Data are provided in tab-limited ASCII format.
Surface Temperature Reconstruction from Borehole Temperature Measurement in WDC05A, Version 1
This data set shows the modeled surface temperature reconstruction from an inversion of the 300 m WDC05A borehole at the West Antarctic Divide Ice core site.
NSIDC does not archive these data.
initial release
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Geographic Coverage |
Literature Citation
As a condition of using these data, we request that you acknowledge the author(s) of this data set by referencing the following peer-reviewed publication.
Orsi, A. J., J. P. Severinghaus, et al. 2012. Little Ice Age Cold Interval in West Antarctica: Evidence from Borehole Temperature at the West Antarctic Ice Sheet (WAIS) Divide, Geophysical Research Letters. 39. Art. #L09710. https://doi.org/10.1029/2012GL051260
Detailed Data Description
The data file contains the best reconstruction for several initial conditions, the standard deviation of the reconstruction, based on 6000 solutions, and one solution with high frequency content that also matches the borehole temperature profile. If you are not interested in the details, and only interested in quoting one profile, use the reconstruction presented in column 2, along with the error bar in column 3.
Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/nsidc0638_severinghaus/ directory. Within this directory, there is one file: WAIS_TempReconstruction_300mBorehole.txt.
The data file is 161 KB.
West Antarctic Ice Sheet Divide ice core. WAIS Divide is situated 24 km west of the Ross–Amundsen ice flow divide and 160 km east of the Byrd ice core site.
79.463° South, 112.125° West
Surface elevation at drill site: 1766 m.
Spatial Resolution
Depth resolution is 5 m.
Temporal coverage of this data set is from years 8 to 2007 C.E.
Temporal Resolution
1 year. The meaningful resolution is variable.
Parameter Description
Table 1 describes the data parameters.
Parameter | Description | Units |
---|---|---|
Time | Year | Year C.E. |
Temperature | Best reconstruction with initial temperature –29.7°C | Degrees Celsius |
Error Bar | Error bar of the reconstruction (1 standard deviation, based on 6000 solutions) | Degrees Celsius |
Best reconstructions -29.9°C | Best reconstructions with initial temperature = –29.9°C | Degrees Celsius |
Best reconstructions -29.8°C | Best reconstructions with initial temperature = –29.8°C | Degrees Celsius |
Best reconstructions -29.6°C | Best reconstructions with initial temperature = –29.6°C | Degrees Celsius |
Best reconstructions -29.5°C | Best reconstructions with initial temperature = –29.5°C | Degrees Celsius |
Best reconstructions -29.4°C | Best reconstructions with initial temperature = –29.4°C | Degrees Celsius |
Random possible solution | Random possible solution, which could also fit the data. (obtained using Equation 6 of Orsi et al. 2012) | Degrees Celsius |
Software and Tools
The data file can be opened using any software capable of reading ASCII text files.
Data Acquisition and Processing
Data were collected using an Omega 44033 thermistor with Fluke 8846A multimeter. In the field, the sensor was held stationary every 5 meters to equilibrate with the surrounding temperature for 20 minutes, and the resistance was integrated over 5 minutes. Logging was done both upwards and downwards, with 2 or 3 measurements at each depth (Orsi et al. 2012).
Error Sources
The reconstruction was run over 2000 years (8-2007 C.E.), but the first 1000 years are sensitive to the initialization of the model, so they should not be trusted.
A single Omega 44033 thermistor was connected to a Fluke 8846A precision multimeter using the 4-wire measurement method. The thermistor was calibrated at Scripps Institution of Oceanography against a secondary reference temperature standard, according to the Steinhart-Hart equation. The accuracy of the absolute temperature of this calibration is 0.1 K, and its relative uncertainty in the range of our borehole measurements is 0.0023 K (Orsi et al. 2012).
References and Related Publications
Contacts and Acknowledgments
Anais J. Orsi and Jeffrey P. Severinghaus
Scripps Institution of Oceanography
Geoscience research division #0244
9500 Gilman Drive
La Jolla, CA 92093-0244
NSF Grant Title: Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate. NSF Grant Numbers: 04-40701 and 05-38657.
Document Information
Document Creation Date
04 June 2015
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