wind direction

High frequency measurements from Lake Vanda Meteorological Station (VAAM), McMurdo Dry Valleys, Antarctica (1994-2022, ongoing)

Abstract: 

As part of the McMurdo Dry Valleys Long Term Ecological Research program, meteorological data are collected from various locations throughout the McMurdo Dry Valleys of Antarctica. This package contains 15-minute data from the Lake Vanda Meteorological Station (VAAM), located in Wright Valley. VAAM was established in 1994, during the 94/95 field season.

LTER Core Areas: 

Dataset ID: 

7015

Associated Personnel: 

836
837
227
229
228
230

Related publications: 

McMurdo Dry Valleys Long-Term Ecological Research (LTER): LTER automatic weather network (LAWN)

Related links: 

Meteorological Task Lists

Short name: 

VAAM

Locations: 

Lake Vanda Meteorological Station

Purpose: 

Meteorological data are collected year-round at each of MCM LTER stations. Data are manually downloaded from the meteorological stations during the austral summer. Raw 15 minute data (Level 0) is processed and provided as Level 1 data on the MCM LTER website. Field notes, sensor information, processing procedures, QA/QC, and metadata is provided in the Meteorological Post Processing Documentation and Task Lists for each field season at the following address: https://mcm.lternet.edu/meteorological-task-lists 

Data sources: 

VAAM_AIRT
VAAM_RADN
VAAM_RH
VAAM_SOILT
VAAM_SURFCHANGE
VAAM_WIND
VAAM_ONYXT
VAAM_WVAPD

Methods: 

During the 1994-1995 field season, the Lake Vanda meteorological station was constructed near the mouth of the Onyx River. 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 20 minutes between November 24, 1994 and December 30, 1994, every hour between December 30, 1994 and November 21, 1995, and every 15 minutes thereafter. This has resulted in approximately 20 values being recorded for final storage in every output interval.

Station was relocated after it was blown away in 2004.  Onyx River temperature (thermistor) ceased then, as seen in the data record, 

Maintenance: 

On September 9, 1999, the data manager added the 1998-1999 data to this dataset. In the process,at the  request of Thomas Nylen, she did some fine-tuning of the data. Revisions included:
 
 1. Removal and flagging of WDir and WDirStd values on Nov 25, 1994 @ 9:20. Since windspeed was zero (0),
 it made no sense to have values for wind direction.
 
 2. Addition of PAR values between Dec 30, 1994 @ 17:00 and Jan 20, 1995 @ 15:00.
 
 On June 1, 2000, the 1999-2000 data was posted. In the process, Denise Steigerwald changed thelayout 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 andminor adjustments were made to the metadata.
 
 On June 1, 2000, relative humidity (RH) values were corrected for a systematic error in themeasurement created  by an instrument manufacturer error. All RH data with air temperaturesbelow 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 tha n or equal to 100 were changed to 99.99and flagged. 
 
 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 2006, metadata was offered in EML format, the specification adopted by the LTER Network. (Gradner, San Gil)
 
In 2014, Metadata was ported to the Drupal Ecological Information Management system (DEIMS, San Gil)
 
In 2015, derived data (daily and monthly averages) were given identifiers and included formally in the MCMLTER data catalog
 
 

Quality Assurance: 

Season 1994/95 Notes

files vaa94501 through vaa94503.dat

1) Day of year is one day greater than it should be (i.e. first day should be 328)

2) Downward-pointing pyranometer is wired and running but not mounted properly, ignore.

3) Wind speeds < threshold (0.9 m/s) zeroed. Data should be flagged 

file vaa94504.dat

1) Day of year fixed

2) Downward-pointing pyranometer running okay.

3) Collected data at 16:08

4) Moved position of river thermistor to closer location on Jan 20.

5) Keypad changes made to vaa945-1 did not get transfered to .doc file. Therefore, new file loaded with claus that zeros wind

Season 1995/96 Notes

Report by Gayle Dana. File vaa95001.dat

1) Moved position of river thermistor to closer location on Jan 20.

2) Keypad changes made to vaa945-1 did not get transfered to .doc file. Therefore, new file loaded with claus that zeros wind speeds < 0.9 m/s. Data should be flagged. This will continue through winters data. 

File vaa95601.dat

1) 2nd battery and diode wiring installed at end of file period.

2) Heads up for overwinter data: station powered down between 13:25 and 14:10 hours on 1/23/96 to install diodes.

3) RH Campbell: 21%; RH Sling Pyschrometer: 28% on 1/23/96

Season 1996/97 Notes

Report by Peter Doran. 

Notes seem to be from previous season.

Season 1997/98 Notes

Report by Peter Doran

1) Wind storm damaged station. All wind and pyranometer data after day 166 is bad. Temperatures, RH, and PAR all appear ok 

2) All wind and pyranometer data is bad. Temperatures, RH, and PAR all appear ok

3) Missing data at end of this file 

4) Data missing before this file

5) All new sensors except for soil and river thermistors

6) file vaa978-1 is one line long with bad time stamp 

Season 1998/99 Notes

Author: Paul Langevin

1) Date in raw data for 1998 103 400 is wrong, it reads 4199 400, changed 4199 to 103

2) Onyx temperature #17, Flagged “B” 

Season 1999/2000 Notes

Report by Thomas Nylen

1. Onyx temperature #17 not working. Flagged “B”

2. On January 26, 2000 (26) @ 942, replaced upward pyranometer. Old sensor is PY27929 and new sensor number is PY25306.

3. On January 26, 2000 (26) @ 1000, replaced Quantum. Old sensor number is Q23210 and new sensor number is Q17248.

4. On January 26, 2000 (26) @ 1021, replaced 207 air temperature probe with 107 temperature probe. Air temperature went from 0.56, measured with 207, to 0.47 C, measured with 107. The shield was raised from 2.7 meters to 2.8 meters above the ground. It is the highest the shield can go without interfering with wind monitor. The bar holding the pyranometer and wind monitor was also raised 10cm. The wind monitor is now 3m from the ground surface. The roughness of the surface is 20cm.

5. The soil temperatures and Onyx temperature wires were switched around to match the specifications in the new program. Flag intervals with logger errors.

6. On January 26, 2000 (26) @ 1100, downloaded file, vaa20001. At 1124, downloaded file, vaa20002.

7. On January 26, 2000 (26) @ 1130, uploaded and compiled new program, vaa990v1 was loaded. 

Season 2000/01 Notes

Thomas Nylen.

No data mssing

The wind monitor was replaced, since it appears the direction component of the monitor was not working. Flag all wind direction and WdirStd as bad. The new sensor appears to be working. Check next time visit station. 

(next file)

Replaced downward pyranometer. Old sensor number is PY28167 and the new number is PY28170. 

(next file)

Wind monitor seems to be working now. 

Season 2001/02

Thomas Nylen

First file: 
1. Data lines missing on April 3, 2001 between 1245 and 1930 

Second file: 
1. Old CR10 clock behind by 00:03:52. Not adjusted 
2. 2 blades on the wind monitor were broken
3. RH3m probe was disconnected on November 23, 2001 @ 1404
4. Wind monitor was disconnected on November 23, 2001 @ 1409
5. Upward and downward pyranometer was disconnected on November 23, 2001 @ 1415
6. Quantum was hooked up on November 23, 2001 @ 1417
7. OnxyT was disconnected on November 23, 2001 @ 1421
8. All temperature was disconnected on November 23, 2001 @ 1421
9. Powered off old CR10 on November 23, 2001 (338) @ 1430, and hooked up new CR10X. All sensors should be working
10. Wind disconnected on November 23, 2001 (338) between ~1515-1530
11. Check wind alignment, rotated 10° counterclockwise 

Third file:

1. Upward and downward pyranometer was disconnected between 1415 and 1445 on November 23, 2001. First two values of file are bad
2. Wind disconnected on November 23, 2001 (337) between ~1515-1530, values flagged as bad between this interval. Minimum wind speed flagged as bad the first 3 of 4 values.
3. Time adjust +00:00:22 on January 18, 2002 @ 11:12 4. Check wind alignment on January 18, 2002 @ 1148, adjusted 5 degrees clockwise
5. Existing sensor numbers – SwRadIn: PY31675, SwRadOut: PY40424, PAR: Q17248
6. Storage Modules replaced with 1 @ SM4M on January 18, 2002 @ 1134
7. Between 1115 and 1130 on January 18, 2002, swapped out Quantum (PAR). New sensor number: Q17248 

Season 2002/03

Thomas Nylen

1. No missing data
2. Adjust time -00:01:25 on November 12, 2002 @ 10:40
3. Checked input values on November 12, 2002 @ 10:39 and 10:45. Everything looked good
4. Check wind alignment on on November 12, 2002 @ 10:43. Pointed north
5. Replaced SM4M with another SM4M on November 12, 2002 @ 10:44 

Season 2003/04

Thomas Nylen

File vaa030401.dat

1. Station blew over on 9/9/03 2145 during a katabatic event. Station was rebuilt on December 8, 2003. All above surface measurements were flagged.
2. Install new pyranometers on December 8, 2003. New sensor numbers are Upward: PY18400 and downward: PY18657
3. Installed new Quantum (PAR) on December 8, 2003. New sensor number is Q19649.
4. Installed new wind monitor, but the wind speed was not working. Need to replace.
5. Installed sonic sensor, about 65 cm (value from CR10X) from the surface. Did not have a ruler so could not measure exact depth.
6. Swapped RH probes for recalibrated head on December 8, 2003
7. Swapped out batteries on December 8, 2003. 

File vaa030402.dat

1. First line of the data file repeats the last line of vaa03401.dat. Use the last line from vaa03401.dat. 

File vaa030403.dat

1. Installed new program, vaa034v1, on December 8, 2003 @ 1500. New program signature is 23474.
2. No missing lines of data
3. Adjust time +23 minutes and 02 seconds on December 8, 2003 @ 1457
4. Replaced SM4M with another SM4M on December 8, 2003 @ 1500

File vaa030404.dat

1. First line of the data file repeats the last line of vaa03403.dat. Use the last line from vaa03403.dat. 

File vaa030405.dat

1. Adjusted datalogger clock ahead by 18 secs on January 26, 2004 (26) @ 1036
2. Check wind monitor alignment on January 26, 2004 (26) @ 1039, pointing north
3. Repositioned ultrasonic sensor and secured with guide wires on January 26, 2004 (26) @ 1100. New height is 55.1 cm.
4. Installed new wind monitor on January 26, 2004 (26) @ 1057
5. Swapped SM4m module for another on January 26, 2004 (26) @ 1110. 

Season 2004/05

Thomas Nylen

File vaa040501.dat

1. Adjusted datalogger clock back by 1 minute and 22 seconds on December 1, 2004 (336) @ 1006
2. Checked wind monitor alignment on December 1, 2004 (336) @ 1006, pointing north
3. Checked input values, everything looks good.
4. Sonic sensor depth is 64.8 cm.
5. Swapped SM4m module for another on December 1, 2004 (336) @ 1015
6. Loaded new program, vaa045v1.dld on December 1, 2004 (336) @ 1015. Added instructions to not turn on sonic when battery voltage is below 11.5.
7. Replaced datalogger on December 1, 2004 (336) @ 1015. Turned off power, swapped the datalogger can, and plugged the power back in, loading the new program from the storage module. May have lost 30 seconds of data. 

File vaa040502.dat

1. Missing line of data on December 1, 2004 (336) @ 1015
2. Adjusted datalogger clock ahead by 20 hours and 52 seconds on January 15, 2005 (15) @ 1002
3. Checked wind monitor alignment on January 15, 2005 (15) @ 1005, pointing north
4. Checked input values on January 15, 2005 (15) @ 1004, everything looks good.
5. Sonic sensor depth is 64.2 cm. 6. Swapped SM4m module for another on January 15, 2005 (15) @

Season 2005/06

Thomas Nylen

File vaa040501.dat

1. No missing data.
2. Adjusted datalogger clock back by 57 seconds on December 16, 2005 (350) @ 1124
3. Checked input values on December 16, 2005 (350) @ 1125, everything looks good.
4. Checked wind monitor alignment on December 16, 2005 (350) @ 1130, pointing north 62
5. Sonic sensor depth is 64.4 cm.
6. Swapped RH sensor on December 16, 2005 (350) @ 1136.
7. Swapped upward facing pyranometer on December 16, 2005 (350) @ 1207. Old sensor # PY18400 with new sensor #PY28169. The upward pyranometer needs new lock screw.
8. Swapped downward facing pyranometer on December 16, 2005 (350) @ 1215. Old sensor # PY18657 with new sensor #PY23277.
9. Swapped quantum PAR on December 16, 2005 (350) @ 1150. Old sensor #Q19469 with new sensor #Q29765.
10. Swapped SM4M module for another December 16, 2005 (350) @ 1201. 

vaa05602.dat

1. No missing data.
2. Adjusted datalogger clock ahead 15 seconds on January 12, 2006 (12) @1154
3. Checked input values on January 12, 2006 (12) @1155, everything looks good.
4. Checked wind monitor alignment on January 12, 2006 (12) @1157, pointing north.
5. Sonic sensor depth is 65.0 cm on January 12, 2006 (12) @1159.
6. Swapped SM4M module for another January 12, 2006 (12) @1203. 64
7. Replaced 1 missing bolt on quantum PAR sensor baseplate. 

Season 2006/07

Thomas Nylen

1. No missing data.
2. Adjusted datalogger clock ahead 1 minute and 55 seconds on December 16, 2006 (350) at 930.
3. Checked input values on December 16, 2006 (350) at 1000. Sonic ranger is down, all else appears to be good.
4. Wind monitor is in alignment on December 16, 2006 (350) at 937. Swapped old sensor for new sensor at 957.
5. Sonic sensor depth is 64.7 cm on December 16, 2006 (350) at 1000.
6. Datalogger power off on December 16, 2006 (350) between 1001 and 1007 to swap batteries and storage module for another

Season 2007/08

Hassan Basagic

File vaa07801.dat
1. No missing data. Two multiple lines on December 8, 2007 at 1200 and 1215, these were duplicate and were removed.
2. Adjusted datalogger clock ahead 5 minute and 52 seconds on December 8, 2007 at 1150.
3. Checked input values and wind alignment on December 8, 2007 at 1150, all appear correct except sonic ranger which is offline. 60
4. Maintenance: Swapped upfacing pyranometer (old#28169, new#41090) at 1205; swapped quantum PAR (old#29765, new#Q17248) at 1212; and RH sensor at 3m at 1215 on December 8, 2007. Repaired Ultrasonic distance ranger by replacing sensor (transducer had failed) at 1224.
5. Sonic sensor depth is 65.6 cm on December 8, 2007 after replacing the sensor.
6. Swapped SM on December 8, 2007 at 1305. 

File vaa07802.dat

1. No missing data. Adjusted datalogger back 10 seconds on January 18, 2008 at 1232.
2. Checked input values and wind alignment on January 18, 2008 at 1233, all appear correct.
3. Sonic sensor depth is 65.3 cm on January 18, 2008 at 1235.
4. Swapped SM on January 18, 2008 at 1248. 

Season 2008/09

Hassan Basagic

1. No missing data. Adjusted datalogger ahead 3 min on December 30, 2008 at 9:37.
2. Checked input values and wind alignment on December 30, 2008 at 9:38, all appear correct.
3. Sonic sensor depth is 65.5 cm on December 30, 2008 at 9:40.
4. Maintenance: on December 30, 2008 swapped wind sensor at 10:00, downfacing pyranometer (old#PY23277, new#PY20561) at 1020, station power off from 1025 to 1054 to swap battery (new: 100 A hr) and swapped power cable.
5. Swapped SM on December 30, 2008 at 1100.

Season 2009/10

Hassan Basagic

1. No missing data. Adjusted datalogger back 2 min on November 20, 2009 at 1454.
2. Checked input values and wind alignment at 1456, all appear correct. Sonic sensor depth is 64.8 cm.
3. Maintenance: on November 20, 2009 swapped quantum PAR sensor (old#Q17248, new#Q30794) at 1509, RH at 1448.
4. Station power off to swap CR10x and SM on November 20, 2009 at 1517.

Season 2010/11

Thomas Nylen

1. No missing data.
2. Adjusted datalogger back 13 min and 35 secs on 11/19/2010 10:32.
3. Checked input values and wind alignment at 10:30, all appear correct. Sonic sensor depth is 65.0 cm.
4. Maintenance: on November 19, 2010 swapped upward pyranometer sensor (old#py41090, new#PY40424) at 11:30, swapped downward pyranometer sensor (old#py20561, new#PY33485) at 11:15, swapped wind mnitor
5. Sonic ultrasonic ranger not working intermediately. Remove to replace resistor.
6. Wind monitor not working properly. Not sure problem. Monitor was replaced.
7. Station power off to load new program and swap SM on November 19, 2010 at 1145. New program is vaa1011v1.

File 2

1. No missing data.
2. Sonic ultrasonic ranger was not working, replaced with the same sonic with new RH chip

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