Towards Long-term Monitoring of the CO2 System in Arctic Rivers
The CO2 systems (pH, pCO2, DIC, and TAlk) in rivers and their estuaries play a critical role in regulating inorganic carbon, including CO2, fluxes into and out of the systems, and yet they have been understudied in the past. Currently, we don’t have a clear understanding of how much this system contributes to global CO2 budget, and can not make reasonable projection on how its fate is going to be under rising atmospheric CO2 concentration that primarily drives global climate change. Previous measurements of the CO2 systems in Arctic rivers and their estuaries are not complete and much less precise than most of seawater measurements. We thus lack of information on their long-term trend and short-term variation, which are essential to predict how they response to apparently accelerated climate change in Arctic region.
The Arctic Ocean receives large amount of riverine fluxes of organic matter, suspended material, and nutrients from surrounding rivers, and the riverine influence is most substantial among all ocean basins. Arctic region is also most sensitive to global climate change. The CO2 systems in Arctic rivers and their estuaries would likely undergo a significant and observable change in a relatively shorter time scale (50 – 100 years). Increase in riverine inorganic carbon fluxes is expected as warming climate may accelerate water cycle and weathering processes. This increase of inorganic carbon load may have significant impacts on riverine and coastal carbon cycles, and their associated ecosystem functioning. The already observed increase of riverine organic carbon flux in Arctic may also enhance microbial respiration and organic carbon degradation, both of which would drive the CO2 level in water towards over-saturation, thus release more CO2 to the atmosphere. To study these potential changes in Arctic rivers, both long-term and short-term measurements are required.
This project aims to initialize a time-series measurements of the CO2 system in Mackenzie River, one of the major Arctic river in North America. The field campaign include both diurnal and monthly sampling of all major CO2 system parameters in river water, and all measurements will be performed by state-of-art instruments to obtain high precision and accuracy as required by the research. This work will serve as the initial step towards long-term measurements and studies of impacts of global warming on the CO2 systems in Arctic rivers, their estuaries, and adjacent coastal waters.