TITLE: CEOP First Half EOP-3 GAPP Fort Peck, MT Flux Data Set


Tilden P. Meyers
Atmospheric Turbulence and Diffusion Division
456 S. Illinois Ave.
Oak Ridge, TN 37830

Telephone: (865) 576-1245
Fax: (865) 576-1327

E-Mail: meyers@atdd.noaa.gov


This data set contains 30-minute resolution flux  data from the 
Coordinated Enhanced Observing Period (CEOP) Global Energy and Water 
Cycle Experiment (GEWEX) Americas Prediction Project (GAPP) Reference 
Site operated by Tilden Meyers (National Oceanic and Atmospheric 
Administration (NOAA) Atmospheric Turbulence and Diffusion Division 
(ATDD) at Fort Peck, Montana.  This data set covers the time period 
1 October 2002 through 31 March 2003.  Further information about the 
Fort Peck flux tower is available at the following URL:


1.1  Site Information

The Fort Peck reference site is located on the Fort Peck Indian
Reservation.  The vegetation is a grassland. The leaf area index varies
but is generally about 2.0.  The canopy height is 20-40 cm.  The flux 
measurement height is 3.5 m.

The flux tower is located at 48.30768 N and 105.10185 W at an 
unknown elevation.

This data set includes observations of CO2 flux, sensible heat flux, and
latent heat flux at 3.5 m height.  Also included is soil heat flux at
the -0.04 m height.


No information is currently available on the make, model or
specifications of the instrumentation used at the Fort Peck, MT 
reference site.


3.1  NOAA/ATDD Data Collection and Processing

Main computer: Shuttle SpaceWalker Mini-Barebones System with 250 MB 
Internal Zip Disk. This is a neat computer box, measuring 270 mm x 
190 mm x 170 mm. It provides a VIA chipset and supports Intel 
PIII/Celeron/VIA C3 processors. It has two PC133 memory slots, an 
onboard 2D/3D graphics engine, two onboard IEEE 1394 ports (FireWire), 
four Universal Serial Bus (USB) ports, one onboard 10/100 MB LAN port,
and one onboard AC '97 audio interface. It also includes S-video and 
TV-out jacks, two 3.5" drive bays, one 5.25 inch drive bay, and one PCI
slot which utilizes a riser card.

Serial Interface: Keyspan USB 4-port serial adapter. This provides four 
RS-232 serial ports in an easily expandable box. The com port 
connections are described below:

Com 1 - RM Young ultrasonic anemometer. The sonic provides 10 Hz 
U, V, W winds and air temperature. In addition, an ATDD IRGA is used to 
measure CO2 and H2O concentrations through the sonic anemometer's
built-in A/D system.

Com 2 - Campbell Scientific CR10/23X Data Logger. The data logger 
collects up to 15 channels of analog data and stores at 1 Hz. All data 
collected by the data logger are downloaded to the Linux computer once 
per day.  Typical data measured include soil moisture and temperature, 
mean wind speed and direction from an RM Young propeller anemometer, 
rainfall data, solar radiation, and air pressure and temperature.

Com 3 - Olympus Camedia digital camera. This camera provides images of 
the site once per hour from 8:00 am until 6:00 pm. These images are 
archived on the 250MB removable Zip disk.

Com 4 - Motorola Cell-Modem back phone. The cellular phone modem is 
connected to Com 4 allowing remote access from a dial-up line. Routine 
data downloads and maintenance is performed using dial-up services 
provided by Kermit.

The Linux software has been developed in-house. 

REA Applications
An extended application of the GEWEX hardware and software involves 
the use of Relaxed Eddy Accumulation to measure fluxes of trace gases 
that cannot be easily measured at high frequency in real-time 
(e.g. Mercury, Methane, Sulfur, etc). 

The software control for the REA system is quite unique and simple. 
The control of the up, mid, and down sampling valves is performed 
using the RS-232 control lines CTS (Clear-To-Send) and DTR 
(Data-Terminal-Ready).  By toggling these two lines high and low, four 
combinations can be obtained. This is easily accomplished in software 
and conveniently uses the vertical winds measured from the sonic 

3.2  UCAR/JOSS Data Processing

The University Corporation for Atmospheric Research/Joint Offfice for
Science Support (UCAR/JOSS) converted the data from the raw format
provided by NOAA/ATDD into the CEOP EOP-3 data format agreed to by
the CEOP Scientific Steering Committee.  This format is described
in detail as part of the CEOP Reference Site Data Set Procedures
Report which is available at the following URL:



4.1  NOAA/ATDD Quality Control Procedures

No information is currently available on the NOAA/ATDD quality
control procedures conducted on the Fort Peck reference site data.

4.2  UCAR/JOSS Quality Control Procedures

UCAR/JOSS conducted two primary quality assurrance/control
procedures on the Fort Peck reference site data.  First the
data has been evaluated by a detailed QA algorithm that verifies
the format is correct, examines any QC flags, and conducts
basic checks on data values.  Second, JOSS conducts a manual
inspection of time series plots of each parameter.

UCAR/JOSS did not apply any QC flags to the Fort Peck reference
site data.


No information is currently available on any gap filling
procedures that may have been conducted on the Fort Peck
reference site data.


No data remarks.


No information is currently available on any reference requirements
for the Fort Peck reference site data.