uid=MCM,o=EDI,dc=edirepository,dc=org all public read LIMNO_CHEMISTRY Ion concentrations in discrete water column samples collected from lakes in the McMurdo Dry Valleys, Antarctica (1991-2019, ongoing) John Priscu jpriscu@montana.edu https://orcid.org/0000-0001-5807-6364 Kathleen Welch kathleen.welch@colorado.edu https://orcid.org/0000-0003-1028-3086 W. Berry Lyons
275 Mendenhall Lab Columbus OH 43210 US
(614) 688-3241 lyons.142@osu.edu http://research.bpcrc.osu.edu/EnvironmentalGeochemistry/ https://orcid.org/0000-0002-3143-7251
McMurdo Dry Valleys LTER http://mcmlter.org/ Renée Brown rfbrown@unm.edu https://orcid.org/0000-0002-4986-7663 data manager Amy Chiuchiolo
LRES, 334 Leon Johnson Hall Bozeman MT 59717 US
(406) 994-2360 (406) 994-5863 achiuchiolo@montana.edu former field crew
Inigo San Gil
Department of Biology, MSC03 2020 University of New Mexico Albuquerque NM 87131 US
(505) 277-2625 (505) 277-2541 isangil@lternet.edu former data manager
2022-02-07 English
As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic aqueous geochemical sampling program has been undertaken. A series of terrestrial water samples have been collected and analyzed for major ion chemistry by ion chromatography. The concentrations of ions cover a wide range of total dissolved solids from fresh to hypersaline lake waters. This dataset shows concentrations of lithium, sodium, potassium, magnesium, calcium, chloride, bromide, silicon, fluoride, SO4, found in various depths of Taylor Valley lakes.
inorganic nutrients LTER Core Areas
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-1637708). 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.
https://mcm.lternet.edu/content/ion-concentrations-discrete-water-column-samples-collected-lakes-mcmurdo-dry-valleys 1991-11-21 2019-12-17 Recent Changes On 2014, Inigo San Gil migrated the metadata into the Drupal Ecological Information System to modernize and improve the McMurdo Dry Valleys LTER services. Older Changes As part of a major database clean-up effort, Kathy Welch and Chris Gardner (database manager) decided to remake this entire table in July of 2007. It was found that there were numerous errors in the old table, including numbers in the wrong columns and errors with Si data. Kathy went through the data year-by-year and verified values against her original Excel files. The database table was remade with only mass values (mg/L) for each ion. The database then calculates molar values dynamically when the table is accessed. This table is now accurate a represents the most updated chemistry record for the dry valley lakes. The original iterations of the 'limnchem' file (limnological chemistry data) were created by Kathy Welch, and submitted to the Institute of Arctic and Alpine Research (INSTAAR) in a July 10, 1997 email message. Following discussions between Kathy Welch (who submitted data) and Denise Steigerwald (data manager), it was decided to remove some fields (eg., dilution factor, sample name), and add others (eg. collection site, collection date, comments for each type of measurement) to these files in order to make them more consistent and relational for future references. The resulting files contain the same name, but have 'xls' extensions. (They were altered using Microsoft Excel). Following these revisions, they were imported into Microsoft Access and saved in a table named "Limnological Chemistry 1991-95 (Welch / Lyons)" Because location name, collection date, and depth are all variables for this table, it was possible to combine each of these files in one table. This table was exported as an ascii, text, comma delimited file named "limnchem.dat" and saved in the appropriate directory to make it accessible on the web page. Data for 1998-2000 was submitted to the Data Manager (Kevin Wheeler) as files Limno_IC_9899.xls and Limno_IC_9900.xls. McMurdo Dry Valleys LTER Information Manager im@mcmlter.org McMurdo Dry Valleys LTER http://mcmlter.org/ McMurdo Dry Valleys LTER
 Lake sampling was carried out by lowering a Niskin bottle through a hole in the ice cover of the lake to specified depths. Samples were then collected in precleaned plastic bottles. Separate aliquots were collected in serum vials for pH and dissolved inorganic carbon (DIC) measurements. Samples were returned to field laboratories for processing and for time-sensitive analyses such as pH.                  Dedicated  sampling equipment for each lake has been important for maintaining the integrity of  the samples. For example, the range of Cl- concentration in the investigated lakes varies by more than three orders of magnitude. This carryover between samples becomes a potential problem. Carryover can also be a potential problem during analysis, and therefore analytical blanks are run to monitor this.                  The initial sample processing was  carried out in field laboratories. A 100-ml sample aliquot was filtered for each anion and cation sample. All samples were filtered through 0.4-microm Nucleopore filters,  usually within 12h of collection. The cation samples were filtered into acid-washed polyethylene bottles which had been rinsed with DI water, while the anion samples were  filtered into DI-washed bottles. The cation samples were acidified by adding 0.5%  (v/v) of concentrated HCl. Quality control was maintained by carefully rinsing all filtration apparatus with DI between samples and by processing filtration blanks which  were later run as samples.                  The majority of water chemistry samples were returned to the Crary Laboratory, McMurdo Station, Antarctica, for analysis. Some of the samples  were returned to the laboratory at the University of Alabama  (pre 2000) or the Ohio State University (post 2000) for analysis owing to  time constraints during the field season.                    DX-300 ion chromatographic system was used for the major ion analyses. The system included a gradient pump module, high-pressure injection valve with a 25-microm sample loop, a Dionex conductivity detector (CDM-3)  advanced computer interface and automated sampler. The timed events and data collection were controlled by the Dionex AI-450 chromatography software for Windows.  The same ion chromatographic system was used but was switched back and forth between anion and cation configurations.                 Appropriate dilutions of the stock standards were used to prepare a range of standards for calibration. Owing to the high salt concentrations in many of the samples, dilutions were made before the samples were run. Dilutions ranged from 1:2 for Lake  Hoare surface water up to 1:6000 for the Lake Bonney deep water. The samples were diluted by serial dilution, using plastic microbeakers and adjustable pipettors.                 Replicate and duplicate samples were run daily. Usually, each sample was injected twice and samples from each batch were run in duplicates to check the precision of the dilutions. In almost every case, the relative standard deviation of the duplicates was less than 1%, even with dilutions of 1:6000. In addition, analytical blanks and filtration blanks were analyzed to check the quality control.                Dissolved Silica analyses were done with the molybdate blue method.  After the 2007-2008 season silica analysis were done on a Skalar nutrient analyzer at the OSU                Lake water samples were analyzed in the field laboratories for DIC with an infrared gas analyzer. The DIC data was used with the other major ion data to calculate ionic balances as a further check on the data 
About Molar Units The Limnology chemistry table only contains mass units (mg/L) - molar units are calculated on the fly by the Oracle database. Therefore the number of significant figures may not be accurate. Please see the mass units for the appropriate number of significant figures
LIMNO_CHEMISTRY Limno chemistry mcmlter-lake-chemistry-20220207.csv 853390 1 1 \n column , " https://mcm.lternet.edu/sites/default/files/data/mcmlter-lake-chemistry-20220207.csv DATASET_CODE DATASET_CODE Code to designate the table name string Code to designate the table name LIMNO_RUN Limno Run Code for lake's sampling location and date string Code for lake's sampling location and date LOCATION NAME Location Name Name of lake where measurement was made string Name of lake where measurement was made LOCATION CODE Location Code Code for site where measurement was made string Code for site where measurement was made DATE_TIME Date/time Date sample was collected date mm/dd/yyyy Required entry None given Depth (m) Depth (m) Distance below the piezometric water level from which sample was drawn meter real Null None given Sample Comments Sample Comments General comments about the sample string General comments about the sample Li (mg/L) Li (mg/L) mass concentrations milligramsPerLiter real NULLr None given Li (mM) Li (mM) millimolar concentration millimoles/liter real NULL None given Li COMMENTS Li comments Comments string Comments Na (mg/L) Na (mg/L) mass concentrations milligramsPerLiter real NULL None given Na (mM) Na (mM) millimolar concentration millimoles/liter real NULL None given Na COMMENTS Na comments Comments on the Sodium concentration measurement string Comments on the Sodium concentration measurement K (mg/L) K (mg/L) mass concentrations milligramsPerLiter real NULL None given K (mM) K (mM) millimolar concentration millimoles/liter real NULL None given K COMMENTS K comments Comments on the potassium concentration measurement string Comments on the potassium concentration measurement Mg (mg/L) Mg (mg/L) mass concentrations milligramsPerLiter real NULL None given Mg (mM) Mg (mM) millimolar concentration millimoles/liter real NULL None given Mg COMMENTS Mg comments Comments on the Magnessium concentration measurement string Comments on the Magnessium concentration measurement Ca (mg/L) Ca (mg/L) mass concentrations milligramsPerLiter real NULL None given Ca (mM) Ca (mM) millimolar concentration millimoles/liter real NULL None given Ca COMMENTS Ca comments Comments on the Calcium concentration measurements string Comments on the Calcium concentration measurements F (mg/L) F (mg/L) mass concentrations milligramsPerLiter real NULLr None given F (mM) F (mM) millimolar concentration millimoles/liter real NULL None given F COMMENTS F comments Comments on the concentration of Iron measurement string Comments on the concentration of Iron measurement Cl (mg/L) Cl (mg/L) mass concentrations milligramsPerLiter real NULL None given Cl (mM) Cl (mM) millimolar concentration millimoles/liter real NULL None given Cl COMMENTS Cl comments Comments on the Chlorine concentration measurements string Comments on the Chlorine concentration measurements Br (mg/L) Br (mg/L) mass concentrations milligramsPerLiter real NULL None given Br (mM) Br (mM) millimolar concentration millimoles/liter real NULL None given Br COMMENTS Br comments Comments on the concentration of Bromide measurement string Comments on the concentration of Bromide measurement SO4 (mg/L) SO4 (mg/L) mass concentrations milligramsPerLiter real NULL None given SO4 (mM) SO4 (mM) millimolar concentration millimoles/liter real NULL None given SO4 COMMENTS SO4 comments Comments string Comments Si (mg/L) Si (mg/L) mass concentrations milligramsPerLiter real NULL None given Si (mM) Si (mM) millimolar concentration millimoles/liter real NULL None given Si COMMENTS Si comments Comments string Comments File Name File Name Original file name before entered into database string Original file name before entered into database DEPTH MASL DEPTH MASL Depth referred to the Sea level. Distance below Mean Average Sea water level reference from which sample was drawn meter 1 real