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CLPX Snow Pit Measurements

Summary

Snow pit data were collected during various Cold Land Processes Experiment (CLPX) investigations in northern Colorado and southern Wyoming, USA. Snow pit data are presented in their respective CLPX data sets, and this document describes the data format and spatial/temporal coverage of all the snow pit measurements. All CLPX snow pit data followed the same general sampling protocol. There are four groups of snow pit data: Intensive Observation Period (IOP) pit data, Local-Scale Observation Site (LSOS) pit data, meteorological station pit data, and Ground-based Passive Microwave Radiometer (GBMR) pit data.

The NASA Cold Land Processes Experiment (CLPX) is a multi-sensor, multi-scale experiment that focuses on extending a local-scale understanding of water fluxes, storage, and transformations to regional and global scales. Within a framework of nested study areas in the central Rocky Mountains of the western United States, ranging from 1-ha to 160,000 km2, intensive ground, airborne, and spaceborne observations are collected. Data collection focuses on two seasons: mid-winter, when conditions are generally frozen and dry, and early spring, a transitional period when both frozen and thawed, dry and wet conditions are widespread.

Citing Snow Pit Data

IOP snow pit data should be cited as follows:

Cline, D., R. Armstrong, R. Davis, K. Elder, and G. Liston. 2002, Updated July 2004. CLPX-Ground: ISA Snow Pit Measurements. Edited by M. Parsons and M.J. Brodzik. Boulder, CO: National Snow and Ice Data Center. Digital Media.

Snow pit data from the Local-Scale Observation Site (LSOS), meteorological stations, and Ground-based Passive Microwave Radiometer (GBMR) pits should be cited as follows (using the GBMR snow pits as an example):

Cline, D., R. Armstrong, R. Davis, K. Elder, and G. Liston. 2002, Updated July 2004. CLPX GBMR Snow Pit Measurements. Edited by M. Parsons and M.J. Brodzik. In CLPX-Ground: Ground Based Passive Microwave Radiometer (GBMR-7) Data, T. Graf, T. Koike, H. Fujii, M. Brodzik, and R. Armstrong. 2003. Boulder, CO: National Snow and Ice Data Center. Digital Media.

Table of Contents

1. Contacts
2. Detailed Data Description
Format
File and Directory Structure
File Naming Convention
File Size
Spatial Coverage
Temporal Coverage
Parameters
Data Set Version History
Quality Assessment
3. Data Access and Tools
4. Data Acquisition and Processing
5. References and Related Publications
6. Document Information

1. Contacts

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

2. Detailed Data Description

Format

All CLPX snow pit data followed the same general sampling protocol. There are four groups of snow pit data: Intensive Observation Period (IOP) pit data, Local-Scale Observation Site (LSOS) pit data, meteorological station pit data, and Ground-based Passive Microwave Radiometer (GBMR) pit data:

1) IOP pit data: These data represent the bulk of the pits sampled during the experiment. They were measured with the strictest levels of quality control, including QC performed in the field, usually within a day of the measurement. They include the so-called "gamma pits" taken along roadsides in the North Park MSA, to coincide with simultaneous airborne gamma overflights.

2) LSOS pit data: These pits were sampled at the LSOS, during each of the IOPs.

3) Met Station pit data: These snow pits were sampled very close to each of the nine Main ISA Meteorological Towers, and the tower at the Fraser Experimental Forest Headquarters (near the LSOS). Each of these pits were sampled once in the months of December 2002, and January, February, March, May, and June 2003.

4) GBMR pit data: Snow pits were sampled near the GBMR-7 instrument periodically (usually coincident with GBMR-7 experiments) during the course of the winter from November 2002 to March 2003.

Snow pit data are available in comma-separated ASCII text files, with a file extension of .csv, and in shapefile spatial data format, with various file extensions.

For each group of pits (LSOS, Met, GBMR and each of the the four IOPs), there are four ASCII files, containing summary, density profile, temperature profile, and stratigraphy profile information.

For each group of pits (LSOS, Met, GBMR and the combined IOPs), there are six shapefiles (with various extensions) for summary, density profile, temperature profile, and stratigraphy profile data. Shapefiles contain everything included in the text files, except for general pit comments, which were too verbose for import into shape format.

During all IOPs, extra pits were dug across the entire North Park MSA, to coincide with simultaneous airborne gamma measurements. These pits have non-standard pit IDs.

Missing data in the ASCII files are identified by "-999". In the shapefiles, missing dates are designated 9999-99-99, missing text fields are designated "NoData", and missing numeric fields are designated -999.

SNOW PIT SUMMARY FILES

Snow pit summary files contain one record per pit, with the following fields:

	Column 1: PIT NAME (MIsp##)
		M = 1-letter code for MSA:
		    f = Fraser
		    n = North Park
		    r = Rabbit Ears
		I = 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
		sp## = snow pit ("sp") and 2-digit pit number (##)
	Column 2: IOP - IOPx (x = 1-4)
	Column 3: SECTOR - sector name (alpha, bravo, charlie, delta)
	Column 4: DATE - yyyymmdd
	Column 5: TIME - hhmm
	Column 6: UTME - UTM Easting (m)
	Column 7: UTMN - UTM Northing (m)
	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: SL-A - soil sample A (Y or N; in later pits, depth of sample in cm)
	Column 11: SL-B - soil sample B (Y or N; in later pits, depth of sample in cm)
	Column 12: CNPY - canopy 
	          c = Coniferous
	          cs = Snow-covered Coniferous
	          f = Deciduous
	          ds = Snow-covered Deciduous
	          g = Grass (only in North Park)
	          s = Sage (only in North Park)
	          n = No Canopy
	Column 13: CNHT - approximate canopy height (cm); only used in North Park (missing for IOP1)
	Column 14: DEPTH - measured snow depth (cm)
	Column 15: SWE - calculated snow water equivalent (mm)
	Column 16: DNS_LYRS - number of density profile layers [set to 1 if SIPRE tube was used
		instead of density cutter]
	Column 17: DNS_AVG - pit average density (kg/m^3)
	Column 18: DNS_MAX - pit maximum density (kg/m^3)
	Column 19: DNS_MIN - pit minimum density (kg/m^3)
	Column 20: T_MEAN - pit average temperature (C)
	Column 21: T_MAX - pit maximum temperature (C)
	Column 22: T_MIN - pit minimum temperature (C)
	Column 23: T_SFC - pit surface temperature (C)
	Column 24: T_BASE - pit base temperature (C)
	Column 25: STR_LYRS - number of stratigraphy layers
	Column 26: SMGR_AVG - pit small grain average (average of [SmallShort*SmallLong]) (mm^2)
	Column 27: SMGR_MAX - pit maximum small grain (mm^2)
	Column 28: SMGR_MIN - pit minimum small grain (mm^2)
	Column 29: MDGR_AVG - pit med grain average (average of [MedShort*MedLong]) (mm^2)
	Column 30: MDGR_MAX - pit maximum medium grain (mm^2)
	Column 31: MDGR_MIN - pit minimum medium grain (mm^2)
	Column 32: LGGR_AVG - pit large grain average (average of [LgShort*LglLong]) (mm^2)
	Column 33: LGGR_MAX - pit maximum large grain (mm^2)
	Column 34: LGGR_MIN - pit minimum large grain (mm^2)
	Column 35: MJ_SHAPE - majority grain shape (New, Round, Mixed, Faceted)
	Column 36: SURVEYOR - surveyor names
	Column 37: QC - list of QC codes for this pit (see the Quality Assessment section of this
		document, below)

Snow Pit ID's:

    IOP Pit IDs: MIsp## 

		M = 1-letter code for MSA:
		    f = Fraser
		    n = North Park
		    r = Rabbit Ears
		I = 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
		sp## = snow pit ("sp") and 2-digit pit number (##)
	   
    "Gamma" Overflight Pit IDs:	surveyor##
		 surveyor = first surveyor's last name
		 ## = 2-digit pit number, gamma pit numbers have no
		      significance, sometimes they indicate
		      sequence of data collection, but
		      sometimes 2 teams of surveyors
		      leap-frogged along the same road, with
		      1st team using odd numbers and second
		      team using even numbers

    GBMR Pit IDs: gbmr##x
		gbmr = pit taken near GBMR instrument
		## = 2-digit pit number, indicates same location throughout the winter				
		x = letter {a,b,c, etc} indicating sequence of pit
		    measurements throughout the winter
			
    LSOS Pit IDs: LABEL##x
		LABEL = snow (iop1);  lsos (iop2-4)
		## = 2-digit pit number
		x = letter {a,b,c, etc.}  

    Met Pit IDs: MImet##{x}
	    M = MSA code (see standard IOP pit IDs for MSA codes)
	    I = ISA code (see standard IOP pit IDs for ISA codes)
		met = indicates a met station pit
		## = 2-digit pit number (numbers are sequential through the winter), thus:
		     01 = December, 2002
		     02 = January, 2003
		     03 = February, 2003
		     04 = March, 2003
		     05 = May, 2003
		     06 = June, 2003
		x = optional letter, {a or b}, only used in North Park in
		    December 2002

Sample Snow Pit Summary Data File:

When a snow pit summary file is opened in a spreadsheet program, such as Excel, the file appears as:

      PIT      IOP    SECTOR    DATE         TIME    UTME      UTMN      SWET    .........
               	    	        	          	    	      	       	    
      fasp01   iop1    alpha    9999-99-99  -999     425983    4410879	 -999    .........
      fasp02   iop1    alpha    2/20/2002   1400     426038    4411259     d     .........
      fasp03   iop1    bravo    2/20/2002   1150     426024    4411419     d     .........

SNOW PIT DENSITY PROFILE FILES

Snow pit density profile files contain one record per density layer measured, with the following fields:

	Column 1: PIT_NAME - pit ID, (see PIT field in summary records, above)
	Column 2: IOP - iopx (x = 1-4)
	Column 3: DATE - yyyy-mm-dd
	Column 4: TIME - hhmm
	Column 5: UTME - UTM Easting (m)
	Column 6: UTMN - UTM Northing (m)
	Column 7: TYPE - instrument used [C(utter) or T(ube)]
	Column 8: TOP - layer top height (cm)
	Column 9: BOT - layer bottom height (cm)
	Column 10: DNS_A - first density measurement (kg/m^3)
	Column 11: DNS_B - second density measurement (kg/m^3)
	Column 12: DNS_AVG - average of DENSITY-A and DENSITY-B
	Column 13: QC - list of QC codes for this density layer

Sample Snow Pit Density Data File:

When a snow pit density file is opened in a spreadsheet program, such as Excel, the file appears as:

    PIT_NAME   IOP   DATE       TIME   UTME     UTMN     TYPE   TOP  BOT  DNS_A  DNS_B  DNS_AVG   QC                                                                              
    fasp02     iop1  2/20/2002  1400   426038   4411259   C     122  112   111    128    119.5   QC(000)
    fasp02     iop1  2/20/2002  1400   426038   4411259   C     112  102   100    92     96      QC(000)
    fasp02     iop1  2/20/2002  1400   426038   4411259   C     102  92    192    190    191     QC(000)                              

SNOW PIT TEMPERATURE PROFILE FILES

Snow pit temperature profile files contain one record per temperature layer measured, with the following fields:

	Column 1: PIT_NAME - pit ID, (see PIT field in summary records, above)
	Column 2: IOP - iopx (x = 1-4)
	Column 3: DATE - yyyy-mm-dd
	Column 4: TIME - hhmm
	Column 5: UTME - UTM Easting (m)
	Column 6: UTMN - UTM Northing (m)
	Column 7: HEIGHT - height (cm)
	Column 8: TEMP - temperature (C)
	Column 9: QC - list of QC codes for this temperature layer

Sample Snow Pit Temperature Data File:

When a snow pit temperature file is opened in a spreadsheet program, such as Excel, the file appears as:

    PIT_NAME  IOP    DATE       TIME    UTME     UTMN    HEIGHT   TEMP   QC
    fasp02    iop1  2/20/2002   1400   426038   4411259   121     -9    QC(000)
    fasp02    iop1  2/20/2002   1400   426038   4411259   111     -9    QC(000)
    fasp02    iop1  2/20/2002   1400   426038   4411259   101     -9    QC(000)
	

SNOW PIT STRATIGRAPHY PROFILE FILES

Snow pit stratigraphy profile files contain one record per stratigraphy layer measured, with the following fields:

	Column 1: PIT_NAME - pit ID, (see PIT field in summary records, above)
	Column 2: IOP - iopx (x = 1-4)
	Column 3: DATE - yyyy-mm-dd
	Column 4: TIME - hhmm
	Column 5: UTME - UTM Easting (m)
	Column 6: UTMN - UTM Northing (m)
	Column 7: TOP - layer top height (cm)
	Column 8: BOT - layer bottom height (cm)
	Column 9: SM_SHT - representative Small grain, Short dimension (mm)
	Column 10: MD_SHT - representative Medium grain, Short dimension (mm)
	Column 11: LG_SHT - representative Large grain, Short dimension (mm)
	Column 12: SM_LNG - representative Small grain, Long dimension (mm)
	Column 13: MD_LNG - representative Medium grain, Long dimension (mm)
	Column 14: LG_LNG - representative Large grain, Long dimension (mm)
	Column 15: GRN_TYPE - grain type (New, Round, Mixed, Faceted)
	Column 16: QC  - list of QC codes for this stratigraphy layer
	Column 17: COMMENT - surveyor's comments

Sample Snow Pit Stratigraphy Data File:

When a snow pit stratigraphy file is opened in a spreadsheet program, such as Excel, the file appears as:

    PIT_NAME  IOP    DATE      TIME   UTME    UTMN    TOP  BOT  SM_SHT  MD_SHT  LG_SHT  SM_LNG  MD_LNG   LG_LNG   GRN_TYPE    QC        COMMENT

    fasp02   iop1   2/20/2002  1400  426038  4411259  122  110    0.2    0.2     0.2     0.5     0.5      0.8         n      QC(000)    new snow, wind slab
    fasp02   iop1   2/20/2002  1400  426038  4411259  110  96     0.2    0.5     0.5     0.3     1        1           n      QC(000)    2/19/02 event
    fasp02   iop1   2/20/2002  1400  426038  4411259  96   90     0.1    0.1     0.1     0.2     0.2      0.2         r      QC(000)    wind slab
	

File and Directory Structure

Each group of pit files (IOP, LSOS, Met, and GBMR) is available in a compressed (tarred and zipped) file that will extract into two directories: "ascii/" contains the .csv version of the data, and "shape_files/" contains the GIS-compatible shapefiles.

File Naming Convention

The following codes 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

ASCII filenames are named pit_GROUP_v#_DATA.csv, where:

pit indicates snow pit data
GROUP = pit group (iop1, iop2, iop3, iop4, lsos, met, or gbmr)
v# = Data release number (e.g., version 2) (note: see the Data Set Version History section of this document)
DATA = type of data in the file: "summary," "density," "temperature," or "strat"
.csv = comma-separated value text file

Shapefile names are pit_GROUP_v#_DATA.ext, where:

pit = indicates snow pit data
GROUP = pit group (iop, lsos, met, or gbmr) *note that all IOP pits are included in a single shapefile
v# = Data release number (e.g., version 2)
DATA = type of data in the file: "summary," "density," "temperature," or "strat"
.ext = shape file extensions {.dbf, .prj, .sbn, .sbx, .shp, .shx}

File Size

ASCII file sizes range from 20 to 300 KB. shapefile sizes range from 1 to 8 MB.

Spatial Coverage

Snow pits were sampled in Fraser, North Park, and Rabbit Ears MSAs in northern Colorado, USA.

CLPX snow pit spatial coverage maps

Schematic diagram of the nested study areas for the CPLX
Study area map
Location of MSAs
Location and characteristics of ISAs

IOP Snow Pits

IOP1 Snow Pits Measured:

MSA Planned number of pits Actual number of pits
Fraser 48 47
North Park 48 48 plus 118 "gamma" pits
Rabbit Ears 48 48

IOP2 Snow Pits Measured:

MSA Planned number of pits Actual number of pits
Fraser 48 48
North Park 48 48 plus 160 "gamma" pits
Rabbit Ears 48 48

IOP3 Snow Pits Measured:

MSA Planned number of pits Actual number of pits
Fraser 48 48
North Park 48 48 plus 92 "gamma" pits
Rabbit Ears 48 18

IOP4 Snow Pits Measured:

MSA Planned number of pits Actual number of pits
Fraser 48 48
North Park 48 48 plus 43 "gamma" pits
Rabbit Ears 48 44

LSOS Snow Pits

LSOS snow pit locations changed between 2002 and 2003. Please refer to the two location diagrams in the CLPX LSOS snow pit documentation for pit locations. No UTM locations were recorded for the 2002 LSOS snow pits. Instead, a general location of 424492 E, 4417690 N was used for all IOP1 and IOP2 pits. For the 2003 snow pits, a GPS location was recorded for each individual pit, but because of GPS inaccuracy, the location of snow pits shown on the maps is more accurate than the GPS data.

Met Snow Pits

Met snow pits were sampled at or near each of the nine Main ISA Meteorological Towers, and at the tower at the Fraser Experimental Forest Headquarters (near the LSOS). Please refer to the ISA Main Meteorological Data document for pit locations.Met snow pit locations (UTME and UTMN coordinates) are not exact. Surveyors were not equipped with GPS receivers, so the recorded pit locations are locations of the corresponding met station towers.

GBMR Snow Pits

GBMR snow pit measurements were taken near the GBMR-7 instrument (please see the CLPX GBMR-7 documentation for more information about the GBMR spatial coverage).

Temporal Coverage

IOP Snow Pits

IOP Snow pits were measured during IOPs 1, 2, 3, and 4.

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.

LSOS Snow Pits

LSOS pits were measured during the four IOPs. On each of the following days in 2002, three snow pits were sampled:

19 February Pits 1, 3, and 5
20 February Pits 2, 4, and 6
21 February Pits 1, 3, and 5
22 February Pits 2, 4, and 6
23 February Pits 1, 3, and 5
24 February Pits 2, 4, and 6
25 March Pits 2, 4, and 6
26 March Pits 1, 3, and 5
27 March Pits 2, 4, and 6
28 March Pits 1, 3, and 5.
29 March Pits 2, 4, and 6
30 March Pits 1, 3, and 5

On each of the following days in 2003, three LSOS snow pits were sampled:

19 February Pits 2, 4, and 6
20 February Pits 1, 3, and 5
21 February Pits 2, 4, and 6
22 February Pits 1, 3, and 5
23 February Pits 2, 4, and 6,
24 February Pits 1, 3, and 5
2 March5 Pits 2, 4, and 6
26 March Pits 1, 3, and 5
2 March7 Pits 2, 4, and 6
28 March Pits 1, 3, and 5.
29 March Pits 2, 4, and 6
30 March Pits 1, 3, and 5

Met Snow Pits

Met pits were measured once each month in December 2002, and January, February, March, May, and June 2003. Precise dates are indicated in the data files.

GBMR Snow Pits

GBMR pits were measured periodically from November 2002 to March 2003. Measurement dates are indicated in the data files.

Because of the general lack of snow in North Park, all pit data were collected on the first day of ground observations. The second day, teams collected data at sites across the entire MSA to coincide with the gamma overflights.

Parameter or Variable

Parameter Description

Parameters include snow density, snow temperature, snow stratigraphy, snow grain size, and snow water equivalent. Snow wetness and surface roughness were also measured at the IOP snow pits.

For a complete description of parameters and measurements, please refer to the Measurements section of the CLPX Plan at http://www.nohrsc.nws.gov/~cline/clp/field_exp/clpx_plan/chapters/CLPX_plan_chap4.htm#4.4.%20GROUND%20DATA.

Data Set Version History

The latest release of snow pit data is Version 2 (v2 in all filenames), current as of 1 June 2004. Previously released copies of files with filenames that do not include "_v2" are obsolete and should be replaced with the v2 copies.

Differences between Version 1 (v1) and Version 2 (v2) files are:

1) IOP1 Pits: some errors leading to erroneous "950" QC codes at North Park were eliminated

2) IOP2 Pits: erroneous 950 QC codes at North Park were corrected

3) IOP3 Pits: erroneous 950 QC codes at North Park were corrected, and during a new QC, a different dominant snow grain type was chosen when two snow grain types were equally present in one snow pit

4) LSOS Pits: IOP2 pits underwent a new QC, and a different dominant snow grain type was chosen when two snow grain types were equally present in one snow pit

5) GBMR Pits: typo in UTME location of pit 4b was corrected

6) All Pits: v2 density, temperature, and stratigraphy profiles contain fields for date, time, and UTM coordinates for every record (these fields were not included in v1 files); v2 files have QC fields in a separate column (in v1 files, the QC values were included at the beginning of the record comment field).

Quality Assessment

The IOP pit data were collected with the strictest levels of quality control, including QC performed in the field, usually within a day of the measurement (this includes the so-called "gamma pits" taken along roadsides in North Park, to coincide with simulataneous airborne gamma overflights).

Snow pit data from other investigations (e.g., LSOS, GBMR) were submitted to NSIDC at a later date, and in some cases were not QC'd and edited until a year after data collection. Although every effort was made to ensure the same quality in measurements, some QC questions have remain unanswered.

Sources of measurement error in the snow pit density data include debris/vegetative matter embedded in the snow pit wall, particularly at or near the bottom of the snow pit, and the practice of "carrying down" the last measured density to the bottom of the pit, when the density cutter could not be used for the lowest measurements. This usually affected the last 10 cm or so, but could affect more, and is indicated in the density profile records with QC code "001". Surveyors did their best to avoid debris in the density cutters, but this situation was not always avoidable, and, where possible, was noted in the surveyors' comments.

Detailed Explanations of Snow Pit QC Codes:

In general:
  codes from   are reserved for QC performed on
  ----------   --------------------------------
  001-099      snow density measurements
  100-199      snow mass measurements ("shallow" pits)
  200-299      snow temperature measurements
  300-399      snow stratigraphy measurements
  400-899      unused
  900-999      general pit information, i.e. header values


Code   Description (what was reset/set/estimated: the reason why)
----   ----------------------------------------------------------
000    QC OK: all tests passed
001    Density value estimated: Surveyor did not measure densities to the ground.
002    Density value calculated from sipre mass: Surveyor used sipre tube instead of density cutter.
003    Reset recorded layer top heights: recorded layer overlapped with layer above.
004    Interpolated layer density: gap in recorded densities.
005    Surveyor entered trace, will be treated as measurement of 0.
105    Surveyor entered trace, will be treated as measurement of 0.
301    Reordered grain sizes from LargeMedSmall:  Relative grain sizes appeared out of expected order.
302    Reordered grain sizes from LargeSmallMed:  Relative grain sizes appeared out of expected order.
303    Reordered grain sizes from MedSmallLarge:  Relative grain sizes appeared out of expected order.
304    Reordered grain sizes from MedLargeSmall:  Relative grain sizes appeared out of expected order.
305    Reordered grain sizes from SmallLargeMed:  Relative grain sizes appeared out of expected order.
310    Reordered grain dimensions from LongShort:  Relative dimensions appeared out of expected order.
311    Reordered grain dims/sizes from LongShort and LargeMedSmall:  Relative grains appeared out of expected order.
312    Reordered grain dims/sizes from LongShort and LargeSmallMed:  Relative grains appeared out of expected order.
313    Reordered grain dims/sizes from LongShort and MedSmallLarge:  Relative grains appeared out of expected order.
314    Reordered grain dims/sizes from LongShort and MedLargeSmall:  Relative grains appeared out of expected order.
315    Reordered grain dims/sizes from LongShort and SmallLargeMed:  Relative grains appeared out of expected order.
320    Grain dims/sizes are ambiguous.
901    Snow pit depth estimated from first density measurement:  Surveyor did not enter pit depth.
902    Snow pit depth estimated from mass measurement depths:  Surveyor did not enter pit depth.
903    Snow pit depth estimated from first stratigraphy depth:  Surveyor did not enter pit depth.
904    Snow pit depth set to 0:  Surveyor did not enter pit depth, no snow measurement taken, but soil samples taken.
905    Warning: Snow pit depth does not match top of density profile.
906    Warning: Snow pit depth does not match top of temperature profile.
907    Warning: Snow pit depth does not match top of stratigraphy profile.
914    Canopy reset to missing value:  Snow depth is 0.
915    Surface roughness reset to n:  Snow depth is 0.
916    Surface wetness reset to missing value:  Snow depth is 0.
917    Canopy height reset to missing value:  Snow depth is 0.
950    Warning: Shallow pit form used, but pit depth > 15 cm.
951    Warning: Deep pit form used, but pit depth < 15 cm.
990    Warning: One or both UTM coordinates are missing.
991    Warning: Missing date and/or time field.
999    No data collected for this pit.

Detailed Explanations:
----------------------
000    QC OK: all tests passed

	No problems were detected, values have not been changed from the
	original forms.

Density QC codes
----------------

001    Density value estimated: Surveyor did not measure densities to the ground.

	The density cutter was 10 cm high, so the final density profile
	was generally not measured all the way to the ground, especially
	in cases where vegetation was present.  This density measurement
	was estimated by carrying the last actual measurement to the
	ground.

002    Density value calculated from sipre tube mass: Surveyor used sipre tube instead of density cutter.

	In some cases, the surveyor used the density profile sheet
	(normally used for density cutter measurements) to record SIPRE
	tube (mass) measurements.  The original measurement is assumed to
	be a mass and has been used to calculate this density.

003    Reset recorded layer top heights: recorded layer overlapped with layer above.

	The recorded density layer overlapped with the layer above it.  In
	order to assure non-overlapping measurements for pit average
	density and SWE, the top height of this layer was reset to the
	bottom height of the layer above it.

004    Interpolated layer density: gap in recorded densities.

	There was a gap in the recorded density layers.  In order to
	assure a continuous set of density measurements for pit average
	density and SWE, this layer was inserted, with a density
	interpolated from the densities of the immediately surrounding
	layers.

005    Surveyor entered trace, will be treated as measurement of 0.

        During IOP3 and IOP4, snow on the ground that was not measurable
        was recorded as a trace, and trace values were included in
        calculated values as zeroes.
	

Mass QC codes
----------------------

105    Surveyor entered trace, will be treated as measurement of 0.

        During IOP3 and IOP4, snow on the ground that was not measurable
        was recorded as a trace, and trace values were included in
        calculated values as zeroes.
	

Stratigraphy QC codes
----------------------

301    Reordered grain sizes from LargeMedSmall:  Relative grain sizes appeared out of expected order.

	The expected order of grain dimensions was short dimension Small,
	Medium, Large followed by long dimension Small, Medium, Large.
	However, when the QC software compared the areas (i.e. ShortSmall
	times LongSmall, etc.) the original values in this stratigraphy
	layer appeared to be reversed (Large, Medium, Small) and have been
	reordered.

302    Reordered grain sizes from LargeSmallMed:  Relative grain sizes appeared out of expected order.

	The expected order of grain dimensions was short dimension Small,
	Medium, Large followed by long dimension Small, Medium, Large.
	However, when the QC software compared the areas (i.e. ShortSmall
	times LongSmall, etc.) the original values in this stratigraphy
	layer appeared to be out of order (Large, Small, Medium) and have
	been reordered.

303    Reordered grain sizes from MedSmallLarge:  Relative grain sizes appeared out of expected order.

	The expected order of grain dimensions was short dimension Small,
	Medium, Large followed by long dimension Small, Medium, Large.
	However, when the QC software compared the areas (i.e. ShortSmall
	times LongSmall, etc.) the original values in this stratigraphy
	layer appeared to be out of order (Medium, Small, Large) and have
	been reordered.

304    Reordered grain sizes from MedLargeSmall:  Relative grain sizes appeared out of expected order.

	The expected order of grain dimensions was short dimension Small,
	Medium, Large followed by long dimension Small, Medium, Large.
	However, when the QC software compared the areas (i.e. ShortSmall
	times LongSmall, etc.) the original values in this stratigraphy
	layer appeared to be out of order (Medium, Large, Small) and have
	been reordered.

305    Reordered grain sizes from SmallLargeMed:  Relative grain sizes appeared out of expected order.

	The expected order of grain dimensions was short dimension Small,
	Medium, Large followed by long dimension Small, Medium, Large.
	However, when the QC software compared the areas (i.e. ShortSmall
	times LongSmall, etc.) the original values in this stratigraphy
	layer appeared to be out of order (Small, Large, Medium) and have
	been reordered.

310    Reordered grain dimensions from LongShort:  Relative dimensions appeared out of expected order.

	The expected order of grain dimensions was 3 short dimensions
	followed by 3 long dimensions, however, original values in this
	stratigraphy layer appeared swapped, and have been reordered.

311    Reordered grain dims/sizes from LongShort and LargeMedSmall:  Relative grains appeared out of expected order.

	A combination of 301 and 310.

312    Reordered grain dims/sizes from LongShort and LargeSmallMed:  Relative grains appeared out of expected order.

	A combination of 302 and 310.

313    Reordered grain dims/sizes from LongShort and MedSmallLarge:  Relative grains appeared out of expected order.

	A combination of 303 and 310.

314    Reordered grain dims/sizes from LongShort and MedLargeSmall:  Relative grains appeared out of expected order.

	A combination of 304 and 310.

315    Reordered grain dims/sizes from LongShort and SmallLargeMed:  Relative grains appeared out of expected order.

	A combination of 305 and 310.

320    Grain dims/sizes are ambiguous.

	The combination of dimensions and grain sizes was ambiguous.
	These grain sizes were left in the order that they were recorded,
	but should probably be treated with care before assuming dimension
	and or size order.

Pit Summary (general mismatches across various fields) QC codes
---------------------------------------------------------------

901    Snow pit depth estimated from first density measurement:  Surveyor did not enter pit depth.

	The pit depth field on the original data sheet was left blank.  It
	has been estimated using the top height of the uppermost density
	measurement.

902    Snow pit depth estimated from mass measurement depths:  Surveyor did not enter pit depth.

	The pit depth field on the original data sheet was left blank, and
	there was no density or stratigraphy profile information.  The pit
	depth has been estimated using the maximum height of the mass
	measurements taken.

903    Snow pit depth estimated from first stratigraphy depth:  Surveyor did not enter pit depth.

	The pit depth field on the original data sheet was left blank, and
	there was no density profile information.  The pit depth has been
	estimated using the top height of the uppermost stratigraphy
	measurement.

904    Snow pit depth set to 0:  Surveyor did not enter pit depth, no snow measurement taken, but soil samples taken.

	The pit depth field on the original data sheet was left blank, and
	there was no density, temperature or stratigraphy profile
	information, but soil samples were taken.  The location is assumed
	to have no snow, and depth has been set to 0.

905    Warning: Snow pit depth does not match top of density profile.

	The pit depth value on the original data sheet is different from
	the top height of the density profile.

906    Warning: Snow pit depth does not match top of temperature profile.

	The pit depth value on the original data sheet is different from
	the top height of the temperature profile.

907    Warning: Snow pit depth does not match top of stratigraphy profile.

	The pit depth value on the original data sheet is different from
	the top height of the stratigraphy profile.

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.

915    Surface roughness reset to n:  Snow depth is 0.

	Measurement protocol was to take a surface roughness photo only
	when snow depth was greater than 0.  In this case a photo was
	taken, but this field was reset to "n" (no) because the snow depth
	was 0.  The roughness photograph at this pit was not deleted,
	however.

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.

917    Canopy height reset to missing value:  Snow depth is 0.

        Canopy height field was introduced (in North Park only) during
        IOP2.  Measurement protocol was to record canopy height only when
        snow depth was greater than 0.  In this case a recorded canopy
        height was reset to missing because the snow depth was 0.

950    Warning: Shallow pit form used, but pit depth > 15 cm.

	Measurement protocol was to use the "shallow" pit form when the
	snow depth was less than 15 cm.

951    Warning: Deep pit form used, but pit depth < 15 cm.

	Measurement protocol was to use the "deep" pit form when the
	snow depth was more than 15 cm.

990    Warning: One or both UTM coordinates are missing.

	Pit coordinates are incomplete or missing.

991    Warning: Missing date and/or time field.

        Date and/or time field are missing.

999    No data collected for this pit.

        Data were not collected at this pit location, due to safety
        hazard, weather conditions, or lack of time.

3. Data Access

CLPX-Ground: ISA Snow Pit Measurements
CLPX-Ground: Snow Measurements at the Local Scale Observation Site (LSOS
CLPX-Ground: ISA Main Meteorological Data
CLPX-Ground: Ground Based Passive Microwave Radiometer (GBMR-7) Data

4. Data Acquisition and Processing

For complete information about the snow pit data sampling protocol, please see the Cold Land Processes Field Experiment Plan Sampling Protocols.

5. References and Related Publications

Please see the References section of the CLPX Plan at http://www.nohrsc.nws.gov/~cline/clp/field_exp/clpx_plan/chapters/CLPX_plan_chap12.htm

ESRI Shapefile Technical Description (http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf)

6. Document Information

List of Acronyms

CLPX = NASA Cold Land Processes Experiment
GBMR = Ground-based Passive Microwave Radiometer
IOP = Intensive Observation Period
ISA = Intensive Study Area
LRSA = Large Regional Study Area
LSOS = Local Scale Observation Site
MSA = Meso-cell Study Area
UTME = Universal Transverse Mercator Coordinates in the Easting Direction
UTMN = Universal Transverse Mercator Coordinates in the Northing Direction

Document Creation Date:

2004-7-20