uid=MCM,o=EDI,dc=edirepository,dc=org all public read limndoc.dat John Priscu jpriscu@montana.edu https://orcid.org/0000-0001-5807-6364 McMurdo Dry Valleys LTER http://mcmlter.org/ Jade Lawrence jlawrence1@unm.edu https://orcid.org/0009-0005-2603-342X field technician Kathleen Welch kathleen.welch@colorado.edu https://orcid.org/0000-0003-1028-3086 lab technician 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 2022-03-21 English

The McMurdo Long Term Ecological Research (LTER) project monitors patterns of organic material transport in perennial ice-capped lakes. This data set addresses this core area of research and quantifies dissolved organic carbon concentrations at specific depths in McMurdo Dry Valley lakes.

dissolved organic carbon lakes LTER Controlled Vocabulary Antarctica carbon dissolved organic carbon DOC lake limnology organic Station Keywords organic matter LTER Core Areas

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.

https://mcm.lternet.edu/content/dissolved-organic-carbon-concentrations-lakes 1993-10-27 2022-01-08   2015 - data and metadata now managed using the Drupal Ecological Information Management System (Inigo San Gil, Ara Kooser and TIna Tacaks-Vesbach)   Data from this table was submitted to INSTAAR by John Priscu's team at Montana State University. The raw data files listed under 'file name' are the names of the original  files submitted. The 1993/94 data is a Microsoft Excel version 6.0 file, and the 1996/97 and 1997/98 data are ascii text files. Upon arrival at INSTAAR, the data manager fine-tuned the location codes and limno runs to match those provided in the "locations, dates, codes for  lake chemistry, biology samples" file. The file was imported into Microsoft Access on  INSTAAR's Unix system, and can currently be found there. The file was then exported in ascii, comma delimited text and MS-DOS text (table layout) to present on the MCM LTER web site. Both  of these files are linked to this web page above. Information for the metadata was obtained from the MetaDOC9697.rtf file. The file was called up using Microsoft Word version 6.0. Text from this file was used to create this page in html format. While processing the 1997-98 data, the data manager noticed that the values provided for dissolved organic carbon (DOC) from Lake Fryxell in the 1996-97 season did not have the appropriate conversion done between DOC (mg/L) and DOC (mM). The mM number should equal the mg/L value divided by 12, but in this  case it was divisible by 2. Craig Wolf was contacted to look into this in November 1999, but since it was the middle of the field season, it took some time to resolve it. On 28-Feb-2000, the 1996-97 DOC (mM) values for Lake Fryxell were updated to the DOC (mg/L) values divided by 12 (rather than DOC (mg/L) divided by 2).   A major revision of the DOC metadata was conducted on 2014. Publication date and associated personnel added, along with new supporting methods metadata and several other corrections. In addition, metadata was liberated from the EML format into the Drupal Ecological Information Management System McMurdo Dry Valleys LTER Information Manager im@mcmlter.org McMurdo Dry Valleys LTER http://mcmlter.org/ McMurdo Dry Valleys LTER

Collection and sample processing methods: Lake water samples are collected at specific depths with a five-liter Niskin bottle during routine LTER limnological sampling. Sub-samples for DOC analysis are decanted into a 1 L amber Nalgene bottle. One-100 mL sub-sample is taken from the one-liter amber Nalgene bottle. The sub-sample is filtered through a combusted (475 degrees celsius for 4 hours) Whatman 25 mm GF/F and collected directly into a 100 mL acid washed, combusted amber borosilicate glass bottle (475 degrees Celsius for 4 hours), preserved with 1 mL of 6N hydrochloric acid (HCL), and capped with a Teflon-lined screw cap. The sample is stored at 4 deg. Celsius until analysis with the Shimadzu 5000 TOC analyzer (before the 0203 season), or the Shimadzu TOC-V (current). The filter is used for chlorophyll-a analysis. To reduce salt interference, samples are diluted as follows in this link https://mcm.lternet.edu/sites/default/files/DilutionsTable%200001-1617.xlsx Method detection limits (MDL) are as follows: 9394-9900: MDL unknown. 0001: 0.1 mg/L. 0102: 0.1 mg/L. 0203: 0.5 mg/L. 0304: 0.2 mg/L. 0405: 0.2 mg/L. 0506: 0.2 mg/L. 0607: 0.2 mg/L. 0708: 0.2 mg/L. 0809: 0.2 mg/L (FRX L1, HOR L1, HOR L3, MIE L2: 0.4 mg/L). 0910: 0.2 mg/L 1011: 0.2 mg/L. 1112: 0.2 mg/L. 1213: 0.2 mg/L. 1314: 0.2 mg/L. 1415: 0.2 mg/L 1516: 0.2 mg/L 1617: 0.2 mg/L Instrument output that could not be quantified are denoted as ND. 

LIMNO_DOC mcmlter-lake-doc-20220321.csv 517831 1 1 \n column , " https://mcm.lternet.edu/sites/default/files/data/mcmlter-lake-doc-20220321.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 Date on which sample was gathered date mm/dd/yyyy Depth (m) Depth (m) Distance below the piezometric water level from which sample was drawn. meter 1 real 1 45 DOC (mg/L) DOC (mg/L) Dissolved organic carbon concentration found at lake depth mass units milligramsPerLiter 0.1 real 0 100 Null None given DOC (mM) DOC (mM) Dissolved organic carbon concentration found at lake depth moles mM 0.01 real 0 20 Null None given DOC Comments DOC Comments Helpful hints about the DOC sample string Helpful hints about the DOC sample File Name File Name Name of file in which data was submitted string Name of file in which data was submitted 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