Western Peatland Flux Station Auxiliary Site Poor Fen (May Tower): Met Data
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Western Peatland Flux Station Auxiliary Site - Poor Fen (May Tower): Met DataFile Name Structure: AB-May_FlxTwr_Met2_YYYY-MM-00.csv Principal Investigator/ Institutional AffiliationDr. Lawrence B. Flanagan Department of Biological Sciences University of Lethbridge 4401 University Drive Lethbridge, Alberta T1K 3M4, CANADA e-mail: larry.flanagan@uleth.ca Telephone: (403) 380-1858 FAX: (403) 329-2082Poor Fen (May Tower) Auxiliary Site Location and DescriptionLatitude: 55.54º N Longitude: 112.33º W Elevation : 730 m a.s.l The auxiliary flux site (Poor Fen (May Tower)) is located approximately 120 km northeast of Athabasca, AB (54.82N, 113.52W). At the nearby town of Athabasca, mean annual precipitation is 503.7 mm, mean annual temperature is 2.1°C, and elevation is 626 m. See the map attached to the end of this file. This fen site is a "patterned fen", characterized by open, wet pools or "flarks", alternating with drier, elevated "strings" in the surface that were orientated perpendicular to the direction of water flow. A distinct microtopography, consisting of alternating hummocks (elevations in the peat surface), and hollows (depressions in the peat surface) is present at this location. The depth of peat was found to be in excess of 4 m. The vegetation is currently dominated by Sphagnum spp. (including a mixture of S. angustifolium, S. magellanicum, and S. fuscum). Other species also present include: Carex limosa, Smilacina trifolia, Andromeda polifolia, Drosera rotundifolia, Menyanthes trifoliata, Oxycoccus microcarpus Salix sp., dwarf Picea mariana, and dwarf Larix laricina . Meteorological InstrumentationA triangular, aluminum instrumentation tower (3 m tall) was installed in November 2003. This tower was equipped with a package of meteorological instruments that continuously monitored environmental conditions. A description of the models and manufacturers of the instruments is provided below, along with the heights (depths) that the instruments are located. All instruments are connected to a data logger (CR23X, Campbell Scientific, Edmonton, Canada), with some connections to the data logger made via a multiplexer (AM416, Campbell Scientific, Edmonton, Canada). The data logger, multiplexer and atmospheric pressure sensor (Vaisala PTB101B, Campbell Scientific, Edmonton, Canada) are located in an enclosure mounted on the instrument tower. The air temperature and relative humidity probe (HMP45C) is mounted inside a naturally ventilated radiation shield (41002, Gill Multi-Plate Radiation Shield, Campbell Scientific, Edmonton, Canada). With the exception of the rain gauge, all meteorological sensors are scanned at 5-second intervals and data are recorded as half-hourly averages. A tipping-bucket rain gauge (CS700, Campbell Scientific, Edmonton, Canada) is used to measure total precipitation recorded in 30-minute intervals. Water table depth relative to average hummock height is measured at each site in a well using a float and counterweight system attached to a potentiometer. Data are downloaded from the data logger to a laptop or palmtop computer system during site visits. Power is supplied to the data logger and instruments by an array of deep-cycle batteries that are charged by three 70 W solar panels. With the exception of the custom built potentiometer and the LiCor quantum sensor, all equipment was purchased from Campbell Scientific, Edmonton, Canada. The LiCor sensor was purchased from LiCor Inc., Lincoln, NE, USA. Net Radiation: Kipp & Zonen NR Lite, mounted at 3 m height Photosynthetically Active Radiation: LiCor Quantum Sensor LI-190SA, mounted at 3 m height Air Temperature and Relative Humidity: Vaisala HMP45C Temperature and RH probe, mounted at 2.0 m height Soil Temperature: Campbell Scientific 107B Thermistor (at various depths, see below) Precipitation (events): Campbell Scientific CS700 Tipping Bucket Rain Gauge Wind Speed and Direction: R.M. Young 05103-10 Wind Monitor, mounted at 3 m height Atmospheric Pressure: Vaisala PTB101B Snow Depth: Campbell Scientific SR50-45 Sonic Ranging Snow Depth Gauge Water Table Depth: Custom Built Potentiometer & Accessories Short-wave Solar radiation: Kipp & Zonen CM3 Pyranometer Organization of the Met Data FilesThe data files are comma delimited text files that include data for a one-month period. The first row of each data file has a header with the parameter names listed below. The second row contains the units for the data columns. The other values in the data files represent 30-minute averages for the time period ending at the noted time stamp. One exception is that the precipitation data represents total precipitation received in the 30-minute period. The units and description for the parameter names are listed below.
Known Problems with the Data For data files from Aug 2003 until February 2005, the wind direction data do not include all possible wind directions (data from about 355 degrees to 10 degrees were not properly recorded). This error was the result of a data logger program error and the data cannot be corrected. Literature References Glenn, A.J., L.B. Flanagan, K.H. Syed, P.J. Carlson. 2006. Comparison of net ecosystem CO2 exchange in two peatlands with contrasting dominant vegetation, Sphagnum and Carex. Agricultural and Forest Meteorology, in press Humphreys, E.R., P.M. Lafleur, L.B. Flanagan, N. Hedstrom, K.H. Syed, A.J. Glenn, R. Granger. 2006. Summer carbon dioxide and water vapour fluxes across a range of northern peatlands. Journal of Geophysical Research (Biogeosciences), in press  |