My research interests include biogeochemistry, environmental modelling and effects of pollution in developing countries. My research work are related acidification and other effects of regional air pollution. I am applying and developing  models  for environmental policiy making and decision support in different contexts. I have several projects related to air pollution and acid rain in China, acidification and critical loads in Norway and Europe and environmental impact assessments for the industry. 

I completed my Ph.D. in 1999 in environmental chemistry at the University of Oslo with a thesis entitled "Acid Deposition and Acidification of Soil and Soil Water in China - Experiments, Field Studies and Modeling". Summary of the thesis is here.

Master theses

At present I supervise Master students working  with:

• Mercury in a Norwegian  lake catchment
• Soil chemistry and critical loads in Norwegian soils
• Pariculate matter composition in Chinese atmosphere
• Heavy metals in Chinese forest soils

Possible Master theses for new students may be:

• Modeling of future acidification, in Norway or China
• Catchment biogeochemistry (field work/modelling/data analysis)
• Effects of air pollution in China
• Environmental model aplications and/or development
• ...and many others!

Projects

• IMPACTS - Integrated Monitoring Program on Acidification of Chinese Terrestrial Systems. www.impacts.cn.net
• DEMAND - Environmental Decision Making in China. Development of an integrated, effect-based, approach for supporting a comprehensive and cost-effective air pollution abatement policy
• EIF Air - Environmental Impact Factor for emissions to air - a tool foreffects based  industry emission reduction prioritizing
• National Focal Centre for critical loads (naturens tålegrenser på Miljøstatus) (NIVA report in pdf) 
• Development of a statistical framework for risk assessment of environmental effects of pollutants from diffuse sources
• Mercury pools and fluxes in the Langtjern catchment
• Modelling of acidification forecast scenarios

Selected publications:

Wright, R.F., Larssen, T., Camarero, L., Cosby, B.J., Ferrier, R.C., Helliwell, R., Forsius, M., Jenkins, A.,
Kopácek, J., Majer, V., Moldan, F., Posch, M., Rogora, M. and Schöpp, W., 2005. Recovery of Acidified
European Surface Waters. Environmental Science and Technology. Vol. 39: 64A–72A.

Aherne, J., Larssen, T., Dillon, P.J. and Cosby, B.J., 2004. Modelling the effects of climate events on elemental
fluxes from forested catchments in Ontario, Canada. Water Air Soil Pollut. Focus. 4:37-48.

Larssen, T., Cosby, B.J. and Høgåsen, T., 2004. Uncertainties in predictions of surface water acidity using the
MAGIC model. Water Air Soil Pollut. Focus. 4:125-137.

Lydersen, E., Larssen, T., Fjeld, E., 2004. The influence of total organic carbon (TOC) on the relationship
between acid neutralizing capacity (ANC) and fish status in Norwegian Lakes. Sci. Tot. Environ. 362:63-69.

Jenkins, A., Cosby, B.J., Ferrier, R.C., Larssen, T., Posch, M., 2003. Assessing emission reduction targets with
dynamic models: deriving target load functions for use in integrated assessment. Hydrol. Earth Syst. Sci. 7:609-
617.

Skjelkvåle, B.L., Evans, C., Larssen, T., Hindar, A. and Raddum, G., 2003. Recovery from acidification in
European surface waters: a view to the future. Ambio32:170-175.

Larssen, T., Brereton, C.I. and  Gunn., J., 2003. Dynamic modelling of Recovery from Acidification of Lakes in
Killarney Park, Ontario, Canada. Ambio 32:244-248.

Tang, D., Lydersen, E. Seip, H.M., Angell, V., Eilertsen, O., Larssen, T., Liu, X., Kong, G., Mulder, J., Semb,
A., Solberg, S., Torseth, K., Vogt, R.D., Xiao, J., Zhao, D., Integrated monitoring program on acidification of
Chinese terrestrial systems (IMPACTS) - A Chinese-Norwegian cooperation project. Water Air Soil Pollut.
130:1733-1738.

Larssen, T., Seip, H.M., Carmichael, G.R. and Schnoor, J.L., 2001. The importantce of calcium deposition
assessing impacts of acod deposition in China.  Water Air Soil Pollut.130:1635-1640.

Hansen, H., Larssen, T., Seip, H.M. and Vogt, R.D., 2000. Heavy metals in forest soils at four sites in southern
China.  Water Air Soil Pollut. 130:1721-1726.

Larssen, T., Schnoor, J.L., Seip, H.M. and Zhao, D., 2000. Evaluation of different approaches for modeling
effects of acid rain on soil in China. Sci. Tot. Environ. 246:175-193.

Larssen, T. and Carmichael, G., 2000. Acid rain and acidification in China: The importance of base cation
deposition. Environ. Pollut. 110:89-102.

Larssen, T., Vogt, R.D., Seip, H.M., Furuberg, G., Liao B., Xiao J., and Xiong J., 1999. Mechanisms of
aluminum release in Chinese acid forest soils. Geoderma. 91:65-86.

Larssen, T., Seip, H.M., Semb, A., Mulder, J., Muniz, I.P., Vogt, R.D., Lydersen, E., Angell, V., Tang, D. and
Eilertsen, O., 1999. Acid rain and its effects in China. Environmental Science and Policy. 2:9-24.

Larssen, T., Xiong, J., Vogt, R.D., Seip, H.M, Liao, B. and Zhao, D., 1998. Studies of soils, soil water and
stream water at a small catchment near Guiyang, China. Water, Air, Soil Pollut. 101:137-162.

The inheritance from the Gulf War - Environmental effects of war. Feature article, Dagbladet 28.02.01.  (In Norwegian)

Seip, H.M., Larssen, T. and Vogt, R.D., 1999. Acid Rain on China. (Sur nedbør på Kina). Apollon.  (In Norwegian)

Larssen, T., Dagang, T., Yi, H. (eds), 2003. Integrated Monitoring Program on Acidification of Chinese Terrestrial Systems - IMPACTS. Annual Report - Results 2003. NIVA-report no. 4905-2004.

Larssen, T., Skjelkvåle, B.L., Høgåsen, T., 2004. Critical loads for lead and cadmium in surface waters in Norway. NIVA Report SNO 4808-2004.

Larssen, T., Hindar, A., Høgåsen, T., 2003. Oppdaterte tålegrenseoverskridelser og prognoser for forsuringsutvikling og kalkbehov i Tovdalsvassdraget. NIVA-Report SNO 4728-2003

Larssen, T., Høgåsen, T., 2002. Tålegrenser og overskridelse av tålegrenser i Norge (Critical loads and exceedances in Norway). NIVA Report SNO 4722-2003.

Larssen, T., Knudsen, S., Høgåsen, T., Bruteig, I., 2003. Environmental Impact Factor for utslipp til luft (EIF luft). Rapport til statoil fra prosjektfaseI. NILU report OR 64/2003.

Jenkins, A., Larssen, T., Moldan, F., Hruška, J., Krám, P. and Kleemola, S. 2003. Dynamic modelling at Integrated Monitoring sites - Model testing against observations and uncertainty. The Finnish Environment 636. Finnish Environment Institute, Helsinki, Finland.

Jenkins, A., Larssen, T., Moldan, F., Posch, M., Wright, R.D., 2002. Dynamic modelling of surface waters: Impacts of emission reduction - possibilities and limitations. ICP Waters; 70/2002. NIVA report 4598.

Larssen, T. Clarke, N., Tørseth, K., Skjelkvåle, B.L., 2002. Prognoses for future recovery from acidification of water, soils and forests: Dynamic modeling of Norwegian data from ICP Forests, ICP IM and ICP Waters. NIVA report 4577.

Duan, L., Larssen, T., 2004. Future scenarios for nitrogen induced acidification of soils and waters in China. Manuscript.

Larssen, T., Høst, G., Huseby, R., Cosby, B.J., Høgåsen, T., 2005. Automated calibration of a process oriented hydrogeochemical model (MAGIC) to time trend observations with uncertainties. Manuscript.

Larssen, T., 2005. Model evaluation and prognoses for future acidification recovery using long term monitoring data . In review.

Larssen,. T. and Holme, J., 2005. Afforestation, seasalt episodes and acidification – A paired catchment study in western Norway. In review.

Larssen, T., Aas, W., Kaste, Ø., de Wit, H., 2005. Three decades of observed trends in concentrations and fluxes of main chemical compounds in three calibrated catchments in Norway. Manuscript.