Dissolved organic carbon (DOC) concentrations in discrete water column samples collected from lakes in the McMurdo Dry Valleys, Antarctica (1993-2022, ongoing)

Summary

Abstract: 

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.

Date Range: 

October 27, 1993 to January 8, 2022
Data Citation
Priscu, J.C. 2022. Dissolved organic carbon (DOC) concentrations in discrete water column samples collected from lakes in the McMurdo Dry Valleys, Antarctica (1993-2022, ongoing). Environmental Data Initiative. DOI: 10.6073/pasta/a5d82d5d2167679c8ecff0d8ad06c0ee. Dataset accessed 20 September 2024.
Dataset(s)

Variables (click to expand): 

DATASET_CODE
  • Label: Dataset Code
  • Definition: Code to designate the table name
  • Type: Nominal
  • Missing values: None specified
LIMNO_RUN
  • Label: Limno Run
  • Definition: Code for lake's sampling location and date
  • Type: Nominal
  • Missing values: None specified
LOCATION NAME
  • Label: Location Name
  • Definition: Name of lake where measurement was made
  • Type: Nominal
  • Missing values: None specified
LOCATION CODE
  • Label: Location Code
  • Definition: Code for site where measurement was made
  • Type: Nominal
  • Missing values: None specified
DATE_TIME
  • Label: Date
  • Definition: Date on which sample was gathered
  • Type: Date/time
  • Date format: mm/dd/yyyy
  • Missing values: None specified
Depth (m)
  • Label: Depth (m)
  • Definition: Distance below the piezometric water level from which sample was drawn.
  • Type: Physical quantity
  • Unit: meter
  • Maximum: 45
  • Minimum: 1
  • Precision: 1
  • Missing values: None specified
DOC (mg/L)
  • Label: DOC (mg/L)
  • Definition: Dissolved organic carbon concentration found at lake depth mass units
  • Type: Physical quantity
  • Unit: milligramsPerLiter
  • Maximum: 100
  • Minimum: 0
  • Precision: 0.1
  • Missing values:
    • Null = None given
DOC (mM)
  • Label: DOC (mM)
  • Definition: Dissolved organic carbon concentration found at lake depth moles
  • Type: Physical quantity
  • Unit: mM
  • Maximum: 20
  • Minimum: 0
  • Precision: 0.01
  • Missing values:
    • Null = None given
DOC Comments
  • Label: DOC Comments
  • Definition: Helpful hints about the DOC sample
  • Type: Nominal
  • Missing values: None specified
File Name
  • Label: File Name
  • Definition: Name of file in which data was submitted
  • Type: Nominal
  • Missing values: None specified
DEPTH MASL
  • Label: DEPTH MASL
  • Definition: Depth referred to the Sea level. Distance below Mean Average Sea water level reference from which sample was drawn
  • Type: Physical quantity
  • Unit: meter
  • Maximum: Not specified
  • Minimum: Not specified
  • Precision: 1
  • Missing values: None specified

File: 

mcmlter-lake-doc-20220321.csv (505.69 KB)

Short name: 

limndoc.dat

Dataset ID: 

60
People

Principal Investigator(s): 

John C. Priscu

Contact: 

McMurdo Dry Valleys LTER Information Manager

Associated Personnel: 

Field Technician
Jade Lawrence
Lab Technician
Kathleen A. Welch
Data Manager
Renée F. Brown
Former Field Crew
Amy Chiuchiolo
Former Data Manager
Inigo San Gil
Related
Methodology

Methods: 

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. 

Maintenance: 

 
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
Categories

Research Section: 

LTER Core Areas: 

MCM Keywords: 

Keywords: 

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