BOREAS AFM-03 NCAR Electra 1994 Aircraft Sounding Data
Summary
The BOREAS AFM-03 team used the NCAR Electra aircraft to make sounding
measurements to study the planetary boundary layer using in situ and remote-
sensing measurements. Measurements were made of wind speed and direction, air
pressure and temperature, potential temperature, dewpoint, mixing ratio of H2O,
CO2 concentration, and ozone concentration. Twenty-five research missions were
flown over the NSA, SSA, and the transect during BOREAS IFCs 1, 2, and 3 during
1994. All missions had from 4 to 10 soundings through the top of the planetary
boundary layer. This sounding data set contains all of the in situ vertical
profiles through the boundary layer top that were made (with the exception of
"porpoise" maneuvers). Data were recorded in 1-second time intervals. These
data are stored in tabular ASCII files.
Table of Contents
* 1 Data Set Overview
* 2 Investigator(s)
* 3 Theory of Measurements
* 4 Equipment
* 5 Data Acquisition Methods
* 6 Observations
* 7 Data Description
* 8 Data Organization
* 9 Data Manipulations
* 10 Errors
* 11 Notes
* 12 Application of the Data Set
* 13 Future Modifications and Plans
* 14 Software
* 15 Data Access
* 16 Output Products and Availability
* 17 References
* 18 Glossary of Terms
* 19 List of Acronyms
* 20 Document Information
1. Data Set Overview
1.1 Data Set Identification
BOREAS AFM-03 NCAR Electra 1994 Aircraft Sounding Data
1.2 Data Set Introduction
The BOReal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology
(AFM)-03 team used the National Center for Atmospheric Research (NCAR) Electra
aircraft to make sounding measurements to study the planetary boundary layer
using in situ and remote-sensing measurements. Measurements were made of wind
speed and direction, air pressure and temperature, potential temperature,
dewpoint, mixing ratio of H2O, CO2 concentration, and ozone concentration.
Twenty-five research missions were flown over the Northern Study Area (NSA),
Southern Study Area (SSA), and the transect during BOREAS Intensive Field
Campaigns (IFCs) 1, 2, and 3 during 1994. All missions had from 4 to 10
soundings through the top of the planetary boundary layer. This sounding data
set contains all of the in situ vertical profiles through the boundary layer top
that were made (with the exception of "porpoise" maneuvers). Data were recorded
in 1-second time intervals. These data are stored in tabular American Standard
Code for Information Interchange (ASCII) files.
1.3 Objective/Purpose
The Electra aircraft was used both to measure surface fluxes and to study the
planetary boundary layer using in situ and remote-sensing measurements.
This sounding data set contains all of the in situ vertical profiles through
the boundary layer top that were made (with the exception of "porpoise"
maneuvers).
1.4 Summary of Parameters
The AFM-03 soundings data include time, date, location, wind speed and
direction, air pressure and temperature, potential temperature, dewpoint, mixing
ratio of H2O, CO2 concentration, and ozone concentration.
1.5 Discussion
A total of 25 research missions were flown, distributed fairly evenly throughout
IFCs 1, 2, and 3. Flights were always along the regional transect, following
the waypoints between Saskatoon and Churchill, except for some deviations north
of the NSA. See Section 7.1 for location of the waypoints. Some missions
concentrated exclusively on the SSA (waypoints A-H). Other missions (at least
one each IFC) went to/from Churchill, Manitoba (YYQ). All missions had from 4
to 10 soundings through the top of the planetary boundary layer. Takeoff and
landing vertical profiles (at Saskatoon (YXE) or Churchill (YYQ)) are included
when they penetrated the top of the boundary layer. Most soundings were
transitions between legs flown at 100 meters above ground level (AGL) to measure
fluxes close to the surface and legs flown above the boundary layer (sometimes
as high as 3,150 meters AGL) to measure continuous water vapor profiles remotely
using a downward-looking water vapor DIAL instrument. These soundings were
flown as circles near the waypoint so that both the low and high legs would
begin/end at the same location. There are several flights, such as R05, where a
very long (in this case 1,000 km) flight at 100 meters was broken up by an "up-
and-down" sounding. All flights had other changes of altitude within the
boundary layer that have not been included in this data set.
1.6 Related Data Sets
BOREAS AFM-01 NOAA/ATDD Long-EZ 1994 Aircraft Flux Data over the SSA
BOREAS AFM-02 Wyoming King Air 1994 Aircraft Flux and Moving Window Data
BOREAS AFM-03 NCAR Electra 1994 Aircraft Flux Data
BOREAS AFM-03 NCAR Electra 1994 Aircraft Moving Window Data
BOREAS AFM-04 NRC Twin Otter Aircraft Flux Data
BOREAS AFM-04 NRC Twin Otter Aircraft Sounding Data
BOREAS AFM-05 Level-1 Upper Air Network Data
BOREAS AFM-05 Level-2 Upper Air Network Standard Pressure Level Data
2. Investigator(s)
2.1 Investigator(s) Name and Title
Donald H. Lenschow
National Center for Atmospheric Research/MMM
Boulder, CO
(303) 497-8903
(303) 497-8181 (fax)
2.2 Title of Investigation
Airborne Investigation of Biosphere�Atmosphere Interactions Over the Boreal
Forest
2.3 Contact Information
Contact 1
----------
Donald H. Lenschow
NCAR/MMM
Boulder, CO
(303) 497-8903
(303) 497-8181 (fax)
lenschow@ncar.ucar.edu
Contact 2
----------
Steven P. Oncley
NCAR/ATD/SSSF
Boulder, CO
(303) 497-8757
(303) 497-8770 (fax)
oncley@ucar.edu
Contact 3
----------
Jeffrey A. Newcomer
Raytheon ITSS
NASA GSFC
Greenbelt, MD
(301) 286-7858
(301) 286-0239 (fax)
3. Theory of Measurements
This section summarizes the capabilities of the Electra as used in BOREAS. For
a complete description, see the Project Summary Documentation for BOREAS
distributed by the Research Aviation Facility (RAF) and associated RAF
Bulletins. Winds were determined by combining measurements of the air motion
relative to the aircraft by pressure sensors connected to five holes on the
radome of the Electra, with aircraft motion measured by a Honeywell laser
inertial reference system (IRS). Corrections to the IRS data were made using
measurements by a Global Positioning System (GPS) satellite receiver. See NCAR
RAF Bulletin No. 23 for a complete description of this system and the data
processing used. In situ measurements of temperature, humidity, atmospheric
pressure, aerosol and cloud droplet size distributions were made by sensors
mounted to the wing and fuselage of the aircraft (RAF Bulletin Nos. 22 and 24).
In situ measurements of chemical constituents were made by drawing outside air
into closed-path sensors within the aircraft cabin. These sensors included a
LI-COR LI-6262 for water vapor and carbon dioxide and two NCAR gas-phase
chemiluminescent sensors for ozone.
4. Equipment
4.1 Sensor/Instrument Description
None given.
4.1.1 Collection Environment
Most data were acquired by an onboard computer that handled serial digital data,
analog data (after anti-alias filtering), and event counters. (The DIAL system
and disjunct sampler each had independent data systems.) Data were written to
8-mm digital tape in flight and were later processed using the Nimbus program to
calibrate, digitally filter (when necessary), and synchronize the final time
series. The time series data sets are available in NetCDF format at two data
rates: 1) all channels output at 1 sample/second, and 2) all turbulence channels
output at 25 samples/second.
4.1.2 Source/Platform
All instruments were mounted on a Lockheed Electra, which is a pressurized, low-
wing, turbo-propeller airplane, designed as a medium-range airliner. It is
powered by four Allison 501-D13 constant-speed, axial-flow, turbine engines that
drive four-bladed, full-feathering, reversible-pitch, turbo-propellers. Flight
is approved in known icing conditions; however, external instrumentation
installations may restrict operations in icing conditions.
4.1.3 Source/Platform Mission Objectives
See Section 1.3.
4.1.4 Key Variables
See Sections 1.4 and 7.3.
4.1.5 Principles of Operation
See Section 4 and associated documents.
4.1.6 Sensor/Instrument Measurement Geometry
Most turbulence sensors are mounted on or near the aircraft radome on the
fuselage. The air-chemistry instruments had sampling inlets protruding from
window locations along the fuselage. Particle size sensors were mounted from
pylons on the wings.
4.1.7 Manufacturer of Sensor/Instrument
None given.
4.2 Calibration
Most of the sensors were calibrated following normal NCAR/RAF procedures. See
the Project Documentation Summary for BOREAS (in particular, the Data Quality
Report), available from Paul Spyers-Duran, for a complete description of the
data used for these calibrations and a list of unique problems. Some general
conclusions:
Wind finding was good once a 10- to 15-degree bias in wind direction was
removed.
Aircraft position and velocity measured by the IRS were adjusted to match
positions from the GPS receiver.
The Lyman-alpha hygrometer failed during flights 3, 9, and 12, and during
periods of flights 17 and 20. For these flights, the LI-COR measurement of
humidity was used.
The bottom dewpoint hygrometer performed worse than a "top" one, so the top
sensor was used for all flights.
The LI-COR carbon dioxide channel was calibrated using a series of measurements
with calibration gases during preflight testing and in-flight. An empirical fit
using pressure and temperature was used, since the manufacturer calibration
equation performed poorly.
4.2.1 Specifications
Specifications for standard Electra sensors are given in RAF Bulletin No. 4.
4.2.1.1 Tolerance
None given.
4.2.2 Frequency of Calibration
See the Project Documentation Summary for BOREAS (in particular, the Data
Quality Report), available from Paul Spyers-Duran. Many sensors are checked
before every flight.
4.2.3 Other Calibration Information
None given.
5. Data Acquisition Methods
Most data were acquired by an onboard computer that handled serial digital data,
analog data (after anti-alias filtering), and event counters. (The DIAL system
and disjunct sampler each had independent data systems.) Data were written to 8-
mm digital tape in flight and were later processed using the Nimbus program to
calibrate, digitally filter (when necessary), and synchronize the final time
series. The time series data sets are available in NetCDF format at two data
rates: 1) all channels output at 1 sample/second, and 2) all turbulence channels
output at 25 samples/second.
6. Observations
6.1 Data Notes
None given.
6.2 Field Notes
Each investigator on the aircraft kept his/her own set of (usually handwritten)
notes. These have not yet been assembled into a complete document.
7. Data Description
7.1 Spatial Characteristics
These data were taken at 1-second intervals during aircraft vertical spiral
maneuvers and during takeoff and landings. At a nominal airspeed of 100 m/s and
climb rate of 10 m/s, this corresponds to measurements every 100 m horizontally
and 10 m vertically. A total of 25 research missions were flown, distributed
fairly evenly throughout IFCs 1, 2, and 3.
Flights were always along the regional transect, following the waypoints between
Saskatoon and Churchill, except for some deviations north of the NSA.
This track was approximately a line from Saskatoon, Saskatchewan (52? N, 107? W)
to a point north of Churchill (61? N, 95? W).
The North American Datum of 1983 (NAD83) are:
Waypoint Latitude Longitude
A 53? 32� N 106? 34� W
H 54? 7� N 104? 13.5� W
K 54? 41.7� N 103? 47.5� W
L 54? 57.3� N 101? 58� W
M 55? 54.8� N 99? 7.5� W
O 55? 53.2� N 98? 00� W
P 60? 30� N 98? 00� W
Q 60? 30� N 95? 30� W
R 59? 00� N 95? 30� W
CH 58? 44.5� N 94? 04� W
Some missions concentrated exclusively on the SSA (waypoints A-H). Waypoints
between A and H:
Waypoint Latitude Longitudes
a 53? 34.7� N 106? 23.8� W
b 53? 42.8� N 105? 52� W
c 53? 55� N 105? 04� W
d 53? 59� N 104? 47.2� W
Other missions (at least one each IFC) went to/from Churchill, Manitoba (YYQ).
All missions had from 4 to 10 soundings through the top of the planetary
boundary layer. Takeoff and landing vertical profiles (at Saskatoon (YXE) or
Churchill (YYQ)) are included when they penetrated the top of the boundary
layer.
7.1.1 Spatial Coverage
All soundings are nominally taken at one point horizontally, though these
usually are in the form of tight (6-km diameter) circles flown near one of
the waypoints listed above. In a few cases (such as takeoffs and landings) the
sounding was taken as an "enroute" climb or descent. The altitude range
typically is 100 meters AGL to about 300 m above the inversion height for these
soundings. Obviously, the takeoff and landing soundings go to 0 meters AGL. In
some cases, the bottom of the soundings are higher.
7.1.2 Spatial Coverage Map
None given.
7.1.3 Spatial Resolution
Individual position measurements should be accurate to 100 m horizontally, and 1
m vertically.
7.1.4 Projection
None given.
7.1.5 Grid Description
None given.
7.2 Temporal Characteristics
The Electra flew 25 missions during the 1994 IFCs (25-May-1994 to 16-Sep-1994):
8 in IFC-1, 8 in IFC-2, and 9 in IFC-3.
7.2.1 Temporal Coverage
Each flight was about 7 hours in duration and was usually between 11:00 a.m. and
4:00 p.m. local time (all daylight hours).
7.2.2 Temporal Coverage Map
Measurements were made from 25-May-1994 to 16-Sep-1994.
7.2.3 Temporal Resolution
Measurements were made at intervals of 1 second. Missions were flown five to
seven times per month.
7.3 Data Characteristics
Data characteristics are defined in the companion data definition file
(afm3as94.def).
7.4 Sample Data Record
Sample data format shown in the companion data definition file (afm3as94.def).
8. Data Organization
8.1 Data Granularity
All of the AFM-03 NCAR Electra 1994 Aircraft sounding Data are contained in one
data set.
8.2 Data Format(s)
The data files contain numerical and character fields of varying length
separated by commas. The character fields are enclosed with single apostrophe
marks. There are no spaces between the fields. Sample data records are shown in
the companion data definition file (afm3as94.def).
9. Data Manipulations
9.1 Formulae
Values are reported at one sample per second. Since all channels on the
aircraft are sampled faster than this rate, these values are "boxcar" averages
over all of the samples acquired during each second.
9.1.1 Derivation Techniques and Algorithms
None.
9.2 Data Processing Sequence
9.2.1 Processing Steps
1. AFM-03 processed data and sent them to the BOREAS Information System
(BORIS).
2. BORIS staff received the data, made necessary conversions to standard units,
and loaded the data into the database.
3. BORIS staff documented the data set and compiled basic statistics about the
data.
9.2.2 Processing Changes
None.
9.3 Calculations
None.
9.3.1 Special Corrections/Adjustments
Most values reported here are copied directly from the standard RAF low-rate
data file. The only exception is radar altitude, which was derived from two
independent sensors. A single radar altitude was synthesized from the low-range
altimeter (HGM) for altitudes less than 780 m, and from the high-range altimeter
(HGME) above 780 m. This synthesized altitude had occasional spikes. These
spikes were detected by testing if the difference between the pressure altitude
and sum of radar altitude plus height of the ground was greater than 50 m. The
ground height was set to the difference between pressure altitude and radar
altitude at the first point in the sounding. Spikes were replaced by pressure
altitude minus the ground height.
9.3.2 Calculated Variables
Most values reported here are copied directly from the standard RAF low-rate
data file. The only exception is radar altitude, which was derived from two
independent sensors. A single radar altitude was synthesized from the low-range
altimeter (HGM) for altitudes less than 780 m, and from the high-range altimeter
(HGME) above 780 m. See Section 9.3.1 for information about corrections to this
parameter.
9.4 Graphs and Plots
None.
10. Errors
10.1 Sources of Error
There were several instrument malfunctions during this program. See the Data
Quality section of the Project Documentation Summary.
Calibration gas was connected to the LI-COR CO2/H2O sensor during some flight
legs. Most of these periods were near the beginning or end of a flight leg and
have been removed by selection of leg start and stop times, but a few cases have
been included.
The LI-COR CO2 calibration is still somewhat uncertain, though it is the best we
can do at this time.
The Lyman-alpha hygrometer has spikes caused by rain that have not yet been
removed from the data.
The radar altimeter has spikes from an unknown source. These have not been
removed, but should not contaminate the mean altitude much. (They should be
detectable by comparing the altitude standard deviation from the radar altimeter
and pressure altitude.)
The dew-point hygrometer sometimes cannot keep up with large changes in
temperature (as occur during ascents and descents), so humidity profiles (not
included in the leg-average data) should be used with caution.
10.2 Quality Assessment
Spot checks of data quality were done in the field, in calibration by NCAR/RAF,
and in post-processing. These checks mostly relied on the experience of the
person checking to determine if values were suspicious. Time series, profiles,
and spectra have been used. According to the AFM03 team, this process is
ongoing and the quality of these products is still unknown.
10.2.1 Data Validation by Source
10.2.2 Confidence Level/Accuracy Judgment
None given.
10.2.3 Measurement Error for Parameters
None given.
10.2.4 Additional Quality Assessments
None given.
10.2.5 Data Verification by Data Center
BOREAS personnel verified that the delivered data agreed with the information
provided by the AFM-03 team.
11. Notes
11.1 Limitations of the Data
None given.
11.2 Known Problems with the Data
See the Data Quality Report (Appendix A.4) for a complete list of data quality
issues. In particular, pay attention to the sections describing the following
sensors:
The Electra carried two dewpoint hygrometers, a Lyman-alpha hygrometer, and a
LI-COR closed-path infrared absorption hygrometer. The dewpoint reported here
came from the dewpoint hygrometer, which was determined to behave the best (by
inspection). Even so, there are periods where this signal has large
oscillations due to the inability of the hygrometer to cycle fast enough to
follow the large changes in humidity often found in soundings. This behavior
can be checked qualitatively by looking at the mean water vapor density, which
was derived from either the Lyman-alpha or LI-COR sensor. However, both of
these sensors have their own problems: the Lyman-alpha can read high after cloud
penetration or rain, and the LI-COR had a pressure dependence that obviously
changed with height. Also, calibrations of the LI-COR often were performed
during soundings.
Mean carbon dioxide (from the LI-COR) and ozone values should not be trusted due
to instrument and calibration problems.
Wind calculations on the Electra depend on accurate measurements of aircraft
acceleration, which is large during the turns typical of these soundings.
Therefore, the wind speed and direction reported here could be in error, though
it is difficult assign a magnitude for this error.
11.3 Usage Guidance
The Lyman-alpha hygrometer can read high after cloud penetration or rain, and
the LI-COR closed-path infrared absorption hygrometer had a pressure dependence
that changed with height.
11.4 Other Relevant Information
None given.
12. Application of the Data Set
These data could be used to verify the quality of the AFM-03 flux and moving
window data.
13. Future Modifications and Plans
None given.
14. Software
14.1 Software Description
None given.
14.2 Software Access
None given.
15. Data Access
15.1 Contact for Data Center/Data Access Information
These BOREAS data are available from the Earth Observing System Data and
Information System (EOS-DIS) Oak Ridge National Laboratory (ORNL) Distributed
Active Archive Center (DAAC). The BOREAS contact at ORNL is:
ORNL DAAC User Services
Oak Ridge National Laboratory
(865) 241-3952
ornldaac@ornl.gov
ornl@eos.nasa.gov
15.2 Procedures for Obtaining Data
BOREAS data may be obtained through the ORNL DAAC World Wide Web site at
http://www-eosdis.ornl.gov/ or users may place requests for data by
telephone, electronic mail, or fax.
15.3 Output Products and Availability
Requested data can be provided electronically on the ORNL DAAC's anonymous FTP
site or on various media including, CD-ROMs, 8-MM tapes, or diskettes.
The complete set of BOREAS data CD-ROMs, entitled "Collected Data of the Boreal
Ecosystem-Atmosphere Study", edited by Newcomer, J., et al., NASA, 1999, are
also available.
16. Output Products and Availability
16.1 Tape Products
All time series as recorded by the investigators are saved on the NCAR Mass-
Store System in NetCDF format and are available from the investigators upon
request. Contact Steven Oncley or Don Lenschow.
16.2 Film Products
Videotapes with imagery from forward-, side (left)-, and downward-looking
cameras are also available from the investigators. The forward-looking is black
and white, and the others are color. The quality is medium, since the tapes
were recorded in "extended play" mode to create one tape for each (6-7 hour)
flight. All videotapes have a time stamp in the image. Contact Steven Oncley
for details.
16.3 Other Products
These data are available on the BOREAS CD-ROM series.
17. References
17.1 Platform/Sensor/Instrument/Data Processing Documentation
Airborne Humidity Measurements. 1987. NCAR Research Aviation Facility Bull. No.
22, Boulder, CO.
Baumgardner, D. 1989. Airborne measurements for cloud microphysics. NCAR
Research Aviation Facility Bull. No. 24, Boulder, CO.
Flight Planning: The NCAR Electra. 1993. NCAR Research Aviation Facility Bull.
No. 7, Boulder, CO.
Glover, V. and L. Bannehr. 1993. Radiation measurements from NCAR aircraft. NCAR
Research Aviation Facility Bull. No. 25, Boulder, CO.
Lenschow, D.H. and P. Spyers-Duran. 1989. Measurement Techniques: Air motion
sensing. NCAR Research Aviation Facility Bull. No. 23, Boulder, CO.
17.2 Journal Articles and Study Reports
Davis, K.J. et al. 1996. 22nd Conference on Agricultural and Forest Meteorology,
Atlanta, GA, Jan. 28-Feb. 2, American Meteorological Society.
Lenschow, D.H., Q. Wang, S.P. Oncley, K.J. Davis, and J. Mann. 1996.
Lake-induced modification of the boundary layer over the boreal forest.
22nd Conference on Agricultural and Forest Meteorology, Atlanta, GA, Jan. 28-
Feb. 2, American Meteorological Society.
Mann, J., K.J. Davis, D.H. Lenschow, S.P. Oncley, C. Kiemle, G. Ehret, A. Giez,
and H.G. Schreiber. 1995. Airborne observations of the boundary layer top, and
associated gravity waves and boundary layer structure. Ninth Symp. on Met. Obs.
and Instrum., Amer. Met. Soc., Boston, MA.
Oncley, S.P., D.H. Lenschow, K.J. Davis, T. Campos, and J. Mann. 1996.
Regional-scale surface flux observations across the boreal forest during
BOREAS. 22nd Conference on Agricultural and Forest Meteorology,
Atlanta, GA, Jan. 28-Feb. 2, American Meteorological Society.
Sellers, P. and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment
Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94).
Sellers, P. and F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment
Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96).
Sellers, P., F. Hall, and K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere
Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94).
Sellers, P., F. Hall, and K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere
Study: 1996 Operations. NASA BOREAS Report (OPS DOC 96).
Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J.
Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J. Ranson, D. Lettenmaier, and D.E.
Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and
early results from the 1994 field year. Bulletin of the American Meteorological
Society. 76(9):1549-1577.
Sellers, P.J., F.G. Hall, R.D. Kelly, A. Black, D. Baldocchi, J. Berry, M.
Ryan, K.J. Ranson, P.M. Crill, D.P. Lettenmaier, H. Margolis, J. Cihlar, J.
Newcomer, D. Fitzjarrald, P.G. Jarvis, S.T. Gower, D. Halliwell, D. Williams, B.
Goodison, D.E. Wickland, and F.E. Guertin. 1997. BOREAS in 1997: Experiment
Overview, Scientific Results and Future Directions. Journal of Geophysical
Research 102 (D24): 28,731-28,770.
17.3 Archive/DBMS Usage Documentation
None.
18. Glossary of Terms
None.
19. List of Acronyms
AFM - Airborne Fluxes and Meteorology
AGL - Above Ground Level
ASCII - American Standard Code for Information Interchange
ATD - Atmospheric Technology Division of NCAR
BL - atmospheric Boundary Layer
BOREAS - BOReal Ecosystem-Atmosphere Study
BORIS - BOREAS Information System
CD-ROM - Compact Disk-Read-Only Memory
DAAC - Distributed Active Archive Center
EOS - Earth Observing System
EOSDIS - EOS Data and Information System
GPS - Global Positioning System
GSFC - Goddard Space Flight Center
HTML - HyperText Markup Language
IFC - Intensive Field Campaign
INS - Inertial Navigation System
IRS - Inertial Reference System
MMM - Mesoscale and Microscale Research Division, NCAR
NAD83 - North American Datum of 1983
NASA - National Aeronautics and Space Administration
NCAR - National Center for Atmospheric Research
NDVI - Normalized Difference Vegetation Index
NRC - National Research Council, Canada
NSA - Northern Study Area
OA - Old Aspen
ORNL - Oak Ridge National Laboratory
PANP - Prince Albert National Park
PPFD - Photosynthetic Photon Flux Density
RAF - Research Aviation Facility, NCAR
SSA - Southern Study Area
SSSF - Sounding and Surface System Facility, NCAR
TF - Tower Flux
URL - Uniform Resource Locator
UTC - Universal Time Code
20. Document Information
20.1 Document Revision Date
Written: 29-Sep-1995
Last Updated: 20-Jul-1999
20.2 Document Review Date(s)
BORIS Review: 30-Jun-1999
Science Review:
20.3 Document ID
20.4 Citation
These data were provided by the National Center for Atmospheric Research, which
is sponsored by the National Science Foundation.
20.5 Document Curator
20.6 Document URL
Atmospheric Pressure
Wind direction
Wind speed
Temperature
Dewpoint temperature
Mixing ratio
Carbon dioxide concentration
Ozone concentration
AFM03_Soundings.doc
08/21/99