warming will likely result in shifts to greater riverine DOC exports from groundwater sources (Walvoord & Kurylyk, 2016). Key calibration and validation data to assist model development include river chemistry and discharge measurements during the shoulder seasons (Shogren et al., 2020) and observations of the quantity and quality of DOC in subsurface flow (Neilson et al., 2018;Connolly et al., 2020).

This study investigates the loading of DOC to rivers of the western Arctic derived from process modeling that involves dynamics of terrestrial hydrology and DOC production and mobilization. Results suggest that simulated runoff reflects the characteristic pattern of high flow following snowmelt, subsequent recession, Northern AK region includes a small area just west of the Mackenzie delta that is not part of the 24 North Slope basins examined in Section 3.2 (Figure 7). Each boxplot depicts the distribution of monthly total loading across each regions for the 30 months over years 1981-2010. Boxplot rectangles bracket the 25th and 75th percentiles. Whiskers extend to the 5th and 95th percentiles. Thick and thin horizontal lines mark the distribution mean and median respectively.