Recent Extreme Runoff Observations From Coastal Arctic Watersheds in Alaska

Abstract

Arctic coastal watersheds, though rarely monitored, are expected to have increased runoff, as climate models predict more precipitation in the Arctic. This study provides a synthesis of streamflow changes in watersheds of the Alaska Arctic Coastal Plain (AACP) based on available historic discharge data and water balance analysis. A comparison of annual runoff from the Putuligayuk River watershed (471 km2) from the period 1970–1986 (78 ± 24.1 mm/yr) to the period 1999–2015 (122 ± 49.6 mm/yr) shows increasing discharge and interannual variability. From this discontinuous record of 32 years, the three lowest runoff years occurred in 1979, 2007, and 2008, and the three highest runoff years occurred in 2003, 2014, and 2015. Other studied AACP watersheds with shorter discharge records demonstrate similar patterns of dry (2007–2008) and wet (2014–2015) years during common periods of observation. A combination of favorable antecedent surface storage conditions and above‐average precipitation is required to generate large volumes of surface runoff. A strong relationship between climate, surface storage, and runoff inherent to AACP watersheds makes these systems highly responsive to sea ice retreat and hydrological intensification. Our new estimates of freshwater flux from the AACP to the Beaufort Sea and Chukchi Sea account for an observed range of runoff variability and provide baseline data for modeling arctic hydrologic systems.

Warming temperatures are impacting the hydrometeorological regime of Russian rivers in the zone of continuous permafrost

“…An earlier start of freshet agrees with identified significant air temperature increases in May at 9 out of the 13 meteorological stations in the region. However, in contrast to the Lena River basin, where strong warming in spring led to an advance of the snowmelt season into late May and resulted in a lower daily maximum discharge in June (Yang et al, 2002;Tan et al, 2001), at the study gauges, streamflow has not been reduced in June (except ID 3510).…”

“…Tananaev et al (2016) found that 30 small and medium-sized rivers out of 100 in the Lena River basin showed trends in mean annual flow. Significant changes have been recently reported for small and middle-sized rivers in northwestern Canada (Spence et al, 2011), Alaska (Stuefer et al, 2017), and the Canadian High Arctic (Lamoureux and Lafrenière, 2018) and attributed to climate change and permafrost disturbances. Further analysis of small river basins could reveal the mechanisms behind ongoing changes, as at larger scales attributing changes can be problematic.…”

Ice roads through lake-rich Arctic watersheds: Integrating climate uncertainty and freshwater habitat responses into adaptive management

“…Climate projections from Polar WRF show a wetting trend for the ACP, but with many extreme dry years interspersed (Figure 3). The summer drought of 2007 is prominent in the recent history of the Alaskan North Slope, resulting in a major tundra fire (Jones et al 2009c), shrinkage of lakes (Jones et al 2009a), and reduced river runoff and hydrologic connectivity (Arp et al 2012b;Betts and Kane 2015;Stuefer et al 2017).…”

“…At the same time as the industrial footprint has expanded on the ACP, climate change has become an increasing concern in the Arctic, with warming much above global trends (Serreze and Barry 2011;Wendler, Moore, and Galloway 2014). Ecosystem responses to climate change on Alaska's North Slope include earlier snowmelt (Stone et al 2002), shrubification (Sturm, Racine, and Tape 2001), permafrost warming Romanovsky, Smith, and Christiansen 2010) and degradation (Jorgenson, Shur, and Pullman 2006;Raynolds et al 2014;Liljedahl et al 2016), new tundra fires (Jones et al 2009c), accelerating coastal erosion (Jones et al 2009b), earlier breakup of lakes and rivers (Smejkalova, Edwards, and Dash 2017), and hydrologic intensification in the form of more variable watershed runoff (Rawlins et al 2010;Stuefer et al 2017). Climate-change impacts on native Inupiaq communities and the petroleum industry in northern Alaska are wide ranging with mixed consequences (Larsen et al 2008;Raynolds et al 2014;Brinkman et al 2016).…”

Qualitative risk assessment of impact of Toxoplasma gondii on health of beluga whales, Delphinapterus leucas from the Eastern Beaufort Sea, Northwest Territories

“…Therefore, EBS beluga would seem to be at lower risk of exposure than many marine mammal populations, due to the low density of human habitation (and presumably ownership of outdoor cats) in the region. However, it is important to note that coastal runoff is changing in the western Arctic of North America (Stuefer et al 2017). …”