Modelling concentrations and depositions of atmospheric trace species in tropical regions using the MATCH model

The present project is a part of the new 2001-2004 Sida-funded Programme on Regional Air Pollution in Developing Countries (RAPIDC) which is co-ordinated by the Stockholm Environment Institute (SEI). The atmospheric modelling project is led by the Swedish Meteorological and Hydrological Institute (SMHI).

Background

Anthropogenic SO₂ is believed to be the main precursor for increased acidifying deposition in most regions of the world. The development and application of an atmospheric transport and deposition model, suitable for tropical conditions, was therefore focused on sulphur species during the previous RAPIDC programme phases. The modelling activities were based on the regional model MATCH, developed at SMHI. That part of the model development is now completed and verified for various applications in the tropics.

Activity description

During the current programme phase, the focus will be on providing improved calculations for nitrogen species and ozone. The calculations will mainly be carried out for South and Southeast Asia using the MATCH model.

Nitrogen species (mainly NO_X and NH₃) are also emitted to the atmosphere in large amounts through human activities and do also contribute significantly to the increased acidifying deposition. Although NH₃ is a base, it can contribute to the acidification of soils through nitrification processes in terrestrial ecosystems. Global - and particularly Asian - emissions of NH₃ is increasing with a high rate and are believed to be one of the major environmental problems in the future due to its acidifying and eutrophicating effects.

Ozone is a photochemically produced species, which have negative health effects. Ozone can also have a detrimental effect on vegetation and high ozone concentrations are known to reduce crop yields in many parts of the world. The potential for elevated concentrations of ozone is particularly high in many areas of Asia because of energy rich solar radiation and high emission of precursors, such as anthropogenic NO_X and VOCs.

The continued development of the MATCH model for tropical conditions will be aided by the co-operation that was built up during the previous programme phases with several institutes in South and Southeast Asia. In particular, SMHI has established close contacts with Malaysian Meteorological Services (MMS) and they will provide access to high quality atmospheric data for many chemical species in the region.

In the previous Programme phase, SMHI assessed the potential for the installation of the MATCH model at an institute in South or Southeast Asia. Previous experiences with such endeavours have shown that a high level of technical infrastructure (computers etc.) and personnel knowledge (i.e. programming skills and scientific knowledge in meteorology, chemistry, mathematics etc.) are needed in order to use the MATCH system successfully. It must be realised that MATCH is still a research tool, more developed towards scientific experiments than "user friendliness". The installation of an atmospheric transport model in Malaysia will increase capacity in the field of atmospheric transport modelling within Asia, and therefore support the objectives of the Composition of Asian Deposition (CAD) network. Ms. Leong Chow Peng, who will lead the project on the MATCH model in Malaysia, has also recently been appointed CAD co-ordinator.

Tasks

The following tasks will be undertaken for the development and application of the MATCH model:

• Further development and application of the MATCH model in collaboration with experts from Asia and southern Africa, specifically for nitrogen species and ozone chemistry.

• Production of maps of nitrogen deposition and ozone concentrations for various parts of Asia and southern Africa.

• Use of MATCH output in integrated assessment studies in South Asia.

• Installation of MATCH model at MMS and training of staff in the usage of the transport model

Collaborating institutions and personnel

SMHI will continue the development of the model and provide new model results (to be used in the RAPIDC Programme). The modelling in southern Africa will be assessed with APINA members.

Duration: 2001-2004

Funded by: Sida

Responsible at SMHI: Magnuz Engardt

Web site: www.rapidc.org

References:

Carmichael, G.R., Hayami, H., Calori, G., Uno, I., Cho, S.Y., Engardt, M., Kim, S.-B., Ichikawa, Y., Ikeda, Y., Ueda, H. and Amann, M. 2001. Model intercomparison study of long range transport and sulfur deposition in East Asia (MICS-Asia). Water, Air, and Soil Pollution 130, 51-62.

Engardt, M. 2001. Sulphur simulations for East Asia using the MATCH model with meteorological data from ECMWF. Water, Air, and Soil Pollution 130, 289-294.

Engardt, M. and Leong, C.P. 2001. Regional modelling of anthropogenic sulphur in Southeast Asia. Atmos. Environ. 35, 5935-5947.

Robertson, L., Langner, J. and Engardt, M. 1999. An Eulerian limited-area atmospheric transport model. J. Appl. Meteor. 38, 190-210.

Robertson, L., Rodhe H. and Granat, L. 1995. Modelling of sulfur deposition in the southern Asian region. Water, Air and Soil Pollution 85, 2337-2343.

Kuylenstierna, J.C.I., Hicks, W.K., Cinderby, S., Vallack, H.W. and Engardt, M. 2001. Variability in mapping acidification risk scenarios for terrestrial ecosystems in Asian countries. Water, Air, and Soil Pollution 130, 1175-1180.

Zunckel, M., Robertson, L., Tyson, P.D. and Rodhe, H. 2000. Modelled transport and deposition of sulphur over Southern Africa. Atmos. Environ. 34, 2797-2808.

Lindström, G., Johansson, B., Persson, M., Gardelin, M., & Bergström, S. (1997) Development and test of the distributed HBV-96 hydrological model. Journal of Hydrology, 201, 272-288.