METADATA file for Mountain Lake Biological Station meteorological data. Mountain Lake Biological Station University of Virginia 238 Gilmer Hall P.O. Box 400327 Charlottesville VA 22904-4327 tel: (434) 982-5486 fax: (434) 982-5626 mlbs.org Data maintained and organized by Eric S. Nagy, Associate Director. Metadata file updated: 22 June 2010 ESN The Mountain Lake Biological Station is a research and teaching facility of the University of Virginia located in the Allegheny Mountains of southwestern Virginia, U.S.A. (37o22'N, 80o31'W) in a deciduous hardwood forest at an elevation of 1,160 meters. Permission for use of these data is granted under the conditions that MLBS is acknowledged as their source and is notified of their use. Data (.dat) files are by year and contain raw meteorological data collected at the Mountain Lake Biological Station. All files are ASCII text. The raw data files follow the Intersite Archival and Exchange File Structure as defined by "Data Management at Biological Field Stations and Coastal Marine Laboratories," January 1992, Report of an Invitational Workshop April 22-26, 1990, at the W.K. Kellogg Biological Station, Michigan State University, sponsored by the Organization of Biological Field Stations and the Southern Association of Marine Laboratories. Prepared for the National Science Foundation, Division of Biotic Systems and Resources, Biological Research Resources Program, John B. Gorentz ed. Outline of data structure: \ log Data files are for full years (julian dates 1-180 and 181-365/6). Data were collected by a Campbell Scientific CR10 Datalogger weather station and Met-One sensors. \ doc Station Year Date Time Temp Humid Pres Speed Dir Rain hv Data column descriptions: Col 1: Station MLBS weather station #1, MLBS1. Col 2: Year 1994 - data collection started mid 1994. Col 3: Date Julian Date, 1-365 or 366. Col 4: Time 2400 clock, EST. Midnight = 2400 and is assigned to the preceding day. Col 5: Temp Temperature in degrees Celsius, C Col 6: Humid Relative humidity, % r.h. Col 7: Pres Barometric pressure, absolute, no elevational adjustment, mbar. Col 8: Speed Wind speed, m/s. 0.447 m/s minimum sensor threshold. Col 9: Dir Wind direction, degrees (0-359) from North. Col 10: Rain Accumulated precipitation (rain or melted snow), mm. Col 11: hv Quanta of light, PAR, micromoles/s/m^2. Julian Date Month Conversions: Non-Leap Year Leap Year (years evenly divisible by 4) January 1 - 31 1 - 31 February 32 - 59 32 - 60 March 60 - 90 61 - 91 April 91 - 120 92 - 121 May 121 - 151 122 - 152 June 152 - 181 153 - 182 July 182 - 212 183 - 213 August 213 - 243 214 - 244 September 244 - 273 245 - 274 October 274 - 304 275 - 305 November 305 - 334 306 - 335 December 335 - 365 336 - 366 Major Breaks in Data: Date Time Date Time 1994: 197 1700 - 197 2130 203 1730 266 1800 - 281 0900 1996: 194 1230 - 221 1630 222 1530 272 1300 - 272 1500 343 1800 1997: 023 1700 - 024 1630 2002: 029 1000 - 123 1430 2003: 089 1700 - 101 1700 2004: 031 0400 - 103 1800 2009: 349 1100 - 352 1030 Known Sensor Failures, Service, Replacement, and other Notes: Wind Speed sensor failure: 1997 Date 110 Wind Speed sensor back on line: 1997 Date 143 Wind direction sensor failed: 1998 Date 081 Time 1500 Wind direction sensor back on line: 1998 Date 210 Time 1230 Wind Speed sensor failed: 1998 Date 275 Time 1300 ** ** WARNING: It is impossible to know, but it appears that wind speed may be underestimated (sensor starting to fail) starting around Date 180 1998. Wind Speed sensor back on line: 1998 Date 309 Time 1000 Wind Speed sensor failure: 2003 Date 115 Wind Speed sensor back on line: 2003 Date 194 wind speed sensor off-line: 2009 Data 212 wind speed sensor replaced (new): 2009 Date 215 PAR Sensor replaced (no failure): 2004 Date 213 Time 1430 ** WARNING: PAR sensors degrade over time. New and old PAR sensors will not return comparable readings. The old PAR sensor had yellowed sustantially. It was giving consistant, but lower readings than the new one. Do not compare light levels between the old and new sensor. In general PAR levels should not be compared over extended time periods (> 1 year approx) Ran Gauge replaced (no failure): 2004 Date 213 Time 1430 Solar Panel installed: 2004 Date 213 Time 1030 NOTE: Battery to be installed perminantly now. Not changed out at data download. Current battery installed May 2004. Note on Time: All time data is collected in Eastern Standard Time (EST = GMT - 05:00), even during periods of the year when Day Light Saving Time (EDT) is in effect. ABSTRACT: None. Row 1 is header. Character variables: col 1 Numeric variables : col 2-11 ASCII data files are space delimited. Individual missing values for variables are indicated by "." Breaks in data are not flagged. Comments MAY occur anywhere in the data, usually following the line being described. Comments noted by "NOTE" in column #1. SOME breaks in data may be indicated by "BREAK" in column #1. Measurements taken at approximately 2.5m above the ground; except for precipitation which is collected at ground level. Copies of Campbel Scientific CR10 data logger weather station program and post-processing formulae are available upon request. History of changes in weather station operation: June 1994 - 22 Jan 1997: All measurements taken and stored once every 30 minutes. 23 Jan 1997 - current: Data collection program rewritten 23 Jan 1997 - All measurements (except barometric pressure) are taken every minute. Data is averaged by the CR10 data logger and stored to internal storage once ever 30 min. Barometric pressure is sampled only once every 30 min. Therefore, all data points, except barometric pressure, are averages (precipitation is the sum) of 30 measurements. 26 May 1997: The weather station was moved from its original location in a clearing behind the Lewis Laboratory to a location on the north bank of the Station pond (approximately 200m north). The move was made to remove interference by the newly constructed Aquatics Lab building. \ type statistical \ header Station Year Date Time Temp Humid Pres Speed Dir Rain hv data Separate files. End of Metadata file.