Nitrogen and phosphorus concentrations in glacial meltwater streams, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing)

Summary

Abstract:

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor the glacial meltwater streams in that region. This table contains macronutrient concentrations (nitrate, nitrite, ammonium, soluble reactive phosphorus) found at specific locations in McMurdo Dry Valley streams.

Date Range:

December 2, 1993 to December 23, 2023

Data Citation

Diaz, M.A., Gooseff, M.N., Lyons, W. 2025. Nitrogen and phosphorus concentrations in glacial meltwater streams, McMurdo Dry Valleys, Antarctica (1993-2023, ongoing). Environmental Data Initiative. DOI: 10.6073/pasta/9435576d5755c30a1aa694a9ebea3e2d. Dataset accessed 17 March 2025.

Dataset(s)

Description:

Details on the stream nutrients spreadsheet, such as scientifics units used, measurement definitions and other supporting information to interpret accurately the data provided in the spreadsheet columns,

Variables (click to expand):

DATASET_CODE

Label: Dataset code
Definition: Code representing stream nutrients dataset
Type: Nominal
Missing values: None specified

strmgageid

Label:
Definition: Code representing stream gauge station
Type: Nominal
Missing values: None specified

LOCATION NAME

Label: Location
Definition: Name of stream gauge station
Type: Nominal
Missing values: None specified

Sample Name

Label:
Definition: An ID to Name the sample
Type: Nominal
Missing values: None specified

DATE_TIME

Label:
Definition: Date/time of sample (McMurdo time)
Type: Date/time
Date format: MM/DD/YYYY HH24:mi
Missing values: None specified

N-NO3 (ug/L)

Label:
Definition: nitrate concentration in mass units
Type: Physical quantity
Unit: microgramsPerLiter
Maximum: Not specified
Minimum: -1.0
Precision: 0.1
Missing values:
- Null = None given

N-NO3 (uM)

Label: N-NO3 (microM)
Definition: nitrate concentration in molar units
Type: Physical quantity
Unit: microM
Maximum: Not specified
Minimum: -1.0
Precision: 0.001
Missing values:
- Null = None given

N-NO2 (ug/L)

Label:
Definition: nitrite concentration in mass units
Type: Physical quantity
Unit: microgramsPerLiter
Maximum: Not specified
Minimum: Not specified
Precision: Not specified
Missing values:
- Null = None given

N-NO2 (uM)

Label: NO2 (microM)
Definition: nitrite concentration in molar units
Type: Physical quantity
Unit: microM
Maximum: Not specified
Minimum: -1.0
Precision: 0.1
Missing values:
- Null = None given

no3_no2_n_ugl

Label:
Definition: Concentration of nitrate + nitrate as N.
Type: Physical quantity
Unit: microgramPerLiter
Maximum: Not specified
Minimum: -1.0
Precision: 0.1
Missing values:
- Null = None given

no3_no2_n_um

Label:
Definition: Concentration of nitrate + nitrate as N.
Type: Physical quantity
Unit: microMole
Maximum: Not specified
Minimum: Not specified
Precision: Not specified
Missing values: None specified

N-NH4 (ug/L)

Label:
Definition: ammonium concentration in mass units
Type: Physical quantity
Unit: microM
Maximum: Not specified
Minimum: -1.0
Precision: 0.1
Missing values:
- Null = None given

N-NH4 (uM)

Label: NH4 (microM)
Definition: ammonium concentration in molar units
Type: Physical quantity
Unit: microMole
Maximum: Not specified
Minimum: Not specified
Precision: Not specified
Missing values:
- Null = None given

SRP (ug/L)

Label:
Definition: Soluble Reactive P concentration in mass units
Type: Physical quantity
Unit: microM
Maximum: Not specified
Minimum: -1.0
Precision: 0.1
Missing values:
- Null = None given

SRP (uM)

Label: SRP (microM)
Definition: Soluble Reactive P concentration in molar units
Type: Physical quantity
Unit: microM
Maximum: Not specified
Minimum: -1.0
Precision: 0.1
Missing values:
- Null = None given

Remarks

Label:
Definition: Remarks about samples.
Type: Nominal
Missing values: None specified

Analytical_Method

Label:
Definition: Method / instrument used to measure nutrient concentrations
Type: Nominal
Missing values: None specified

File:

mcmlter-strm-nutrients-20250227.csv (691.11 KB)

Short name:

STREAM_NUTRIENTS

Dataset ID:

People

Principal Investigator(s):

Melisa A. Diaz

Michael N. Gooseff

W. Berry Lyons

Contact:

McMurdo Dry Valleys LTER Information Manager

Associated Personnel:

Lab Technician

Data Manager

Methodology

Methods:

See analytical_method column.

Maintenance:

In 2025, NO3-N + NO2-N column added to reflect new analytical method. Comments fields were standardized and merged into a single remarks field.

In 2016, data gathered at non-core locations (places monitored for the long term) was added to this dataset, going back to the 2007/2008 season.

In 2015, the metadata was migrated to DEIMS to enhance the McMurdo LTER services.

In 2008, Kathy Welch and the Information Manager (Chris Gardner went through the stream nutrients table and QA/QCd every season. All molar units were converted back to mass units (ug/L) and an Oracle View was created to make the conversion to molar units automatic in order to avoid human conversion errors. Many previously-reported values were also found to be below the known detection limit analyzed on the Lachat. These were flagged as ND, and put into the comments column. All pre-LTER data were removed from the table because there were many duplicate stream gauge ID/ dates with no times. There were also many non-core locations in the table. Constraints were added to the new database to ensure non-core data are not added in the future, and no duplicate stream gauge ID/DATE_TIMEs can be added. The original iterations of the 'strmnutr' file (stream nutrient data) were created by Kathy Welch, and submitted to Denise Steigerwald (the data manager) at the Institute of Arctic and Alpine Research (INSTAAR). These files are currently located on the PC in the data manager's office at INSTAAR. Following discussions between Kathy Welch and Denise Steigerwald, it was decided to add some fields (eg. strmgageid, collection date, comments for each type of measurement) to these files in order to make them more consistent and relational for future references. Following these revisions, they were imported into Microsoft Access and saved in a table named "Stream Nutrients". This table was exported as an ascii, text, comma delimited file (strmnutr.dat) and as an MS-DOS text, table layout file (strmnutr.txt), to present on the MCM LTER web site. Both of these files are linked to this web page above.

Research Section:

LTER Core Areas:

inorganic nutrients

MCM Keywords:

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