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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 Data

File Name Structure: AB-May_FlxTwr_Met2_YYYY-MM-00.csv

Principal Investigator/ Institutional Affiliation

Dr. Lawrence B. Flanagan

Department of Biological Sciences

University of Lethbridge

4401 University Drive

Lethbridge, Alberta



Telephone: (403) 380-1858

FAX: (403) 329-2082

Poor Fen (May Tower) Auxiliary Site Location and Description

Latitude: 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 (54.82N, 113.52W). 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 Instrumentation

A 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 Files

The 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.






Meterological Data (Met2)









Year UTC



Day of Year UTC



Hour Minute UTC (e.g. 730: 30 minutes after the hour 7)



Vaisala HMP45C at 2.0 m



Vaisala HMP45C at 2.0 m



Atmospheric Pressure Vaisala PTB101B

NrL_NetRad_ AbvCnpy_3m


Net radiation, Kip & Zonen NR Lite at 3.0 m



Incoming Photon Flux Density (400-700 nm) LI-190SA at 3.0 m



Outgoing Photon Flux Density (400-700 nm) LI-190SA at 3.0 m



Hollow Soil Temp 2 cm depth Campbell Scientific 107B



Hummock Soil Temp 2 cm depth Campbell Scientific 107B



Hollow Soil Temp 5 cm depth Campbell Scientific 107B



Hummock Soil Temp 5 cm depth Campbell Scientific 107B



Hollow Soil Temp 10 cm depth Campbell Scientific 107B



Hummock Soil Temp 10 cm depth Campbell Scientific 107B



Hollow Soil Temp 20 cm depth Campbell Scientific 107B



Hummock Soil Temp 20 cm depth Campbell Scientific 107B



Hollow Soil Temp 50 cm depth Campbell Scientific 107B



Hummock Soil Temp 50 cm depth Campbell Scientific 107B



Hollow Soil Temp 100 cm depth Campbell Scientific 107B



Hummock Soil Temp 100 cm depth Campbell Scientific 107B



Water table level relative to average Hummock surface

(negative values represent water below hummock surface)



Average wind speed R.M. Young 05103-10 at 3.0 m



Compass direction of wind R.M. Young 05103-10 at 3.0 m



Event Precipitation Campbell Scientific CS700



Snow Depth Campbell Scientific SR50-45



Incoming Short wave Solar radiation, Kip & Zonen CM3 at 3.0 m



CPI: checked by PI; PRE: preliminary



Date Data Last Revised by PI

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

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