Physical oceanographic conditions and a sensitivity study on meltwater runoff in a West Greenland fjord: Kangerlussuaq

•A hydrodynamic model was set up for the fjord Kangerlussuaq.•The circulation was primarily oriented along the long axis of the fjord, characterised by fast [1.3 m/s] currents in the inner part of the fjord as opposed to slow currents [0.05 m/s] in the outer part.•The current regime in summertime is characterised by down-fjord currents in the upper 20 m due to the ice sheet runoff and up-fjord currents below.•The deep-lying water mass in the inner part of the fjord is nearly dynamically decoupled from the open ocean during summertime.•A sensitivity study of meltwater runoff shows that increasing the runoff considerably strengthens stratification in the upper 100 m of the water column.