Dr Jalkanen is the lead developer of Ship Traffic Emission Assessment Model (STEAM) of the Finnish Meteorological Institute. This emission model has been used in several international initiatives to support decision making, for example the "Assessment of the environmental impacts and health benefits of a nitrogen emission control area in the North Sea" report of the PBL Netherlands Environmental Assessment Agency, the "Economic Impact Assessment of a NOx Emission Control Area in the North Sea", report of the Danish Environmental Protection Agency and the HELCOM proposal "Proposal to designate the Baltic Sea as an Emission Control Area for Nitrogen Oxide" are all based on the work done by Dr Jalkanen. He is also responsible for annual emission reporting of Baltic Sea shipping for the benefit of the Helcom member states. Dr Jalkanen was a national represenative to the Greenhouse Gas expert group of the International Maritime Organization as well as the Black Carbon correspondence group. He was also part of the international consortium responsible for the update work of the 3rd IMO GHG study 2014.

Dr Jalkanen is the lead developer of Ship Traffic Emission Assessment Model (STEAM), which is used in several international initiatives to support decision making.