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PRINCIPAL INVESTIGATOR: KEYWORDS: lake, limnology, dissolved organic carbon, DOC, Antarctica
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.
VARIABLES: limno run, location name, location code, date, depth (m),
DOC (mg L-1), DOC (mM), DOC comments, file name
RESEARCH LOCATION: Samples were collected from the East Lake Bonney, West Lake Bonney, Lake Hoare, Lake Fryxell,
Lake Joyce, and Lake Miers limnological sampling stations, located in the McMurdo Dry Valleys of Antarctica, as well as from Pony
Lake on Ross Island. 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. Sub-samples were
decanted into three-1 L Nalgene bottles (2-light and 1-amber), two-500 mL amber
Nalgene bottles, three-150 mL borosilicate glass bottles, two-20 mL scintillation
vials, and one-30 mL serum vial. One-100 mL dissolved organic carbon sub-sample was
taken from the one-liter amber Nalgene bottle. The sample was filtered through a
combusted (475°C for 4 hours) Whatman 25 mm GF/F filter using a bell jar apparatus.
The filtrate was collected in a 100 mL acid washed, combusted amber bottle (475°C for
8 hours) and preserved with 1 mL of concentrated phosphoric acid. The sample was
stored at 4°C until analysis by ASA Analytical Services. The filter was used for
chlorophyll-a analysis.
TIMING: Samples were collected from the following sites and dates:
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 DOC (mg/L) Number Dissolved organic carbon concentration found at lake depth mg / liter Null 0 100 0.1 DOC (mM) Number Dissolved organic carbon concentration found at lake depth mM of carbon Null 0 20 0.01 DOC Comments Text Helpful hints about the DOC sample Null n/a n/a n/a File Name Text Name of file in which data was submitted 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 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) & 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).
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.
Season East Bonney West Bonney Hoare Fryxell Joyce Miers Pony Lake Trough
1993-1994 27-Oct-1993 29-Oct-1993 16-Nov-1993
24-Nov-1993 26-Nov-1993 7-Dec-1993
23-Dec-1993 7-Jan-1994
18-Jan-1994
1996-1997 30-Oct-1996 1-Nov-1996 26-Oct-1996 26-Oct-1996 14-Nov-1996 10-Dec-1996 22-Jan-1997
3-Nov-1996 4-Nov-1996 2-Nov-1996 27-Oct-1996 5-Dec-1996
24-Nov-1996 26-Nov-1996 8-Nov-1996 9-Nov-1996
15-Jan-1997 17-Jan-1997 10-Nov-1996 19-Nov-1996
23-Nov-1996 12-Dec-1996
2-Dec-1996 2-Jan-1997
13-Dec-1996 9-Jan-1997
12-Jan-1997 24-Jan-1997
20-Jan-1997
1997-1998 8-Nov-1997 11-Nov-1997 15-Nov-1997 18-Nov-1997 9-Dec-1997 5-Dec-1997
20-Dec-1997 22-Dec-1997 12-Dec-1997 29-Dec-1997
26-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
none
none