ABSTRACT:

A series of hyporheic exchange studies were conducted in watersheds 01 and 03 during the summer of 2010 using saline tracers coupled with electrical resistivity to image the temporal and spatial extent of the hyporheic zone during baseflow recession. A series of four 48-hr tracer tests were conducted in each watershed on a rotational schedule with each tracer test starting approximately 2 weeks following the start of the previous test in each watershed. Each tracer injection was targeted to enrich the stream electrical conductivity by ~100 uS/cm. Electrical resistivity surveys were conducted on up to 6 transects of electrodes (12 electrodes per transect) in each watershed for each test. Resistivity surveys were collected, on a high temporal frequency ranging from continuous to every 4 hrs, for pre-injection, injection, and post-injection until conductivity measurements in the shallow groundwater well network returned to pre-injection magnitudes. During each injection conductivity magnitudes were measured in the stream and each accessible groundwater well in the watershed using a handheld conductivity meter on a frequency ranging from near continuous (~15-30 min), during tracer start-up and shutoff, to every 2-6 hrs depending on position within the tracer test. Hydraulic head data was collected approximately every 15 minutes by downwell pressure transducers from a select set of groundwater wells in each watershed for nearly the full summer 2010.

These data were published in a series of papers outlined below.

ABSTRACT:

The goal of this study is to assess the potential effects of aufeis (i.e., river icings) on the structure and function of arctic river-floodplain ecosystems in a warming climate. Aufeis are massive accumulations of ice that are features of many arctic rivers. They form during freeze-up when thickening surface ice causes local overflows. Successive cycles of overflow result in accumulations of enormous volumes of ice, with aufeis on some Alaskan rivers attaining thicknesses of 3-5 m, covering more than 20 square km, and storing as much as 30% of the annual river discharge. Although aufeis have been studied by hydrologists and are known to be required for winter and spawning habitat for some fish, understanding of their ecology is poor. We propose that aufeis be viewed as winter oases due to their wet bases that supply water and heat to otherwise frozen habitats. Aufeis function as summer oases by providing a stable supply of water to hyporheic and downstream habitats.

These data come from intensive study of the Kuparuk River Aufeis field. We collected stage and water temperature data in 50 wells that were ~1m deep, and stage, temperature, electrical conductivity, and dissolved oxygen data from several points in the surface channel of the aufeis field. Where we could deploy loggers, we have continuous data collection.

NOTE that these data are identical to those uploaded to the Arctic Data Center database (sometime in July or August 2019).