Skip to main content
ORNL DAAC HomeNASA Home

DAAC Home > Get Data > Field Campaigns > First ISLSCP Field Experiment (FIFE) > Dataset Documentation
AIRCRAFT FLUX-DETRENDED: U OF WY. (FIFE)
Get Data

Aircraft Flux - Detrended: U of Wy. (FIFE)

Summary:

The University of Wyoming (UW) King Air atmospheric boundary layer measurement missions were flown in 1987 during IFCs 3 and 4. This Boundary Layer Fluxes data set contains parameters that describe the environment in which the flux data were collected and the flux data itself . The fluctuations in all variables were calculated with three different methods (the arithmetic means removed, the linear trends removed, or filtered with a high-pass recursive filter) prior to the eddy correlation calculations. This data set contains the linearly detrended data. All the flux measurements were obtained with the eddy-correlation method, wherein the aircraft is equipped with an inertial platform, accelerometers, and a gust probe for measurement of earth-relative gusts in the x, y, and z directions. Gusts in these dimensions are then correlated with each other for momentum fluxes and with fluctuations in other variables to obtain the various scalar fluxes, such as temperature (for sensible heat flux) and water vapor mixing ratio (for latent heat flux). The summary of data calculated from each aircraft pass includes various statistics, correlations, and fluxes calculated after the time series for each variable with the linear trends removed.

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:

Data Set Identification:

Aircraft Flux - Detrended: U of Wy. (FIFE)
(Detrended Boundary Layer Fluxes from the UW King Air).

Data Set Introduction:

This Bounday Layer Fluxes data set contains parameters that describe the environment in which the flux data were collected (e.g., aircraft position, atmospheric temperature, pressure, wind) and the flux data itself (e.g., gust statistics, temperature statistics, momentum flux statistics, and latent and sensible heat fluxes). The data has contains the detrended data.

Objective/Purpose:

The objectives of this investigation were:

  1. To study the boundary-layer, sensible and latent heat fluxes over the FIFE site,
  2. To use airborne flux profiles to predict surface flux values and to compare these predicted fluxes to those measured at the surface,
  3. To use various flight patterns to study sensible and latent heat budgets in the boundary layer in the FIFE study area.

Summary of Parameters:

Two types of parameters are available in this data set. The first type are those which describe the environment in which the flux data were collected. These parameters include aircraft position, atmospheric temperature, pressure, wind, and downwelling and upwelling radiation. The second type of parameters are the flux data themselves, these include the gust statistics, temperature statistics, momentum flux statistics, and latent and sensible heat fluxes. These data have had the linear trends removed (i.e., DETREND data).

Discussion:

The University of Wyoming (UW) King Air atmospheric boundary layer measurement missions were flown in 1987 during IFCs 3 and 4. Most of the flux-measurement missions during IFC-3 and IFC-4 were flown using coordinated patterns involving the Wyoming King Air and the Twin Otter. The Wyoming King Air usually flew a series of identical horizontal flight lines each at a lower altitude than the last.

This series of horizontal passes at different altitudes is referred to as a "stack". Three basic patterns of stacks were used:

  1. Repeated stacks along one line;
  2. Repeated stacks along one line flown in a time-centered pattern to allow removal of first order, time trends; and
  3. Double stacks, with one stack at each end of the FIFE site (north and south ends), also flown in a time-centered pattern to allow removal of first-order time trends. These are described in Betts et al. (1990) and Kelly et al. (1992) (see the References Section).

Related Data Sets:

FIS Data Base Table Name:

AIRCRAFT_FLUX_DATA_DETREND.

2. Investigator(s):

Investigator(s) Name and Title:

Dr. Robert D. Kelly
Dept. of Atmospheric Science

Title of Investigation:

Flux profiles and flux budgets in FIFE boundary layer.

Contact Information:

Contact 1:
Robert D. Kelly
University of Wyoming
Laramie, WY
(307) 766-4955
rkelly@coati.uwyo.edu

Requested Form of Acknowledgment.

The boundary layer flux data were collected during 1987 by Robert D. Kelly using the University of Wyoming King Air aircraft. His contribution of these data is particularly appreciated.

3. Theory of Measurements:

All the flux measurements were obtained with the eddy-correlation method, wherein the aircraft is equipped with an inertial platform, accelerometers, and a gust probe for measurement of earth-relative gusts in the x, y, and z directions. Gusts in these dimensions are then correlated with each other for momentum fluxes and with fluctuations in other variables to obtain the various scalar fluxes, such as temperature (for sensible heat flux) and water vapor mixing ratio (for latent heat flux). The fluctuations in all variables were calculated with three different methods prior to the eddy correlation calculations (see the Data Manipulations Section).

4. Equipment:

Sensor/Instrument Description:

Collection Environment:

Airborne.

Source/Platform:

King Air Aircraft.

Source/Platform Mission Objectives:

See the Objective/Purpose Section.

Key Variables:

The important parameters in this data set are as follows:

  1. Means of air temperature, potential air temperature, mixing ratio, north/south and east/west wind components, and atmospheric pressure.
  2. Root mean square and linear trend of the means listed above.
  3. Root mean square and skewness of the vertical gust wind velocity, north/south and east/west wind gust velocity, along-wind and cross-wind component of the wind gust velocity, potential temperature and water mixing ratio.
  4. Momentum flux and the correlation coefficient for north/south and east/west wind gusts and vertical velocity, and along-wind and across-wind component of the wind gust velocity and vertical velocity.
  5. Sensible and latent heat flux and the correlation coefficients for these fluxes.
  6. Moist air density times specific heat capacity.
  7. Latent heat of vaporization.
  8. Moist air density.

Principles of Operation:

See the Theory of Measurements Section.

Sensor/Instrument Measurement Geometry:

Manufacturer of Sensor/Instrument:

University of Wyoming King Air equipment.

            Variable          Instrument                  
----------        -------------
Air temp.         Rosemount               
Dewpoint temp.    Cambridge Model 1373C   
Vapor density     In-house Lyman-alpha    
Mag. heading      King KPI553/Sperry C14-43 
Static press.     Rosemount 1201FA1B1A        
Geom. Alt.        Stewart Warner APN159       
Geom. Alt.        King KPA 405               
Rate of climb     Rosemount 1241A4BCDE  
Total press.      Rosemount 831CPX        
Azimuth VOR       King KNR615 VOR      
Distance DME      King KNR705A DME     
Lat/lon           Texas Inst 91 LORAN-C  
Lat/lon           Litton LTN-51 INS   
Ground veloc.     Litton LTN-51 INS     
Vert. veloc.      Litton LTN-51 INS  
Pitch/roll        Litton LTN-51 INS     
Platform hdg.     Litton LTN-51 INS         
Pitch/roll        Humphrey SA0905021 gyro.   
Flow angle        Rosemount 858AJ/831CPX     
Vert. accel.      Humphrey SA0905021 accel. 

Calibration:

Instruments subject to calibration as follows: Air temperature Manufacturer's one-time calibration was used. Lyman-alpha Calibrated by correlation with dew-point hygrometer data from slow-rate ascent sounding at start of each flight. Resulting regression was applied to all data from that flight. Pressure sensors for static pressure and gust differential pressures were calibrated at the beginning of each IFC against a Mercury column standard.

5. Data Acquisition Methods:

Most of the flux-measurement missions during IFC-3 and IFC-4 involved coordinated patterns with the Wyoming King Air and the Twin Otter. One such flight included a horizontal grid pattern for the twin Otter and a vertical "stack" of horizontal passes for the King Air. The "stack" in this case included W-to-E then E-to-W passes at each of four different altitudes (1010, 730, 580, and 520 meters above Mean Sea Level), followed by a repeat of the same pattern. The data for each flight were subdivided into the horizontal passes (each about 2-3 minutes) for processing, and are presented in this archive on a pass-by-pass basis. The information for each pass includes time, aircraft heading, and pass end-points, which allow reconstruction of the overall pattern used for that particular experiment.

6. Observations:

Data Notes:

Not available.

Field Notes:

Not available at this revision.

7. Data Description:

Spatial Characteristics:

The FIFE study area, with areal extent of 15 km by 15 km, is located south of the Tuttle Reservoir and Kansas River, and about 10 km from Manhattan, Kansas, USA. The northwest corner of the area has UTM coordinates of 4,334,000 Northing and 705,000 Easting in UTM Zone 14.

Spatial Coverage:

Each horizontal flight pass covered either the E-W or the N-S horizontal extent of the FIFE study area (15x15 km). Vertically, all the passes were within the mixed-layer portion of the planetary boundary layer, i.e., within the layer of nearly constant potential temperature and mixing ratio.

Spatial Coverage Map:

Not available.

Spatial Resolution:

The King Air eddy correlation data were collected at 10 Hz and an average true airspeed of about 85 m/s, giving an average spatial resolution of about 9 m. However, each data point in this archive represents an entire horizontal pass and therefore has a resolution no smaller than the FIFE study area itself (15 km).

Projection:

Not available.

Grid Description:

Not available.

Temporal Characteristics:

Temporal Coverage:

The King Air data cover IFCs 3 and 4 of 1987 (Aug. and Oct. 1987). The duration of individual flights ranged 2-4 hours.

Temporal Coverage Map:

Not available.

Temporal Resolution:

Each aircraft pass took about 2-3 minutes, which then represents the minimum resolution of the data in this archive. The times required to complete the single and double stacks of horizontal passes ranged from ½ to 2 hours, which then represents the minimum resolution of the flux profiles and budgets.

Data Characteristics:

The SQL definition for this table is found in the AF_DTRND.TDF file located on the FIFE CD-ROM Volume 1.


Parameter/Variable Name
Parameter/Variable Description Range Units Source
OBS_DATE The date the observation was made on, in the format (DD-MMM-YY).
START_TIME The starting time for the [GMT] observation run in GMT, in the format (HHMM). The seconds for this time is stored in START_SECONDS.
START_SECONDS The seconds component of the [GMT] START_TIME (format SS).
DURATION The duration of the flight in the format (MMSS).
AIRCRAFT_ID The ID name for the aircraft which made the observation run.
START_LAT The starting latitude for the observation run.
START_LON The starting longitude for the observation run.
START_NORTHING The starting northing position of [meters] the aircraft in UTM coordinates.
START_EASTING The starting easting position of [meters] the aircraft in UTM coordinates.
END_LAT The ending latitude for the observation run.
END_LON The ending longitude for the observation run.
END_NORTHING The ending northing position of [meters] the aircraft in UTM coordinates.
END_EASTING The ending easting position of [meters] the aircraft in UTM coordinates.
HEADING The heading of the aircraft. [degrees from North]
HEIGHT_ABOVE_MEAN_SEA_LVL The altitude of the aircraft [meters] above mean sea level, as determined by air pressure.
HEIGHT_ABOVE_GRND_LVL The altitude of the aircraft [meters] above the ground, as determined by radar.
AIR_TEMP_MEAN The mean air temperature. [degrees Celsius]
POTNTL_TEMP_MEAN The potential mean air temperature. [degrees Kelvin]
MIX_RATIO_MEAN The mixing ratio taken from a [grams] dew-point hygrometer. [kg^-1]
NS_WIND_VELOC_MEAN The mean north/south wind [meters] component (V), with north being [sec ^-1] positive.
EW_WIND_VELOC_MEAN The mean east/west wind component [meters] (U), with east being positive. [sec ^-1]
PRESS_MEAN The mean air pressure. [millibars]
SURF_TEMP_MEAN The mean surface temperature. [degrees Celsius]
DOWNWELL_RADTN_MEAN The mean downwelling radiation [Watts] count. [meter^-2]
UPWELL_RADTN_MEAN The mean upwelling radiation count. [Watts] [meter^-2]
VEG_INDEX_MEAN The mean vegetation (greenness) index.
AIR_TEMP_RMS The root mean square of the [degrees temperature recorded in column Celsius] AIR_TEMP_MEAN.
POTNTL_TEMP_RMS The root mean square of the [degrees potential temperature recorded in Kelvin] the column POTNTL_TEMP_MEAN.
MIX_RATIO_RMS The root mean square of the [grams] mixing ratio recorded in the [kg^-1] column MIX_RATIO_MEAN, taken from a dew-point hygrometer.
NS_WIND_VELOC_RMS The root mean square of the [meters] north/south wind component [sec ^-1] recorded in column NS_WIND_VELOC_MEAN.
EW_WIND_VELOC_RMS The root mean square of the [meters] east/west wind component recorded [sec ^-1] in column EW_WIND_VELOC_MEAN.
PRESS_RMS The root mean square of the [millibars] pressure recorded in column PRESS_MEAN.
SURF_TEMP_RMS The root mean square of the [degrees surface temperature recorded in Celsius] column SURF_TEMP_MEAN.
DOWNWELL_RADTN_RMS The root mean square of the [Watts] downwelling radiation count [meter^-2] recorded in column DOWNWELL_RADTN_MEAN.
UPWELL_RADTN_RMS The root mean square of the [Watts] upwelling radiation recorded in [meter^-2] column UPWELL_RADTN_MEAN.
VEG_INDEX_RMS The root mean square of the vegetation (greenness) index recorded in column VEG_INDEX_MEAN.
AIR_TEMP_LINEAR The linear trend of the [degrees temperature recorded in the column Celsius] AIR_TEMP_MEAN. [meter^-1]
POTNTL_TEMP_LINEAR The linear trend of the potential [degrees temperature recorded in column Kelvin] POTNTL_TEMP_MEAN. [meter^-1]
MIX_RATIO_LINEAR The linear trend of the mixing [grams] ratio recorded in column [kg^-1] MIX_RATIO_MEAN (derived from dew [meter^-1] point).
NS_WIND_VELOC_LINEAR The linear trend of the [meters] north/south wind component [sec ^-1] recorded in column [meter^-1] NS_WIND_VELOC_MEAN.
EW_WIND_VELOC_LINEAR The linear trend of the east/west [meters] wind component recorded in column [sec ^-1] EW_WIND_VELOC_MEAN. [meter^-1]
PRESS_LINEAR The linear trend of the pressure [millibars] recorded in column PRESS_MEAN. [meter^-1]
SURF_TEMP_LINEAR The linear trend of the surface [degrees temperature recorded in column Celsius] SURF_TEMP_MEAN. [meter^-1]
DOWNWELL_RADTN_LINEAR The linear trend of the [Watts] downwelling radiation count [meter^-2] recorded in DOWNWELL_RADTN_MEAN. [meter^-1]
UPWELL_RADTN_LINEAR The linear trend of the upwelling [Watts] radiation count recorded in column [meter^-2] UPWELL_RADTN_MEAN. [meter^-1]
VEG_INDEX_LINEAR The linear trend of the vegetation (greenness) index recorded in column VEG_INDEX_MEAN.
MOIST_AIR_DENSITY_X_CP The moist air density times [Watts][sec] specific heat capacity (CP). [degrees Kelvin^-1]
LATENT_HEAT_OF_VAPOR The latent heat of vaporization [Watts][sec] at 20 degrees Celsius. [gram^-1]
MOIST_AIR_DENSITY The moist air density. [kg] [meter^-3]
VERT_GUST_VELOC_RMS_DET The root mean square of the [meters] vertical wind gust velocity. [sec ^-1]
NS_GUST_VELOC_RMS_DET The root mean square of the [meters] north/south wind (U) gust velocity. [sec ^-1]
EW_GUST_VELOC_RMS_DET The root mean square of the [meters] east/west wind (V) gust velocity. [sec ^-1]
ALONG_WIND_VELOC_RMS_DET The root mean square of the [meters] along-wind component of the wind [sec ^-1] gust velocity.
ACROSS_WIND_VELOC_RMS_DET The root mean square of the [meters] across-wind component of the wind [sec ^-1] gust velocity.
POTNTL_TEMP_RMS_DET The root mean square of the [degrees potential temperature. Kelvin]
WATER_MIX_RATIO_RMS_DET The root mean square of the water [grams] mixing ratio (lyman alpha). [kg^-1]
CO2_MIX_RATIO_RMS_DET The root mean square of the [milligrams] carbon dioxide content. [kg^-1]
VERT_GUST_VELOC_SKEW_DET The skewness of the vertical gust wind velocity.
NS_GUST_VELOC_SKEW_DET The skewness of the north/south wind gust velocity.
EW_GUST_VELOC_SKEW_DET The skewness of the east/west wind gust velocity.
ALONG_WIND_VELOC_SKEW_DET The skewness of the along-wind component of the wind gust velocity.
ACROSS_WIND_VELOC_SKEW_DET The skewness of the across-wind component of the wind gust velocity.
POTNTL_TEMP_SKEW_DET The skewness of the potential temperature.
WATER_MIX_RATIO_SKEW_DET The skewness of the water mixing ratio.
CO2_MIX_RATIO_SKEW_DET The skewness of the carbon dioxide content.
NS_MOMNTM_FLUX_DET The north/south momentum flux, [Newtons] calculated from W*V (wind [meter^-2] components).
EW_MOMNTM_FLUX_DET The east/west momentum flux, [Newtons] calculated from W*U (wind [meter^-2] components).
ALONG_MOMNTM_FLUX_DET The along-wind momentum flux, [Newtons] calculated from W*along-wind gust [meter^-2] (wind components).
ACROSS_MOMNTM_FLUX_DET The across-wind momentum flux, [Newtons] calculated from W*across-wind gust [meter^-2] (wind components).
SENSIBLE_HEAT_FLUX_DET The sensible heat flux. [Watts] [meter^-2]
LATENT_HEAT_FLUX_DET The latent heat flux. [Watts] [meter^-2]
CO2_FLUX_DET The carbon dioxide flux. [kg] [hectare^-1] [hour^-1]
NS_MOMNTM_CC_DET The correlation coefficient for vertical wind velocity and north/south wind gusts.
EW_MOMNTM_CC_DET The correlation coefficient for vertical wind velocity and east/west wind gusts.
ALONG_MOMNTM_CC_DET The correlation coefficient for vertical wind velocity and along-wind component of the wind gust velocity.
ACROSS_MOMNTM_CC_DET The correlation coefficient for vertical wind velocity and across-wind component of the wind gust velocity.
SENSIBLE_HEAT_CC_DET The correlation coefficient for the sensible heat flux.
LATENT_HEAT_CC_DET The correlation coefficient for the latent heat flux.
CO2_FLUX_CC_DET The correlation coefficient for the CO2 flux.
MIX_RATIO_CC_DET The correlation coefficient for the mixing ratio * potential temperature.
COMMENTS Any comments pertaining to this record.
FIFE_DATA_CRTFCN_CODE The FIFE Certification Code for * the data, in the following format: CPI (Certified by PI), CPI-??? (CPI - questionable data).
LAST_REVISION_DATE data, in the format (DD-mmm-YY).

Footnote:

* Valid levels

The primary certification codes are: EXM Example or Test data (not for release) PRE Preliminary (unchecked, use at your own risk) CPI Checked by Principal Investigator (reviewed for quality) CGR Checked by a group and reconciled (data comparisons and cross checks)

The certification code modifiers are: PRE-NFP Preliminary - Not for publication, at the request of investigator. CPI-MRG PAMS data that is "merged" from two separate receiving stations to eliminate transmission errors. CPI-??? Investigator thinks data item may be questionable.

Sample Data Record:

     OBS_DATE    START_TIME   START_SECONDS    DURATION   AIRCRAFT_ID   START_LAT
---------   ----------   -------------   ----------  -----------   ----------
11-OCT-87      1725            25           255          WYO         3903.5
11-OCT-87      1731            43           319          WYO         3903.5
11-OCT-87      1738            49           315          WYO         3903.5
11-OCT-87      1752            11           326          WYO         3903.7
      START_LON   START_NORTHING  START_EASTING    END_LAT     END_LON    END_NORTHING
----------   --------------  -------------   ----------  ----------  ------------
-9636.7                                    3903.2      -9626.3
-9626.3                                    3903.8      -9637.2
-9637.2                                    3903.5      -9626.8
-9626.9                                    3903.5      -9637.6
     END_EASTING    HEADING    HEIGHT_ABOVE_MEAN_SEA_LVL   HEIGHT_ABOVE_GRND_LVL
-----------   ----------  -------------------------   ---------------------
92                925                      684
271                926                      692
90                585                      334
270                588                      344
     AIR_TEMP_MEAN   POTNTL_TEMP_MEAN   MIX_RATIO_MEAN   NS_WIND_VELOC_MEAN
-------------   ----------------   --------------   ------------------
.61              281.89           2.11                .83
.72              281.96           2.12                .91
4.07              282.09           2.15                .88
4.32              282.36           2.14                .43
     EW_WIND_VELOC_MEAN   PRESS_MEAN   SURF_TEMP_MEAN   DOWNWELL_RADTN_MEAN
------------------   ----------   --------------   -------------------
.24                907             99.9                9999
.08                906.8           99.9                9999
.8                944.9           99.9                9999
1.48                944.6           99.9                9999
     UPWELL_RADTN_MEAN   VEG_INDEX_MEAN   AIR_TEMP_RMS   POTNTL_TEMP_RMS
-----------------   --------------   ------------   ---------------
999                 9.99           .13             .15
999                 9.99           .12             .13
999                 9.99           .11             .14
999                 9.99           .09             .13
     MIX_RATIO_RMS   NS_WIND_VELOC_RMS   EW_WIND_VELOC_RMS  PRESS_RMS
-------------   -----------------   -----------------  ----------
.11              1.22               .94              .8
.11              1.21               .94              .8
.09               .93               .83              .8
.08               .87               .86              .7
     SURF_TEMP_RMS   DOWNWELL_RADTN_RMS   UPWELL_RADTN_RMS   VEG_INDEX_RMS
-------------   ------------------   ----------------   -------------
99.9                999              999               9.99
99.9                999              999               9.99
99.9                999              999               9.99
99.9                999              999               9.99
     AIR_TEMP_LINEAR   POTNTL_TEMP_LINEAR   MIX_RATIO_LINEAR
---------------   ------------------   ----------------
.00000606          -.00000199        -.00000544
.0000106            .0000101          .000000979
.0000121            .00000565        -.0000101
-2.500E-08           -.00000206         .00000915
     NS_WIND_VELOC_LINEAR   EW_WIND_VELOC_LINEAR   PRESS_LINEAR
--------------------   --------------------   ------------
.0000505               -.0000911            .00000841
-.00000794               .00000549           .00000831
.0000147                .0000178            .0000361
.0000396               -.0000056           -.0000207
     SURF_TEMP_LINEAR   DOWNWELL_RADTN_LINEAR   UPWELL_RADTN_LINEAR
----------------   ---------------------   -------------------
.999                  .999                  .999
.999                  .999                  .999
.999                  .999                  .999
.999                  .999                  .999
     VEG_INDEX_LINEAR   MOIST_AIR_DENSITY_X_CP   LATENT_HEAT_OF_VAPOR
----------------   ----------------------   --------------------
.999                 1158.3                  2453.53
.999                 1157.6                  2453.53
.999                 1191.7                  2453.53
.999                 1190.2                  2453.53
     MOIST_AIR_DENSITY   VERT_GUST_VELOC_RMS_DET   NS_GUST_VELOC_RMS_DET
-----------------   -----------------------   ---------------------
1.153                  1.24                     1.2
1.152                  1.28                     1.21
1.186                  1.21                      .93
1.184                  1.25                      .86
     EW_GUST_VELOC_RMS_DET   ALONG_WIND_VELOC_RMS_DET   ACROSS_WIND_VELOC_RMS_DET
---------------------   ------------------------   -------------------------
.85                       1.19                         .86
.94                       1.22                         .93
.82                        .98                         .77
.86                        .86                         .86        
     POTNTL_TEMP_RMS_DET   WATER_MIX_RATIO_RMS_DET   CO2_MIX_RATIO_RMS_DET
-------------------   -----------------------   ---------------------
.15                     .17                       9.99
.13                     .16                       9.99
.14                      .1                       9.99
.13                      .1                       9.99
     VERT_GUST_VELOC_SKEW_DET   NS_GUST_VELOC_SKEW_DET   EW_GUST_VELOC_SKEW_DET
------------------------   ----------------------   ----------------------
.532                        -.482                  -.238
.555                        -.288                   .158
1.113                        -.348                  -.117
.905                        -.022                   .099
     ALONG_WIND_VELOC_SKEW_DET   ACROSS_WIND_VELOC_SKEW_DET
-------------------------   --------------------------
-.419                         .135
-.336                        -.156
.037                        -.147
.037                        -.129
     POTNTL_TEMP_SKEW_DET   WATER_MIX_RATIO_SKEW_DET   CO2_MIX_RATIO_SKEW_DET
--------------------   ------------------------   ----------------------
1.192                    -.478                    9.999
.886                    -.724                    9.999
.706                    -.325                    9.999
.973                    -.769                    9.999
     NS_MOMNTM_FLUX_DET   EW_MOMNTM_FLUX_DET   ALONG_MOMNTM_FLUX_DET
------------------   ------------------   ---------------------
-.01                 -.17                  -.05
-.21                 -.09                  -.22
-.03                  .09                   .04
-.25                 -.08                  -.15
     ACROSS_MOMNTM_FLUX_DET   SENSIBLE_HEAT_FLUX_DET   LATENT_HEAT_FLUX_DET
----------------------   ----------------------   --------------------
.16                       35                       159
.07                      -33                       174
-.09                      103                        73
-.21                      104                        40
     CO2_FLUX_DET   NS_MOMNTM_CC_DET   EW_MOMNTM_CC_DET   ALONG_MOMNTM_CC_DET
------------   ----------------   ----------------   -------------------
999.9                0             -.14                -.03
999.9             -.12             -.07                -.12
999.9             -.02              .08                 .03
999.9             -.19             -.07                -.12
     ACROSS_MOMNTM_CC_DET   SENSIBLE_HEAT_CC_DET   LATENT_HEAT_CC_DET
--------------------   --------------------   ------------------
.13                      .17                 .3
.05                     -.18                .35
-.08                      .51                .23
-.17                      .55                .12
     CO2_FLUX_CC_DET   MIX_RATIO_CC_DET   COMMENTS            
---------------   ----------------   --------------------
99.99            99.99                     
99.99            99.99                     
99.99            99.99                     
99.99            99.99                     
     FIFE_DATA_CRTFCN_CODE   LAST_REVISION_DATE
---------------------   ------------------
CPI                   25-AUG-92
CPI                   25-AUG-92
CPI                   25-AUG-92
CPI                   25-AUG-92

8. Data Organization:

Data Granularity:

The King Air eddy correlation data has an average spatial resolution of about 9 m. However, each data point in this archive represents an entire horizontal pass and therefore has a resolution no smaller than the FIFE study area itself (15 km). Each aircraft pass took about 2-3 minutes, which then represents the minimum resolution of the data in this archive. The times required to complete the single and double stacks of horizontal passes ranged from ½ to 2 hours, which then represents the minimum resolution of the flux profiles and budgets.

A general description of data granularity as it applies to the IMS appears in the EOSDIS Glossary.

Data Format:

The CD-ROM file format consists of numerical and character fields of varying length separated by commas. The character fields are enclosed with a single apostrophe. There are no spaces between the fields. Each file begin with five header records. Header records contain the following information: Record 1 Name of this file, its table name, number of records in this file, and principal investigator name. Record 2 Path and filename of the previous data set, and path and filename of the next data set. (Path and filenames for files that contain another set of data taken at the same site on the same day.) Record 3 Path and filename of the previous site, and path and filename of the next site. (Path and filenames for files of the same data set taken on the same day for the previous and next sites, sequentially numbered by SITEGRID.) Record 4 Path and filename of the previous date, and path and filename of the next date. (Path and filenames for files of the same data set taken at the same site for the previous and next date.) Record 5 Column names for the data within the file, delimited by commas. Record 6 Data records begin.

Each field represents one of the attributes listed in the chart in the Data Characteristics Section and described in detail in the TDF file. These fields are in the same order as in the chart.

9. Data Manipulations:

Based on re-examination of the Wyoming King Air data and on comparisons with data from the Twin Otter, several corrections have been applied to the Lyman-alpha water vapor density and mixing ratio data. These corrections include

  1. Correction of the vapor fluxes for the effects of heat flux (Webb et al. 1980) and
  2. Correction of all the correlations and fluxes involving the Lyman-alpha to account for a 0.3 second time lag between that instrument and the others on the aircraft. In addition, it appears that both the instrument offset and gain tended to drift somewhat during flights. The change in offset does not present a problem in the flux calculations, since all simple offsets are removed by de-meaning, detrending, or filtering for each aircraft pass. Such processing does not, however, correct for changes in instrument gain. The correlations and fluxes involving the Lyman-alpha data have been included here for completeness, but should be used with caution.

    The summary of data calculated from each aircraft pass includes various statistics, correlations, and fluxes calculated after the time series for each variable had been treated with the linear trends removed.

10. Errors:

Sources of Error:

Errors have been introduced into the water vapor and mixing ratio parameters because of errors associated with the Lyman-alpha instrument. As described in the Usage Guidance Section below, it appears that both the instrument offset and gain tended to drift somewhat during flights. The change in offset does not present a problem in the flux calculations, since all simple offsets are removed by detrending the data for each aircraft pass.

Such processing does not, however, correct for changes in instrument gain. The correlations and fluxes involving the Lyman-alpha data have been included here for completeness, BUT SHOULD BE USED WITH CAUTION.

Quality Assessment:

Data Validation by Source:

The major effort at data validation was by inter-comparison of data from the various flux aircraft used in FIFE, based on wing-to-wing horizontal flights over the FIFE study area, at the same altitudes as those used in the various experiments. An excellent summary of these comparisons is contained in MacPherson et al. 1992.

Confidence Level/Accuracy Judgment:

The detrended data are recommended for future analysis. The raw and filtered data are not recommended for future use.

Measurement Error for Parameters:

              Variable           Accuracy           Resolution
---------        -----------         -------------  
Air temp.         0.5 C              .006 C
Dewpoint temp.    0.5 C, >0 C        .006 C
Vapor density     n/a                .0006 g/m**3
Mag. heading      1 deg              .02 deg
Static press.     1 mb               .06 mb
Geom. Alt.        1% reading         .24 ft
Geom. Alt.        3%, <500 ft        1 m
5%, >500 ft
Rate of climb     1%, <15000 ft      .004 m/s
2%, >25000 ft
Total press.      1 mb               .005 mb
Azimuth VOR       1 deg              .02 deg
Distance DME      .2 n mi            .1 n mi
Lat/lon           <.01 deg           .0017 deg
Lat/lon           <1 nm/hr drift     .0017 deg
Ground veloc.     <1 nm/hr drift     .04 m/s
Vert. veloc.      1 m/s              .02 m/s
Pitch/roll        .01 deg            .005 deg
Platform hdg.     .05 deg            .005 deg
Pitch/roll        .2 deg             .0006 deg
Flow angle        .2 deg             .00075 deg
Vert. accel.      .002 g             .0001 g

Additional Quality Assessments:

FIS staff applied a general QA procedure to the data to identify inconsistencies and problems for potential users. As a general procedure, the FIS QA consisted of examining the maximum, minimum, average, and standard deviation for each numerical field in the data table. Inconsistencies and problems found in the QA check are described in the Known Problems With The Data Section.

Data Verification by Data Center:

The data verification performed by the ORNL DAAC deals with the quality of the data format, media, and readability. The ORNL DAAC does not make an assessment of the quality of the data itself except during the course of performing other QA procedures as described below.

The FIFE data were transferred to the ORNL DAAC via CD-ROM. These CD-ROMs are distributed by the ORNL DAAC unmodified as a set or in individual volumes, as requested. In addition, the DAAC has incorporated each of the 98 FIFE tabular datasets from the CD-ROMs into its online data holdings. Incorporation of these data involved the following steps:

Each distinct type of data (i.e. "data set" on the CD-ROM), is accompanied by a documentation file (i.e., .doc file) and a data format/structure definition file (i.e., .tdf file). The data format files on the CD-ROM are Oracle SQL commands (e.g., "create table") that can be used to set up a relational database table structure. This file provides column/variable names, character/numeric type, length, and format, and labels/comments. These SQL commands were converted to SAS code and were used to create SAS data sets and subsequently to input data files directly from the CD-ROM into a SAS dataset. During this process, file names and directory paths were captured and metadata was extracted to the extent possible electronically. No files were found to be corrupted or unreadable during the conversion process.

Additional Quality Assurance procedures were performed as follows:

As errors are discovered in the online tabular data by investigators, users, or DAAC staff, corrections are made in cooperation with the principal investigators. These corrections are then distributed to users. CD-ROM data are corrected when re-mastering occurs for replenishment of CD-ROM stock.

11. Notes:

Limitations of the Data:

Not available.

Known Problems with the Data:

None.

Usage Guidance:

Following are STATEMENTS OF GUIDANCE FROM THE PI as to the use of these data:

Any Other Relevant Information about the Study:

Not available.

12. Application of the Data Set:

The Detrended Boundary Layer Fluxes data set can be utilized to predict surface flux values and to compare these predicted fluxes to those measured at the surface. In addition, sensible and latent heat budgets in the boundary layer in the FIFE study area can be analyzed.

13. Future Modifications and Plans:

The FIFE field campaigns were held in 1987 and 1989 and there are no plans for new data collection. Field work continues near the FIFE site at the Long-Term Ecological Research (LTER) Network Konza research site (i.e., LTER continues to monitor the site). The FIFE investigators are continuing to analyze and model the data from the field campaigns to produce new data products.

14. Software:

Software to access the data set is available on the all volumes of the FIFE CD-ROM set. For a detailed description of the available software see the Software Description Document.

15. Data Access:

Contact Information:

ORNL DAAC User Services
Oak Ridge National Laboratory

Telephone: (865) 241-3952
FAX: (865) 574-4665

Email: ornldaac@ornl.gov

Data Center Identification:

ORNL Distributed Active Archive Center
Oak Ridge National Laboratory
USA

Telephone: (865) 241-3952
FAX: (865) 574-4665

Email: ornldaac@ornl.gov

Procedures for Obtaining Data:

Users may place requests by telephone, electronic mail, or FAX. Data is also available via the World Wide Web at http://daac.ornl.gov.

Data Center Status/Plans:

FIFE data are available from the ORNL DAAC. Please contact the ORNL DAAC User Services Office for the most current information about these data.

16. Output Products and Availability:

Boundary Layer Fluxes from the UW King Air are available on FIFE CD-ROM Volume 1. The CD-ROM file name is as follows:

\DATA\AIR_FLUX\AF_DTRND\ydddMULT.WYD for the DETREND data

Note: capital letters indicate fixed values that appear on the CD-ROM exactly as shown here, lower case indicates characters (values) that change for each path and file.

The format used for the filenames is: ydddMULT.sfx, where y is the last digit of the year (e.g., 7 = 1987, and 9 = 1989), and ddd is the day of the year (e.g., 061 = sixty-first day in the year). The filename extension (.sfx), identifies the data set content for the file (see the Data Characteristics Section) and is equal to .WYD for this data set.

17. References:

Satellite/Instrument/Data Processing Documentation.

Not available at this revision.

Journal Articles and Study Reports.

Betts, A.K., R.L. Desjardins, J.I. MacPherson, and R.D. Kelly. 1990. Boundary layer heat and moisture budgets from FIFE. Boundary Layer Meteorology. 50:109-137.

Budak, A. 1974. Passive and Active Network Analysis and Synthesis, Houghton Mifflin Co. Boston. 733 pp.

Jacquot, R.G. 1981. Modern Digital Control Systems. Marcel Dekker. Inc. New York. 355 pp.

Kelly, R.D. 1992. Atmospheric boundary layer studies in FIFE: challenges and advances. J. Geophys. Rsch. 97(D17):18,373-18,376.

Kelly, R.D., E.A. Smith, and J.I. MacPherson. 1992. A comparison of surface sensible and latent heat fluxes from aircraft and surface measurements in FIFE 1987. J. Geophys. Rsch. 97(D17):18,445-18,453.

MacPherson, J.I., R.L. Grossman, and R.D. Kelly. 1992. Inter-comparison results for FIFE flux aircraft. J. Geophys. Rsch. 97(D17):18,499-18,514.

Webb, E.K., G.I. Pearman, and R. Leuning 1980. Correction of flux measurements for density effects due to heat and water vapor transfer. Quart. J. Roy. Meteor. Soc. 106:85-100.

Archive/DBMS Usage Documentation.

Contact the EOS Distributed Active Archive Center (DAAC) at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee (see the Data Center Identification Section). Documentation about using the archive and/or online access to the data at the ORNL DAAC is not available at this revision.

18. Glossary of Terms:

A general glossary for the DAAC is located at Glossary.

19. List of Acronyms:

BL Boundary Layer CD-ROM Compact Disk, Read-Only Memory DAAC Distributive Active Archive Center EOS Earth Observing System EOSDIS EOS Data and Information System FIS FIFE Information System FIFE First ISLSCP Field Experiment IFC Intensive Field Campaign INS Inertial navigation system ISLSCP International Satellite Land Surface Climatology Project LTER Long-Term Ecological Research ORNL Oak Ridge National Laboratory PBL planetary boundary layer SQL Structured Query Language TDF Table Definition File URL Uniform Resource Locator UTM Universal Transverse Mercator

A general list of acronyms for the DAAC is available at Acronyms.

20. Document Information:

April 28, 1994 (citation revised on October 10, 2002).

This document has been reviewed by the FIFE Information Scientist to eliminate technical and editorial inaccuracies. Previous versions of this document have been reviewed by the Principal Investigator, the person who transmitted the data to FIS, a FIS staff member, or a FIFE scientist generally familiar with the data. It is believed that the document accurately describes the data as collected and archived on the FIFE CD-ROM series.

Document Review Date:

February 28, 1996

Document ID:

ORNL-FIFE_AF_DET_K.

Citation:

Cite this data set as follows:

Kelly, R. D. 1994. Aircraft Flux - Detrended: U of Wy. (FIFE). Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/4. Also published in D. E. Strebel, D. R. Landis, K. F. Huemmrich, and B. W. Meeson (eds.), Collected Data of the First ISLSCP Field Experiment, Vol. 1: Surface Observations and Non-Image Data Sets. CD-ROM. National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland, U.S.A. (available from http://www.daac.ornl.gov).

Document Curator:

DAAC Staff

Document URL:

http://daac.ornl.gov