DISSOLVED INORGANIC CARBON CONCENTRATIONS IN MCMURDO DRY VALLEY LAKES


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DISSOLVED INORGANIC CARBON CONCENTRATIONS IN MCMURDO DRY VALLEY LAKES
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PRINCIPAL INVESTIGATOR: John Priscu
Address:Department of Biology, Montana State University, Bozeman MT, 59717
Phone:(406)994-3250
E-Mail:ubijp@gemini.oscs.montana.edu or JPriscu@LTERnet.edu

KEYWORDS: lake, limnology, dissolved inorganic carbon, DIC, Antarctica

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.

VARIABLES: limno run, location name, location code, date, depth (m), DIC (mg C L-1), DIC (mM), DIC comments, file name

RESEARCH LOCATION: Samples were collected from the East Lake Bonney, West Lake Bonney, Lake Hoare, and Lake Fryxell limnological sampling stations, located in the McMurdo Dry Valleys of Antarctica. Descriptions of these lakes can be found in the McMurdo Dry Valley Lake Descriptions file.

METHODS: Lake water samples were collected at specific depths with a five-liter Niskin bottle during normal LTER limnological sampling. Dissolved inorganic carbon samples were decanted directly from the Niskin bottle into a 30 mL serum vial. Lake water was allowed to overflow from the serum vial and completely displace the initial sample volume. The sample was preserved with 0.15 mL chloroform, capped with a rubber stopper and crimped with an aluminum cap. Samples were stored in the dark at 4°C until analysis. Analyses were performed with either a MSA Lira infrared gas analyzer with a HP Integrator or a Licor 6252 CO2 analyzer, depending on the analysis location (i.e. field lab or McMurdo), following N2 sparging in 6 N H2S04. The Licor instrument automatically calculates integrated peak areas. A DIC standard (60 mg C L-1) was prepared and incremental samples were injected (0.1, 0.3, 0.5, 0.7, 0.9 mL) into the sparging chamber and analyzed by the IRGA. The slope of the peak areas was used to calculate the dissolved inorganic carbon concentrations of the lake water sample.

TIMING: Samples were collected from the following sites and dates:


 
Season		East Bonney	West Bonney	Hoare		Fryxell		Trough
1993-1994	27-Oct-1993	29-Oct-1993	 6-Nov-1993	16-Nov-1993
 		10-Nov-1993	12-Nov-1993	 1-Dec-1993	 7-Dec-1993
 		24-Nov-1993	26-Nov-1993	30-Dec-1993	 7-Jan-1994
 		 7-Dec-1993	 9-Dec-1993	19-Jan-1994	18-Jan-1994
 		21-Dec-1993	23-Dec-1993
 													
1994-1995	 2-Nov-1994	 5-Nov-1994	10-Nov-1994	14-Nov-1994
 		23-Nov-1994	25-Nov-1994	30-Nov-1994	 4-Dec-1994
 		17-Dec-1994	19-Dec-1994	24-Dec-1994	30-Dec-1994
 		10-Jan-1995	12-Jan-1995	20-Jan-1995	17-Jan-1995
 		
1995-1996	19-Sep-1995	21-Sep-1995	 7-Sep-1995	14-Sep-1995
						14-Sep-1995
  		 6-Oct-1995	 4-Oct-1995	25-Sep-1995	28-Sep-1995
 		17-Oct-1995	19-Oct-1995	10-Oct-1995	14-Oct-1995
 		 2-Dec-1995	 5-Dec-1995	21-Nov-1995	26-Nov-1995
 		 1-Jan-1996	 4-Jan-1996	23-Dec-1995	27-Dec-1995
 					 
1996-1997	 3-Nov-1996	 1-Nov-1996	 8-Nov-1996	26-Oct-1996
 		24-Nov-1996	26-Nov-1996	 2-Dec-1996	19-Nov-1996
 		 1-Jan-1997	17-Jan-1997	12-Jan-1997	 9-Jan-1997
 		 					
1997-1998	8-Nov-1997	11-Nov-1997	15-Nov-1997	18-Nov-1997		
 						12-Dec-1997	16-Dec-1997
 		20-Dec-1997	22-Dec-1997	26-Dec-1997	29-Dec-1997

1998-1999	 9-Nov-1998	11-Nov-1998	 3-Nov-1998	28-Oct-1998
		 6-Dec-1998	 9-Dec-1998 	 1-Dec-1998	23-Nov-1998
		30-Dec-1998	 1-Jan-1999	26-Dec-1998	20-Dec-1998	23-Dec-1998

1999-2000	 6-Nov-1999	11-Nov-1999	17-Nov-1999	30-Oct-1999
		 3-Dec-1999	 5-Dec-1999	12-Dec-1999	27-Nov-1999
		28-Dec-1999	30-Dec-1999	 4-Jan-2000	23-Dec-1999

 						 

CITATIONS:

COMMENTS:

STATUS: Public Access (Type 1).

VARIABLE DESCRIPTION:

VARIABLE

TYPE

DESCRIPTION

UNITS

MISSING VALUE INDICATOR

MINIMUM

MAXIMUM

PRECISION

Limno Run

Text

Code for lake's sampling location and date

none

Required entry

n/a

n/a

n/a

Location Name

Text

Name of lake where measurement was made

none

Required entry

n/a

n/a

n/a

Location Code

Text

Code for site where measurement was made

none

Required entry

n/a

n/a

n/a

Date

Date

Date on which sample was gathered

mm/dd/yy

Required entry

01/01/93

12/31/99

dd

Depth (m)

Number

Distance below ice from which sample was drawn

meters

Required entry

1

45

1

DIC (mg C/l)

Number

Dissolved inorganic carbon concentration found at lake depth

mg of carbon / liter

Null

0

3000

0.1

DIC (mM)

Number

Dissolved inorganic carbon concentration found at lake depth

mM of carbon

Null

0

500

0.1

DIC Comments

Text

Helpful hints about the DIC sample

none

Null

n/a

n/a

n/a

File Name

Text

Name of file in which data was submitted

none

Null

n/a

n/a

n/a

LOG: 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.

NOTE: 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 (; (303)492-4639) so that the data can be corrected or qualified. Thus, these data may be modified and future data will be appended.