Andreas Stohl is a senior scientist at the Norwegian Institute for Air Research (NILU). His research interests are on all aspects of transport in the atmosphere, ranging from pollution transport to the transport of water vapor. He is the main author of the widely used Lagrangian particle dispersion model FLEXPART. Areas of active research are on the intercontinental transport of air pollution, the long-range transport of fire emissions, Arctic air pollution and climate issues, inverse modeling of greenhouse gas emissions, radioactive, as well as of volcanic emissions. Andreas Stohl has led many national and international projects such as STACCATO or POLARCAT and has authored or co-authored more than 260 peer-reviewed publications.
Source-term is a key parameter after accidents and usually takes a long time to be determined in detail. We have developed an inversion algorithm to calculate the emissions of greenhouse gases or volcanic sulfur dioxide and ash emissions. Depending on the application, the algorithm incorporates different types of observation data and can be based on forward or backward calculations with FLEXPART model. The same algorithm was applied to determine the emissions of 133Xe and 137Cs from the accident in Japan in 2011.
Forward modeling can be proved a powerful tool when assessing accidental releases in terms of radiation protection countermeasures to the public and the ecosystem. Once the source is known, models can run online to estimate the fate of dispersion of radionuclides and hence, to predict the long-term effects on the public (prior to epidemiology) and the environment (prior to evolutionary changes). Here, we present some results on the recent accident in Fukushima (2011).