In‐situ infrasonic calibrations at Windless Bight, Antarctica.

Abstract

The array elements at the Comprehensive Nuclear‐Test‐Ban Treaty Organization (CTBTO) infrasound station I55US (Windless Bight, Antarctica) are covered with more than a meter of snowfall each year between maintenance visits. During these service trips, in the austral summer, the microphones and their attached wind reduction pipe arrays are brought back to the surface of the Ross Ice Shelf snow. During the November 2010 maintenance visit, an in‐situ calibration reference microphone system was used in an attempt to characterize the effect of this compacted snow layer on the performance of the wind reducing elements associated with each microphone. In order to accomplish this, measurements were taken before and after the digging at certain elements. Additionally, one element was measured before and after a meter of fresh snow fell on the dug‐up sensor and pipes. This presentation will address the basic technique, developed for the CTBTO arrays, our results, and broader potential applications.