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SMEX03 Ancillary Soil Characteristics Data

Summary

The SMEX03 Ancillary Soil Characteristics data set contains data for the regional study areas of Alabama, Georgia, and Oklahoma, USA as part of the 2003 Soil Moisture Experiment (SMEX03). The original data were extracted from a multi-layer soil characteristics database for the conterminous United States and generated using Environmental Systems Research Institute (ESRI) ArcMap software for each regional study area. Parameters for this data set include available water capacity, bulk density, permeability, porosity, rock fragment class, rock fragment volume, percent sand, percent clay, and texture class. The temporal coverage is approximate, as these data are representative of the conditions present in each regional study area during the general timeline of the SMEX03 campaign. The total volume for these data sets is approximately 2.8 gigabytes. Data are provided in ASCII text files and are available via FTP.

These data were collected as part of a validation study for the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). AMSR-E is a mission instrument launched aboard NASA's Aqua Satellite on 04 May 2002. AMSR-E validation studies linked to SMEX are designed to evaluate the accuracy of AMSR-E soil moisture data. Specific validation objectives include assessing and refining soil moisture algorithm performance; verifying soil moisture estimation accuracy; investigating the effects of vegetation, surface temperature, topography, and soil texture on soil moisture accuracy; and determining the regions that are useful for AMSR-E soil moisture measurements.

Citing These Data

We kindly request that you cite the use of this data set in a publication using the following citation example. For more information, see our Use and Copyright Web page.

Cosh, M. and J. Birch. 2008. SMEX03 Ancillary Soil Characteristics Data. [indicate subset used]. Boulder, Colorado USA: NASA DAAC at the National Snow and Ice Data Center.

Overview Table

Category Description
Data format ASCII Grid data files
Spatial coverage and resolution Alabama:
Southernmost Latitude: 34.66° N
Northernmost Latitude: 35.19° N
Westernmost Longitude: 87.77° W
Easternmost Longitude: 87.08° W

Georgia:
Southernmost Latitude: 30.96° N
Northernmost Latitude: 31.90° N
Westernmost Longitude: 83.97° W
Easternmost Longitude: 83.36° W

Oklahoma North:
Southernmost Latitude: 36.10 ° N
Northernmost Latitude: 36.87 ° N
Westernmost Longitude: 98.39 ° W
Easternmost Longitude: 97.41 ° W

Oklahoma South:
Southernmost Latitude: 34.44 ° N
Northernmost Latitude: 35.42 ° N
Westernmost Longitude: 98.04° W
Easternmost Longitude: 97.70 ° W
Temporal coverage and resolution ~June - July 2003
Tools for accessing data No special tools are required to view these data.
File naming conventions rg_ppd.txt
File size 10 - 26 MB
Parameters Available Water Capacity
Bulk Density
Permeability
Porosity
Rock Fragment Class
Rock Fragment Volume
Percent Sand
Percent Clay
Texture Class
Procedures for obtaining data Data are available via FTP.

Table of Contents

  1. Contacts and Acknowledgments
  2. Detailed Data Description
  3. Data Access and Tools
  4. Data Acquisition and Processing
  5. References and Related Publications
  6. Document Information

1. Contacts and Acknowledgments

Investigator(s)

Michael H. Cosh
HydrologyRemote Sensing Laboratory
US Department of Agriculture (USDA) - Agricultural Research Service (ARS)
Bldg. 007, Rm. 104, BARC-West
Beltsville, MD 20705 USA

Joanna Birch
Hydrology/Remote Sensing Laboratory
US Department of Agriculture (USDA) - Agricultural Research Service (ARS)
Bldg. 007, Rm. 104, BARC-West
Beltsville, MD 20705 USA

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

Acknowledgements

The investigators thank the Earth System Science Center at Pennsylvania State University for providing the data used in this data set through the Soil Information for Environmental Modeling and Ecosystem Management database.

2. Detailed Data Description

Format

Data are provided in ArcInfo ASCII Grid data files. The first six rows of each file contain header information, while the following rows contain the actual grid data. Refer to Table 2 for clarification of ASCII Grid header variables, or to the Sample Record section of this document to view the sample data record. Missing data are represented by -9999. The image dimensions for each regional study area are described in Table 1.

 

Table 1. Study Area Image Dimensions
Alabama 1920 rows by 4000 columns
Georgia 3432 rows by 1855 columns
Oklahoma 600 rows by 2080 columns

 

Table 2. ArcInfo ASCII Grid Header Values
Variable Description
ncols Number of columns in the grid
nrows Number of rows in the grid
xllcorner Western edge of the grid
yllcorner Southern edge of the grid
cellsize Spatial resolution of the grid
NODATA_value Refers to value representing missing data, such as -9999


File and Directory Structure

The top directory level contains subdirectories for each SMEX03 study region and the readme.txt file, as shown in Figure 1.

Top Level Directory Snapshot

Figure 1. Top Level Directory
Structure of SMEX03 Ancillary Data

File Naming Conventions

The soil text files for each data set are named according to the following convention and as described in Table 3:

rg_ppd.txt

Where:

Table 3. Description of File Name Variables
Variable Description
rg Regional Study Areas (al: Alabama; ga: Georgia; on: Oklahoma North; os: Oklahoma South)
pp
Parameter Abbreviation Parameter Description
awc Available Water Capacity
bd Bulk Density
poros Porosity
perm Permeability
sand Sand
clay Clay
rvol Rock Fragment Volume
dtc Dominant Textural Code
rfc Rock Fragment Class
d
Depth Code Depth from soil surface
1 0 - 5 cm
2 5 - 10 cm
3 10 - 20 cm
4 20 - 30 cm
   
Note: Files containing awc data do not include a depth code in the file name as in the file al_awc100.txt, for example, where 100 denotes cm rather than depth code value. There is only one awc file for each regional study area. AWC was computed for the top 100 cm from the surface.
.txt Indicates that this is a text file.

Example: al_bd1.txt

 

File Size

File sizes for each region are described below:

Alabama

There are 33 ASCII text files containing Alabama soil data that range from 10 to 26 MB each, for a total of approximately 850 MB.

Georgia

There are 32 ASCII text files containing Georgia soil data that range from 10 to 26 MB each, for a total of 680 MB.

Oklahoma

There are 66 ASCII text files containing Oklahoma soil data that range from 10 to 26 MB each, for a total of 1380 MB.

 

Spatial Coverage

This data set covers the regional study areas as referenced by the following:

Alabama

Southernmost Latitude: 34.668845602° N
Northernmost Latitude: 35.194353404° N
Westernmost Longitude: 87.777562595° W
Easternmost Longitude: 87.087325703° W

Georgia

Southernmost Latitude: 30.961064855° N
Northernmost Latitude: 31.903257457° N
Westernmost Longitude: 83.970846870° W
Easternmost Longitude: 83.36425277° W

Oklahoma North

Southernmost Latitude: 36.107428397 ° N
Northernmost Latitude: 36.871048244 ° N
Westernmost Longitude: 98.394729898 ° W
Easternmost Longitude: 97.418165280 ° W

Oklahoma South

Southernmost Latitude: 34.443677450 ° N
Northernmost Latitude: 35.422765186 ° N
Westernmost Longitude: 98.046657639° W
Easternmost Longitude: 97.700276141 ° W

 

Spatial Resolution

The pixel size is 30 m by 30 m.

Projection

The projection is the Universal Transverse Mercator (UTM) with the World Geodetic System 1984 Datum (WGS 84) applied. The UTM zones for each regional study area are listed in Table 4.


Table 4. UTM Zones of Study Areas
Alabama Zone 16
Georgia Zone 17
Oklahoma Zone 14

 

Temporal Coverage

While the United States SMEX03 campaign took place in Alabama, Georgia, and Oklahoma between June 23 and July 18, 2003, these Ancillary Soil Characteristics data are representative of the conditions to be expected in the US regional study areas during the approximate timeline of the SMEX03 campaign.

Parameters or Variables

Parameters for each data set include the following and are further described in Table 5:

Parameter Range

Parameters and respective parameter ranges for the Alabama, Georgia, and Oklahoma data files are described in Table 5.

Table 5. Parameter Description
Parameters Values Given As
Available Water Capacity Volumetric percent, computed for a column length of 100 cm, measured from the surface of the soil
Bulk Density Mean bulk density (g/cm3) of soil
Permeability Mean permeability rate (cm/hr) of soil
Porosity Mean porosity (g/cm3) of soil
Rock Fragment Class
Rock Fragment Class Code Description
0 No Data
1 Bouldery
2 Cobbly
3 Channery
4 Cherty
5 Flaggy
6 Gravelly
7 Rubbly
8 Shaly
9 Stony
10 Slaty
11 Organic Materials
12 Water
13 Bedrock
14 No Rock Fragments
15 Other
Rock Fragment Volume Percent of rock by volume in soil
Percent Sand Percent of sand in soil
Percent Clay Percent of clay in soil
Texture Class
Texture Class Code Description
0 No Data
1 Sand
2 Loamy Sand
3 Sandy Loam
4 Silt Loam
5 Silt
6 Loam
7 Sandy Clay Loam
8 Silty Clay Loam
9 Clay Loam
10 Sandy Clay
11 Silty clay
12 Clay
13 Organic Materials
14 Water
15 Bedrock
16 Other

Sample Data Record

Figure 2 displays a partial sample of the data file al_bd1.txt containing Alabama bulk density data. The first six rows display ArcInfo ASCII Grid header information, while the last six rows contain mean bulk density measurements, of which, only the first thirteen columns are shown in this sample. For clarification of ASCII Grid header variables, refer to Table 2 in the Format section.


Figure 2 . Sample Data Record
ncols 4000                  
nrows 1920                  
xllcorner 492000                  
yllcorner 3837000                  
cellsize 30                  
NODATA_value -9999                  
1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 ...
1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 ...
1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 ...
1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 ...
1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 ...
1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 1.47 ...

3. Data Access

Data are available via FTP.

Volume

Total volume is approximately 2.8 GB for all data. Volume by region is approximately:

Alabama: 850 MB

Georgia: 680 MB

Oklahoma: 1380 MB

Software and Tools

No special tools are required to view these data.

Related Data Collections

4. Data Acquisition and Processing

Data Source and Acquisition Methods

Alabama, Georgia, and Oklahoma ancillary soil characteristics data were retrieved from the Soil Information for Environmental Modeling and Ecosystem Management database hosted by the Earth System Science Center at Pennsylvania State University. The data for the regional study areas were retrieved from a multi-layer soil characteristics data set for the conterminous United States, called CONUS-SOIL. The data were then exported with ESRI ArcMap and exported as ASCII Grid data files.

5. References and Related Publicationss

Please visit the USDA SMEX03 Web site for in-depth information on the science mission and goal of the SMEX project.

6. Document Information

Acronyms and Abbreviations

Table 6 lists acronyms and abbreviations used in this document.

Table 6. Acronyms and Abbreviations
AL Alabama
AMSR-E Advanced Microwave Scanning Radiometer - Earth Observing System
ASCII American Standard Code for Information Interchange
AWC Available Water Capacity
BD Bulk Density
CONUS-SOIL Conterminous United States - Soil
DAAC Distributed Active Archive Center
DTC Dominant Textural Code
ESRI Environmental Systems Research Institute
FTP File Transfer Protocol
GA Georgia
NASA National Aeronautics and Space Administration
NSIDC National Snow and Ice Data Center
OK Oklahoma
ON Oklahoma North
OS Oklahoma South
PERM Permeability
POROS Porosity
RFC Rock Fragment Class
RVOL Rock Fragment Volume
SMEX03 Soil Moisture Experiment 2003
URL Uniform Resource Locator
WGS 84 World Geodetic System 1984

Document Creation Date

May 2008

Document URL

http://nsidc.org/data/docs/daac/nsidc0339_smex03_ancillary_soils.gd.html