The FIFE Radiosonde Data Set contains temperatures, wind speed, and temperature profiles in the atmospheric boundary layer measured by means of radiosondes that were analyzed in the framework of Monin-Obukhov similarity theory, with the objective of determining the regional surface heat flux. Profiles of temperature, humidity and wind velocity in the atmosphere were measured by means of intensive radiosoundings conducted approximately between 900 and 1800 CDST in northeastern Kansas during the five FIFE Intensive Field Campaigns in spring, summer and fall of 1987, and in the late summer of 1989. Some 445 radiosondes were released to generate the measurements needed to obtain profiles of wind velocity dry-bulb and wet-bulb temperature. The launch site was located near the northern edge of the experimental area to ensure that these profiles reflect surface conditions over the fetch of the experimental area in the general direction of the prevailing southerly wind.
The raw radiosonde data described here have been corrected for sensor delays (see the FIFE Temperature and Humidity Profiles) and algorithm inconsistencies, (see the FIFE Radiosonde Wind Profiles) and have been interpolated to a set of standard pressure levels (see the FIFE Standard Pressure Level Radiosonde Data). These derived data sets are described separately.
FIFE Atmospheric Profiles: Brutsaert (FIFE)
(FIFE Radiosonde Data).
The FIFE Radiosonde Data Set contains variables measured directly by the instrument (i.e., raw data) these variables are pressure, dry-bulb temperature, wet-bulb temperature, azimuth angle of the balloons position, and elevation angle of the balloon position. In addition, the data set also includes the following derived variables: potential temperature, relative humidity, mixing ratio, wind velocity, wind direction, height above ground-level of radiosonde and height above ground-level of wind speed measurement.
In this study radiometrically obtained temperatures in hilly prairie terrain together with wind speed and temperature profiles in the atmospheric boundary layer measured by means of radiosondes were analyzed in the framework of Monin-Obukhov similarity theory, with the objective of determining the regional surface heat flux.
Atmospheric pressure, dry bulb temperature, wet bulb temperature, mixing ratio, potential temperature, wind speed, wind direction, wind height, relative humidity.
Profiles of temperature, humidity and wind velocity in the atmosphere were measured by means of intensive radiosoundings conducted approximately between 900 and 1800 CDST in northeastern Kansas during the five FIFE Intensive Field Campaigns in spring, summer and fall of 1987, and in the late summer of 1989.
These intensive radiosonde flights, conducted by Dr. Wilfred H. Brutsaert allowed the measurement of the atmospheric profiles of wind velocity (magnitude and direction), temperature and relative humidity. The raw radiosonde data described here have been corrected for sensor delays (see the FIFE Temperature and Humidity Profiles) and algorithm inconsistencies, (see the FIFE Radiosonde Wind Profiles) and have been interpolated to a set of standard pressure levels (see the FIFE Standard Pressure Level Radiosonde Data). These derived data sets are described separately.
BRUT_SONDE_DATA.
Dr. Wilfred H. Brutsaert
Cornell University
Radiosonde analysis of wind velocity measurements in the boundary layer above a hilly prairie.
Contact 1:
Dr. Wilfred H. Brutsaert
Cornell University
Tel.: (607) 255-3676
Email: WBH@CORNELLA.BITNET
WHB@CORNELLA.CIT.CORNELL.EDU (Internet)
The FIFE Radiosonde Data were measured by a team from Cornell University, directed by Prof. W. Brutsaert. Their contribution of these data is particularly appreciated.
Combination of surface potential temperature with potential temperature and wind speed profiles in the atmospheric boundary layer allows the application of similarity theory to estimate surface sensible heat flux. The relevant profile equations have been described (Sugita and Brutsaert 1990), taking into consideration the stability correction functions for momentum and sensible heat. Some 445 radiosondes were released to generate the measurements needed to obtain profiles of wind velocity dry-bulb and wet-bulb temperature. The launch site was located near the northern edge of the experimental area to ensure that these profiles reflect surface conditions over the fetch of the experimental area in the general direction of the prevailing southerly wind.
The radiosonde system (type AIR-3A, Atmospheric Instrumentation Research) consisted of disposable sondes with dry-bulb and wet-bulb temperature and pressure sensors, a receiving unit on the ground and an optical theodolite to track the sonde.
Airborne.
Free flying balloons tracked by optical theodolite. Measurements were transmitted to a ground-based receiver and stored on tape and on floppy disks.
To measure atmospheric profiles with pressures down to 600 hPa.
Variables measured directly by the instrument (i.e., raw data) are pressure, dry-bulb temperature, wet-bulb temperature, azimuth angle of the balloons position, and elevation angle of the balloon position. Both azimuth and elevation angles are measured with the manually operated (from ground) optical theodolite.
Variables derived from the raw data are potential temperature, relative humidity, mixing ratio, wind velocity, wind direction, height above ground-level of radiosonde and Height above ground-level of wind speed measurement.
Every 5 to 6 seconds, pressure, dry-bulb temperature and wet-bulb temperature, together with azimuth and elevation angles of sonde position (optical theodolite) are measured by the ascending sonde.
Spintype "Airsonde" (Standard deployment).
Air, Inc.
8401 Baseline Road
Boulder, C0 80303
Information on the Calibration of the radiosonde system (type AIR-3A, Atmospheric Instrumentation Research) is provided by the manufacturer (Air, Inc. of Boulder, Colorado).
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The FIFE site 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.
The radiosonde data was collected from balloon releases within the FIFE site.
SITEGRID_ID STATION_ID NORTHING EASTING LATITUDE LONGITUDE ----------- ---------- -------- ------- -------- --------- 0928-RSB 102 4332188 710674 39 06 55 -96 33 48 ELEVATION --------- 342
For each flight the spatial coverage can be deduced from the horizontal distance and direction the sonde traveled from the launch site.
Not available.
These are point data. The vertical resolution is approximately 15 to 20 m.
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Not available.
The data was collected during FIFE's five IFC's, covering the period from May 26, 1987 through August 12, 1989.
IFC# Dates ----- ------------------- IFC-1 05/26/87 - 06/06/87 IFC-2 06/25/87 - 07/11/87 IFC-3 08/06/87 - 08/21/87 IFC-4 10/05/87 - 10/16/87 IFC-5 07/24/89 - 08/12/89
Not available.
The soundings were made at 2 to 3 hour intervals, depending on weather conditions.
During flight the sonde measures and transmits the data in cycles of approximately 4.8 seconds in the following sequence: dry-bulb temperature is measured at time zero; 0.6 and 1.8 seconds later wet-bulb temperature and pressure are measured, respectively; then after approximately 3.0 seconds the dry-bulb temperature measurement is made again to begin the next cycle. According to the manufacturer, the response of the pressure sensor is practically instantaneous, but the dry-bulb and wet-bulb sensors have time constants of 3 and 12 seconds, respectively.
The SQL definition for this table is found in the BRUT_SND.TDF file located on CD-ROM volume 1.
Parameter/Variable Name
Parameter/Variable Description Range Units Source
SITEGRID_ID This is a FIS grid location code. Site grid codes (SSEE-III) give the south (SS) and east (EE) cell number in a 100 x 100 array of 200 m square cells. The last 3 characters (III) are an instrument identifier.
STATION_ID The Station ID number for the location of the observations.
OBS_DATE The observation date for this min = 26-MAY-87, CORNELL radiosonde flight. max = 12-AUG-89 UNIVERSITY
OBS_TIME The time the observation was min = 1407, [GMT] FIS taken. max = 2212
OBS_SECONDS The seconds portion of the min = 0, [GMT] FIS OBS_TIME. max = 30
FLIGHT_NUM This is the flight number FIS of the radiosonde balloon flight where the data was recorded.
ATMOSPHERIC_PRESS The air pressure at the min = 1, [millibars] ANEROID observation height. max = 1 SENSOR
HEIGHT_ABV_GRND_LVL The height above the min = 0, [meters] CORNELL ground-level where this max = 8541, UNIVERSITY observation was made. missing = -999
DRY_BULB_TEMP The temperature measured min = -21.61, [degrees THERMISTOR using a conventional max = 37.21 Celsius] thermometer.
WET_BULB_TEMP The temperature to which air min = -15.38, [degrees THERMISTOR may be cooled by evaporating max = 26.36, Celsius] water into it at a constant missing = -999 pressure until it is saturated.
MIX_RATIO The mixing ratio of water to min = -.51, [grams] FIS air: grams of water per max = 22.2, [kg^-1 kilogram of dry air (mass missing = -999 of air] of air minus mass of water).
POTNTL_TEMP The potential temperature min = -.01, [degrees CORNELL at the observation height; max = 503.54 Kelvin] UNIVERSITY the temperature an air sample attains if reduced to 1000 millibars pressure without any external heat exchange.
AZIM_ANG The azimuth angle of the min = 85.8, [degrees FIS radiosonde balloon, as viewed max = 259.1 from North] from the ground.
ELEV_ANG The elevation angle of the min = 85.8, [degrees] FIS radiosonde balloon as viewed max = 259.1 from the ground.
WIND_SPEED The velocity of the wind at min = 0, [meters] RADIOSONDE the observation height. max = 360 [sec^-1]
WIND_DIR The direction from which the min = 0, [degrees] NOAA wind is blowing. max = 360
WIND_HEIGHT This is the height of the wind [meters] measurement, in meters.
REL_HUMID The relative humidity at the min = 14.82, [percent] FIS observation height. max = 98.4
FIFE_DATA_CRTFCN_CODE * The FIFE Certification Code CPI=Checked by FIS for the data, in the following Principal format: CPI (Certified by PI), Investigator CPI-??? (CPI - questionable data).
LAST_REVISION_DATE data, in the format (DD-MMM-YY). max = 08-AUG-90
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.
SITEGRID_ID STATION_ID OBS_DATE OBS_TIME OBS_SECONDS FLIGHT_NUM ----------- ---------- -------- -------- ----------- ---------- 0928-RSB 102 28-MAY-87 1228 42 5 0928-RSB 102 28-MAY-87 1228 47 5 0928-RSB 102 28-MAY-87 1228 52 5 0928-RSB 102 28-MAY-87 1228 57 5 ATMOSPHERIC_PRESS HEIGHT_ABV_GRND_LVL DRY_BULB_TEMP WET_BULB_TEMP ----------------- ------------------- ------------- ------------- 972.9 23 15.990 14.870 969.8 49 16.060 14.760 966.5 79 16.080 14.620 963.2 108 16.040 14.450 MIX_RATIO POTNTL_TEMP AZIM_ANG ELEV_ANG WIND_SPEED ---------- ----------- --------- --------- ---------- 10.510 291.4300 16.980 15.300 -999.0000 10.390 291.7600 12.770 20.060 13.1500 10.260 292.0600 11.170 23.530 13.1500 10.120 292.3100 11.000 25.330 9.4900
This data set contains point data collected via soundings that were made at 2 to 3 hour intervals, depending on weather conditions. The vertical resolution is approximately 15 to 20 m.
A general description of data granularity as it applies to the IMS appears in the EOSDIS Glossary.
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 begins 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, path and name of the document that describes the data in this file, and name of principal investigator for these data.
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_ID)).
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.
The wind velocity data listed in the original data files were calculated by means of an algorithm (developed by the manufacturer) involving the radius of the Earth, the curvature of the surface, etc. This algorithm is correct but produces wind speeds and directions with a large degree of noise and scatter. Corrected values using a simpler "flat-Earth" algorithm are found in the FIFE Radiosonde Wind Profiles document on FIFE CD-ROM Volume 1.
Not available at this revision.
Not available at this revision.
For details see the FIFE Radiosonde Wind Profiles document and the FIFE Temperature and Humidity Profiles document on FIFE CD-ROM Volume 1.
The height above ground-level, mixing ratio, potential temperature, wind velocity, wind direction, wind height and relative humidity data in this data set are derived values.
None.
The humidity values become inaccurate when the Wet-Bulb reservoir dries out or freezes, or when the air temperature goes below 0 degrees C.
The derived variables height above ground-level, mixing ratio, potential temperature, wind velocity, wind direction, wind height and relative humidity for most applications are sufficiently accurate. However, for certain detailed analyses, especially wind speed and humidity in the boundary layer, the user may wish to redo these calculations from the raw data by means of his/her own algorithms.
In the column RELATIVE_HUMIDITY, value -999 refers to data that is missing. If there are good values for wet-bulb and dry-bulb temperatures the humidity may have been lost in data transfer between cassette tape and floppy disk. Humidity values may become greater than 100% due to small errors in the wet-bulb and dry-bulb temperatures. This usually happened when the sonde went through clouds. Wet-bulb temperatures and humidity become questionable (if not completely wrong) when the wet-bulb thermometer freezes, i.e. has negative values. The humidity values greater than 100% were left in the data set to give the user a sense of the accuracy of the data.
Not available at this revision.
Not provided by Principal Investigator.
This data set is composed of "raw" data submitted as recorded and processed by the radiosonde receiving instrumentation. No attempt was made before submission to "clean" these data, under the assumption that the user would re-analyze the raw data as appropriate for each application. Subsequently, several cleaned or improved data sets were also produced (see the Related Data Sets Section).
FIS staff applied a general QA procedure to the data to identify inconsistencies and problems for potential users. There were some inconsistencies in the way missing values were recorded. In all obvious cases, these values were converted to -999 in preparing the data for publication on CD-ROM. However, there may still be some cases in the data where positive sequences of 9's (of different lengths) occur.
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. An attempt was made to find an explanation for unexpected high or low values, values outside of the normal physical range for a variable, or standard deviation that appeared inconsistent with the mean. In some cases, histograms were examined to determine whether outliers were consistent with the shape of the data distribution. Note, however, that there are almost 140,000 data records from some 400 balloon flights. the resources were not available to examine the details of each flight or each suspect data record. The user is advised to conduct a detailed analysis for specific uses (see also the Usage Guidance Section).
The discrepancies, which were identified, are reported as problems in the Known Problems with the Data Section. In general, there are two main sources of problems, both of which should be obvious upon inspection of the data for a specific flight. There is a "leader" of 10 - 100 data records before the actual release of the balloon. During this period, indicated by constant near zero, and sometimes negative heights, the reported values are unreliable (manual checks and launch positioning are occurring).
A second suspect period occurs at the end of each flight, as the sonde unit descends after the balloon bursts. These descending values are not generally considered usable data, since the rapid rate of descent generally outpaces the time lags in the instruments. Also, the explosion of the balloon itself causes a release and rapid expansion of the helium gas within it. In some cases, the sonde appears to be buffeted by the shock wave generated by the expanding gas, or even to enter the gas cloud for a period. The effects on the instruments, and their permanence, are unknown. These occurrences are evident in the data record by a minimum in the pressure (maximum in height) values. The values of all variables generally show erratic behavior, for varying lengths of time, after this.
A third variety of problem occurs when the balloon enters a cloud and manual tracking of its position ceases. In these cases, identified by loss of the azimuth and elevation angle data, the instruments still continue to function normally as the balloon ascends. The loss of the positional information, however, compromises the usefulness of the remaining values.
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.
Not available.
As of the revision data of this document, the following discrepancies or errors in the data have been reported:
Results of the FIS staff quality assessments:
The variables pressure, dry-bulb temperature, wet-bulb temperature, azimuth angle of balloon and elevation angle of balloon are the so-called raw data. The variables height above ground-level, mixing ratio, potential temperature, wind velocity, wind direction, wind height and relative humidity are variables derived from the raw data.
Not available at this revision.
This data set can be used to determine the regional surface heat flux.
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.
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.
ORNL DAAC User Services
Oak Ridge National Laboratory
Telephone: (865) 241-3952
FAX: (865) 574-4665
Email: ornldaac@ornl.gov
EOSDIS Distributed Active Archive Center
Oak Ridge National Laboratory
USA
Telephone: (865) 241-3952
FAX: (865) 574-4665
Email: ornldaac@ornl.gov
Users may place requests by telephone, electronic mail, or FAX. Data is also available via the World Wide Web at http://daac.ornl.gov.
FIFE data are available from the ORNL DAAC. Please contact the ORNL DAAC User Services Office for the most current information about these data.
FIFE Radiosonde Data are available on FIFE CD-ROM Volume 1. The CD-ROM filename is as follows:
\DATA\ATMOS\BRUT_SON\YyyMmm\ydddNnnn.WBR
Where yy is the last two digits of the year (e.g., Y87 = 1987), and mm is the month of the year (e.g., M12 = December). 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: ydddNnnn.sfx, where Nnnn is the flight number (ranges from 002 - 450), 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 .WBR for this data set.
ADAS Operating Manual, AIR, Inc. Boulder CO.
Brutsaert, W., M. Sugita and L.J. Fritschen. 1990. Inner region humidity characteristics of the neutral boundary layer over prairie terrain. Water Resour. Res. 26:2931-21936.
Brutsaert, W. and M. Sugita. 1990. The extent of the unstable Monin-Obukhov layer for temperature and humidity above complex hilly grassland. Boundary-Layer Meteor. 51:383-400.
Brutsaert, W. and M. Sugita. 1991. A bulk similarity approach in the atmospheric boundary layer using radiometric skin temperature to determine regional surface fluxes. Boundary-Layer Meteor. 55:1-23.
Brutsaert, W. and M. Sugita. 1992. Self-preservation in the diurnal evolution of the surface energy budget to determine daily evaporation. J. Geophys. Res. 97:18,377-18,382.
Brutsaert, W. and M. Sugita. 1992. Regional surface fluxes under non-uniform and patchy soil moisture conditions during drying, Water Resour. Res. 28:1669-1674.
Sugita, M. and W. Brutsaert. 1990. Wind velocity measurements in the neutral boundary layer above hilly prairie. J. Geophys. Res. (Atmos.). 95(D6):7617-7624.
Sugita, M. and W. Brutsaert. 1990. How similar are temperature and humidity profiles in the unstable boundary layer? J. Appl. Meteor. 29:489-497.
Sugita, M. and W. Brutsaert. 1990. Regional surface fluxes from remotely sensed skin temperature and lower boundary layer measurements. Water Resour. Res. 26:2937-2944.
Sugita, M. and W. Brutsaert. 1991. Daily evaporation over a region from lower boundary layer profiles measured with radiosonde. Water Resour. Res. 27:747-752.
Sugita, M. and W. Brutsaert. 1992. Landsat surface temperatures and radiosoundings to obtain regional surface fluxes of heat and water vapor. Water Resour. Res. 28:1675-1679.
Sugita, M. and W. Brutsaert. 1992. The stability functions in the bulk similarity formulation for the unstable boundary layer. Boundary-Layer Meteor. 61:65-80.
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.
A general glossary for the DAAC is located at Glossary.
A general list of acronyms for the DAAC is available at Acronyms.
April 26, 1994.
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 as archived on the FIFE CD-ROM series.
August 28, 1996 (citation revised on October 3, 2002).
ORNL-FIFE_BRUT_SON.
Brutsaert, W. H. 1994. Atmospheric Profiles: Brutsaert (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/15. 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).