Hemispheric modelling
The model computation domain covers the whole Northern Hemisphere with spatial resolution 2.5° both in zonal and meridional directions. To avoid a singularity at the pole point, peculiar to the spherical coordinates, the grid has a special circular mesh of radius 1.25° including the North Pole. In the vertical direction the model domain consists of eight irregular levels of terrain-following sigma-pressure (s-p) coordinate defined as a ratio of local atmospheric pressure to the ground surface pressure [Jacobson, 1999].
Horizontal grid structure of the hemispherical model domain.
Geographical coordinates with 2.5° x 2.5° resolution and the pole grid cell.
Vertical grid structure of the model domain.
Eight terrain-following s-levels:
1 - s = 0.99; 2 - 0.96; 3 - 0.91; 4 - 0.85; 5 - 0.77; 6 - 0.68; 7 - 0.55; 8 - 0.4
 MSCE-POP-Hem transport model
In view of POP physical-chemical properties, some pollutants can be transported and accumulated in the environment on the hemispherical and global scale. This is confirmed both by monitoring data from remote regions (e.g. the North Atlantic, the Arctic) and by model assessment of long-range transport potential. In addition, preliminary model assessment shows that considerable part of annual emissions of substances like HCB, PCBs and g-HCH can be transported outside the European region and reach remote areas. This suggests that the pollution inflows to the EMEP region from external sources probably is tangible. Therefore, the estimate of transport of these pollutants should be made on the hemispheric scale. Another argument in favour of the hemispheric modelling is the possibility of pollution evaluation for countries, located at the EMEP boundary and outside. Due to their physical-chemical properties, POP can be accumulated in the environmental compartments (soil, vegetation, seawater) with subsequent re-emission. Hence, a multicompartment approach is used for POP modelling.
The hemispheric version of the MSCE-POP transport model is under development [Shatalov et al., 2003]. This is a multicompartment 3-dimensional model including such media as: the atmosphere, soil, seawater, vegetation, sediments and sea ice with spatial resolution of 2.5x2.5 degree. The atmospheric transport is simulated by advection Bott scheme [Bott, 1989a; 1989b]. The main processes in the environmental media are parameterised similar to the regional model.
Some recent results on the model assessment of PCBs and g-HCH transport over the Northern Hemisphere are presented here.
Reports:
MSC-E Technical Report 4/2003 "Persistent Organic Pollutants in the Environment"
V.Shatalov, M.Fedyunin, E.Mantseva, B.Strukov, N.Vulykh
EMEP/MSC-E Technical Report for AMAP [2003] "Assessment of long-range transport of Hg, PCBs and g-HCH to the Russian North"
AMAP [2004] "Persistent Toxic Substances, Food Security and Indigenous Peoples of the Russian North" Final report
Regionally Based Assessment of Persistent Toxic Substances: Europe Regional Report. UNEP Chemicals
Regionally Based Assessment of Persistent Toxic Substances: Mediterranean Regional Report. UNEP Chemicals
Regionally Based Assessment of Persistent Toxic Substances: South East Asia and South Pacific Regional Report
UNEP Chemicals
MSC-E Technical Note 11/2005 "Hemispheric model (MSCE-Hem) of persistant toxic substances dispersion in the environment"
MSCE-HM-Hem transport model
Model MSCE-HM-Hem was developed in order to evaluate the long-range atmospheric transport, chemical transportations and deposition of mercury over the Northern Hemisphere. It is an Eulerian-type three-dimensional model. The description of this model is available here.
Results on the model assessment of mercury transport over the Northern Hemisphere are presented here.
Reports:
MSC-E Technical Note 8/2001 "Hemispheric
Model of Airborne Pollutant Transport" O.Travnikov
MSC-E Technical Report 6/2002 "Modelling
of Mercury Hemispheric Transport and Depositions"
O.Travnikov, A.Ryaboshapko
MSC-E Technical Report 5/2003 "Heavy Metals: Transboundary Pollution of the Environment"
EMEP/MSC-E Technical Report for AMAP [2003] "Assessment of long-range transport of Hg, PCBs and g-HCH to the Russian North"
AMAP [2004] "Persistent Toxic Substances, Food Security and Indigenous Peoples of the Russian North" Final report
MSC-E Technical Note 11/2005 "Hemispheric model (MSCE-Hem) of persistant toxic substances dispersion in the environment"
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