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THERMAP: Antarctic Shallow Firn Temperature Data
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Data set description paraphrased from:
Richard P. Goldthwait
USNC-IGY Antarctic Glaciological Data, Field Work 1957 and 1958
Report 825-1-Part II, December 1958
Ohio State University Research Foundation
Englacial temperatures were obtained by using a series of thermohm cables and direct reading Leeds-Northrup Wheatstone bridge during the Wintering over a period of 1957 at Byrd Station. Approximately 100 meters from the depths of .5, 1, 2, 4, 8, and 16 meters. A thermohm was lowered to the bottom of each hole. The hole was then filled with loose surface snow and packed as solid as possible by tamping with lengths of augering extension pipes. The thermohm cables were connected to a selector switch which enabled the observer to obtain all the temperature readings merely by connecting the Wheatstone bridge to the selector switch and turning through the positions on the switch. A seventh thermohm was included to record the surface snow temperature. This surface measurement was made by depressing the thermohm s sensitive element into and just below the snow surface. The selector switch was housed in a snow tight box which stood on a pedestal rising about one meter above the surface.
The thermohms were emplaced May 3, 1957 and readings were begun on May 6. By the end of October 1957, 30 cms of snow had accumulated. Therefore, when viewing the temperature record, a gradual increase in all thermohm depths should be considered, with exception for the surface element which was rest at the surface.
View Map of Byrd Firn Temperature Site
Data set description paraphrased from:
John Pirrit and George A. Doumani
IGC Antarctic Glaciological Data, Field Work 1959
Report 968-2, January 1961
Ohio State University Research Foundation
The system of thermohms set up by V. H. Anderson in 1957 is still in operation, and at the same place relative to Byrd Station. The same methods were followed in 1959 in using the Wheatstone bridge and the selector switch.
Daily readings were obtained whenever possible. Toward the end of the winter months, enough snow had accumulated to endanger the selector switch box. The box was removed, and seven new cables, each 40 inches in length, were spliced to the original ones. This operation resulted in a change in the order of depths relative to the selector switch. The new system was posted on the cover of the box, and a record of it was kept in all glaciological reports left at the station.
The surface thermohm readings may not be reliable as the surface thermohm was buried under one meter of snow by the middle of September. A check was the Weather Bureau revealed that their surface thermohm also has been erroneous. It was dug out on 15 September and a noticeable change in readings was observed. Thus, one meter was added to the original depths of the thermohms. The present depths should read 1 (surface, previously), 1.5, 2, 3, 5, 9, and 17 meters respectively.
The table below shows the original depths, and the present depths, relative to the respective selector-switch numbers:| Selector Switch: | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| Original Depth: | 0.5 | 1 | 2 | 4 | 8 | 16 | Surface |
| Present Depth: | 1.5 | 2 | 17 | 3 | 9 | 5 | 1 |
