BOREAS AFM-05 Level-2 Upper-Air Network Standard Pressure Level Data

Summary

The BOREAS AFM-05 team collected and processed data from the numerous radiosonde 
flights during the project.  The goals of the AFM-05 team were to provide large 
scale definition of the atmosphere by supplementing the existing AES aerological 
network, both temporally and spatially.  This data set includes basic upper-air 
parameters interpolated at 0.5 kiloPascal increments of atmospheric pressure 
from data collected from the network of upper-air stations during the 1993, 
1994, and 1996 field campaigns over the entire study region.  The data are 
contained 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-05 Level-2 Upper-Air Network Standard Pressure Level Data

1.2 Data Set Introduction

The BOReal Ecosystem-Atmosphere Study (BOREAS) Aircraft Flux and Meteorology 
Team 5 (AFM-05) oversaw the launch of radiosonde balloons during each Intensive 
Field Campaign (IFC) in 1993, 1994, and 1996.  These launches helped to provide 
a better understanding of the atmosphere during the data measurement periods.

1.3 Objective/Purpose

The goals of the AFM-05 team were to provide large-scale definition of the 
atmosphere by supplementing the existing Atmospheric Environment Service (AES) 
aerological network, both temporally and spatially; provide a large and fine 
enough mesh to satisfy the spatial requirements of mesoscale modelers; and 
provide appropriate temporal frequency to resolve diurnally varying atmospheric 
processes.

1.4 Summary of Parameters

The data include parameters of location, date, time, geopotential height, 
atmospheric pressure, temperature, dew point temperature, wind direction and 
speed, u and v components of the wind, potential temperature and equivalent 
potential temperature, mixing ratio, relative humidity (RH), radiosonde range, 
radiosonde azimuth angle, radiosonde elevation, and the type of field measured.

1.5 Discussion

The BOREAS upper-air data network operated during the 1993, 1994, and 1996 IFCs.  
Three proximate sites in the existing AES network (at Saskatoon, SK; The Pas, 
MB; and Churchill, MB) and two military stations (at Primrose Lake, AB and 
Shilo, MB) contributed soundings, augmenting their routine 1200 and 0000 
Universal Time Code (UTC) soundings with an additional 1800 (UTC) sounding.  A 
separate National Aeronautics and Space Administration (NASA) activity made a 
limited number of 1200 UTC soundings at Lynn Lake, MB during the 1994 IFC-2.

BOREAS augmented the existing network in 1994 with three additional sites at 
Candle Lake, SK, Key Lake, SK and Thompson, MB. Soundings were made routinely at 
1200, 1800 and 0000 (UTC), and additionally at 1400, 1600, 2000 and 2200 (UTC) 
on fair-weather days in IFCs 1 to 3 at Candle Lake and Thompson.

The Shilo data (collected in 1994) are not included in the BOREAS Information 
System (BORIS) data set because of their very coarse resolution and SHilos 
distance from the area.

In 1996, routine soundings were performed at 1200 and 0000 (UTC) daily at
three existing upper-air sites near the BOREAS study areas (Saskatoon, The Pas, 
and Churchill).  BOREAS augmented the existing network in 1996 with upper-air 
sites at Candle Lake and Thompson where soundings were typically performed at 
1200, 1600, 1800, 2000, 2200 and 0000 (UTC) on fair-weather days and at 1200, 
1800 and 0000 (UTC) on poor-weather days.

1.6 Related Data Sets

BOREAS AFM-05 Level-1 Upper-Air Network Data

2. Investigator(s)

2.1 Investigator(s) Name and Title

Alan Barr
Atmospheric Environment Service
National Hydrology Research Center

Alan Betts
Atmospheric Research

2.2 Title of Investigation

Upper-air Network (AFM-05) Boundary Layer Research For BOREAS (AFM-08)

2.3 Contact Information

Contact 1
-----------
Alan Barr
Atmospheric Environment Service
National Hydrology Research Center
Saskatoon, SK
(306)975-4324
(306)975-6516 (fax)
alan.barr@ec.gc.ca

Contact 2
-----------
Charmaine Hrynkiw
Atmospheric Environment Service
National Hydrology Research Center
Saskatoon, SK
(306)975-5793
(306)975-6516 (fax)
hrynkiwc@nhrisv.nhrc.sk.ec.gc.ca

Contact 3
-----------
Alan Betts
Atmospheric Research
Pittsford, VT 
(802)483-2087
(802)483-6167 (fax)
akbetts@aol.com

3. Theory of Measurements

Pressure, temperature, humidity, and wind measurements were converted from
radiosonde signals received and processed by an upper-air receiver.  The 
measurements were interpolated at 0.5 kiloPascal (kPa) increments for easier use 
by
researchers. 

Wind observations utilized radio-navigation.  Wind speed and direction were
determined by navigation networks (NAVAID) or via a radiotheodolite positioned 
near the release site.  The NAVAID signals were relayed to the ground station 
for processing and wind vector computation. The radiotheodolite received signals 
from the radiosonde and recorded azimuth, elevation, and altitude, from which 
the trajectory of the radiosonde was calculated.

Depending on the system, higher level processing was conducted after the 
pressure, temperature, humidity, and radiosonde position signals were converted 
(i.e., Vaisala).

4. Equipment

4.1 Sensor/Instrument Description

Vaisala (Candle Lake, Key Lake, Thompson, and Churchill)
Radiosonde Type: Vaisala RS80 Series Description

VIZ W9000 (Saskatoon, Lynn Lake, The Pas - 1996)
Radiosonde Type: VIZ-BEUKERS LO-CATE MICROSONDE

Atmospheric Instrumentation Research, Inc. (A.I.R.)
Radiosonde Type: A.I.R.

Aerological Data REduction System (ADRES), The Pas - 1994
Radiosonde Type: 1680 MHz radiosonde


Candle Lake Surface Observation Instruments
-------------------------------------------
Temperature: mercury thermometer
Humidity: wet bulb mercury thermometer
Pressure: Druck digital
Wind Direction and Speed: estimated
Sling psychrometer (1996)
Anemometer (1996)
Aneroid barometer (1996)


Thompson Surface Observation Instruments
----------------------------------------
Temperature: mercury thermometer
Humidity: wet bulb mercury thermometer
Pressure: Setra 270
Wind Direction and Speed: U2A
Sling psychrometer (1996) was used to measure surface temperature and humidity.
Anemometer (1996)
Setra pressure transducer (1996)

Key Lake and Churchill Surface Observation Instruments
------------------------------------------------------
Temperature: thermistor
Humidity: lithium chloride dew cell
Pressure: Setra
Wind Direction and Speed: 78D

The Pas Surface Observation Instruments
---------------------------------------
Temperature: thermistor
Humidity: lithium chloride dew cell
Pressure: standard mercury barometer
Wind Direction and Speed: U2A


Saskatoon Surface Observation Instruments and Method
----------------------------------------------------
Temperature: mercury thermometer (sling psychrometer)
Humidity: wet bulb mercury thermometer (sling psychrometer)
Pressure: Ruska digital barometer
Wind Direction and Speed: U2A

Primrose Lake Surface Observation Instruments and Method
--------------------------------------------------------
Temperature: mercury thermometer (ventilated Stevenson Screen)
Humidity: wet bulb mercury thermometer (ventilated Stevenson Screen)
Pressure: Ruska digital barometer
Wind Direction and Speed: U2A


4.1.1 Collection Environment

Upper-air data were collected in varying ambient weather conditions.

4.1.2 Source/Platform

The platforms for the data collection were weather balloons.

4.1.3 Source/Platform Mission Objectives

The objective of the balloon was to carry the sonde up through the atmosphere.

4.1.4 Key Variables

The primary quantities measured, both on the surface and in the upper
atmosphere, were pressure, temperature, humidity, wind direction and wind
speed.

4.1.5 Principles of Operation

The radiosondes used a small battery powered transmitter that relayed messages 
to a receiver on the ground.  As the radiosonde passed through the
atmosphere, the sensors detected changes in pressure, temperature and humidity.

These changes were sent as signals to the receiver which were then decoded
as values of pressure, temperature and humidity. An automatic tracking
device determined the position of the radiosonde, which was translated into
wind speed and direction by the receiver.

A radiosonde consisted of the following major components:  Meteorological
sensors that responded mechanically or electrically to changes in the
parameters being measured (temperature, humidity, and pressure); a switching
mechanism that connected the sensor outputs to the modulator circuitry;
a modulator for regulating the carrier signal at a rate dependent on the
electrical resistance of the temperature and humidity sensors; a transmitter
for transmitting radio frequency signals back to the ground equipment;
a power supply (battery) that produced the current required to operate the
electronic circuitry; and a container or case made from polystyrene and 
cardboard used to house the electronic and mechanical components (this container 
was also designed to provide suitable exposure for the sensors).

4.1.6 Sensor/Instrument Measurement Geometry

The measurements made by the sensor or calculated from the measurements varied 
in their geometric representation depending on the flight conditions.

4.1.7 Manufacturer of Sensor/Instrument

Vaisala Radiosondes (Candle L., Churchill, Key L., Thompson):
Vaisala Inc.
100 Commerce Way
Woburn, MA   01801
Ph: (617) 933-4500
Fax: (617) 933-8029

VIZ (Saskatoon, Lynn Lake, The Pas (1996)):
VIZ Manufacturing Company
335 East Price Street
Philadelphia, PA 19144-5782
Ph: (215) 844-2626
Fax: (215) 844-4410

A.I.R. (Primrose L.):
Atmospheric Instrumentation Research, Inc.
8401 Baseline Road
Boulder, CO 80303
Ph: (303) 499-1701
Fax: (303) 499-1767

4.2 Calibration

4.2.1 Specifications

Vaisala: Radiosondes were factory calibrated.  Calibration tape accompanying 
each radiosonde was fed into the MW15 prior to launch.  A calibration correction 
was applied to RH as described in section 9.1.

Vaisala (Candle Lake, Key Lake, Thompson and Churchill)
Radiosonde Description:
Type: Vaisala RS80 Series Description:
Pressure Sensor: Capacitive aneroid; Resolution: 0.01 kPa, Precision: 0.05 kPa
Humidity Sensor: Humicap thin film capacitor; Resolution: 1% RH;
                 Precision: 2% RH; Lag: 1 s (for 6 m.s-1 flow at 100 kPa)
Temperature Sensor: Capacitive bead; Resolution: 0.1 deg C;
                    Precision: 0.2 deg C;
                    Lag: < 2.5 s (for 6 m/sec flow at 100 kPa)
Wind Direction and Speed: NAVAID (Loran-C or Omega)


VIZ:  Radiosondes were factory calibrated.

VIZ W9000 (Saskatoon, Lynn Lake, The Pas - 1996)
Radiosonde Description:
Type: VIZ-BEUKERS LO-CATE MICROSONDE
Pressure Sensor: Aneroid capsule (Ni-Span-C); Resolution: 0.01 kPa;
Precision: 2 kPa
Humidity Sensor: carbon type, 10000; Resolution: .01% RH; Precision: 4% RH
Temperature Sensor: Thermistor, rod type, 1400 ohms; Resolution: 0.01 deg
C; Precision: 0.4 deg C
Wind Direction and Speed: NAVAID (Loran-C or Omega)


A.I.R.: Radiosondes were factory calibrated.  Calibration coefficients were
transmitted by the radiosonde.

A.I.R.
Radiosonde Description:
Type: A.I.R.
Intellesonde Description:
Pressure Sensor: aneroid pressure cell; Resolution: 0.01 kPa; Precision: 1 kPa
Humidity Sensor: carbon hygristor; Resolution: .01% RH; Precision: 3% RH
Temperature Sensor: Thermistor; Resolution: 0.01 deg C; Precision: 0.5 deg C
Wind Direction and Speed: Automatic Digital Radiotheodolite
Each Intellisonde was factory calibrated with calibration coefficients stored in 
read-only memory (ROM). These coefficients were automatically transmitted to the 
receiver on power-up.

ADRES, The Pas - 1994.
Radiosonde Description:
Temperature Sensor: Thermistor
Wind Direction and Speed: Radiotheodolite

4.2.1.1 Tolerance

Upper-air Observations:

Vaisala
A radiosonde was accepted if:
- Temperature reading was within +/- 2 degrees C of the manually observed 
temperature;
- Pressure was within +/- 5 mb of the manually observed pressure;
- Relative humidity was within +/- 20 percentage points of the manually observed 
  relative humidity.

Precision (Vaisala UAD Technical Manual):
The following data were based on the twin ascent method. Two Vaisala series
RS 80 radiosondes were suspended from one balloon and tracked by two
independent receiving systems.  The standard deviation of the differences
was obtained after a number of ascents.  Pressure measurement precision
(1060 to 3 mb) is 0.05 mb. Temperature measurement precision was 0.2 degrees C 
and
humidity was 3%. Wind vector measurement precision was 2 knots typical
(Omega/Alpha) and 1 knot typical (Loran-C).

VIZ
A radiosonde was accepted if pressure was stable and was within 5 mb of the
standard pressure measurement.

A.I.R.
The A.I.R. software compared the manually entered surface observation and
alerted the user if a variable was far enough out of range to justify
rejection of the radiosonde.

Surface Observations:  Not applicable.

4.2.2 Frequency of Calibration

Upper-air

Each radiosonde was checked against the surface observation before release.

Surface Observations:

Surface pressure sensors at Candle Lake, Saskatoon and Thompson were checked 
against the AES regional standard pressure sensor prior to installation. Checks 
were performed at the beginning and end of the 1994 BOREAS field season.

The surface pressure sensor at The Pas was checked once a year against the AES 
traveling standard pressure sensor, which in turn, was checked against the AES 
regional standard.

No checks were performed on the ordinary thermometers used at Candle Lake,
Thompson Zoo, Saskatoon and Key Lake.

The dew cell sensors at Key Lake and Churchill were checked once a week in 1994.

4.2.3 Other Calibration Information

None.

5. Data Acquisition Methods

Vaisala Data Reception and Signal Processing
Radiosonde (wind) tracking: NAVAID (Loran-C or Omega);
Receiver: DigicoraII MW15

The Vaisala receiver (MW15) received and processed radiosonde signals in
real time. The signals were converted to pressure, temperature and relative
humidity and wind, and transferred to a PC.

After all signals were converted to pressure, temperature, relative
humidity and wind speed and direction, proprietary higher level processing
was conducted.

Main Functions of the Main Processor Unit (p.12 Vaisala UAD Technical Manual):
1) Error message handling and diagnostic analysis: Monitors operations by
sending a message to the console upon detecting an error. Reads and
analyzes error maps from other processor boards. If an error occurs,
control is taken over by the error message handler.
2) Console command handling: Interprets commands given via console to
application programs and to other processor boards.
3) Data handling and operational control: Transfers untreated, raw data
from the receiver for processing, editing and smoothing programs. Detects
radiosonde launch and radiosonde burst.

DATA EDITING (Appendix A, p.1 Vaisala UAD Program Manual)
Using established physical equations, the raw data (at two, five or ten second 
intervals) are edited to obtain the so-called filtered data. The purpose of data 
editing is to reject physically inconsistent data points.

Editing is a nonlinear, non-recursive method of data quality control. It is
necessary because of the presence of telemetry noise which tends to distort
the determination of the signal frequency. Data editing is carried out in real 
time. There are four phases:
- coarse filtering
- fine filtering
- completion of the data set by interpolation
- data smoothing between turning points

WIND EDITING (Appendix B, p1 Vaisala UAD Program Manual)
The wind vector is computed based on the rate of change of the signal phase
(phase derivatives) which is caused by the movement of the radiosonde. The
rate of change of the phase depends on the movement of the radiosonde with
respect to the transmitters and on the change in the distance between the
radiosonde and the ground station.  The basic solution is the so-called 
hyperbolic solution where at least three signals are needed to locate the 
radiosonde and to compensate for drift of the local oscillator and the change in 
the distance between the radiosonde and the ground station.

Computed wind vectors are passed through a quality control program to
ensure that deviating vectors are rejected. Cubic spline fitting method is
used to smooth the wind data after all stray points are rejected (according
to Grubbs criterion).


VIZ W9000 (Saskatoon, Lynn Lake, The Pas - 1996)
A basic system consisted of the following:
- Preamplifier/Antenna- Local NAVAID Antenna
- A rack with a P90 bus interconnecting the backplane with the following:
  - 403 MHz Synthesized Receiver Module
  - System Interface Module
  - 403 Mhz Antenna Control Module
  - Loran-C or Omega Amplifier Modules
  - NAVAID Tracker Module(s)
  - System computer, keyboard, hard drive and two floppy drives
  - Color monitor
  - Printer

Winds were determined by either Loran or Omega tracking. All available
Loran chains or Omega stations were displayed to the user. The chains or
stations were selected for the current tracker.


A.I.R.
Pressure was measured from 1050 to 5 mb by a capacitance type pressure sensor. 
An internal temperature sensor located near the pressure sensor provided 
temperature compensation.  Temperature was measured by a precision thermistor 
protected by a reflective coating intended to minimize radiation errors at high 
altitude.  Relative humidity was measured by a carbon hygristor mounted on a
double-shielded aerodynamic duct.

The automatic ground station included an IBM compatible computer with an A.I.R. 
data decoder board installed in a standard expansion slot. The computer was used 
to calculate pressure, temperature humidity and winds.  The calculated 
parameters were then archived on the computer's hard disk.

The A.I.R. system at Primrose Lake received 250mW radiosonde transmissions
which were decoded and transferred to a personal computer where unmodified
pressure, temperature and humidity data were saved.

Wind data were automatically gathered using the A.I.R. Automatic Digital
Radiotheodolite.  This mechanism used a microprocessor controlled planar
phased array rather than a parabolic dish for tracking.  The A.I.R.
radiotheodolite electronically measured the small tracking error associated
with the slew rate of the antenna and corrected the output signal generated
by the optical encoders.  The antenna position, combined with the pressure,
temperature and humidity data from the radiosonde was used by the ground
station to compute wind speed and direction. The receiver, control
microprocessor, power supply and switching array all were housed within the
radiotheodolite.

The radiosonde type used was a 1680 MHz Intellisonde, which was manufactured by 
A.I.R. The Intellisonde measured temperature, humidity and pressure with digital 
precision. Sensor output was converted to digital words in the radiosonde. 
Pressure, temperature, humidity data and sensor references were then formatted 
into a digital message.  Contamination of pressure, temperature and humidity 
data by telemetry noise was determined by error detection codes.


ADRES is a Canadian rawindsonde system designed and produced by AES. It
was in use for twenty years and is being phased out. The Pas was one of the
last existing ADRES stations in Canada.  ADRES was designed to partially 
automate upper-air soundings while allowing significant observer
intervention.  Significant and mandatory level data were read manually from 
strip charts.  The data were then entered manually and processed by the ADRES 
software.  The observer was limited to a maximum of sixty levels.

A 1680 MHz radiosonde was the instrument launched. The pressure was measured by 
means of a temperature-compensated single cell aneroid.  Temperature was 
measured using a thermistor. This thermistor was a thin rod of semiconductor 
ceramic material with a negative temperature coefficient of electrical 
resistance.  Humidity was measured using an electrolytic element called a 
hygristor, whose electrical resistance varied proportionally to the relative 
humidity of the air.  The hygristor consisted of a small plastic strip coated 
with a thin film of carbon.  The two long edges were coated with metallic 
electrodes between which the resistance measurements were made.


Candle Lake Surface Observation Instruments and Method
------------------------------------------------------
Dry and wet bulb temperatures were manually read from mercury in glass
thermometers mounted in a non-ventilated Stevenson screen. Depending on dew
point temperature, the wet bulb thermometer was moistened using either a wick or 
a muslin sleeve.  When the wet bulb temperature was greater than 0 C, a wick 
was used. A muslin sleeve was used when the wet bulb temperature ranged from 0 
degrees C to -10 degrees C. The sleeve or wick was replaced once weekly.

Temperature and dew point measurements were then corrected according to the 
factor specified by the thermometer serial number. Non-ventilated psychrometric 
tables were used to determine dew point temperature and relative humidity after 
the correction had been applied.

An instantaneous pressure value was manually taken using a Druck pressure 
sensor. No correction was applied.

A two minute average of wind speed and direction was estimated by the observer.  
Wind direction was estimated in eight-point compass degrees.

In 1996, a sling psychrometer was used to measure surface temperature and 
humidity.  Wind speed and direction were taken as a 2-minute average measured 
electronically by an anemometer.  Pressure was taken from an aneroid barometer.


Thompson Surface Observation Instruments and Method
---------------------------------------------------
Temperature and humidity were measured following the same procedure as at
Candle Lake. The only difference was that the dry and wet bulb thermometers
were in a ventilated Stevenson screen; therefore, ventilated psychrometric
tables were used to determine dew point temperature and relative humidity.

Two minute averages of wind direction and speed were measured using the U2A
wind measurement system. Direction was read to 10 degrees and speed to one knot.

An instantaneous pressure value was manually read using a Setra 270 pressure 
sensor. No correction was applied.

In 1996, a sling psychrometer was used to measure surface temperature and 
humidity.  Wind speed and direction were taken as a 2-minute average measured 
electronically by an anemometer.  Pressure was taken from a Setra pressure
transducer.

Key Lake and Churchill Surface Observation Instruments and Method
-----------------------------------------------------------------
Temperature and humidity readings were taken by a READAC automatic weather 
station. The temperature sensor type was a thermistor and the humidity sensor 
was a lithium chloride dew cell. Both were housed in a ventilated Stevenson 
screen 1.25m above the ground. No corrections were applied.

Pressure was measured via two Setra sensors; the lower of the two readings was 
output.  Wind direction and speed were measured using 78D sensors.  These 
sensors use vector averaging to calculate two minute wind direction and speed.

In the event of automatic weather station failure, standard thermometers also 
housed in the READAC were used. If the wind sensors were not available, an 
estimation of wind direction was determined using the eight points of the 
compass and wind speed was estimated in knots.

No data were measured at Key Lake during BOREAS 1996.  Surface observations at 
Churchill were not investigated for BOREAS 1996.


The Pas Surface Observation Instruments and Method
--------------------------------------------------
Temperature and humidity were measured in a ventilated Stevenson screen using a 
dew cell and thermistor. Temperature and dew point were displayed 
instantaneously. No correction was applied.

Wind was measured using the same method as outlined for Thompson Zoo.

Pressure was measured using a standard mercury barometer.  No correction was 
applied.

BOREAS 1996:
In 1996, surface observations were not taken at The Pas.


Saskatoon Surface Observation Instruments and Method
----------------------------------------------------
Temperature and wet bulb temperatures were measured using a sling psychrometer. 
Relative humidity and dew point were determined via psychrometric tables. No 
corrections were applied.

Pressure was measured by a Ruska digital barometer that was situated 
approximately 11m higher than the radiosonde release point. A correction for 
this height discrepancy was applied during processing.

Wind direction and speed were determined from the U2A output generated by the 
automatic weather station.

Primrose Lake Surface Observation Instruments and Method
--------------------------------------------------------
Temperature and dew point - same as at Candle Lake and Thompson Zoo (BOREAS
1994).

Pressure sensor - displayed instantaneous pressure.  Wind direction and speed 
displayed instantaneously by dials or was determined from wind direction and 
speed plotted on a rolling strip chart.

Two ordinary thermometers (same as at Candle Lake and Thompson Zoo for BOREAS 
1994) were housed in a ventilated Stevenson screen. Dew point temperature was 
determined using the same method as at Candle Lake and Thompson Zoo except that 
ventilated psychrometric tables were used to determine the relative humidity and 
dew point.  It is unknown what procedure was followed regarding the wick/muslin 
sleeve or if corrections were applied for each thermometer.

A two minute wind average was measured using a U2A instrument (as described for 
Thompson Zoo for BOREAS 1994). Winds may also have been observed from a strip 
chart produced by the U2A system.

Pressure was measured using a standard mercury barometer.  No correction was 
applied.


6. Observations

6.1 Data Notes

Organized by date.  Example: CANDL 94-Apr-13 11Z.  CANDL= site ID, 94=Year,
04=Month, 13=Day of Month, 11Z=Hour during which the sonde was released (in
UTC).

THOMP=Thompson, CANDL=Candle Lake, PRIMR=Primrose Lake, CHURH=Churchill,
THEPAS=The Pas, STOON=Saskatoon, LYNNL=Lynn Lake, KEY L=Key Lake.

-KEY L 94-Apr-12 17Z: Early burst, second release performed.
-CANDL 94-Apr-13 11Z: RH incorrectly calculated using a correction for wet bulb 
of -1.0 instead of -0.1. RH was entered as 41% instead of 54%. Dew point may be 
recorded incorrectly.
-CANDL 94-Apr-13 17Z: Dew point may be incorrect.  94-Apr-14 11Z: Light snow at
release time, turning into heavy snow, quit at 1230. Local power surge
followed by outage at 11:32, 11:33, 11:45 and 12:02. Outage at 12:02 - remained 
out until flight terminated.
-STOON 94-Apr-13 17Z: No wind data.
-STOON 94-Apr-13 23Z: No wind data.
-STOON 94-Apr-14 23Z: Computer lost sonde signal.
-STOON 94-Apr-15 23Z: No flight information - radiosonde technical problems.
-CANDL 94-Apr-16 17Z: String connecting radiosonde to balloon did not appear to 
unwind fully.
-STOON 94-Apr-16 11Z: No flight information - radiosonde technical problems.
-STOON 94-Apr-16 17Z: No flight information - radiosonde technical problems.
-THOMP 94-Apr-18 11Z: Lost signal - unable to find.
-THOMP 94-Apr-19 11Z: Old looking balloon
-THOMP 94-Apr-19 17Z: Old looking balloon
-THOMP 94-Apr-20 17Z: Lost signal for a while.
-CANDL 94-Apr-21 11Z: String did not appear to unwind.
-KEY L 94-Apr-21 11Z: This flight was very short. The balloon had burst at
49min 20sec.
-KEY L 94-Apr-22 11Z: This flight was unsuccessful due to an early burst.
Second release will be performed.
-THOMP 94-Apr-22 11Z: Second launch.
-CANDL 94-Apr-23 11Z:  String did not appear to unwind.
-KEY L 94-Apr-23 11Z: Poor weather and poor visibility delayed arrival to site
(about 5AM).
-CANDL 94-Apr-24 11Z: Problem with wet bulb temperature therefore RH was
entered at 72%, which was the local Environment Canada calculation at
10:00Z.
-KEY L 94-Apr-24 11Z: Balloon burst early at 38min 30sec.
-THOMP 94-Apr-24 11Z: Had problems with signal between 90 mb and 60 mb.
-THOMP 94-Apr-24 17Z: Lost signal between 232 mb and 192 mb
-STOON 94-Apr-25 17Z: Manual flight end.
-THOMP 94-Apr-25 11Z: Lost signal for a while.
-THOMP 94-Apr-25 17Z: Lost signal for a while.
-THOMP 94-Apr-25 11Z: Lost signal for a while.
-CANDL 94-Apr-26 11Z: Problem with RH -- METHOD?
-KEY L 94-Apr-26 17Z: Flight was unsuccessful due to an early burst, a second
release will be performed.
-THOMP 94-Apr-26 11Z: Lost wind direction and speed for a while.
-THOMP 94-Apr-26 17Z: Lost signal around 90 mb.
-KEY L 94-Apr-27 17Z: Flight was unsuccessful due to an early burst, a second
release will be performed.
-THOMP 94-Apr-27 11Z: First radiosonde rejected.  Surface temperature should
be -10.0 instead of 10.0.
-CANDL 94-Apr-28 11Z: String did not appear to unwind.
-STOON 94-Apr-28 17Z: No wind data.
-CANDL 94-Apr-29 11Z: String did not appear to unwind.
-KEY L 94-Apr-30 11Z: Flight was delayed due to a defective balloon.
-THOMP 94-Apr-30 17Z: Clock set on Digicora and computer.
-THOMP 94-May-02 11Z: Radiosonde temperature gauge broken. Unable to make a
copy of the April 30 diskette. Having trouble with telemetry, Digicora said
that data were out of bounds. Monitoring sonde returned. Lost wind direction
and speed at 94.2 mb.

-CANDL 94-May-24 11Z: Balloon had a visible weak spot on one side but it did
not seem to have any effect.
-CANDL 94-May-24 23Z: Radiosonde failure.
-KEY L 94-May-24 11Z: Flight was unsuccessful. Second release will be performed. 
There was missing data for wind direction/speed (5min 25sec to 11min 35sec and 
12min 15sec to 17min 45sec and 20min 55sec to termination).  Range missing from 
5min 25sec to termination.
-KEY L 94-May-24 17Z: There was an electrical outage from 9:30AM(CST) to 11:45AM 
(CST). Because there was no power, the automatic weather station was 
inoperative. The surface weather observation was taken manually from the 
Stevenson screen barometer, wind charts and psychrometric tables.
-CANDL 94-May-25 11Z: String did not unwind.
-CANDL 94-May-25 20Z: Re-launch just after 20:00Z because two bad humidities
on sondes forced two re-launches. Authorized by Alan Betts.
-CANDL 94-May-25 21Z: MW15 possibly picked up another instrument still in the
air even though radio frequencies of the second release was 401.38. Flight
automatically ended at 21:50Z. No second release attempt due to time 
constraints.
-KEY L 94-May-25 11Z: Flight was delayed due radiosonde difficulties.  The
first one was rejected due to a high humidity reading (153%).  The second
and third radiosondes give similar readings but did not correspond within
range for the READAC's observations. The second and third radiosondes were
giving acceptable readings.  Since there was very little time, the
Stevenson screen was used for the temperature, dew point, and RH. The
radiosonde was unacceptable range in relation to the Stevenson screen. The
psychrometric table was unclear to what the RH factor was. 49% was used for
the observation.
-THOMP 94-May-25 11Z to 94-Jun-06 15Z: No wind information.
-CANDL 94-May-26 19Z: Manual termination due to bad data. 100% RH and bad
temperature.
-THPAS 94-May-26 17Z: Strong convection, lots of ascent rate changes and
superadiabatic layers.
-THPAS 94-May-26 23Z: Many supers off surface (7). MISDA STRATUM DUESCT. SGN.
NO APPARENT CAUSE.??
-KEY L 94-May-27 23Z: Flight was unsuccessful due to an early burst.  Second
release will be performed.
-THPAS 94-May-27 11Z: Many supers!!
-THPAS 94-May-27 17Z: Many supers!!!
-STOON 94-May-28 19Z: Second launch.
-THPAS 94-May-28 17Z: Many supers. Ground equipment trouble delayed release.
-CANDL 94-May-29 11Z: No wind data until 484hPa. Winds lost again at 250hPa.
-CANDL 94-May-29 19Z: Flight released at 19:03Z at Alan Betts' request. Rain
showers approaching.
-CANDL 94-May-29 21Z: Flight released at 21:08 at Alan Betts' request.
-CANDL 94-May-30 11Z: No wind data until 544.9hPa.
-CANDL 94-Jun-01 11Z: Balloon has a very irregular shape. No wind data until
862hPa.
-CANDL 94-Jun-01 15Z: No wind data until 794hPa.
-KEY L 94-Jun-03 11Z: Flight was unsuccessful. Second release will be
performed. There was missing data for wind direction/speed (6min 5sec to
15min 55sec and 17min 25sec to termination. Range missing from 6min 5sec to
termination.)
-THPAS 94-Jun-03 17Z: Power failure near end.  ADRES used to finish.
-CANDL 94-Jun-04 11Z: Odd shaped balloon. Balloon was touching top of tent -
may be over 500 grams.
-KEY L 94-Jun-04 11Z: Flight came very close to being delayed because the 
READAC's observations were not corresponding within range with the radiosondes. 
Three radiosondes were compared with the READAC's observations. All three gave 
similar readings but were slightly out of range with the READAC. The radiosonde 
was in range with the Stevenson screen. The READAC was also not giving wind 
observations. The winds were estimated for direction and speed.
-KEY L 94-Jun-04 17Z: Flight was unsuccessful. Second release will be performed. 
There was missing data for wind data from 30min 25sec to termination.
-KEY L 94-Jun-05 11Z: Flight was unsuccessful because the receiver had lost the 
signal from the sonde. Second release will be performed.
-KEY L 94-Jun-05 17Z: Flight was unsuccessful because the receiver had lost the 
sonde's signal. Second release will be performed.
-THPAS 94-Jun-05 11Z: Many supers off surface.
-THPAS 94-Jun-05 23Z: Instrument hit CB base.
-CANDL 94-Jun-06 11Z: String did not unwind.
-KEY L 94-Jun-07 11Z: Flight was unsuccessful. There was missing wind data from 
22min 35sec to termination. Second release will be performed.
-CANDL 94-Jun-08 11Z: Approximately 20 minutes into the flight TELEM became very 
weak - RH jumping from 8% to 160%. Flight ended -second release.
-CANDL 94-Jun-08 12Z: String did not fully unwind.  TELEM problems.
-CANDL 94-Jun-08 19Z: String did not appear to unwind all the way.
-KEY L 94-Jun-08 12Z: Surface wind direction and speed were estimated. This was 
required because the READAC was giving no wind observations.
-CANDL 94-Jun-09 11Z: String did not unwind fully.
-CANDL 94-Jun-10 11Z: Balloon slightly lopsided.  Didn't look like string 
unwound all the way.
-CANDL 94-Jun-10 19Z: Signal very weak.
-KEY L 94-Jun-10 11Z: The sonde was not in range with the READAC.  Three sondes 
were tried and compared to the READAC but were all out of range. All three 
sondes were giving similar readings.  Stevenson screen was compared to the 
sondes and was found to be within range.
-STOON 94-Jun-10 19Z: Third launch. First launch - lost signal and ended flight.  
Second launch - couldn't locate sonde.
-CANDL 94-Jun-11 11Z: String only unwound as far as the plastic antennae cord
then stopped.
-KEY L 94-Jun-11 12Z: Flight was unsuccessful. Flight ended at about 13:20 
Greenwich Mean Time (GMT). Because there was little time left, a third release 
was not performed. There was missing wind data from 11min 55sec to termination.
-KEY L 94-Jun-11 23Z: Flight was unsuccessful due to an early burst.  Second
release will be performed.
-KEY L 94-Jun-12 11Z: Unsuccessful flight. Second release will be performed. 
There was missing wind data from 25min 45sec to termination.
-KEY L 94-Jun-12 23Z: A power outage made the READAC inoperative. Observations 
were taken manually.
-CANDL 94-Jun-13 11Z: String did not fully unwind.
-CANDL 94-Jun-13 23Z: String unwound only to end of plastic cord (again).
-STOON 94-Jun-13 00Z: Second launch. First launch - sonde not located at launch.
-PRIMR 94-Jun-14 17Z: Balloon defect.
-STOON 94-Jun-14 23Z: Second launch. First launch - sonde not located at launch.
-CANDL 94-Jun-15 13Z: String did not unwind at launch.
-CANDL 94-Jun-15 15Z: String did not unwind at launch.
-CANDL 94-Jun-15 17Z: String did not unwind at launch.
-CANDL 94-Jun-15 19Z: String did not unwind at launch.
-KEY L 94-Jun-15 23Z: Surface observations taken manually. The READAC was not on 
line.
-PRIMR 94-Jun-15 12Z: Balloon burst.
-STOON 94-Jun-15 18Z: Second launch. First launch - sonde not located at launch.
-STOON 94-Jun-15 23Z: Second launch. First launch - sonde not located at launch.
-THOMP 94-Jun-15 11Z: Snow, rain and fog outside.
-CANDL 94-Jun-16 11Z: String only unwound to end of plastic cord.
-CANDL 94-Jun-16 13Z: String only partially unwound.
-KEY L 94-Jun-16 11Z: Flight delayed - alarm clock failed to go off.
-STOON 94-Jun-16 23Z: Second launch. First launch - sonde not located at launch.

-THPAS 94-Jul-18 23Z: 5 supers.
-CANDL 94-Jul-19 11Z: Early burst.
-CANDL 94-Jul-19 12Z: Second release.  Early burst??
-CANDL 94-Jul-19 12Z: Third release.  Early burst??
-CANDL 94-Jul-19 23Z: Technical problems delayed release.
-STOON 94-Jul-19 18Z: Second release. First release - lost sonde signal at 
launch.
-THOMP 94-Jul-19 11Z: Second release. Technical problems on first release.
-THPAS 94-Jul-19 11Z: Late release.
-KEY L 94-Jul-21 23Z: LORAN reception was very poor. This caused a large amount 
of wind data loss.
-LYNNL 94-Jul-21 11Z: National Scientific Balloon Facility (NSBF) balloon: used 
a special, large mylar balloon to obtain high altitude wind data above 5mb.
-STOON 94-Jul-21 18Z: Second release. First release - lost sonde signal at 
launch.
-CHURH 94-Jul-22 11Z: No winds.
-STOON 94-Jul-22 00Z: Second release. First release - lost sonde signal at 
launch.
-CHURH 94-Jul-23 11Z: Second release.  No flight - equip. fail.
-KEY L 94-Jul-23 11Z: LORAN reception was very poor. This caused a large amount 
of wind data loss.
-THPAS 94-Jul-23 23Z: 5 supers.
-CHURH 94-Jul-24 11Z: Second release.
-KEY L 94-Jul-24 23Z: Flight was unsuccessful. Second release will be
performed. There was missing wind data from 7min 45sec to 22min 45sec and 33min 
55sec to termination.
-THPAS 94-Jul-24 23Z: 5 supers.
-CANDL 94-Jul-25 11Z: Surface data entered in error as 66% (correct RH not 
available).
-CHURH 94-Jul-25 11Z: No winds.
-LYNNL 94-Jul-25 11Z: NSBF High Altitude Balloon.
-STOON 94-Jul-25 11Z: Second launch - lost sonde signal at launch.
-THPAS 94-Jul-25 17Z: Early release - observer error.
-STOON 94-Jul-26 13Z: Third release. First and Second release - lost sonde
signal at launch.
-CANDL 94-Jul-27 19Z: 2 low ascent rates - balloons inflated the same as usual.
-CHURH 94-Jul-27 12Z: Second release.  No winds for first release.
-KEY L 94-Jul-27 17Z: No wind data.
-STOON 94-Jul-27 00Z: Second release. First release - lost sonde signal at 
launch.
-STOON 94-Jul-27 12Z: Second release. First release - lost sonde signal at 
launch.
-THPAS 94-Jul-27 17Z: 4 supers.
-THPAS 94-Jul-27 23Z: 6 supers.
-LYNNL 94-Jul-28 11Z: Special NSBF balloon.
-LYNNL 94-Jul-29 11Z: Special NSBF balloon.
-STOON 94-Jul-29 12Z: Second release. First release - lost sonde signal at 
launch.
-STOON 94-Jul-30 11Z: No winds.  Second release required.
-STOON 94-Jul-30 12Z: Third release. Second release - lost sonde signal at 
launch.
-STOON 94-Jul-30 18Z: Second release First release - lost sonde signal at 
launch.
-STOON 94-Jul-31 18Z: Three attempts to release - lost sonde signal at launch
for all three. No flight information.
-STOON 94-Aug-01 00Z: Second release. First release - lost sonde signal at 
launch.
-STOON 94-Aug-01 14Z: Third release. First and second release - lost sonde 
signal at launch.
-THPAS 94-Aug-01 11Z: 3 supers.
-PRIMR 94-Aug-02 12Z: No flight due to conflict with range operations.
-STOON 94-Aug-02 12Z: Second release. First release - lost sonde signal at 
launch.
-THOMP 94-Aug-02 13Z: Launch delayed. Operator had to wait for approval from
flight control until 13:42Z, then when balloon released, the twine between
the balloon and the sonde broke. The sonde was damaged in the fall. Second
release made.
-THOMP 94-Aug-02 19Z: Launch delayed by air traffic control.
-THPAS 94-Aug-02 11Z: 3 supers.
-KEY L 94-Aug-03 17Z: Flight was unsuccessful. There was missing wind data from 
0min 5sec to 5min 5sec and 5min 25sec to 10min 15sec and 16min 45sec to 28min 
15sec and 28min 55sec to 34min25sec and 34min 35sec to
termination. Second release will be performed.
-LYNNL 94-Aug-03 11Z: Special NSBF balloon. No data recorded for first run.
-PRIMR 94-Aug-03 12Z: No flight due to conflict with range operations.
-STOON 94-Aug-03 11Z: Second release. First release - lost sonde signal at 
launch.
-STOON 94-Aug-03 18Z: Second release. First release - lost sonde signal at 
launch.
-KEY L 94-Aug-04 23Z: Flight was unsuccessful, There was missing wind data from 
7min 15sec to termination. Second release will be performed.
-PRIMR 94-Aug-04 and 94-Aug-05:  No flights due to base commitments.
-STOON 94-Aug-04 12Z: Second release. First release - lost sonde signal at 
launch.
-THPAS 94-Aug-04 17Z: 2 supers.
-THPAS 94-Aug-04 23Z: 4 supers.
-LYNNL 94-Aug-05 11Z: Special NSBF balloon.
-THOMP 94-Aug-05 15Z: Launch delayed by air traffic control.
-THPAS 94-Aug-05 17Z: 2 supers.
-THPAS 94-Aug-05 23Z: 4 supers.
-STOON 94-Aug-06 13Z: Second release. First release - lost sonde signal at 
launch.
-STOON 94-Aug-06 23Z: Flight lost - terminated and disk save.
-THOMP 94-Aug-06 11Z: Not able to make this flight as keys to the zoo had been 
lost during the evening. Not able to access the zoo until 9AM.
-LYNNL 94-Aug-07 11Z: Special NSBF balloon.
-THPAS 94-Aug-07 17Z: 6 supers.
-PRIMR 94-Aug-08 17Z: Flight ended at 200mb (low stability sonde used).
-STOON 94-Aug-08 23Z: Omega tracking.  Winds mostly missing.
-THPAS 94-Aug-08 17Z: 6 supers.
-STOON 94-Aug-09 01Z: Omega tracking.  Second launch.

-THPAS 94-Aug-30 17Z: 6 supers.
-THPAS 94-Aug-30 23Z: 6 supers.
-STOON 94-Aug-31 17Z: No wind data.
-THPAS 94-Aug-31 11Z: 1 super.
-THPAS 94-Aug-31 17Z: 5 supers.
-THPAS 94-Aug-31 23Z: 7 supers.
-STOON 94-Sep-01 11Z: No wind data.
-THPAS 94-Sep-01 17Z: 1 super.
-THPAS 94-Sep-01 23Z: 4 supers.
-STOON 94-Sep-02 11Z: No wind data.
-STOON 94-Sep-02 17Z: No wind data.
-THPAS 94-Sep-02 17Z: 1 super.
-THPAS 94-Sep-02 23Z: 4 supers.
-STOON 94-Sep-03 12Z: Second launch. First launch - stuck in monitoring for
launch mode.
-THOMP 94-Sep-03 12Z: Sonde late because Charles Fenner (operator) did not show 
up. Launched by Alan Betts and Jo Lutley.
-THPAS 94-Sep-03 17Z: Power failure - ADRES crash. ADRES used to finish. No 
winds.
-THPAS 94-Sep-04 23Z: 1st release at 23:15 failed due to G.E.F.
-KEY L 94-Sep-07 11Z: Flight was unsuccessful due to a signal loss.  Second 
release will be performed. Surface observations were taken manually because the 
READAC was not giving any data due to a hard disk drive failure.
-KEY L 94-Sep-07 13Z: Flight was delayed because the computer had difficulties
sending out the UM, UG, UF and UQ data.  Observations were taken manually
because the READAC still had a hard disk drive failure. As of 13:50 GMT, 
security reports the READAC in good working order and READAC observations will 
be available for the 18:00 Zulu flight.
-THOMP 94-Sep-07 23Z: Surface RH needs correction in data: to 54% -wick was 
loose.
-STOON 94-Sep-08 00Z: Second launch. First launch - sonde located; monitor for
launch mode.
-THPAS 94-Sep-08 13Z: Late release - operator slept in.
-CANDL 94-Sep-10 15Z: Late because first sonde had bad humidity.  Weak 
telemetry.
-KEY L 94-Sep-10 11Z: Flight was delayed because the first radiosonde would not 
give any surface weather conditions. Receiver indicated no signal even though 
the radiosonde was transmitting a strong signal. This radiosonde was rejected. 
The second radiosonde was good.
-STOON 94-Sep-10 01Z: Second launch. First launch - sonde located; monitor for
launch mode.
-STOON 94-Sep-10 13Z: Second launch.
-THPAS 94-Sep-10 11Z: 4 supers.
-THPAS 94-Sep-10 17Z: 4 supers.
-THPAS 94-Sep-10 23Z: 3 supers.  Missing RH 960mb to 896mb.
-KEY L 94-Sep-11 11Z: Surface observations were taken manually because the 
READAC was not on line with the security gate house.
-KEY L 94-Sep-11 17Z: Surface observations were taken manually because the 
READAC still remains inoperative.
-THPAS 94-Sep-11 23Z: 2 supers.
-THPAS 94-Sep-12 17Z: 1 super.  Transponder sonde.
-THPAS 94-Sep-12 23Z: 2 supers.
-THPAS 94-Sep-13 11Z: 2 supers.
-KEY L 94-Sep-14 11Z: No flight was performed because there were no radiosondes. 
Radiosondes were shipped out during the middle of last week but still have not 
arrived at Key Lake.
-THPAS 94-Sep-14 23Z: 5 supers.
-THPAS 94-Sep-14 11Z: 3 supers.
-STOON 94-Sep-15 23Z: Loran tracking starts.
-THPAS 94-Sep-15 23Z: 3 supers.
-CANDL 94-Sep-16 11Z: No wind at surface - darkness - couldn't see balloon.
-THOMP 94-Sep-16 11Z: No flight (no explanation provided).
-CHURH 94-Sep-17 12Z: Second release.
-THPAS 94-Sep-17 11Z: 4 supers.
-THPAS 94-Sep-18 17Z: 2 supers.
-THPAS 94-Sep-18 23Z: 6 supers.
-STOON 94-Sep-19 19Z: Second launch. First launch - flight went into disk save
immediately.


-CANDL 96-Jul-08 17Z: Sfc P entered incorrectly at release time.  Changed
manually from 967.3 to 966.3 (correction of -0.69 not applied to 966.3
because it was already applied in the field).  Correction of -0.69 applied
to the surface pressure as indicated on the barometer for the soundings
listed below.  Those not on the list below were corrected by the flight
operator at the time of release.
96-Jul-09 15Z, 96-Jul-09 17Z, 96-Jul-09 21Z, 96-Jul-09 23Z, 96-Jul-10 11Z, 96-
Jul-10 15Z,
96-Jul-10 17Z, 96-Jul-10 19Z, 96-Jul-10 21Z, 96-Jul-10 23Z, 96-Jul-11 11Z, 96-
Jul-11 17Z,
96-Jul-11 23Z, 96-Jul-13 11Z, 96-Jul-13 15Z, 96-Jul-13 17Z, 96-Jul-13 19Z, 96-
Jul-13 21Z,
96-Jul-13 23Z, 96-Jul-14 11Z, 96-Jul-14 15Z, 96-Jul-14 17Z, 96-Jul-14 19Z, 96-
Jul-14 20Z,
96-Jul-14 21Z, 96-Jul-14 23Z, 96-Jul-15 11Z, 96-Jul-15 15Z, 96-Jul-15 17Z, 96-
Jul-15 19Z,
96-Jul-15 21Z, 96-Jul-15 23Z, 96-Jul-16 11Z, 96-Jul-16 17Z, 96-Jul-16 23Z, 96-
Jul-17 11Z,
96-Jul-17 17Z, 96-Jul-17 19Z, 96-Jul-17 21Z, 96-Jul-17 23Z, 96-Jul-18 11Z, 96-
Jul-18 17Z,
96-Jul-18 23Z, 96-Jul-19 11Z, 96-Jul-19 17Z, 96-Jul-19 19Z, 96-Jul-19 21Z, 96-
Jul-19 23Z,
96-Jul-20 11Z, 96-Jul-20 15Z, 96-Jul-20 17Z, 96-Jul-20 19Z, 96-Jul-20 21Z, 96-
Jul-20 23Z,
96-Jul-21 11Z, 96-Jul-21 17Z, 96-Jul-21 23Z, 96-Jul-22 11Z, 96-Jul-22 15Z, 96-
Jul-22 17Z,
96-Jul-22 19Z, 96-Jul-22 21Z, 96-Jul-22 23Z, 96-Jul-23 11Z, 96-Jul-23 17Z, 96-
Jul-23 23Z,
96-Jul-24 11Z, 96-Jul-24 15Z, 96-Jul-24 17Z, 96-Jul-24 19Z, 96-Jul-24 21Z, 96-
Jul-24 23Z,
96-Jul-25 11Z, 96-Jul-25 15Z, 96-Jul-25 17Z, 96-Jul-25 18Z, 96-Jul-25 23Z, 96-
Jul-29 11Z,
96-Jul-29 15Z, 96-Jul-29 17Z, 96-Jul-29 19Z, 96-Jul-29 21Z, 96-Jul-29 23Z, 96-
Jul-30 11Z,
96-Jul-30 15Z, 96-Jul-30 17Z, 96-Jul-30 19Z, 96-Jul-30 21Z, 96-Jul-30 23Z, 96-
Jul-31 11Z,
96-Jul-31 15Z, 96-Jul-31 17Z, 96-Jul-31 23Z, 96-Aug-01 11Z, 96-Aug-01 15Z, 96-
Aug-01 17Z,
96-Aug-01 19Z, 96-Aug-01 21Z, 96-Aug-01 23Z, 96-Aug-02 11Z, 96-Aug-02 15Z, 96-
Aug-02 17Z,
96-Aug-02 19Z, 96-Aug-02 21Z, 96-Aug-02 23Z, 96-Aug-03 11Z, 96-Aug-03 17Z, 96-
Aug-03 23Z,
96-Aug-04 11Z, 96-Aug-04 17Z, 96-Aug-04 23Z, 96-Aug-05 11Z, 96-Aug-05 17Z, 96-
Aug-05 23Z,

-CANDL 96-Jul-09 11Z: No data available - software and technical problems
during sounding.
-THOMP 96-Jul-09 23Z: First and only flight done that day because helium for
balloons had not been delivered until late in the day.
-THPAS 96-Jul-09 11Z: Removed excess error messages in Flight Log (JNL) file.
-THPAS 96-Jul-09 23Z: RH too high; Thermo data missing between 3 and 7 min.
-THOMP 96-Jul-10 19Z: Vaisala RH bad - removed flight from archive
-STOON 96-Jul-10 23Z: Sonde signal lost prior to launch - picked up again at
926.63 mb.  Applied a correction to elapsed time by determining the ascent
rate using the 1st and 20th observation (following the surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Jul-11 23Z: Possibly poor signal above 500mb - reflected in thermo 
data.  P increases and decreases alternately from approximately 14.4 to 16.03 
min.  Full resolution file archived but an interpolated version was not 
produced.
-THPAS 96-Jul-11 11Z: Removed excess error messages in Flight Log (JNL) file.
-STOON 96-Jul-12 11Z: Possibly poor signal - reflected in thermo data. Out-of-
range windspeed at 4min.
-THOMP 96-Jul-12 23Z: Temperature and humidity probably interpolated by the 
Vaisala system from surface to approx. 950mb.
-THOMP 96-Jul-13 15Z: Sfc RH entered incorrectly at launch time.  Replaced the 
original value of 25% with 48% (which was the value shown in the surface
observation log just prior to release).
-CANDL 96-Jul-14 20Z: Flight ended at 2 min 12 sec.  Although this flight was
released during the hour of 21Z, it was named 20Z so as not to be confused with 
the second release, which was also launched during the hour of 21Z.
-CANDL 96-Jul-17 17Z: Vaisala humidity probably too high.
-THOMP 96-Jul-18 19Z: Surface RH probably too high - correction NOT applied.
-STOON 96-Jul-20 11Z: Bad Pressure data - removed flight from archive.
-STOON 96-Jul-20 23Z: No wind info.
-THOMP 96-Jul-20 11Z: Temperature probably interpolated by the Vaisala system 
from surface to approx. 900 mb.
-THOMP 96-Jul-21 23Z: Temperature and humidity possibly interpolated by the 
Vaisala system from surface to approx. 880mb.
-THPAS 96-Jul-21 23Z: Launch and End of Flight time edited manually in Flight 
Log (JNL) file.
-THOMP 96-Jul-25 17Z: Sfc P incorrect - should have been 998.9 rather than 
989.9.  Corrected this problem by adding 9 to all Pressure measurements in the 
sounding.
-CANDL 96-Jul-26 22Z: Flight ended at 18 min.  Although this flight was released 
during the hour of 23Z, it was named 22Z so as not to be confused with the 
second release, which was also launched during the hour of 23Z.
-STOON 96-Jul-26 11Z: Excess error messages in Flight Log (JNL) file removed 
manually.
-THPAS 96-Jul-26 23Z: End of Flight time edited manually in Flight Log (JNL) 
file.
-THOMP 96-Jul-27 22Z: Flight ended at 6 min 56 sec.  Although this flight was 
released during the hour of 23Z, it was named 22Z  so as not to be confused with 
the second release, which was also launched during the hour of 23Z
-STOON 96-Jul-28 11Z: Launch and End of Flight time edited manually in Flight 
Log (JNL) file.
-THOMP 96-Jul-28 23Z: Sfc wet bulb temperature (of 16.4) accidentally entered 
into the u/a system instead of the actual surface temp of 24.6.  This has been 
corrected.
-CANDL 96-Jul-29 11Z: Sfc P entered incorrectly at release time.  Changed 
manually from 964.1 to 963.1 (then -0.69 applied to 963.1).
-THOMP 96-Jul-29 17Z: Sfc P incorrect - should have been 998.9 rather than 
989.9.  Corrected this problem by adding 9 to all Pressure measurements in the 
sounding.  Temperature and humidity possibly interpolated by the Vaisala system 
from surface to approximately 930mb.  Sfc RH also incorrect. Wet bulb 
temperature entered into the system instead of RH by mistake. Observed RH=79%.  
Unfortunately, the Vaisala system interpolated RH from the surfce to 
approximately 930mb using the incorrect RH (of 19%) as the starting point.  
Removed levels starting with the first above-surface level to 940.2 mb.
-STOON 96-Jul-30 23Z: P increases for a few levels near 50.4 minutes.  P
increases and decreases alternately from approximately 76.05 to 76.67 min.
Full resolution file archived but an interpolated version was not produced.
-THPAS 96-Jul-31 11Z: Launch time edited manually in Flight Log (JNL) file.
-STOON 96-Aug-01 11Z: Launch time edited manually in Flight Log (JNL) file.
-STOON 96-Aug-02 11Z: Launch time edited manually in Flight Log (JNL) file.
-THPAS 96-Aug-03 23Z: First pressure following surface was higher than the 
surface pressure.  Removed this level.
-STOON 96-Aug-05 11Z: Excess error messages in Flight Log (JNL) file removed
manually.
-STOON 96-Aug-05 23Z: Launch time edited manually in Flight Log (JNL) file.
-THPAS 96-Aug-05 11Z: Sonde signal lost prior to launch - picked up again at 
921.21 mb.  Applied a correction to elapsed time by determining the ascent rate 
using the 1st and 20th observation (following the surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Aug-06 23Z: Out-of-range wind speeds near end of flight.
-THOMP 96-Aug-07 19Z: Manually measured sfc T/RH very different from Vaisala 
T/RH - possibly because ob. taken 28min prior to launch.  Replaced sfc T/RH with 
HMP (autostation) values.
-STOON 96-Aug--Aug- 11Z: No Temperature data.
-CHURH 96-Oct-01 11Z: Errors in original site diskette.  Repaired file but was
unable to convert to American Standard Code for Information Interchange (ASCII).
-STOON 96-Oct-04 23Z: Sonde signal lost prior to launch - picked up again at
896.7 mb.  Time (sec) in raw file: 1326.5   P=945.78 (before lost signal)
---> then skipped to: 1599.7  P=896.7  (when signal found again).  Assumed that 
launch occurred somewhere in between.  Applied a correction to elapsed time by 
determining the ascent rate using the 1st and 20th observation (following the 
surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Oct-05 11Z: End of Flight message patched into Flight Log (JNL) file.
-STOON 96-Oct-08 11Z: Sonde signal lost prior to launch - picked up again at 
896.7 mb.  Time (sec) in raw file: 142.6  P=955.19 (before lost signal)
---> then skipped to: 274.4  P=907.63 (when signal found again).  Assumed that 
launch occurred somewhere in between.  Applied a correction to elapsed time by 
determining the ascent rate using the 1st and 20th observation (following the 
surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Oct-08 23Z: End of Flight message patched into Flight Log (JNL) file.
-STOON 96-Oct-09 11Z: Sonde signal lost prior to launch - picked up again at 
731.6 mb.  Time (sec) in raw file:  67.6 =962.41 (before lost signal) ---> then 
skipped to: 493.3  P=731.6  (when signal found again).  Assumed that launch 
occurred somewhere in between.  Applied a correction to elapsed time by 
determining the ascent rate using the 1st and 20th observation (following the 
surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Oct-11 11Z: Removed P=971.48 at 1560.5 sec. in raw file.  P goes bad 
after approx. 6 min.  Removed from archive.
-STOON 96-Oct-12 11Z: End of Flight message patched into Flight Log (JNL) file.
Sonde signal lost prior to launch - picked up again at 939.8 mb.  Time (sec) in 
raw file:2316.2  P=952.72 (before lost signal) ---> then skipped to:2350.9  
P=939.8  (when signal found again).  Assumed that launch occurred somewhere in 
between.  Applied a correction to elapsed time by determining the ascent rate 
using the 1st and 20th observation (following the surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Oct-14 11Z: Possibly a poor signal between 750 and 475 mb.
-STOON 96-Oct-14 23Z: Flight not available.
-STOON 96-Oct-15 11Z: Flight not available.
-THPAS 96-Oct-15 23Z: End of Flight message patched into Flight Log (JNL) file.
-STOON 96-Oct-16 23Z: Sonde signal lost prior to launch - picked up again at
667.86 mb.  Time (sec) in raw file:   0.0  P=955.2 (before lost signal)
---> then skipped to:  12.9  P=667.86 (when signal found again).  Assumed that 
launch occurred somewhere in between.  Applied a correction to elapsed time by 
determining the ascent rate using the 1st and 20th observation (following the 
surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Oct-17 11Z: Sonde signal lost prior to launch - picked up again at
949.54 mb.  Time (sec) in raw file: 124.1  P=960.97 (before lost signal)
---> then skipped to: 156.3  P=949.54 (when signal found again).  Assumed that 
launch occurred somewhere in between.  Applied a correction to elapsed time by 
determining the ascent rate using the 1st and 20th observation
(following the surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Oct-17 23Z: Full resolution data not archived.  Significant and 
mandatory levels available.
-STOON 96-Oct-18 11Z: Sfc P incorrect.  Sfc P at YXE (airport) = 1012.7.
Probably P was entered as 905.7, instead of 950.7.  Used P=949.9, which was 
taken approx. 30 min prior to release.
-THPAS 96-Oct-18 23Z: Flight data file n/a - used a hardcopy version of 
significant and mandatory level data.
-STOON 96-Oct-19 00Z: Sonde signal lost prior to launch - picked up again at 
920.52 mb.  Time (sec) in raw file:2058.1  P=938.19 (before lost signal)
---> then skipped to:2094.0  P=920.52 (when signal found again).  Assumed that 
launch occurred somewhere in between.  Applied a correction to elapsed time by 
determining the ascent rate using the 1st and 20th observation (following the 
surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Oct-19 23Z: Edited a bogus "Launch Detected" time into Flight Log
(JNL) file.  Also, an extra "Operator Edited Launch" message removed from Flight 
Log (JNL).
-THPAS 96-Oct-19 11Z: Full resolution thermo data file not available. Used 
significant and mandatory level data.
-STOON 96-Oct-20 11Z: Sonde signal lost prior to launch - picked up again at 
948.3 mb.  Time (sec) in raw file:1463.3  P=956.54 (before lost signal)
---> then skipped to:1509.0  P=948.3  (when signal found again).  Assumed that 
launch occurred somewhere in between.  Applied a correction to elapsed time by 
determining the ascent rate using the 1st and 20th observation
(following the surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate
-STOON 96-Oct-21 11Z: Sonde signal lost prior to launch - picked up again at 
916.94mb.  Time (sec) in raw file:1486.2  P=961.75 (before lost signal)
---> then skipped to:1595.9  P=916.94 (when signal found again).  Assumed that 
launch occurred somewhere in between.  Applied a correction to elapsed time by 
determining the ascent rate using the 1st and 20th observation (following the 
surface ob.)
                           AscentRate=(Height2-Height1)/(Time2-Time1)
                           TimeToAdd=(Height1-SiteElev.)/AscentRate


6.2 Field Notes

See Section 6.1

7. Data Description

7.1 Spatial Characteristics

7.1.1 Spatial Coverage

The upper-air data were recorded from several stations that span the BOREAS 
study region.  The North American Datum of 1983 (NAD83) corner coordinates of 
the 1,000 x 1,000 km BOREAS study region are: 

           Latitude    Longitude
Northwest 59.97907 N   111.00000 W
Northeast 58.84379 N    93.50224 W
Southwest 51.00000 N   111.00000 W
Southeast 50.08913 N    96.96951 W

The description of the individual launch sites follow:

Candle Lake (BOREAS 1994 and 1996)
----------------------------------
The Vaisala Digicora II MW15 was located inside the Sno-Drifters Lodge on
the Recreation Center grounds. The building used to inflate the balloons (1994 
only) was located on the west side of the Sno-Drifters Lodge.  The Sno-Drifters 
Lodge was in the northeast corner of a somewhat rectangular clearing measuring 
approximately 260 meters wide and 170 meters across. The clearing was surrounded 
by 12 - 15 meter tall trees of a mixed variety.

The Stevenson screen (BOREAS 1994) was located along the northern edge of the 
clearing about nine meters away from the Sno-Drifters Lodge.  The exposure was 
non-standard because more appropriate spots near the Lodge were used as fuel 
caches and as a helicopter landing pad.

The surrounding topography was somewhat hilly boreal forest with a mixture of 
coniferous and deciduous trees with 3 lakes nearby oriented in a NW to SE 
direction. Candle Lake was 17 km long and 12 km wide (at the widest) and was 
located approximately 1.5 km to the north. Torch Lake was 8 km long and 2.5 km 
wide and lied approximately 500 to 600 m to the west.  There was a nameless 
small body of water 3 km long and 700 m wide 250 m east of the release site.

In 1996, surface temperature and humidity were measured using a sling 
psychrometer, away from the sun's radiation.  Wind direction and speed were
measured (not estimated) at a fixed point by an RM Young anemometer,
approximately 4 m above the ground.  Northerly wind direction and speed at
Candle Lake may have been obstructed or altered by trees or the Sno-Drifters 
lodge.


Thompson Zoo
------------
The instruments were housed on the mezzanine floor of the Thompson Zoo
operations building. The release area was located at the south end of the
zoo operations building. This area was flat and unobstructed to the south
and east. Obstructions to release included the two storey zoo building to
the north and electrical lines to the west. The observers had the
opportunity to maneuver around these obstructions by releasing from the
north side of the operations building.  The receiving antennae were located on 
the roof of the operations building and as a result were unobstructed in all 
directions.

In 1996, surface temperature and humidity were measured using a sling
psychrometer, away from the sun's radiation.  Wind direction and speed were
measured (not estimated) at a fixed point by an RM Young anemometer, 
approximately 4 m above the ground.  There were no major obstructions to the
anemometer wind direction and speed.


Key Lake (BOREAS 1994)
----------------------
The Vaisala Digicora II MW15 was located in an office in the terminal
building at the Key Lake airport.  The instruments associated with the READAC 
were located on a level, open sandy area with sparse grass cover at the Key Lake 
Mine airport. The instrument area consisted of a 90 x 90 m clearing in an old 
burn area. The clearing was surrounded by 2 to 3 m tall jack pine.

The balloon inflation shed was southeast of the READAC instrument area near
the airport terminal building.  The surrounding countryside was jack pine forest 
with rolling hills and the occasional small lake.

Saskatoon (BOREAS 1994 and 1996)
--------------------------------
The VIZ W9000 system and pressure sensor were located in the Saskatchewan
Environmental Services Center (third floor) in Saskatoon. The instrument used to 
observe wind speed and direction was mounted on a tower on the roof of the 
building housing the weather services office (approximately 15 m above the 
ground).

The release site was within a baseball diamond located approximately 200 m
from the VIZ system. The balloon inflation site was in a storage building next 
to the release site. Surface sling psychrometer observations were taken outside 
of the storage building.  The release site was unobstructed.

Primrose Lake (BOREAS 1994)
---------------------------
Two different sites were used for release at Primrose Lake.  Most of the
balloons were released on top of a hill overlooking Primrose Lake to the
northeast. Instrumentation used for surface observations was also situated
on this hill. This location was higher than the rest of the terrain 
(approximately 100 m) and was comprised of scrub brush and grasses. To the
west of the release site was a forested area which consisted of small boreal 
forest tree cover. The release site was unobstructed.

The Pas, Lynn Lake and Churchill
--------------------------------
No site descriptions are available.


The verification data measured at the surface was collected at the following 
sites:

BOREAS 1994:  Primrose Lake, Alberta (WIQ); Candle Lake, Saskatchewan
(WLZ); Thompson Zoo, Manitoba (WTH); Saskatoon Weather Services Office,
Saskatchewan (WXE); Key Lake, Saskatchewan (YKJ); The Pas, Manitoba (YQD);
Lynn Lake, Manitoba (YYL); Churchill, Manitoba (YYQ).

BOREAS 1996:  Candle Lake, Saskatchewan (WLZ); Thompson Zoo, Manitoba
(WTH); Saskatoon Weather Services Office, Saskatchewan (WXE); The Pas,
Manitoba (YQD); Churchill, Manitoba (YYQ).


7.1.2 Spatial Coverage Map

Not available.

7.1.3 Spatial Resolution

The spatial resolution of the measurements is dependent on flight and 
atmospheric conditions.

7.1.4 Projection

Not applicable.

7.1.5 Grid Description

Not applicable.

7.2 Temporal Characteristics

7.2.1 Temporal Coverage

The dates during which data were collected varied by station.  The data 
collected in 1993 cover the period of 16-Aug to 20-Aug.  The data collected in 
1994, cover the period of 09-Apr to 19-Sep with intermittent gaps of a couple 
weeks.  In 1996, the data cover the period of 08-Jul to 22-Oct.


7.2.2 Temporal Coverage Map

Not available.

7.2.3 Temporal Resolution

Sonde release times (generally) coincided with each other.  During BOREAS 1994, 
the balloon release times were scheduled to follow the times determined by AES. 
The times of release (Greenwich Mean Time or Zulu) were intended to be at 15 
minutes after the hours of 11:00, 13:00, 15:00, 17:00, 19:00, 21:00, and 23:00. 
The operators were allowed a window of time in which to make the release, 
spanning from 15 minutes to 25 minutes after the hours specified above. However, 
these release times were not always the rule.

Thompson and Candle Lake released the most sondes (6 or 7 per day on most
days and 3 per day otherwise), while the other sites were restricted to 2-3
releases per day.

During BOREAS 1996, Candle Lake and Thompson released radiosondes between
12 and 25 minutes after the hours of: 11:00, 15:00, 17:00, 19:00, 21:00,
23:00 (UTC) on fair-weather days and 11:00, 17:00 and 23:00 (UTC) on
poor-weather days.  Radiosondes at Saskatoon, The Pas and Churchill were 
released between 12 and 25 minutes after the hours of: 11:00 and 23:00.

During an ascent, the nominal time step between data points was :

1993:
Candle Lake - 1 sec.
Thompson - 1 sec.
Saskatoon - approx. 1.3 sec thermodynamics and 1 minute winds.
Lynn Lake - approx. 1.3 sec thermodynamics and 1 minute winds.
The Pas - no data.
Churchill - 10 sec.
Key Lake - 1 sec.
Primrose Lake - approx. 1.3 sec.

1994:
Candle Lake - 5 sec.
Thompson - 5 sec.
Saskatoon - approx. 1.3 sec thermodynamics and 1 minute winds.
Lynn Lake - approx. 1.3 sec thermodynamics and 1 minute winds.
The Pas - significant and mandatory level thermodynamics and 1 minute winds.
Churchill - 10 sec.
Key Lake - 10 sec.
Primrose Lake - approx. 1.3 sec.

1996:
Candle Lake - 2 sec
Thompson - 2 sec
Saskatoon - approx. 1.3 sec thermodynamics and 1 minute winds.
Lynn Lake - no data
The Pas - approx. 1.3 sec thermodynamics and 1 minute winds.
Churchill - 10 sec
Key Lake - no data
Primrose Lake - no data


7.3 Data Characteristics

Data characteristics are defined in the companion data definition file 
(aes_upl2.def).

7.4 Sample Data Record

Sample data format shown in the companion data definition file (aes_upl2.def).

8. Data Organization

8.1 Data Granularity

The Level-2 Upper Air Network Standard Pressure Level Data for each intensive 
field campaign (by year) are listed in separate files.

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  a single apostrophe 
marks. There are no spaces between the fields.  Sample data records are shown in 
the companion data definition files (aes_upl2.def).

9. Data Manipulations

9.1 Formulae

9.1.1 Derivation Techniques and Algorithms

Definition of terms (for below formulae):

T = temperature (deg. C)
P = pressure (mb)
RH = relative humidity (%)
MixRat = mixing ratio (g per kg)
Ts = saturation (LCL) temperature (K)
Ps = saturation (LCL) pressure (mb)
Tv = virtual temperature (K)
Theta = Potential temperature (K)
Rd = gas constant = 287.05 (J per kg per Kelvin)
G0 = acceleration due to gravity = 9.80665 (m per s sq)
ln = natural log
exp = exponential
TK = air temperature (K)

An evaluation of Vaisala RS80 radiosonde humidity sensor calibration showed
a negative bias in humidity measurements.  Three sets of humidity measurements 
were available to evaluate Vaisala RH: 1) M3 (laboratory calibration instrument) 
RH vs.Vaisala RH in controlled laboratory conditions, 2) Routine pre-launch 
(station) surface temperature and dew point vs. pre-launch Vaisala RH, 3) Sling 
psychrometer temperature and dew point vs. Vaisala RH in the field.  Analysis of 
all three data sets (with emphasis on laboratory tests) resulted in the 
following equations for Vaisala RH Correction (where h = Vaisala RH), expressed 
as a fraction of 0 to 1:

Bias1 = -0.14286h + 0.10204h2  (utilized when Vaisala RH is < or = 90%)
Bias2 = -0.4592 (1 - h)         (utilized when Vaisala RH is > 90%)
Corrected RH = Vaisala RH - Bias

(These equations gave a maximum negative bias of -5% RH at 70% RH, and zero
bias at 0% RH and 100% RH.)

Geopotential Height: is computed step by step as a cumulative sum of height
differences between two different altitudes using the hydrostatic equation.
Z(2)-Z(1) = (Rd/G0)((Tv(2)+Tv(1))/2)*ln(P(1)/P(2))
	where: Virtual Temperature = (T+273.16)*(1.0+Rd/0.62197)/(1.0+Rd)-273.16

Mixing Ratio (Wexler):
622/((16.361/RH)*P*exp(-17.67*T/(T+243.5))-1)

Potential Temperature (Theta):  (T+273.15)*(1000/P)(R/cp)
	where: R/cp = 0.2854*(1-0.28*MixRat/1000)

Saturation (LCL) Temperature:
      55+(2840/(3.5*ln(Theta)-ln(1000*MixRat/(622+MixRat))-4.805))

Saturation (LCL) Pressure:  1000*(Ts-Theta)3.4965

Equivalent Potential Temperature (Bolton):  Theta*exp(2.67*MixRat/Ts)

P, T, RH, U, V, Wdir, Wspd, Range, Azimuth and Elevation: measured by the
upper-air system.

9.2 Data Processing Sequence

9.2.1 Processing Steps

Interpolation

AFM-05 personnel interpolated each sounding to regular 5 mb intervals where the 
values specify the mean pressure of that interval by layer averaging.  For 
example, the 950 mb interval extends from 952.5 to 947.5 mb (i.e., 2.5 mb on 
either side of 950 mb).

The following variables were interpolated directly:  elapsed time, geopotential 
height, temperature, dew point temperature,  potential temperature, equivalent 
potential temperature, relative humidity, mixing ratio, the u and v wind speed 
components, and balloon position (in Cartesian coordinates).  The following 
variables were estimated from the interpolated variables:  wind speed and wind 
direction (computed from interpolated u and v) and range, azimuth and elevation 
(computed from interpolated balloon position).

Please note that the derived thermodynamic variables (potential temperature, 
equivalent potential temperature and mixing ratio) were not recalculated from 
the 5 mb averages of the measured thermodynamic variables (temperature and 
relative humidity).  Instead, the derived thermodynamic variables were 
interpolated directly.  In most cases, the two values will only be subtly 
different.

Interpolation used layer averaging, as follows.  Let's consider the 5 mb
interval at 950 mb, which extends from 952.5 to 947.5 mb.
(1) We identified the measured data within the 5 mb subinterval.  We will
denote the number of points as n.
(2) We estimated the data values at the interval's two endpoints (e.g. at
952.5 and 947.5 mb), by linear interpolation of measured data.
(3) We divided each 5 mb interval (with n measured data points and two
interpolated endpoints) into (n+1) subintervals.
(4) For each of the (n+1) subintervals, we calculated the subinterval mean
(the average of its two endpoints), and the subinterval size (P(2)-P(1)).
(5) The layer average was then calculated as an average of the n+1
subinterval means, weighted by the subinterval size.

Here is an example for Temperature in Kelvins (TK) where n = 2.  The values 
marked "**", are the interpolated interval endpoints.

Measured P (mb): 953.0, 951.0, 948.0, 946.0
Measured T (K): 300.0, 300.8, 300.8, 300.0
Subinterval P (mb): 952.5**, 951.0, 948.0, 947.5**
Subinterval T (K): 300.2**, 300.8, 300.8, 300.6**
P(2)-P(1): 1.5, 3.0, 0.5
0.5*(TK(1)+TK(2)): 300.5, 300.8, 300.7

TKLayerAvg = Sum from i=1 to n+1 [(0.5*(TK(i)+TK(i+1)) * (P(i)-P(i+1))) /
(5mb)]

Each interpolated data line includes information in the LEVEL_TYPE field showing 
the number of raw thermodynamic and wind levels within that 5 mb interval used 
to average that layer.  For example, a LEVEL_TYPE value of Int-T5W3 means that 5 
thermodynamic levels and 3 wind levels were available within that 5 mb interval.  
If there were no raw data within that 5 mb interval, the LEVEL_TYPE will 
indicate that 0 levels (i.e., Int-T0W0) were available for interpolation of that 
layer.  If the raw data gap was greater than 100 mb, the variables were not 
interpolated and were shown to be missing (-9999.00).

Note that for Vaisala sites (Candle Lake, Thompson, Churchill and Key Lake), the 
original RH is not available in the interpolated files.  Instead, the corrected 
RH, along with the variables which were derived from this corrected RH (Td, 
Theta, ThetaE, MixRat) is available.

After loading the data into the relational data base, BORIS personnel converted 
the pressure values to units of kiloPascals for consistency with other pressure 
measurements.

9.2.2 Processing Changes

None given.

9.3 Calculations

9.3.1 Special Corrections/Adjustments

Corrections/adjustments have been made for:
1) RH (Vaisala, all flights)
2) Elevation and surface pressure (Saskatoon, 1994 flights only)
3) Increasing pressure (A.I.R., Primrose Lake)
4) Some surface observations when required.

See Section 9.2.1 for more information.

9.3.2 Calculated Variables

zGeoPot, Td, Td_c, Theta, Theta_c, ThetaE, ThetaE_c, MixRat, MixRat_c, RH_c.
See Section 9.1.1 for more information on these variables.

9.4 Graphs and Plots

None given.

10. Errors

10.1 Sources of Error

Surface Observations (see Section 5 for more information):

Ordinary Thermometers (housed in Stevenson screens during 1994 at Primrose
Lake, Candle Lake and Thompson):

Dust or moisture on the instrument could affect the temperature. Human error or 
a break in the mercury column could also have resulted in an incorrect 
observation.  Wet bulb temperature could have been incorrect if the wick or 
sleeve had dried out. A dirty or fallen wick/sleeve could have resulted in an 
error. Also, the observer should have applied the required correction factor for 
each thermometer and used the psychrometric tables properly to determine the 
relative humidity.

READAC at Key Lake (1994) could have given improper readings if the temperature 
probe or dew cell was dirty. Moisture inside the dew cell containment could also 
have resulted in erroneous data.

Wind may have been observed improperly by automated sensors if they were 
defective (i.e. worn bearings). Incorrect observations may have resulted if the 
dials on the sensor were not properly adjusted.

Many problems are associated with estimating wind speed and direction (i.e. at 
Candle Lake in 1994). Location, improper timing of 2 minute average, gusts, etc. 
are some of the perceived problems.

Sling Psychrometers (Candle Lake and Thompson - 1996, also Saskatoon - 1994
and 1996):
Radiation errors may have resulted if the instrument was not shaded properly.  
If the instrument was not rotated for more than 1 minute, the temperature may 
not have stabilized.  However, if the instrument was rotated too much, the wet 
bulb sleeve may have dried out, resulting in a humidity measurement that was too 
high.  Other sources of error include improper readings, a dirty sleeve or a 
break in the mercury column.

Pressure from the Barometers at Candle Lake and Thompson (1996):
Errors could have resulted from improper readings or incorrect calibration.

Wind direction and Speed (1996):
Northerly winds at Candle Lake may have been subject to errors due to 
obstructions by trees and buildings, however, the anemometer at Thompson was 
unobstructed in all directions.

Surface Observations were not investigated at The Pas and Churchill for BOREAS 
1996.

Upper-air:

Possible sources of error associated with radiosondes include:
Improper handling (touching the sensors, dropping the instrument); improper
storage (too warm or cold); balloon defects (such as leaks, weak spots);
improper balloon inflation (over or under-inflation); dirty instruments;
radiosonde not equilibrated with the outside atmosphere for the required
duration.

10.2 Quality Assessment

10.2.1 Data Validation by Source

Graphs and plots have been produced to flag obvious problems in pressure, 
temperature, humidity and winds. Any problems were noted.

Computed variables (such as potential temperature, mixing ratio, and pressure 
height) have been scrutinized by comparing different versions of formulae used 
to compute these variables.

Processed variables have been compared with the raw data to ensure that no
significant changes have occurred. Any discrepancies have been noted and fixes 
made. If errors stemmed from the raw data file, the problems were noted and 
corrections made if necessary.

10.2.2 Confidence Level/Accuracy Judgment

The upper-air data, for the most part, are reliable and few soundings were 
rejected.

Vaisala: measured RH and temperature with precision, and in particular, gave 
reliable RH measurements below 20% RH. However, the accuracy of wind data were 
sometimes questionable between the surface and 1-2 km geopotential height. Some 
Vaisala flights also had high oscillations in wind direction and speed 
throughout the flight, especially at the most northerly site, Churchill.

VIZ W9000: measured humidity and temperature at high resolution but only 
produced 1 or 2 minute wind direction and speed.

A.I.R.: measured both thermodynamic and wind data at high resolution.  Minimal 
data filtering was performed by these systems well, but few problems were found 
with both thermodynamic and wind data.

ADRES: Due to the nature of these data (significant and mandatory thermodynamic 
levels), most of its accuracy relied on the system operator. Few problems were 
encountered with both thermodynamic and wind data provided by this system.

10.2.3 Measurement Error for Parameters

See Section 4.1 for instrument precision.

10.2.4 Additional Quality Assessments

Not applicable.

10.2.5 Data Verification by Data Center

BORIS personnel reviewed the data for consistency and format.  In addition, the 
values from randomly selected flights were plotted and viewed for any seemingly 
abnormal values.

11. Notes

11.1 Limitations of the Data

None given.

11.2 Known Problems with the Data

1) Ekman spirals found in Vaisala wind data (usually below 3 km geopotential
height).
2) Missing wind data at the start of 1994 IFC 1 until 6 June 15Z at
Thompson Zoo due to an equipment failure.
3) Some full resolution flight data near the end of IFC-1 (1994) at Saskatoon 
was accidentally overwritten. These data have been replaced with significant 
level data.
4) Many flights from Candle Lake for the 1996 Fall IFC, terminated prematurely.  
The cause was not determined.

11.3 Usage Guidance

1) Be aware that different systems produce slightly different measurements at 
different temporal resolutions.
2) The upper-air data has been manipulated by various computer programs, all of 
which have been scrutinized carefully, but there is still some chance of human 
error.
3) Be aware that Vaisala RH and all other humidity variables have been corrected 
based on field and lab tests. The user is recommended to use this corrected 
data, but the original Vaisala RH is available as well.
4) Be aware that the Vaisala system performed data filtering and gap
filling on both wind and thermodynamic data. The other upper-air systems 
provided less quality control than Vaisala.

11.4 Other Relevant Information

None given.

12. Application of the Data Set

The data can be used for monitoring the development of the boundary layer and 
atmospheric movement and condition during the ascents.  In addition, the data 
can be used for comparisons with field studies occuring during respective IFCs.

13. Future Modifications and Plans

None given.

14. Software

14.1 Software Description

The software used to process BOREAS upper-air data were developed within AES
and consisted of a number of different programs written in C++ and
QuickBasic.  The software was capable of converting the original flight
files, which were usually in binary format, to ASCII text.  Following this
conversion, certain variables were computed and/or interpolated, then the
files were put into a common format.  See Sections 9.1 and 9.2 for more
information.

14.2 Software Access

The software used to process BOREAS data can be accessed through:

Alan Barr or Geoff Strong
National Hydrology Research Centre
Saskatoon, SK

15. Data Access

15.1 Contact Information

Ms. Beth Nelson
BOREAS Information System
NASA GSFC
Greenbelt, MD 
(301) 286-4005
(301) 286-0239 (fax)
beth@ltpmail.gsfc.nasa.gov

15.2 Data Center Identification

See Section 15.1

15.3 Procedures for Obtaining Data

Users may place requests on line or by telephone, electronic mail, or FAX. 

15.4 Data Center Status/Plans

The level-2 upper-air 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

16. Output Products and Availability

16.1 Tape Products

None.

16.2 Film Products

None.

16.3 Other Products

Tabular ASCII files.

17. References

17.1 Platform/Sensor/Instrument/Data Processing Documentation

Atmospheric Instrumentation Research, Inc., Automatic Radiotheodolite Model
AIR-3A-RT (Brochure)

Atmospheric Instrumentation Research, Inc., Intellisonde Digital Radiosonde
IS-4A Series (Brochure)

Atmospheric Instrumentation Research, Inc., RAWIN Upper-Air Sounding Systems 
(Brochure)

Vaisala, 1993, UAD Technical Manual.

VIZ Meteorological Instruments, VIZ-BEUKERS LO-CATE MICROSONDE(Brochure)

17.2 Journal Articles and Study Reports

Atmospheric Environment Service. 1994. Inspection Reports.

Barr, Alan and Alan Betts. 1994. Preliminary Summary of BOREAS Upper-Air
Soundings Candle Lake and Thompson 1994 Intensive Field Campaigns, Version 0.

BOREAS Experiment Plan, May 1994, Chapters 1-3, Version 3.0

Beukers, John M. and Friedman, Maurice. 1981. A Digital Radiosonde For Automated 
Observations In the 1980's. Beuker's Laboratories, Inc., St. James, New York.

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. and F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue. 

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, F.E. Guertin. 1997. BOREAS in 1997: Experiment overview, 
scientific results, and future directions. Journal of Geophysical Research. 
102(D24):28731-28770.

Strong, G.S., A.G. Barr, and C.L. Hrynkiw. 1996. Intercomparisons of the Vaisala 
and Airsonde Sounding Systems During BOREAS. CMOS Bulletin, June 1996.

17.3 Archive/DBMS Usage Documentation

None.

18. Glossary of Terms

None.

19. List of Acronyms

    ADRES   - Aerological and Data Reduction System
    AES     - Atmospheric Environment Service
    AFM-05  - Aircraft Flux and Metrorology Team 5
    A.I.R.  - Atmospheric Instrumentation Research, Inc.
    ASCII   - American Standard Code for Information Interchange
    BOREAS  - BOReal Ecosystem-Atmosphere Study
    BORIS   - BOREAS Information System
    CANDL   - Candle Lake
    CD-ROM  - Cmpact Disk Read-Only memory
    CHURCH  - Churchill
    DAAC    - Distributed Active Archive Center
    EOS     - Earth Observing System
    EOSDIS  - EOS Data and Information System
    GMT     - Greenwich Mean Time
    GSFC    - Goddard Space Flight Center
    IFC     - Intensive Field Campaign
    KEY     - Key Lake
    LYNNL   - Lynn Lake
    NAD83   - North American Datum of 1983
    NASA    - National Aeronautics and Space Administration
    NSA     - Northern Study Area
    NSBF    - National Scientific Balloon Facility
    ORNL    - Oak Ridge National Laboratory
    PANP    - Prince Albert national Park
    PRIMR   - Primrose Lake
    ROM     - Read-Only memory
    SSA     - Southern Study Area
    STOON   - Saskatoon
    THEPAS  - The Pas
    THOMP   - Thompson
    URL     - Uniform Resource Locator
    UTC     - Universal Time Code
    WIQ     - Primrose Lake, Alberta
    WLZ     - Candle Lake, Saskatchewan
    WTH     - Thompson Zoo, Saskatchewan
    WXE     - Saskatoon, Saskatchewan
    YKJ     - Key Lake, Saskatchewan
    YQD     - The Pas, Manitoba
    YYL     - Lynn Lake, Manitoba
    YYQ     - Churchill, Manitoba
    Z       - Zulu Time (equivalent to Greenwich Mean Time)


20. Document Information

20.1 Document Revision Date

Written: 07-Feb-1997
Revised: 08-May-1998

20.2 Document Review Date(s)

     BORIS Review:  13-Apr-1998
     Science Review:

20.3 Document ID

20.4 Citation

Please contact Dr. Alan Barr or Dr. Alan Betts for an appropriate citation.

20.5 Document Curator

20.6 Document URL

KEYWORDS
UPPER-AIR
RADIOSONDE


AFM05_Upper_Air_L2.doc
05/26/98