Chemical characteristics of supraglacial stream water on Canada Glacier, McMurdo Dry Valleys, Antarctica during the 2015-2016 austral summer

This data package contains chemical characteristics of water samples collected along four supraglacial streams on Canada Glacier, located in Taylor Valley, McMurdo Dry Valleys, Antarctica. Samples were collected during the 2015-16 and 2016-17 austral summers in order to characterize the spatial and temporal evolution of glacial meltwater as it travels over and off Canada Glacier. Samples from the 2015-16 austral summer have been fully analyzed and those data are included here. Samples from the 2016-17 austral summer have been stored frozen since collection and have not been analyzed. This package may be amended in the future if analysis of the 2016-17 samples occurs.

Data Policies This data package is released under the Creative Commons Attribution 4.0 International License (CC BY 4.0; http://creativecommons.org/licenses/by/4.0/), which allows consumers (hereinafter referred to as “Data Users”) to freely reuse, redistribute, transform, or build on this work (even commercially) so long as appropriate credit is provided. Accordingly, Data Users are required to properly cite this data package in any publications or in the metadata of any derived products that result from its use (in whole or in part). A recommended citation is provided on the summary metadata page associated with this data package in the McMurdo Dry Valleys LTER Data Catalog (https://mcmlter.org/data), and a generic citation may be found on the summary metadata page in the repository where this data package was obtained. When these data contribute significantly to the contents of a publication, Data Users must also acknowledge that data were provided by the NSF-supported McMurdo Dry Valleys Long Term Ecological Research program (OPP-2224760). This data package has been released in the spirit of open scientific collaboration. Hence, Data Users are strongly encouraged to consider consultation, collaboration, and/or co-authorship (as appropriate) with the data package creator(s). Data Users should be aware these data may be actively used by others for ongoing research; thus, coordination may be necessary to prevent duplicate publication. Data Users should also recognize that misinterpretation of data may occur if they are used outside the context of the original study. Hence, Data Users are urged to contact the data package creator(s) if they have any questions regarding methodology or results. While substantial efforts are made to ensure the accuracy of this data package (with all its components), complete accuracy cannot be guaranteed. Periodic updates to this data package may occur, and it is the responsibility of Data Users to check for new versions. This data package is made available “as is” and comes with no warranty of accuracy or fitness for use. The creator(s) of this data package and the repository where these data were obtained shall not be liable for any damages resulting from misinterpretation, use, or misuse of these data. Finally, as a professional courtesy, we kindly request Data Users notify the primary contact referenced in the metadata when these data are used in the production of any derivative work or publication. Notification should include an explanation of how the data were used, along with a digital copy of the derived product(s). Thank you.

This package contains data from 40 sampling sites, with 10 sites each on four streams on Canada Glacier. Stream 1 drains the southwest part of the glacier, stream 2 drains the southeast corner, stream 3 drains the northwest side of the ablation zone, and stream 4 drains the northeast side of the ablation zone. Samples were collected in triple DI-washed 500 ml polyethylene bottles. In some cases, an ice lid had to be chopped away with an ice axe to access liquid water. In cases where the stream was too narrow or shallow to fill the bottle, the bottle was filled using water scooped with the bottle cap. These conditions are indicated in the notes. After collection, samples were brought back to the field camp where water was distributed into a 20 ml glass scintillation vial, one triple DI-washed and one acid-washed 60 ml polyethylene bottle, and one acid-washed 125 ml bottle. The scintillation vial was stored at 4º C, all polyethylene bottles were frozen at -20º C, and all samples were shipped back to Boulder, Colorado for further analyses. One 60 ml bottle was thawed at 4º C in the Crary lab at McMurdo Station and analyzed by ion chromatography for Cl-, SO4-, and NO3-. Atomic absorption spectroscopy was used to analyze samples for Ca2+, Na+, K+, Mg2+, and by Latchet for NH4+ in the Arikaree Lab at the University of Colorado Boulder. Samples were analyzed for water isotopes using cavity ring-down spectroscopy on a Picarro in the Barnard Lab at the University of Colorado Boulder. Contributing areas to each sampling point were calculated using a MD-Infinity flow routing algorithm on a sink-filled 1 m lidar-derived DEM.