHM-pollen – som er en version der er under udvikling til at lave prognoser for pollen på Europæisk skala.

DEHM er en Eulersk model, hvormed man beregner koncentrationer og depositioner i et net af gitterceller, der ligger fast. I det vandrette plan er der fx i det tredje domæne af DEHM 96 x 96 gitterceller som hver har en størrelse (opløsning) på 17 km x 17 km. Tilsammen dækkes et område på 1600 km x 1600 km placeret med Danmark i midten. I det lodrette plan er der 20 lag, som tilsammen dækker de nederste 15 km af atmosfæren, hvilket er tilstrækkeligt i luftforureningsmodeller. De nederste lag er relativt tynde (ca. 60 m), hvilket hænger sammen med, at modellen skal kunne beregne afsætning af luftforureningen til land- og vandoverflader, samt at den skal kunne give en realistisk opblanding af emissionerne i den øvrige luftmasse. De øverste lag er til gengæld relativt tykke (ca. 2000 m), hvilket hænger sammen med at luften i denne del af atmosfæren er mere homogen end i den nederste del tæt ved overfladen.

Alene for det tredje domæne består modellen altså af ca. 180.000 gitterceller, og for hver af disse beregnes transporten og den kemiske omdannelse af luftforureningen. Transporten er bestemt af de meteorologiske forhold og foregår ud og ind af de enkelte gitterceller i såvel lodret - som vandret plan.

Udslip af luftforurening til atmosfæren beregnes i modellen ved at gittercellerne i de nederste lag tilføres luftforureningen. De lave kilder (biler, køer, private oliefyr m.m.) tilføres til det nederste lag. De høje kilder (høje skorstene på fx forbrændingsanlæg og kraftværker) fordeles i forskellige lag i modellen.

Afsætning på land- og vandoverfladerne estimeres ved at modellen beregner depositionen af de enkelte luftforureningskomponenter på basis af koncentrationerne i det nederste lag. Den afsatte luftforurening fjernes herefter fra gittercellerne i det nederste lag.

Referencer til DEHM modellen:

Internationale artikler med peer review ordning

  1. Christensen, J. "Testing Advection Schemes in a Three-Dimensional Air Pollution Model". Mathl. Comput. Modelling, 18 (1993) 75-88.
  2. Christensen, J.: The Danish Eulerian Hemispheric Model - a Three Dimensional Air Pollution Model Used for the Arctic. Atmospheric Environment, 31 (1997) 4169-4191.
  3. Heidam, N. Z., Wåhlin, P. and Christensen, J. H., 1999: Tropospheric Gases and Aerosols in Northeast Greenland. Journal of Atmospheric Sciences, 56, pp 261-278..
  4. L. A. Barrie, Y. Yi, U. Lohmann, W.R.Leaitch, P. Kasibhatla, G.-J. Roelofs, J. Wilson5, F. McGovern, C. Benkovitz, M.A. Meliere, K. Law, J. Prospero, M. Kritz, D.Bergmann, C. Bridgeman, M. Chin, J. Christensen, R. Easter, J. Feichter, A. Jeuken, E. Kjellstrom, D. Koch, C. Land, P. Rasch: A comparison of large scale atmospheric sulphate aerosol models (cosam): overview and highlights. Tellus, 53B, pp 615-645, 2001.
  5. U. Lohmann, W.R. Leaitch, K. Law, L. Barrie, Y. Yi, D. Bergman, C, Bridgeman, M. Chin, J. Christensen, R. Easter, J. Feichter, A. Jeuken, E. Kjellstrom, D. Koch, C. Land, P. Rasch, G.-J Roelof: Vertical distributions of sulphurspecies simulated by large scale atmospheric models in cosam: Comparison with observations. Tellus, 53B, pp 646-672, 2001
  6. G.J. Roelofs, P. Kasibhatla, L. Barrie, D. Bergmann, C, Bridgeman, M. Chin, J. Christensen, R. Easter, J. Feichter, A. Jeuken, E. Kjellström, D. Koch, C. Land, U. Lohmann, P. Rasch: Analysis of regional budgets of sulfur species modelled for the COSAM exercise. Tellus, 53B, pp 673-694, 2001
  7. Frohn, L. M., J. H. Christensen, J. Brandt and O. Hertel, 2001: "Development of a high resolution integrated nested model for studying air pollution in Denmark". Physics and Chemistry of the Earth (B), Vol. 26, No. 10, pp. 769-774, 2001.
  8. Frohn, L. M. J. H. Christensen and J. Brandt, 2002: "Development of a high resolution nested air pollution model – the numerical approach". Journal of Computational Physics. Vol. 179, pp. 68-94, 2002.
  9. Geels, C., J. H. Christensen, L. M. Frohn and J. Brandt, 2002: "Simulating spatiotemporal variations of atmospheric CO2 using a nested hemispheric model". Physics and Chemistry of the Earth, Parts A/B/C,Vol. 27, No. 35, pp. 1495-1505, 2002.
  10. Frohn, L. M., J. H. Christensen, J. Brandt, C. Geels and K. M. Hansen, 2003: "Validation of a 3-D hemispheric nested air pollution model". Atmospheric Chemistry and Physics Discussions. Vol. 3, pp. 3543-3588, 2003.
  11. Skov, H M.C.Nielsdóttir, M.E.Goodsite, J.Christensen, C.A.Skjøth, G.Geernaert, O. Hertel, J.Olsen, 2003:" Measurements and Modelling of gaseous elemental mercury (GEM) on the Faroe Islands; a case study of the difficulties of measuring GEM". Asian Chemistry Letters, Vol. 7, N. 2&3, pp. 151-158.
  12. Geels, C., S. Doney, R. Dargaville, J. Brandt and J. H. Christensen, 2004: "Investigating the sources of synoptic variability in atmospheric CO2 measurements over the Northern Hemisphere continents – a regional model study". Tellus, 56B, pp. 35-50, 2004.
  13. Christensen, J. H., J. Brandt, L. M. Frohn and H. Skov, 2004: "Modelling of mercury in the Arctic with the Danish Eulerian Hemispheric Model. Atmospheric Chemistry and Physics. Vol. 4, pp 2251-2257, 2004.
  14. Hansen, K. M., J. H. Christensen, J. Brandt, L. M. Frohn and C. Geels, 2004: "Modelling atmospheric transport of I -hexachlorocyclohexane in the Northern Hemisphere with a 3-D dynamic model: DEHM-POP". Atmospheric Chemistry and Physics, Vol. 4, pp. 1-13, 2004.
  15. Geels, C., J. H. Christensen, A. W. Hansen, S. Kiilsholm, N. W. Larsen, S. E. Larsen, T. Pedersen, L. L. Sørensen, J. Brandt, L. M. Frohn and S. Djurhuus, 2004: " Identifying the European fossil fuel plumes in the atmosphere over the Northeast Atlantic region through isotopic observations and numerical modelling", pp. 35. Submitted to Environmental Monitoring and Assessment, July 2004.
  16. Geels, C., P. Bousquet, J. Brandt, J. H. Christensen, P. Ciais, R. Dargaville, L. M. Frohn, M. Gloor, M. Heimann, U. Karstens, C. Rödenbeck, P. Peylin, L. Rivier, and A. T. Vermeulen, 2004: "Comparing Atmospheric Transport Models for Regional Inversions over Europe. Part 1: Mapping the CO2 Atmospheric Signals. Journal of Geophysical Research. In preparation.
  17. Vermeulen, A. T., P. Ciais, P. Peylin, M. Gloor, P. Bousquet, T. Aalto, J. Brandt, J. H. Christensen, R. Dargaville, L. M. Frohn, C. Geels, M. I. Gusti, M. Heimann, S. Houweling, U Karstens, S. Körner, I. Levin. V. Montandon, M. Ramonet, C. Rödenbeck, and M. Schmidt, 2004: "Comparing Atmospheric Transport Models for Regional Inversions over Europe. Part 2: Mapping the 222Rn Atmospheric Signals". Journal of Geophysical Research. In preparation.
  18. Bousquet, Ph., Brandt J., Ciais Ph., Geels C., Gloor M., Heimann M., Karstens U., Peylin Ph., Rivier L., R"odenbeck C., 2004: "Comparing Atmospheric Transport Models for Regional Inversions over Europe. Part 3: Inverse modelling of CO2 using high-resolution data - budgets for Europe". Journal of Geophysical Research. In preparation.
  19. Brandt, J., J. H. Christensen, Lise M. Frohn, C. Geels, K. M. Hansen and C. A. Skjøth, 2004: "The THOR integrated air pollution forecast system". In preparation for Journal of Geophysical Research.
  20. Heidam, N. Z., J. Christensen, P. Wåhlin and H. Skov, 2004: " Arctic Atmospheric Contaminants in NE Greenland: Seasonal Variations, Origins, Transport, Transformations and Trends 1990 – 2001". Science of the Total Environment, 331 (2004) 5-28.
  21. Skov, H. , J. Christensen, M. E. Goodsite, N. Z. Heidam, B. Jensen, P. Wåhlin and G. Geernaert, 2004 " The fate of elemental mercury in Arctic during atmospheric mercury depletion episodes and the load of atmospheric mercury to the Arctic". Environmental Science & Technology, 38 (2004), 2373-2382.
  22. Frohn, L. M., Droste-Franke, B., Andersen, M. S., Brandt, J., Christensen, J. H., Nielsen, J. S., Geels, C., Jensen, S. S., Hvidberg, M., Frydendall, J. and Pedersen, J., 2005: "A new system for modeling air pollution related externalities in Denmark – System description and comparison with EcoSense data". In preparation for Environmental Science and Technology.
  23. van Loon, M., M. Schaap, B. Bessagnet, L. Rouil, R. Bergstrøm, J. Langner, J. Brandt, J. Christensen, L. M. Frohn, C. Geels, E. Vignati, P.J.H. Builtjes, R. Stern, P. Wind, J.E. Jonson, L. Tarrsón, L. White, P. Roberts, K. Cuvelier, P. Thunis, 2005: Model validation and inter-comparison of seven regional air quality models and their ensemble for ozone. In preparation.
  24. Schaap, M., M. van Loon, B. Bessagnet, L. Rouil, R. Bergstrøm, J. Langner, J. Brandt, J. Christensen, L. M. Frohn, C. Geels, E. Vignati, P.J.H. Builtjes, R. Stern, P. Wind, J.E. Jonson, L. Tarrsón, L. White, P. Roberts, K. Cuvelier, P. Thunis, 2005: Model validation and inter-comparison of seven regional air quality models and their ensemble for aerosols. In preparation.
  25. Hedegaard, G. B., J. Brandt, J. H. Christensen, L. M. Frohn, C. Geels and E. Kaas, 2005: "Modelling the impacts of climate change on air pollution levels in the Northern Hemisphere". In preparation.

Konference artikler

  1. Christensen, J., 1993 "A Three dimensional hemispheric air pollution model used for the Arctic". In:"Proceedings of the 5th International Symposium on Arctic Air Chemistry, Copenhagen, Denmark, September 8-10, 1992. National Environmental Research Institute, Technical Report No. 70, 1993.
  2. Christensen, J., 1994 "A Three dimensional hemispheric air pollution model used for the Arctic". In: "Air Pollution Modelling and its Application X". (S.-E. Gryning and M.M. Millán, eds.), Plenum Press, New York, 119-127.
  3. Christensen, J., 1996 "The Danish Eulerian Hemispheric Model". In: "Air Pollution Modelling and its Application XI". (S.-E. Gryning and Schiermeier, eds.), Plenum Press, New York, 249-256.
  4. Christensen, J.: The Danish Eulerian Hemispheric Model. In " The AMAP International Symposium on Environmental Pollution in the Arctic. Extended abstracts. Tromsø, Norway June 1-5, 1997". 145-146.
  5. Christensen, J.: The Danish Eulerian Hemispheric Model. In proceedings from "A Comparison of the Performance of Large Scale Models in Simulating Atmospheric Sulphate Aerosols (COSAM), Halifax, Canada, October 19-21, 1998.
  6. Christensen, J.: An overview of modelling the Arctic mass budget of metals and sulphur: Emphasis on source apportionment of atmospheric burden and deposition. In "Modelling and Sources: A Workshop on Techniques and Associated Uncertainties in Quantifying the Origin and Long-Range Transport of Contaminants to the Arctic. Report and extended abstracts of the workshop, Bergen, 14-16 June 1999"
  7. Frohn, L. M., J. H. Christensen, J. Brandt, and O. Hertel, 1999: "Development of a high resolution model for studying air pollution". Special issue on Global and Regional Atmospheric Modelling, Istituto Universitario Navale Napoli. Annali, Faclota Di Scienze Nautiche, Napoli 2000. Proceedings from the 3rd GLOREAM workshop, Ischia (Napoli), Italy, September 22-24. Eds.: G Barone, P.J. Builtjes and G. Giunta, pp. 3-13.
  8. Christensen, J.H. Skov, H. Goodsite, M.: Danish measurements and modelling of atmospheric mercury in the Arctic. THE GERMAN/CANADIAN ENV-58/2 WORKSHOP November 27-28, 2000 Environment Canada, 4905 Dufferin Street, Downsview, Ontario, Canada.
  9. Christensen, J.: Modelling of Mercury with the Danish Eulerian Hemispheric Model. The international Workshop on Trends and Effects of Heavy Metals in the Arctic , McLean, Virginia, 18-22 June 2001.
  10. Christensen, J.: Atmospheric modelling activities inside the Danish AMAP program. The workshop: Photooxidants, Fine Particles, and Haze Across the Arctic and North Atlantic: Transport Observations and Models, CIESIN, Columbia University, Palisades, New York, June 12-15, 2001.
  11. Frohn, L. M., J. H. Christensen and J. Brandt, 2001: "Testing and validating the hemispheric REGIonal high resolutioN Air pollution model (REGINA)", The fifth GLOREAM workshop, Wengen, Switzerland, September 24-26, 2001.
  12. Geels, C., S. C. Doney, R. Dargaville, J. Brandt and J. H. Christensen, 2001: "Deconvolving the sources of synoptic variability in atmospheric CO2 over the Northern Hemispheric continents – a mesoscale model study". Sixth International Carbon Dioxide Conference, Sendai, Japan, October 1-5, 2001. Extended Abstracts, Vol. II, pp. 786-789.
  13. Brandt, J., C. Geels, J. H. Christensen, L. M. Frohn, 2001: "A Hemispheric Nested Model for CO2". Proceedings from the fifth GLOREAM workshop, Wengen, Switzerland, September 24-26, 2001, pp. 19
  14. Ciais, P., T. Alto, P. Bousquet, J. Brandt, A. Chevillard, J. H. Christensen, L. M. Frohn, C. Geels, M. Gloor, M. Gusti, M. Heimann, S. Houwelling, U. Karstens, S. Koerner, P. Peylin, C. Roedenbeck, A. Vermeulen, and A. S. Denning, 2002:."Intercomparison of mesoscale transport models for CO2 and Rn over Europe: a concerted action within the AEROCARB project". The AGU 2002 Spring Meeting. Washington Convention Center. Washington, DC, 28 - 31 May 2002. To appear.
  15. Frohn, L. M., J. H. Christensen, J. Brandt, C. Geels and K. M. Hansen, 2002: "DEHM – et modelværktøj til vurdering af luftforurening", Natur- og Miljøforsknings-konference, 22.-23. august 2002, H. C. Ørsted Instituttet, Copenhagen, Denmark, pp. 161-162.
  16. Geels, C., J. H. Christensen, J. Brandt and L. M. Frohn, 2002: "Model simuleringer af atmosfærisk CO2 over Europa", Natur- og Miljøforsknings-konference, 22.-23. august 2002, H. C. Ørsted Instituttet, Copenhagen, Denmark. pp. 181-182.
  17. Geels, C., J. H. Christensen, J. Brandt, L. M. Frohn and K. M. Hansen, 2003: "A nested hemispheric model for simulations of atmospheric CO2". 26th NATO/CCMS International Meeting on Air Pollution Modelling and its Application, May 26-30, 2003, Istanbul, Turkey. Eds.: C. Borrego and S. Incecik, Kluwer Academic, pp. 215-223.
  18. Hansen, K. M., J. H. Christensen, J. Brandt, L. M. Frohn and C. Geels, 2004: Modelling the atmospheric transport and environmental fate of persistent organic pollutants in the Northern Hemisphere using a 3-D dynamic model. 27th NATO/CCMS International Technical Meeting on Air Pollution Modelling and its Application. 24-29 October 2004, Banff, Canada. pp 158-165.
  19. Geels, C., J. Brandt, J. H. Christensen, L. M. Frohn, Kaj M. Hansen and C. A. Skjøth, 2004: "Long-term calculations with a comprehensive nested hemispheric air pollution transport model", NATO ARW workshop in Borovetz, Bulgaria, 9-13 May 2004. In "Advances in Air Pollution Modeling for Environmental Security", eds. Farago et al., pp 185-196, Springer.
  20. Brandt, J., J. H. Christensen, L. M. Frohn, C. Geels, K. M. Hansen and C. A. Skjøth, 2004: "The THOR integrated air pollution forecast system – current status and ongoing developments". Proceedings from the 2nd GLOREAM/EURASAP Workshop, Modern developments in modelling and chemical data analysis, Copenhagen, September 6-8, 2004. pp. 10, To appear.
  21. Brandt, J., J. Christensen, L. M. Frohn, R. Berkowicz, C. A. Skjøth, C. Geels, K. M. Hansen, J. Frydendall, G. B. Hedegaard, O. Hertel, S. S. Jensen, M. Hvidberg, M. Ketzel, H. R. Olesen, P. Løfstrøm, and Z. Zlatev, 2005: " THOR – an operational and integrated model system for air pollution forecasting and management from global to local scale", First ACCENT Symposium, Urbino, Italy, 12th-16th September 2005, pp. 2, Extended Abstract.

PhD afhandlinger

  1. Christensen, J. 1995: "Transport of air pollution in the troposphere to the Arctic. PhD Thesis. National Environmental Research Institute, Roskilde, Denmark, 377 pp.
  2. Geels, C., 1993: "Simulating the Current CO2 Content of the Atmosphere: Including Surface Fluxes and Transport Across the Northern Hemisphere". PhD thesis, National Environmental Research Institute, Roskilde, Denmark, 238 pp.
  3. Frohn, L. M., 2004: "A study of long-term high-resolution air pollution modelling". PhD thesis, National Environmental Research Institute, Roskilde, Denmark, 444 pp.
  4. Feilberg, K. L., 2005: "Stable Isotope Analysis of the Atmospheric Carbon Cycle". PhD thesis, University of Copenhagen, Denmark.
  5. Hansen, K. M., 2005: "Modelling of POP’s into the Arctic". PhD thesis. To appear.
  6. Skjøth, C. A., 2008: "High-resolution modelling of Pollen". An ongoing PhD project.

Videnskabelige rapporter

  1. Xiaoshan, Zh., Christensen, J., Zlatev, Z. and Wazniewsky, J.: Studying Sulphur Concentrations in China by a Three-dimensional Eulerian Model. report UNIC-93-08.
  2. Aarkrog, A., P. Aastrup, G. Asmund, P. Bjerregaard, D. Boertmann, L. Carlsen, J. Christensen, M. Cleemann, R. Dietz, A. Fromberg, E. Storr-Hansen, N. Z. Heidam, P. Johansen, H. Larsen, G. B. Paulsen, H. Petersen, K. Pilegaard, M.E. Poulsen, G. Pritzl, F. Riget, H. Skov, H. Spliid, P. Weihe and P. Wåhlin: AMAP Greenland 1994-1996. Arctic Monitoring and Assessment Programme (AMAP). Under the series "Enviromental Project from the Danish Environmental Protection Agency". Report Nr. 356, 1997, 792 pp.
  3. Heidam, N. Z., P. Waahlin, H. Skov and J. Christensen: Pollution of the Arctic Troposphere: Northeast Greenland 1990 - 1996. NERI/ATMI report November 1997.
  4. Kämäri, J., P. Joki—Heiskala, J. Christensen, E. Degerman, J. Derome, R. Hoff and A.-M Kähkönen: Acidifying Pollutants, Arctic Haze, and Acidifications in the Arctic, Chapter 9 in: AMAP Assesment Report: Arctic Pollution Issues. Arctic Monitoring and Assessment Programme (AMAP). S. Wilson, J. Murray and H. Huntington, Ed, 1998.
  5. Christensen, J. H., M. Goodsite, N. Z. Heidam, H. Skov and P. Wåhlin: Chapter 1. Atmospheric Environment. In: Riget, F., J. Christensen & P. Johansen (eds). AMAP Greenland and the Faeroe Islands 1997-2001 Vol2: The Environment of Greenland. Ministry of Environment, Denmark Department of Atmospheric Environment, National Environmental Research Institute of Denmark, Frederiksborgvej 399, Box 358, DK-4000 Roskilde, Denmark
  6. AMAP 2004. AMAP assessment 2002: Heavy Metals in the Arctic, Chapter 3: Transport Pathways and processes Leading to Environmental Exposure, Steve Lindberg, Steve Brooks, Jozef Pacyna, Jesper Christensen, Alexey Gusev, Keith Puckett, Oleg Travnikov, Simon Wilson (Atmosphere) Viacheslav Gordeev, Robie Macdonald (Water), Suzanne Marcy
  7. Loon, M. van, Roemer, M. G. M., Builtjes, P. J. H., Bessagnet, B., Rouill, L., Christensen, J., Brandt, J., Fagerli, H., Tarrason, L., Rodgers, I., Stern, R., Bergström, R., Langner, J., Foltescu, V., 2004: "Model inter-comparison. In the framework of the review of the Unified EMEP model". TNO-report, TNO-MEPO – R 2004/282, pp. 86, June 2004.
  8. Brandt, J., 2005: "THOR - an Integrated Air Pollution Forecasting and Scenario Mamangement System". Frontiers in the Transport and Transformation of Pollutants. The report of the Barnsdale Expert Meeting, 2004, Transport and Transformation of Pollutants (ACCENT-T&TP), May 2005, pp. 71-73, P. Monks & P. Borrell, Eds.