Fig. 4
Regulation of upwelled macronutrient flux by the subglacial discharge flux and glacier grounding line depth. a NO3 flux as a function of subglacial discharge flux (m3 s−1 runoff) and glacier depth (relative to sea-level). The gray region shows where the plume equilibrates below the photic zone (defined as 0–50 m). b Macronutrient fluxes for a constant subglacial discharge of 500 m3 s−1, with varying glacier grounding line depth. Upper and lower shaded error bars are defined as 25 and 75% quartiles on macronutrient, temperature, and salinity data (Supplementary Fig. 2). c The relative importance of the macronutrient fluxes sourced from subglacial discharge (sg) and from entrainment into the plume. For marine-terminating glaciers, the plume macronutrient flux is generally dominated by nutrients from entrained seawater
