Limno run codes, dates, and locations associated with vertical lake profile data collected in the McMurdo Dry Valleys, Antarctica (1991-2023, ongoing)

Summary

Abstract:

This data package provides a summary of "limno runs" performed each season in lakes located throughout the McMurdo Dry Valleys of Antarctica as part of the McMurdo Dry Valleys Long Term Ecological Research program. Each limno run is identified by unique code that allows one to compile a complete set of limnological data from a particular lake and location at specific time points. There are usually two or three limno runs performed per lake per austral summer field season, although the number of runs may vary by lake and by season depending on site access, site conditions, and other external factors.

Date Range:

November 21, 1991 to January 7, 2023

Data Citation

Priscu, J. 2023. Limno run codes, dates, and locations associated with vertical lake profile data collected in the McMurdo Dry Valleys, Antarctica (1991-2023, ongoing). Environmental Data Initiative. DOI: 10.6073/pasta/fafc7bc34b22d2e9a93f75e632cfb9d3. Dataset accessed 4 October 2023.

Dataset(s)

Variables (click to expand):

DATASET_CODE

Label:
Definition: Code to identify the data containing entity - LIMNO_RUN_CODING
Type: Nominal
Missing values: None specified

Limno_Run

Label:
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

STARTING_DATE

Label:
Definition: Date on which sampling began
Type: Date/time
Date format: MM/DD/YYYY
Missing values:
- Required entry = None given

ENDING_DATE

Label:
Definition: Date on which sampling ended
Type: Date/time
Date format: MM/DD/YYYY
Missing values:
- Required entry = None given

LAT

Label: Latitude
Definition: Point of Latitude of the sampling and CTD deployment hole.
Type: Physical quantity
Unit: dimensionless
Maximum: 1
Minimum: 0
Precision: 0.0001
Missing values:
- Null = None given

LON

Label: Longitude
Definition: Point of Longitude of the sampling and CTD deployment hole.
Type: Physical quantity
Unit: dimensionless
Maximum: 1
Minimum: 0
Precision: 0.0001
Missing values:
- Null = None given

COMMENTS

Label:
Definition: Comments about the particular limno run
Type: Nominal
Missing values: None specified

File:

mcmlter-lake-limno_runs-20230711.csv (44.3 KB)

Short name:

LIMNO_RUN_CODING

Dataset ID:

People

Principal Investigator(s):

John Priscu

Contact:

McMurdo Dry Valleys LTER Information Manager

Associated Personnel:

Field Technician

Data Manager

Former Field Crew

Methodology

Methods:

Two 10-cm-diameter sampling holes are drilled through the ice by auger at the deepest site of each lake and then melted out to a diameter of ~30 cm. One hole is used for

water column PAR profiles and the primary productivity incubation; the other hole is used for discrete water sampling (Van Dorn or Niskin bottles) and CTD deployment and

is protected with an opaque cover.

Discrete water samples are collected at specific depths relative to the water level in the borehole in each lake to capture important vertical characteristics. Appendix 6.1 in the Limnology Methods Manual lists the target depths at which samples are collected. However, due to environmental conditions (ice thickness, bottom depth in area of sample hole caused by lake level variation) the samples immediately beneath the ice and nearest to the bottom cannot always be replicated. Consequently, the top sample is collected ~0.5m below the bottom of the ice cover, and the bottom sample as close to the bottom of the lake as possible without disturbing the sediment.

Maintenance:

Aug 2016 - Fixes typos in lat/lon variables reported by Amy C.Metadata enhanced in 2016 using the Drupal Ecological Information Management System (DEIMS)

Additional information:

Research Section:

MCM Keywords:

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