Dissolved inorganic carbon (DIC) 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 inorganic material transport in perennial ice-capped lakes. This data set addresses this core area of research and quantifies dissolved inorganic carbon concentrations at specific depths in McMurdo Dry Valley lakes. Dissolved inorganic carbon is also necessary for the computation of primary productivity.

Date Range:

October 27, 1993 to December 22, 2022

Data Citation

Priscu, J.C. 2023. Dissolved inorganic carbon (DIC) 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/fadcc745b6ecb6d1942dda95ef373eab. Dataset accessed 27 April 2024.

Dataset(s)

Description:

Dissolved Organic Carbon data

Variables (click to expand):

DATASET_CODE

Label:
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:
Definition: Name of lake where measurement was made
Type: Nominal
Missing values: None specified

Location Code

Label:
Definition: Code for site where measurement was made
Type: Nominal
Missing values: None specified

DATE_TIME

Label:
Definition: Date on which sample was gathered
Type: Date/time
Date format: mm/dd/yyyy
Missing values: None specified

Depth (m)

Label:
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

DIC (mg C/l)

Label:
Definition: Dissolved inorganic carbon concentration found at lake depth - mass units
Type: Physical quantity
Unit: milligramsPerLiter
Maximum: 3000
Minimum: 0
Precision: 0.1
Missing values:
- Null = None given

DIC (mM)

Label:
Definition: Dissolved inorganic carbon concentration found at lake depth - moles
Type: Physical quantity
Unit: mM
Maximum: 500
Minimum: 0
Precision: 0.1
Missing values:
- Null = None given

DIC Comments

Label:
Definition: Helpful hints about the DIC sample
Type: Nominal
Missing values: None specified

File Name

Label:
Definition: Name of file in which data was submitted
Type: Nominal
Missing values: None specified

DEPTH MASL

Label:
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-dic-20230711.csv (403.21 KB)

Short name:

limndic.dat

Dataset ID:

People

Principal Investigator(s):

John C. Priscu

Contact:

McMurdo Dry Valleys LTER Information Manager

Associated Personnel:

Field Technician

Lab Technician

Data Manager

Former Field Crew

Former Data Manager

Methodology

Methods:

General Methodology

Lake water samples are collected at specific depths with a five-liter Niskin bottle during normal LTER limnological sampling. Dissolved inorganic carbon samples (1 at each depth) are decanted through tubing directly from the Niskin bottle into a 30 mL serum vial. Lake water is allowed to overflow from the serum vial and completely displace the initial sample volume. Each sample is preserved with 0.15 mL chloroform, capped with a rubber stopper and crimped with an aluminum cap. Samples are stored in the dark at 4 degrees C until analysis. Samples are analyzed in at least duplicate following a method of sample acidification followed by infrared gas analysis using an IRGA (Infrared Gas Analyzer), and comparison to a standard curve. The standard curve is created by analyzing incremental samples of a 60 mgC/L DIC standard. The reported dissolved inorganic carbon concentrations of the lake water samples are averages of the replicate sample analyses. Analyses were performed with either an MSA Lira IRGA with HP Integrator or a Licor 6252 CO2 analyzer prior to the 2003-2004 season, with an MSA Lira IRGA with HP Integrator or Peak Simple Chromatography Data System from the 2003-2004 – 2006-2007 season, and with a Qubit Systems Infrared CO2 Analyzer with Peak Simple Chromatography Data System from the 2007-2008 season to present.

Notes on 2006-2007 Season DIC Data and methods

The IRGA malfunctioned during the 0607 season yielding DIC data that were highly suspect. Alkalinity titrations were done according to standard methods and DIC was estimated based on Wetzel R.G. and G.E. Likens. 1991. Limnological Analyses. 2nd Edition. Springer-Verlag New York Inc. pp. 111-118. Note that hydrogen acceptors other than the carbonate system exist in the lakes yielding an overestimate of DIC. We also computed average DIC values from the 05-06 and 07-08 seasons. DIC data changes relatively little over time; A paired t-test revealed that there was no significant difference between DIC for these 2 years (p>0.05). We report in the database DIC data computed from alkalinity titrations, and provide a link in the metadata to DIC data computed from averages of 05-06 and 07-08 DIC. The file containing DIC values computed from the average of previous and next season DIC values can be found in the following link: http://mcmlter.org/data/lakes/chemistry/core/LIMNO_DIC_0607.csv">http://mcmlter.org/data/lakes/chemistry /core/LIMNO_DIC_0607.csv

Maintenance:

2015 - data and metadata managed now using the Drupal Ecological Information Management System

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 and 1994/95 datasets are Microsoft Excel version 6.0 files, and the 1995/96, 1996/97 and 1997/98 datasets 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 Metadic9697.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.

Additional information:

Data contained in these files has been subjected to quality control standards imposed by the investigator. The user of this data should be aware that, while efforts have been taken to ensure that these data are of the highest quality, there is no guarantee of perfection for the data contained herein and the possibility of errors exists. If you encounter questionable data, please contact the MCM LTER data manager corrected or qualified. Thus, these data may be modified and future data will be appended.

Research Section:

LTER Core Areas:

inorganic nutrients

MCM Keywords:

Keywords:

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