| Data Tables, Images, and Other Entities: |
| Data Table: | Air_Temperature_Units
View Table Metadata
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| Data Table: | File_and_Record_Numbers
View Table Metadata
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| Data Table: | Ice_Surface_Change_Units
View Table Metadata
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| Data Table: | Ice_Temperature_Units
View Table Metadata
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| Data Table: | Solar_Radiation_Units
View Table Metadata
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| Data Table: | Relative_Humidity_Units
View Table Metadata
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| Data Table: | Ice_Surface_Temperature_Units
View Table Metadata
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| Data Table: | Wind_Measurement_Units
View Table Metadata
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| Data Table: | Water_Vapor_Density_Units
View Table Metadata
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Short Name: | commonwealth_met |
| Online Distribution Info: |
| Schema Name: | http://www.mcmlter.org/queries/met_results.jsp |
| Description: |
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You can build your own query for all the data in this station using the URL http://www.mcmlter.org/queries/met_results.jsp and
the described parameters, or you can just visit the URL http://www.mcmlter.org/queries/met_queries.jsp and simply use the form to build your
own metereology query from any McMurdo Dry Valleys Metereological station
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Here is an example to query for the barometric pressure from March 1998 to April 2000 at Lake Hoare:
http://www.mcmlter.org/queries/met_results.jsp?begDate=03/01/1998&endDate=04/01/2000&mask=MM/DD/YYYY%20HH24:Mi&metStation=HOEM&dataType=PRESSTA
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variable (dataType) abbreviations list for Commonwealth Glacier Meteorological Station - COHM
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RH (relative humidity at 3m)
AIRT (air temperature @ 3m)
WIND (wind speed, direction, etc)
RADN (radiation)
ICET (ice temperature)
ICESURFCHANGE (Ice surface change)
SURFTEMP (thermal infrared surface temperature)
WVAPD (water vapor density)
FLINE (file and record numbers)
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| begDate: |
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| Desired begin date for the data, use format MM/DD/YYYY |
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| endDate: |
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| Desired End Date for the data query |
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| mask: |
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| Associated Date format for the data record. (I.e, a mask value that works here is
MM/DD/YYYY HH24:Mi or - decimal - for a decimal year) |
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| metStation: |
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| Code Name for the metereological station from which the data is asked, for this station is commonwealth - COHM |
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| dataType: |
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| variable abbreviation for the parameter of interest, such as wind speed or air temperature. For a list of the used abbreviations, see the description section above |
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| Data Set Owner(s): |
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Individual: | Andrew G. Fountain |
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Address: |
| Department of Geology, |
| 17 Cramer Hall, |
| 1721 SW Broadway, |
| Portland State University , |
| Portland, OR 97207-0751
USA |
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Phone:
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Email Address:
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| Metadata Provider(s): |
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Organization: | McMurdo Dry Valleys LTER |
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Address: |
| Byrd Polar Research Center , |
| 108 Scott Hall, |
| 1090 Carmack Rd, |
| Columbus, OH 43210-1002 USA |
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Phone:
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Phone:
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Email Address:
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| Associated Party: |
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Individual: | Hassan Basagic |
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Address: |
| Department of Geology, |
| Portland State University , |
| Portland, OR 97207-0751
USA |
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Email Address:
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Role:
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| Abstract: |
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As part of the Long Term Ecological Research in the McMurdo Dry Valleys of Antarctica, meteorological data was collected from various
locations throughout Taylor, Wright and Victoria Valleys. These files contain data for the Commonwealth Glacier meteorology station (in Taylor Valley).
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| Keywords: |
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- glacier
(theme)
- meteorology
(theme)
- air temperature
(theme)
- ice temperature
(theme)
- wind
(theme)
- relative humidity
(theme)
- radiation
(theme)
- snow depth
(theme)
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| Additional Information: |
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| Comments |
Meteorological data is collected year-round at each of the stations in the McMurdo Dry Valleys of Antarctica.
After retrieving this data (usually every January), the parameters that are recorded are processed from level 0 (raw) to level
1 (processed, provided on the web). The raw data file descriptions and task lists summarize what was done to get from
level 0 to level 1 for all station found at the following address:
http://www.mcmlter.org/data/meteorology/tasks/task_lists.htm
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| Citations |
Doran, Peter T., Gayle L. Dana, Jordan T. Hastings and Robert A. Wharton, Jr. 1995.
McMurdo Dry Valleys Long-Term Ecological Research (LTER): LTER automatic weather network (LAWN).
Antarctic Journal of the U.S. 30(5): 276-280.
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| Notes |
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 (telephone: 303-492-4639) so that the
data can be corrected or qualified. Thus, these data may be modified and future
data will be appended.
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| License and Usage Rights: |
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| MCM LTER data may be used freely with the following restrictions: |
The Principal Investigator be sent a notice stating reasons for acquiring any data and a description of the publication intentions.
The Principal Investigator of the data set be sent a copy of the report or manuscript prior to submission and be adequately cited in any resultant publications.
A copy of any resultant publications should be sent to the McMurdo data manager and principal investigator.
The end-user follow the guidelines set forth in the LTER Network Data Access Policy, Data Access Requirements, and General Data Use Agreement found at http://www.mcmlter.org/data_guidelines.htm
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| Geographic Coverage: |
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Geographic Description: | The Commonwealth Glacier meteorology station is
located at a latitude of 77 48.52343 S, a longitude of 163 16.80872383 E, and
an elevation of 290.2 meters above sea level. Descriptions of this and other
McMurdo Dry Valley meteorology stations can be found at
http://www.mcmlter.org/data/meteorology/locations/metlocs.html.
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Bounding Coordinates:
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| West: | 163.28015 degrees
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| East: | 163.28014 degrees
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| North: | -77.80871 degrees
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| South: | -77.80872 degrees
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Mimimum Altitude: | 290 meter |
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Maximum Altitude: | 290 meter |
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| Temporal Coverage: |
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Begin:
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End:
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| Maintenance: |
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Description:
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While processing the 1997-98 files, Peter Doran identified an error in the LWRadIn values for
the Commonwealth station in 1996-97's data from Julian day 319 of 1996 at 15:45 local time to
Julian day 27 of 1997 at 9:00 local time. To correct the LWRadIn values during this period the
values needed to be multiplied by 0.800514. The data manager at INSTAAR did this and provided
updated versions of the data sets in May, 1999.
On August 18, 1999, the data manager added the 1998-1999 data to this dataset. In the process,
she did some fine-tuning of the data, which included:
1. removal of the relative humidity values from November 14, 1996 through December 4,
1996, as requested by Peter Doran. Since the temperatures were bad during this period,
and relative humidity is based on temperature, the RH data needed to be voided as well.
They had been marked as subjectively voided in the comments field, but needed the
values removed from the RH field.
2. removal of records on 5/20/1994 2:00:00 and 5/20/1994 11:00:00. These contained
incorrect data.
3. removal of SwRadOut va lues on 12/25/1994 13:00:00, 12/25/1994 13:20:00, and
12/25/1994 13:40:00. These records had very high SwRadOut and no SwRadIn values, so
Peter Doran determined that it was best to delete the 3 SwRadOut values.
4. removal of ThmIR values of -999.99 from the 1994 data. This was a level 0 campbell
code and should not have been in the level 1 data set.
5. making the file layout consistent from year to year. This results in many null values being
present for periods when certain values were not collected. However, it simplifies
combining data from different years.
6. making corrections so that the files containing data for a given year started on January 1
at 0:00 and ended on December 31 at 23:45. Up to this point, records for January 1
between 0:00 and 12:45 were appearing in the previous year's file.
On August 31, 1999, at the request of Thomas Nylen, more updates were made including:
1. removal of wind direction and wind direction standard deviation values for records where
wind speed = 0;
2. removal of all commas from the comments fields, since commas cause spreadsheet
software packages to add additional columns;
3. addition of relative humidity values from Jan 23, 1995 @ 14:20 to Nov 27, 1995 @
10:20. The task sheet gives no explanation nor data to indicate why it was omitted. The
data looks good when plotted, so it was decided to include it.
4. addition of ice temperature values (at 20 cm and 1 m depths) from Nov 27, 1995 @ 12:15
to Jan 24, 1996 @ 10:30. Up to this point, the values were omitted from the data column
and flagged. Looking at the values before and after this time period, the ice temperature
data was also flagged, but the values were left in the data column. The data appears to be
continous across each of these time periods, and it was not logical why one period was
omitted, but the before and after values were not. The data between Nov 27, 1995 @
12:15 and Jan 24, 1996 @ 10:30 was therefore placed back, though flagged.
5. addition of wind direction values from Dec 19, 1995 @ 15:15 to Jan 24, 1996 @ 10:15.
The task list stated that the arm was rotated 13 degrees on Jan 24. According to Peter
Doran, the data should be left, but flagged.
6. removal of ThmIR values between 12/19/1995 11:15 and 12/19/1995 13:00.
7. updating of SwRadIn and SwRadOut values between Nov 25, 1997 @ 13:00 and Jan 16,
1998 @ 9:45. The wrong multiplier was used for SwRadIn and SwRadOut between Nov
25, 1997 @ 13:00 and Jan 16, 1998 @ 9:45. Two flags for SwRadOut, 01/02/1998 11:30
and 01/02/1998 12:00 were removed with the recalculated values.
8. removal of LwRadIn2 and LwRadOut2 values between Jan 1, 1999 and Jan 22, 1999 @
10:15. These values were bad for the whole dataset.
9. removal of 1998-99 IceT20cm values above 0 (above the range limit).
In May 2000, the 1999-2000 data was posted. In the process, Denise Steigerwald changed the
layout of the files so that they were sorted by category (air temperatures, humidity, radiation,
wind etc.) rather than by year. Files containing monthly and daily averages were generated and
minor adjustments were made to the metadata.
On May 17, 2000, relative humidity (RH) values were corrected for a systematic error in the
measurement created by an instrument manufacturer error. All RH data with air temperatures
below freezing were corrected using the vapor pressure over ice (rather than over water which
was used initially). The error became quite large for very cold temperatures (the correction could
grow to around 30%). The formula used for the correction was:
RH_corr=RH_orig/((A*temp*temp)+(B*temp)+C)
where
RH_corr = corrected relative humidity
RH_orig = original relative humidity
temp = air temperature
A = 4.165E-5
B = 9.7E-3
C = 1.0
For example, with an air temperature of -2.3 and RH_orig of 50.6, the RH_corr will be 51.7.
Records that showed corrected RH values greater than or equal to 100 were changed to 99.99
and flagged.
On June 6, 2000, the dataset showing longwave radiation measurements was updated. Thomas
Nylen had gone through values recorded before January 22, 1999 and made some changes to
these values and their corresponding flags (comments). Many of the fields were originally left
blank but have now been assigned an appropriate number.
In June 2000, summary files were added to the web containing daily and monthly statistics.
These were generated by creating "views" of daily and monthly means, minimums, maximums
and counts of the records represented in the Oracle database's meteorology tables.
In April 2003, the LwRadOut2 data were adjusted between 01/20/1999 12:45 PM and
01/23/2003 04:15 PM to account for erroneous dome thermister measurements made by the
Eppley precision spectral pyranometer. The problem was identified by Eppley when
recalibrating the instrument. The dome and case temperatures should be about the same,
especially in the winter. The voltage measured by the dome thermister was consistently 9%
higher than the case thermister. To correct the problem the dome thermister were divided by
1.09 and the LwRadOut2 values were calculated again using the methods outlined in Procedures
for Correcting Eppley Pyrgeometer Data. The revised values were on average 11.2% higher
than the previous calculated values.
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In 2007, it was realized that the RH error was still present in parts of the dataset. Hasan Basagic made
the above corrections to the COHM dataset for the date range 1/19/2004 14:45 - 1/18/2007 11:15 (105,106 records).
In September, 2007 the information manager (Chris Gardner) removed all old RH data and re-inserted then newly
calculated values and associated comments. The original files are archive in the 'submitted data' section of the
mcmlter server.
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Frequency:
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| Contact: |
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Organization: | McMurdo Dry Valleys LTER |
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Position: | Data Manager |
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Address: |
| Byrd Polar Research Center , |
| 108 Scott Hall, |
| 1090 Carmack Rd, |
| Columbus, OH 43210-1002 USA |
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Phone:
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Email Address:
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| Publisher: |
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Organization: | McMurdo Dry Valleys LTER |
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Address: |
| Byrd Polar Research Center , |
| 108 Scott Hall, |
| 1090 Carmack Rd, |
| Columbus, OH 43210-1002 USA |
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Phone:
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| Methods Info: |
| Step 1: |
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Description:
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At the start of the 1993-1994 field season, the Commonwealth
Glacier meteorological station was constructed at the same coordinates as stake
11 on the glacier's mass balance grid. The station was set up to sample sensors every 30 seconds and send summary
statistics (for example, averages and maximums) to solid-state storage modules every:
3 hours between November 22 and December 3, 1993,
30 minutes between December 3 and December 24, 1993,
30 minutes for the main array andamp; every 24 hours for the max/min thermal infrared between December 24, 1993 and; January 12, 1994,
6 hours for the main array andamp; every 24 hours for the max/min thermal infrared between January 12, 1994 and; January 18, 1994,
20 minutes between January 18, 1994 and November 27, 1995,
15 minutes thereafter.
This has resulted in approximately 20 values being recorded for final storage in every output interval.
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Sampling Coverage:
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| Geographic Coverage: |
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Geographic Description: | The Commonwealth Glacier meteorology station is
located at a latitude of 77 48.52343 S, a longitude of 163 16.80872383 E, and
an elevation of 290.2 meters above sea level. Descriptions of this and other
McMurdo Dry Valley meteorology stations can be found at
http://www.mcmlter.org/data/meteorology/locations/metlocs.html.
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Bounding Coordinates:
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| West: | 163.28015 degrees
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| East: | 163.28014 degrees
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| North: | -77.80871 degrees
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| South: | -77.80872 degrees
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Mimimum Altitude: | 290 meter |
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Maximum Altitude: | 290 meter |
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Sampling Description:
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| Sampling and Averaging Intervals |
For Sampling frequency and Data Logger output and averaging intervals please visit:
http://www.mcmlter.org/data/meteorology/methods/Interval_Dates.pdf
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| Seasonal Task Summary |
To view the data post-processing steps for each season please visit:
http://www.mcmlter.org/data/meteorology/tasks/task_lists.htm
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