Collaborative Research: Laboratory Studies of Isotopic Exchange in Snow

Summary

This data set contains sublimation rate data from laboratory studies of snow. Parameters include flow rate, measured sublimation rate, and theoretical maximum sublimation rate. Data were collected in cold rooms at the Cold Regions Research and Engineering Laboratory (CRREL), in Hanover, NH, during 2005 and 2006. The data were collected as part of a collaborative research project. The project aims to develop a quantitative understanding of the processes active in isotopic exchange between snow/firn and water vapor, which is important to Antarctic ice core interpretation.

Data are available via FTP in Microsoft Excel (.xls) format.

Citing These Data

The following example shows how to cite the use of this data set in a publication. For more information, see our Use and Copyright Web page.

The following example shows how to cite the use of this data set in a publication. List the principal investigators, year of data set release, data set title, publisher: NSIDC, and digital media.

Neumann, Thomas A. 2009. Collaborative Research: Laboratory Studies of Isotopic Exchange in Snow. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N51834DX.

Overview Table

Category	Description
Data format	Microsoft Excel Spreadsheet (.xls)
Spatial coverage and resolution	Southernmost Latitude: 43°N Northernmost Latitude: 43°N Westernmost Longitude: 72°W Easternmost Longitude: 72°W
Temporal coverage and resolution	Data were collected in 2005 and 2006.
File naming convention	sub_rate_data.xls
File size	The data file is 32 KB.
Parameter(s)	Flow Rate Measured Sublimation Rate Theoretical Maximum Sublimation Rate
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)

Dr. Thomas Neumann
Cryospheric Sciences Branch
NASA Goddard Space Flight Center
Greenbelt, MD 20770

Technical Contact

Acknowledgements

This research was supported by National Science Foundation (NSF) Office of Polar Programs (OPP) grant number 0338008.

2. Detailed Data Description

Format

Data are in Microsoft Excel (.xls) format.

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/neumann_nsidc_0445/ directory. The data set consists of one Microsoft Excel spreadsheet, sub_rate_data.xls.

File Naming Convention

The file, sub_rate_data.xls contains laboratory measurement data of snow sublimation rates.

File Size

The data set is 32 KB.

Spatial Coverage

Snow was collected outdoors, and processed in the Cold Regions Research and Engineering Laboratory in Hanover, New Hampshire, USA.

Southernmost Latitude: 43°N
Northernmost Latitude: 43°N
Westernmost Longitude: 72°W
Easternmost Longitude: 72°W

Temporal Coverage

Data were collected in 2005 and 2006.

Parameter or Variable

This data set contains snow sublimation rate data, measured under specified temperatures in a laboratory setting.

Parameter Description

Table 1. Description of Parameters in the sub_rate_data.xls File

Parameter	Description
Flow rate (SLPM)	Measured flow rate in standard liters per minute
Measured sublimation rate	Measured sublimation rate in kilograms per second
Theoretical maximum sublimation rate	Theoretical maximum sublimation rate, in kg per second
Mass-transfer coefficient	Mass-transfer coefficient (meters per second) was calculated as a function of Reynolds Number.

Sample Data Record

Sublimation Rate Data
T = -5C	flow rate (SLPM)			9.64E-01	1.76E+00	3.69E+00	8.12E+00
	measured sublimation rate			5.12E-08	8.87E-08	1.64E-07	3.26E-07
	theoretical maximum sublimation rate			5.64E-08	9.43E-08	1.82E-07	3.79E-07

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The data set is 32 KB.

Software and Tools

Data are accessible using spreadsheet software.

Related Data Collections

• Studies of Isotopic Exchange in Snow: Snow Accumulation and Snow Melt in a Mixed Northern Hardwood-Conifer Fores (NSIDC-0441)

4. Data Acquisition and Processing

Theory of Measurements

Data consists of sublimation rate measurements at a specified, fixed temperature. Samples consisted of approximately 100-gram sieved snow samples of a specific grain radius that had dry air drawn through them at specified flow rates. Measured flow rates were compared with theoretical maximum sublimation rates to assess the degree to which equilibrium was achieved. The mass transfer coefficient was determined from the measured sublimation rates. These data are expressed as a function of Reynolds number, and are provided in the spreadsheet.

Sensor or Instrument Description

For details of laboratory setup and instrumentation, see Neumann et. al., 2009.

Derivation Techniques and Algorithms

The Mass-transfer coefficient (hm) was derived as a function of Reynolds Number (Re). Calculations were done assuming all sublimation happens in approximately 4 mm of the sample thickness. Other values of hm for 1 mm and 1 cm are given in Neumann et. al., 2009.

5. References and Related Publications

Neumann, T. A., M. R. Albert, C. Engel, Z. Courville, and F. Perron. 2009. A Revised Method of Calculating Snow Sublimation Rate Based on Laboratory Experiments and Mass-Transfer Theory. International Journal of Heat and Mass Transfer, 52, 309-315.

Neumann, T. A., M. R. Albert, R. Lomonaco, C. Engel, Z. Courville, F. Perron. 2008. Experimental Determination of Snow Sublimation Rate and Stable Isotopic Exchange. Annals of Glaciology, v.49, 1-6.

The following related documents are available on the NSIDC Web site:

Table 2. Related Documents

Document	Description	URL
Antarctic Glaciological Data Center	Data Center Web site	http://nsidc.org/agdc/

6. Document Information

Acronyms

The following acronyms are used in this document.

Table 3. Acronyms and Abbreviations

Acronym	Description
FTP	File Transfer Protocol
HM	Mass-transfer coefficent
NSIDC	National Snow and Ice Data Center
URL	Uniform Resource Locator
RE	Reynold's Number
.XLS	Microsoft Excel File Format

Document Creation Date

4 January 2010

Document URL

http://nsidc.org/data/docs/agdc/nsidc0445_neumann/index.html