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This data set consists of snow depth data from nine study areas, within three larger-scale areas in northern Colorado (Fraser, North Park, and Rabbit Ears Meso-cell Study Areas (MSAs)). The study areas range from low-relief (flat topography) unforested areas with shallow snow covers, to high-relief (complex topography) densely forested areas with deep snow covers.
Data Set ID:
NSIDC-0175
CLPX-Ground: ISA Snow Depth Transects and Related Measurements, Version 2
This is the most recent version of these data.
Overview
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Citing These Data
As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.
Cline, D., R. Armstrong, R. Davis, K. Elder, and G. E. Liston. 2003. CLPX-Ground: ISA Snow Depth Transects and Related Measurements, Version 2. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5060/D4MW2F23. [Date Accessed].Documentation
Detailed Data Description
Format
Data are stored in ASCII text files with a file extension of .txt and JPEG images with a file extension of .jpg.
Missing data are identified by "-999". Double quotes are used to delimit text within fields, and commas contained within the double quotes do not indicate a new field. Because of the general lack of snow in North Park, all the depth data were collected on the first day of ground observations.
There are three depth transect files (one per ISA) per MSA. Snow transect filenames are depth_iopNMI_v1.txt, where:
Depth_iop indicates snow depth data
N = IOP number (1-4)
M = MSA letter code
I = ISA letter code
v1 = Data release version 1
.txt = plain text file
Early copies of files with filenames that do not include "_v1" are obsolete and should be replaced with the v1 copies.
Transect files contain one record per transect location, with the following fields:
Column 1: TRANSECT - transect ID
1-letter code for MSA:
F = Fraser
N = North Park
R = Rabbit Ears
1-letter code for ISA:
A = Alpine
B = Buffalo Pass
F = Fool Creek
I = Illinois River
M = Michigan River
P = Potter Creek
S = Spring Creek (if MSA Code = R) or
St. Louis Creek (if MSA Code = F)
W = Walton Creek
1-letter sector ID: A,B,C, or D
2-digit cell number: 01-25
. decimal point
1-digit location number: 1-5
Column 2: IOP - IOPx (x = 1-4)
Column 3: DATE - yyyymmdd
Column 4: TIME - hhmm
Column 5: UTME - UTM Easting (m)
Column 6: UTMN - UTM Northing (m)
Column 7: DEPTH - snow depth (cm)
Column 8: SWET - surface wetness:
d = Dry
m = Moist
w = Wet
vw = Very Wet
Column 9: SRUF - surface roughness photo taken (Y or N)
Column 10: CNPY - canopy
c = Coniferous
cs = Snow-covered Coniferous
g = Deciduous
ds = Snow-covered Deciduous
g = Grass (only used in North Park)
s = Sage (only used in North Park)
n = No Canopy
Column 11: TEMP(F) - soil temperature, degrees Fahrenheit (only measured in North Park)
Column 12: SURVEYOR - surveyor names
Column 13: COMMENTS - surveyor comments, prepended with Quality Control flags for this record ["QC(XXX)", see below for QC flags]
Field comments for depth data were recorded per cell of an ISA sector. For purposes of data consistency, they were reproduced for each data point within that cell.
There are three depth transect summary files (one per ISA) per MSA. Snow transect summary filenames are depth_iopNMI_v1_summary.txt, where:
Depth_iop indicates snow depth data
N = IOP number (1-4)
M = MSA letter code
I = ISA letter code
v1 = data release number 1
summary = content is summary record for each transect
.txt = plain text file
Transect summary files contain one record per transect, with the following fields:
Column 1: TRANSECT - transect ID
1-letter code for MSA:
F = Fraser
N = North Park
R = Rabbit Ears
1-letter code for ISA:
A = Alpine
B = Buffalo Pass
F = Fool Creek
I = Illinois River
M = Michigan River
P = Potter Creek
S = Spring Creek (if MSA Code = R) or
St. Louis Creek (if MSA Code = F)
W = Walton Creek
1-letter sector ID: A,B,C, or D
2-digit cell number: 01-25
Column 2: IOP - IOPx (x = 1-4)
Column 3: DATE - yyyymmdd
Column 4: TIME - hhmm
Column 5: UTME - UTM Easting (m)
Column 6: UTMN - UTM Northing (m)
Column 7: #DONE - number of points measured / number of points expected
Column 8: MEAN - mean of non-missing depth measurements (cm)
Column 9: SDEV - standard deviation of non-missing depth measurements (cm)
Column 10: MIN - minimum depth measured (cm)
Column 11: MAX - maximum depth measured (cm)
Columns 12,13,14,15,16: WETNESS - count of wetness values by category (dry/moist/wet/very wet/missing
Column 17: SRUF@PNT - transect point number where surface roughness photo was taken
Column 18: SURVEYOR - surveyor names
Column 14: QC() - list of quality control flags triggered by this transect
Column 15: COMMENTS_FOUND? - YES or NO indicator that surveyors included comments at this transect
Photos
Each JPEG (Joint Photographic Experts Group) file contains one digital photo. At least one snow roughness photo should have been taken at each sector cell. A photo of the general terrain was taken out along the depth transects. These photos should contain a card identifying the location of the photo using the misc.n convention.
Additional photos may also have been taken to show the general field work in progress for public relations purposes.
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File and Directory Structure
Data are organized in the following structure:
clp/
ground_data/
nsidc0175_snow_transects/
msa/
data/
iop/
photos/
iop/
isa/
other/
roughness/
terrain/
- MSA's are: fraser,
north_park, andrabbit_ears - One LSOS, at Fraser
- ISA's are: alpine,
buffalo_pass,fool_creek,illinois_river,michigan_river, potter_creek, spring_creek, st_louis_creek, and walton_creek.
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File Naming Convention
The following code, known as "misc.n", are used in filenames (and for site names in the raw data):
MSA Code
F = Fraser
N = North Park
R = Rabbit Ears
ISA Code
A = Alpine
B = Buffalo Pass
F = Fool Creek
I = Illinois River
M = Michigan River
P = Potter Creek
S = Spring Creek (if MSA Code = R) or
St. Louis Creek (if MSA Code = F)
W = Walton Creek
ISA Sector
A = Lower Left Quadrant - SW
B = Upper Left Quadrant - NW
C = Upper Right Quadrant - NE
D = Lower Right Quadrant - SE
Sector Cell Number (1-25, referring to 100-m x 100-m grid cells)
Transect point number (1-5)
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File Size
ASCII file sizes range from 3 to 215 KB. JPG file sizes range from 500 to 750 KB.
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Spatial Coverage
Fraser, North Park, and Rabbit Ears MSAs in northern Colorado, US.
Schematic diagram of the nested study areas for the CPLX
Study area map
Location of MSAs
Location and characteristics of ISAs
IOP1 Transects Measured:
| MSA | Planned number of transects | Actual number of transects |
|---|---|---|
| Fraser | 1,500 | 1,243 |
| North Park | 1,500 | 1,500 |
| Rabbit Ears | 1,500 | 1,484 |
IOP2 Transects Measured:
| MSA | Planned number of transects | Actual number of transects |
|---|---|---|
| Fraser | 1,500 | 1,486 |
| North Park | 1,500 | 1,460 |
| Rabbit Ears | 1,500 | 1,505* |
*An extra transect was taken near location RWB08. The pole was moved from its location in IOP1. Surveyors measured at the pole's new location, and at the original location.
IOP3 Transects Measured:
| MSA | Planned number of transects | Actual number of transects |
|---|---|---|
| Fraser | 2,052 | 2,042 |
| North Park | 2,052 | 2,047 |
| Rabbit Ears | 2,052 | 1,803 |
IOP4 Transects Measured:
| MSA | Planned number of transects | Actual number of transects |
|---|---|---|
| Fraser | 2,052 | 2,045 |
| North Park | 2,052 | 2,052 |
| Rabbit Ears | 2,052 | 2,036 |
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Temporal Coverage
IOP1 took place 19-24 February 2002.
IOP2 took place 25-30 March 2002.
IOP3 took place 20-25 February 2003.
IOP4 took place 26-31 March 2003.
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Parameter or Variable
Parameters include snow depth, surface wetness, surface roughness (photos only), canopy, and soil temperature.
For a complete description of parameters and measurements, please refer to the Measurements section of the CLPX Plan.
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Quality Assessment
Snow Depth Quality Control Flags
Code Description (what was reset/set/estimated: the reason why)
---- ----------------------------------------------------------
000 QC OK: all tests passed
201 Temperature converted from Celsius to Fahrenheit: surveyor's probe measured Celsius.
914 Canopy reset to missing value: Snow depth is 0.
916 Surface wetness reset to missing value: Snow depth is 0.
990 Warning: One or both UTM coordinates are missing.
991 Warning: Missing date and/or time field.
Detailed Explanations:
----------------------
000 QC OK: all tests passed
No problems were detected, values have not been changed from the
original forms.
N.B. Soil temperature measurments were only taken in North Park;
precision differed by surveying team, some surveyors measured to
the nearest degree, some measured to the nearest tenth degree.
During quality control, every effort was made to retain the
precision recorded by the surveyor.
Temperature QC codes
--------------------
201 Temperature converted from Celsius to Fahrenheit: surveyor's probe measured Celsius.
Measurement protocol in North Park MSA included soil measurements
at each transect point. During IOP1 only, all but one of the
thermometers used measured Fahrenheit temperatures. The
thermometer used by surveyor Armstrong and party was a Celsius
thermometer. Actual measurements at the location this surveyor
measured were taken to the nearest tenth of a Celsius degree, and
have been converted to the nearest tenth of Fahrenheit degree
during the QC.
914 Canopy reset to missing value: Snow depth is 0.
Measurement protocol was to record canopy only when snow depth was
greater than 0. In this case a recorded canopy was reset to
missing because the snow depth was 0.
916 Surface wetness reset to missing value: Snow depth is 0.
Measurement protocol was to record surface wetness only when snow
depth was greater than 0. In this case a recorded surface wetness
was reset to missing because the snow depth was 0.
990 Warning: One or both UTM coordinates are missing.
Transect coordinates are incomplete or missing.
991 Warning: Missing date and/or time field.
Date and/or time field are missing.
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Data Access and Tools
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Data Acquisition and Processing
For complete information about data acquisition and processing, please see the CLPX Plan Web Site.
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References and Related Publications
Contacts and Acknowledgments
Contributor(s) / Investigator(s):
Kelly Elder
Research Hydrologist
Rocky Mountain Research Station
USDA Forest Service
240 W. Prospect Road
Fort Collins, CO USA 80526
Don Cline
National Weather Service
National Operational Hydrologic REmote Sensing Center
1735 Lake Drive W.
Chanhassen, MN 55317
Document Information
DOCUMENT CREATION DATE
12 August 2003
