Fig. 3.

Comparison of 2012 simulated meltwater production M (magenta) and runoff R (blue) from the MAR regional climate model, observed proglacial discharge (outflow) exiting the ice sheet in the Isortoq river (vertical gray bars, spanning measurement uncertainty), and total supraglacial river moulin discharge estimated for ∼52% of the Isortoq ice watershed during 18–23 July 2012 (dark gray box, spanning measurement uncertainty). Observed proglacial outflows are lower than MAR modeled runoff, especially in June. A record melt on the ice sheet occurred 11–13 July 2012.