TITLE: CEOP EOP-3 and EOP-4 ARM NSA Meteorological Tower Data Set


CONTACT:


Raymond McCord
Building 1507
PO Box 2008, MS 6407
Oak Ridge, TN 37831-6407

Telephone: (865) 574-7827
Fax: (865) 574-4665

E-Mail: mccordra@ornl.gov


1.0  DATA SET OVERVIEW


This data set contains 30-minute resolution meteorological tower
data from the Coordinated Enhanced Observing Period (CEOP) Reference 
Site operated by the Atmospheric Radiation Measurement (ARM) Program at its 
North Slope of Alaska (NSA) facility in Alaska.  This data set 
includes observations from two locations.  This data set covers the 
time period 1 October 2002 through 31 December 2004.  Further information 
about the ARM NSA site is available at the 
following URL: http://www.arm.gov

1.1  Station Locations

Site                Elev (m)  Latitude  Longitude
-------------------------------------------------
C1_Barrow   AK         8.0    71.32300  -156.60900
C2_Atqasuk  AK        20.0    70.47180  -157.40660 

1.2 Time Period Covered by Data

All stations cover the complete EOP-3 and EOP-4 period (1 October 2002
to 31 December 2004).

1.3  Temporal Resolution

All data are 30-minute resolution.  See the instrumentation section for
further information.


The C1_Barrow station has the following observations at the specified 
heights:
# At the 2.00 m height: station pressure, temperature, dew point, relative 
  humidity, specific humidity, wind speed, wind direction, U wind component, 
  V wind component.
# At the 10.00 m height: temperature, dew point, relative humidity, wind speed, 
  wind direction, U wind component, V wind component.
# At the 20.00 m height: temperature, dew point, relative humidity, wind speed, 
  wind direction, U wind component, V wind component.
# At the 40.00 m height: temperature, dew point, relative humidity, wind speed, 
  wind direction, U wind component, V wind component. 

The C2_Atqasuk station has the following observations at the specified
heights:
# At the 2.00 m height: station pressure, temperature, dew point, relative 
  humidity, specific humidity.
# At the 5.00 m height: temperature, dew point, relative humidity.
# At the 6.00 m height: temperature, dew point, relative humidity. 

As detailed below, the instrumentation changed at the C2_Atqasuk site
on 6 November 2003 and the parameters that were measured at the 6.00
m height prior to that date were measured at the 5.00 m height from
that date forward.


2.0  INSTRUMENTATION DESCRIPTION

The ARM NSA meteorological tower measurements at the Barrow site are 
from their Barrow Meteorology (BMET) tower.  At the Atqasuk site the 
meteorological tower measurements are from their Atqasuk Meteorology
(AMET) tower.  Starting on 6 November 2003 C2_Atqasuk changed 
instrumentation to the METTWR2H and on 31 October 2003 C1_Barrow
changed instrumentation to the METTWR4H.  The radiation data
come from the GNDRAD and SKYRAD instrumentation at both sites.

2.1  BMET Sensors (Barrow site)

Full descriptions of the instruments used at the Barrow site prior
to 31 October 2003 are available in the pdf file Other_NSA_BMET.pdf 
included with your order.
ARM 
NSA BMET Handbook.

2.2  AMET (Atqasuk) Sensors

Full descriptions of the instruments used at the Atqasuk site prior
to 6 November 2003 are available in the pdf file Other_NSA_BMET.pdf 
included with your order.
ARM
NSA AMET Handbook.

2.3  METTWR2H (Atqasuk) Sensors

Full descriptions of the instruments used at the Atqasuk site starting
to 6 November 2003 are available in the pdf file Other_NSA_METTWR2H.pdf
included with your order.
ARM
NSA METTWR2H Handbook.

2.4  METTWR4H (Barrow) Sensors

Full descriptions of the instruments used at the Barrow site starting
to 31 October 2003 are available in the pdf file Other_NSA_METTWR4H.pdf
included with your order.
ARM
NSA METTWR4H Handbook.

2.4  GNDRAD and SKYRAD  Sensors

Full descriptions of the radiation instruments used at both sites
are available in the pdf file Other_GNDRAD.pdf and Other_SKYRAD.pdf included 
with your order.
ARM
NSA GNDRAD Handbook and 
ARM
NSA SKYRAD Handbook.


3.0  DATA COLLECTION AND PROCESSING


3.1  ARM Data Collection and Processing

For complete information on the SKYRAD instrumentation see the
ARM
SKYRAD Handbook.

For complete information on the GNDRAD instrumentation see the
ARM
GNDRAD Handbook.

For complete information on the METTWR4H instrumentation see the
ARM
METTWR4H Handbook.

For complete information on the METTWR2H instrumentation see the
ARM
METTWR2H Handbook.

For complete information on the AMET instrumentation see the
ARM
AMET Handbook.

For complete information on the BMET instrumentation see the
ARM
BMET Handbook.


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 ARM 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:

http://www.joss.ucar.edu/ghp/ceopdm/refdata_report/ceop_met_tower_format.html

The METTWR4H, METTWR2H, AMET, BMET , GNDRAD and SKYRAD provide 
1 minute measurements, the observations at the 00 and 30 minute 
marks of every hour are included in the final data set.


4.0  QUALITY CONTROL PROCEDURES


4.1  ARM Quality Control Procedures

For futher information on ARM QC Procudures see the instrument
handbooks mentioned above and in the references below.

4.2  UCAR/JOSS Quality Control Procedures

UCAR/JOSS converted the ARM QC flags into the CEOP QC flags in the 
following manner.  If a parameter failed one of the ARM QC checks it was 
flagged as Questionable/Dubious ("D") and if it failed two or more ARM 
QC checks it was flagged as Bad ("B").

Additionally, UCAR/JOSS conducted two primary quality assurrance/control
procedures on the 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.


5.0  GAP FILLING PROCEDURES


No gap filling procedures were applied to these data by either
ARM or UCAR/JOSS.


6.0  DATA REMARKS


6.1 ARM Data Quality Report for station C2 (Atqasuk) All Parameters

Missing data from 0029 UTC on 22 September 2002 to 1935 UTC on
21 November 2002:

Due to unknown wiring differences and pin changes by Vaisala to their
Wind Speed and Direction sensors, a power feedback into the QLI data
collector occurred.  This caused an overload which shut the QLI data
collector down.  Once trouble shooting pinpointed the power feedback,
wiring diagrams were created and the differences were found.  Wiring
was changed to prevent and remove the power feedback.

6.2 ARM Data Quality Report for station C2 (Atqasuk) All parameters

From 1430 UTC on 25 November 2002 to 2229 UTC on 26 March 2003:

Missing met, present weather, and snow depth data due to comm error

An error in the communication sub-routine of the Bridgeview collection
software occurred resulting in data loss from the Snow Depth sensor,
Present Weather Sensor and the Barometer.


7.0  REFERENCE REQUIREMENTS


To support the continuation of this program, please include the
following 'credit line' in the acknowledgments of your
publication:

"Data were obtained from the Atmospheric Radiation Measurement
(ARM) Program sponsored by the U.S. Department of Energy, Office
of Science, Office of Biological and Environmental Research,
Environmental Sciences Division."


8.0  REFERENCES


For complete information on the SKYRAD instrumentation see the
ARM
SKYRAD Handbook.

For complete information on the GNDRAD instrumentation see the
ARM
GNDRAD Handbook.

For complete information on the METTWR4H instrumentation see the
ARM
METTWR4H Handbook.

For complete information on the METTWR2H instrumentation see the
ARM
METTWR2H Handbook.

For complete information on the AMET instrumentation see the
ARM
AMET Handbook.

For complete information on the BMET instrumentation see the
ARM
BMET Handbook.