Peter T. DoranAndrew G. Fountain 2014-11-04 High frequency measurements from Lake Brownworth Meteorological Station (BRHM), McMurdo Dry Valleys, Antarctica (1994-2022, ongoing) tabular digitial data McMurdo Dry Valleys LTER McMurdo Dry Valleys LTER 10.6073/pasta/4ab14239b3692b0f9d1118f95fb68394 https://mcm.lternet.edu/content/high-frequency-measurements-lake-brownworth-meteorological-station-brhm-mcmurdo-dry-valleys 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 data package contains 15-minute data from the Lake Brownworth Meteorological Station (BRHM), located in Wright Valley (Latitude: -77.43344, Longitude: 162.7036, Elevation: 279 meters above sea level). BRHM was established in 1994, during the 94/95 field season. 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  1994-12-30 2022-12-13 ground condition The first 96 records found in the 978/brh/brh97f01 file contained the same dates/times as the latter portion of the 967/brh/brh96702 file (overlap of records in the 1996/97 and 1997/98 files). Although the values in these files did not contain exact matches, a choice had to be made on which records to use. The data manager subjectively decided to use the 1996/97 records. This explains why the first record number (fline#) from the 978/brh/brh97f01 file is '978/brh/brh97f01.96', rather than 978/brh/brh97f01.0. If you have any questions, please contact the data manager. On August 17, 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:removal of the relative humidity data from November 1995 through April 1996, as requested by Peter Doran. The values during this period were unquestionably low, so it was recommended that the values be marked as bad and not included in the data files.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.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.Fine-tuning of the comments fields so they were more concise and/or explanatory. For example, radiation comments were updated from "SwRadIn flagged with an 'S'" to "Negative value for SwRadIn zeroed out". The 'WDir Comments' field was renamed to 'Wind Comments'.With the exception of removal of the relative humidity values described above, data values were not changed. On August 27, more fine-tuning of the data occurred. This included:addition of NetRad from Nov 24, 1995 @ 16:45 to Jan 23, 1996 @ 11:00.addition of SwRadOut and PAR from Nov 13, 1996 @ 15:15 to Jan 25, 1997 @ 10:15.On July 3, 2001, Thomas Nylen adjusted the data. This included:Added 37 degrees (clockwise) to WDir results between 11/20/1995 16:00 and 11/27/1998 11:15Subjectively voided WDir and WDirStD between 3/1/1996 00:15: and 04/19/96 23:30In 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 16, 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. 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 May 2003, SwRadIn values between 12/30/1994 10:00:00 PM and 4/19/1996 11:30:00 PM were changed because it was determined the wrong multiplier was used. The values were corrected by dividing by 88.4 (mAmps m-2) and multiplying by 113.12 (W m-2). On June 4, 2004, the relative humidity (RH) values after January 26, 2000 @ 1545 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 polynomials used for the correction is based on Lowe (1977). The original RH value is multiplied by the saturation vapor pressure over water and divided by the the saturation vapor pressure over ice RH3m_corr=[RH3m]*(6.107799961 + [AirT3m] * (0.4436518521 + [AirT3m] * (0.01428945805 + [AirT3m] * (0.0002650648471 + [AirT3m] *(0.000003031240396 + [AirT3m] * (0.00000002034080948 + 0.00000000006136820929 * [AirT3 m])))))) / (6.109177956 + [AirT3m] * (0.503469897 + [AirT3m] * (0.01886013408 + [AirT3m] * (0.0004176223716 + [AirT3m] * (0.00000582472028 + [AirT3m] * (0.00000004838803174 + 0.0000000001838826904 * [AirT3m]))))))) Records that showed corrected RH values greater than or equal to 100 were changed to 99.99 and flagged.The ultrasonic ranger sensor that measures surface height change has been broken since November 2010, with no plans to replace as of July 2023. As needed Located west of Lake Brownworth.ID: BHRM 162.703600000000 162.703600000000 -77.434400000000 -77.434400000000 279m 279m meter LTER Core Areas disturbance None <cntperp> <cntper>McMurdo Dry Valleys LTER Information Manager</cntper> </cntperp> <cntemail>im@mcmlter.org</cntemail> Name: Krista F. Myers Role: field technician Name: RenĂ©e F. Brown Role: data manager Name: Maciej K. Obryk Role: former field crew Name: Hassan Basagic Role: former field crew Name: Thomas Nylen Role: former field crew Name: Inigo San Gil Role: former data manager Not Applicable Not Applicable Field and/or Lab Methods During the 1994-1995 field season, the McMurdo LTER, in collaboration with NZARP (New Zealand Antarctic Research Programme), established a meteorology station at Lake Brownworth in Lower Wright Valley at the head 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 hour between December 30, 1994 and November 24, 1995, and every 15 minutes thereafter. This has resulted in approximately 20 values being recorded for final storage in every output interval.Sampling and Averaging Intervals For Sampling frequency and Data Logger output and averaging intervals please visit: http://mcmlter.lternet.edu/data/meteorology/methods/Interval_Dates.pdf  During the 1994-1995 field season, the McMurdo LTER, in collaboration with NZARP (New Zealand Antarctic Research Programme), established a meteorology station at Lake Brownworth in Lower Wright Valley at the head 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 hour between December 30, 1994 and November 24, 1995, and every 15 minutes thereafter. This has resulted in approximately 20 values being recorded for final storage in every output interval.Sampling and Averaging Intervals For Sampling frequency and Data Logger output and averaging intervals please visit: http://mcmlter.lternet.edu/data/meteorology/methods/Interval_Dates.pdf  unknown BRHM_AIRT BRHM - Air Temperature DATASET CODE Code for given set of information for Lake Brownworth meteorology station The data provider Code for given set of information for Lake Brownworth meteorology station METLOCID Location code for Lake Brownworth meteorology station The data provider Location code for Lake Brownworth meteorology station DATE_TIME Date/time of sample (New Zealand DST, +13 UTC) The data provider calendar date/time MM/DD/YYYY HH24:MI gregorian calendar AIRT3M Average air temperature at 3 m above ground The data provider celsius 0.01 AIRTMAX Maximum air temperature at 2.5 - 3 m above ground The data provider celsius 0.01 AIRTMIN Minimum air temperature at 2.5 - 3 m above ground The data provider celsius 0.01 air temperature comments Noted comments by the investigator about the particular measure of air temperature The data provider Noted comments by the investigator about the particular measure of air temperature McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-clim-brhm_airt-15min-20230630.csv None BRHM_RADN BRHM - Solar Radiation DATASET CODE Code for given set of information for Lake Brownworth meteorology station The data provider Code for given set of information for Lake Brownworth meteorology station METLOCID Location code for Lake Brownworth meteorology station The data provider Location code for Lake Brownworth meteorology station DATE_TIME Date/time of sample (New Zealand DST, +13 UTC) The data provider calendar date/time MM/DD/YYYY HH24:MI gregorian calendar PAR Photosynthetically active radiation The data provider micromols/second/meter2 0.1 SWRADIN Incoming shortwave radiation/solar flux The data provider W/m2 0.1 SWRADOUT Outgoing shortwave radiation/solar flux The data provider W/m2 0.1 UVA Incoming ultraviolet-A radiation The data provider W/m2 0.1 UVB Incoming ultraviolet-B radiation The data provider W/m2 0.1 NETRAD Net radiation The data provider W/m2 0.1 radiation comments Noted comments by the investigator about the particular measure of radiation The data provider Noted comments by the investigator about the particular measure of radiation McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-clim-brhm_radn-15min-20230630.csv None BRHM_RH BRHM - Relative Humidity DATASET CODE Code for given set of information for Lake Brownworth meteorology station The data provider Code for given set of information for Lake Brownworth meteorology station METLOCID Location code for Lake Brownworth meteorology station The data provider Location code for Lake Brownworth meteorology station DATE_TIME Date/time of sample (New Zealand DST, +13 UTC) The data provider calendar date/time MM/DD/YYYY HH24:MI gregorian calendar RH Relative humidity at 3 meters The data provider percent 0.1 relative humidity comments Noted comments by the investigator about the particular measure of relative humidity The data provider Noted comments by the investigator about the particular measure of relative humidity McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-clim-brhm_rh-15min-20230630.csv None BRHM_SOILT BRHM - Soil Temperature DATASET CODE Code for given set of information for Lake Brownworth meteorology station The data provider Code for given set of information for Lake Brownworth meteorology station METLOCID Location code for Lake Brownworth meteorology station The data provider Location code for Lake Brownworth meteorology station DATE_TIME Date/time of sample (New Zealand DST, +13 UTC) The data provider calendar date/time MM/DD/YYYY HH24:MI gregorian calendar SOILT0CM Soil temperature at 0 cm depth The data provider celsius 0.01 SOILT5CM Soil temperature at 5 cm depth The data provider celsius 0.01 SOILT10CM Soil temperature at 10 cm depth The data provider celsius 0.01 SOILT_COMMENTS Noted comments by the investigator about the particular measure of SOILT_ The data provider Noted comments by the investigator about the particular measure of SOILT_ McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-clim-brhm_soilt-15min-20230630.csv None BRHM_SURFCHANGE BRHM - Surface Change DATASET CODE Code for given set of information for Lake Brownworth meteorology station The data provider Code for given set of information for Lake Brownworth meteorology station METLOCID Location code for Lake Brownworth meteorology station The data provider Location code for Lake Brownworth meteorology station DATE_TIME Date/time of sample (New Zealand DST, +13 UTC) The data provider calendar date/time MM/DD/YYYY HH24:MI gregorian calendar SURFCHANGE_CM Surface Height Change - snowfall / sediment accumulation or loss The data provider centimeter 0.4 surface change comments Noted comments by the investigator about the particular measure of surface change The data provider Noted comments by the investigator about the particular measure of surface change McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-clim-brhm_surfchange-15min-20230630.csv None BRHM_WIND BRHM - Wind Direction & Speed DATASET CODE Code for given set of information for Lake Brownworth meteorology station The data provider Code for given set of information for Lake Brownworth meteorology station METLOCID Location code for Lake Brownworth meteorology station The data provider Location code for Lake Brownworth meteorology station DATE_TIME Date/time of sample (New Zealand DST, +13 UTC) The data provider calendar date/time MM/DD/YYYY HH24:MI gregorian calendar WDIR Average wind direction The data provider degreesfromnorth 0.1 WDIRSTD Standard deviation of wind direction The data provider degreesfromnorth 0.1 WSPD Wind speed The data provider metersPerSecond 0.1 WSPDMAX Maximum wind speed The data provider metersPerSecond 0.1 WSPDMIN Minimum wind speed The data provider metersPerSecond 0.1 WIND_COMMENTS Noted comments by the investigator about the particular measure of WIND_ The data provider Noted comments by the investigator about the particular measure of WIND_ McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 1 column , https://mcm.lternet.edu/sites/default/files/data/mcmlter-clim-brhm_wind-15min-20230630.csv None BRHM_WVAPD BRHM - Water Vapor Density DATASET CODE Code for given set of information for Brownsworth meteorology station The data provider Code for given set of information for Brownsworth meteorology station METLOCID Location code for Brownsworth meteorology station The data provider Location code for Brownsworth meteorology station DATE_TIME Date/time of sample (New Zealand DST, +13 UTC) The data provider calendar date/time MM/DD/YYYY HH24:MI gregorian calendar WVAPD Water vapor density The data provider gramspercubicmeter 0.1 WVAPD_COMMENTS Noted comments by the investigator about the particular measure of WVAPD_ The data provider Noted comments by the investigator about the particular measure of WVAPD_ McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 27 column , https://mcm.lternet.edu/sites/default/files/BRHM_WVAPD.csv None 2014-11-04 2014-11-04 McMurdo Dry Valleys LTER http://mcmlter.org/ Biological Data Profile of the Content Standards for Digital Geospatial Metadata devised by the Federal Geographic Data Committee. 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