High Arctic Biocomplexity Research - Thule, Greenland

Hydrology and solute transport

measuring a stream

Figure 1 We study 3 drainages: North Mountain, with a drainage
area of 5 km2; North River, with an ice free drainage area of 100 km2;
and South River, with ice free drainage area of 150 km2.

Full-sized image

The amount, temperature, and quality of freshwater runoff from high latitude areas ultimately affect water stratification, nutrient cycle and formation of deep water current in the ocean. Freshwater is conveyed from Greenland to the ocean in a multitude of medium sized rivers for which little is known about discharge and water quality.

Records of high resolved river runoff in connection with weather records from a typical high Arctic area in NW Greenland will increase the understanding of the interaction between climate, landscape processes and river runoff.

To address how seasonal weather pattern and landscape processes affect runoff and water quality, as well as examine weathering and carbon budgets in the drainage, we monitor water discharge, water temperature, and water chemistry (cation, anion, dissolved organic and inorganic carbon) of these rivers. North River and South River originate as melt water runoff from the Greenland Ice Sheet. The North Mountain stream is fed by local snowmelt and summer rain events. Climate data along with soil moisture and temperature are recorded with automated stations at two locations.

North Mountain catchment aerial photograph The potential sources of river water are thawing permafrost, local snowmelt, rain, and melting of glacial ice that have a discriminative isotopic signature of water (&delta D and &delta 18O). Stable isotopes therefore, are used to separate the hydrograph into these sources to help us relate discharge pattern and water quality to climate (precipitation, temperature) and landscape processes (thawing of permafrost, weathering, decomposition of organic matter). To trace the origin of dissolved nutrients and to study the cycling of nutrients through the atmosphere - soil - plant system we measure Sr isotopes (87Sr/86Sr) in soil and stream water.

Figure 2 Aerial photograph of part of the North Mountain catchment with numerous lakes. In the upper left corner is the Wolstenholm Fjord.

Origin of North River at the Greenlandic Ice Sheet.

This water looks cold!

Figure 3 (above) Discharge measurement.

Figure 4 (right) Origin of North River at the Greenlandic Ice Sheet.

Figure 5 (below) Discharge record from the North River 2004. Discharge follows temperature, which indicates that meltwater from the ice sheet significantly contributes to runoff.

Discharge record from the North River 2004

Weather record from June to September 2004 from our North Mountain climate station

Figure 6 (above) We continuously monitor weather at two stations to compare climate to processes in soil and to river discharge. Here a weather record from June to September 2004 from our North Mountain climate station. In addition to the data shown we also monitor Net radiation and soil moisture and soil temperature.

rainbow