Acoustic travel time and hydrostatic pressure measurements from Sermilik Fjord, southeastern Greenland, 2011-2016

• Main Author: Andres, Magdalena
• Format: Dataset
• Language: English
• Published: NSF Arctic Data Center 2017
• Subjects: Greenland; Sermilik
• Online Access: https://dx.doi.org/10.18739/a2xk84q8c; https://arcticdata.io/catalog/view/doi:10.18739/A2XK84Q8C

This project will develop and test a non-traditional method to measure the time-varying heat content and vertical temperature profile in high-latitude seas, shelves, and fjords using pressure-sensor-equipped inverted echo sounders (PIES). PIES, which are installed on the seafloor below the reach of destructive iceberg keels, present a promising and inexpensive way to improve understanding of fjord dynamics and shelf-fjord interactions and will increase long-term monitoring capabilities in high latitudes where remoteness and harsh conditions hamper traditional in situ observation techniques. The use of PIES to characterize variability at high latitudes is a novel repurposing of an existing technology, but rests on the same principle as the traditional blue-water uses for PIES: due to the dependence of sound speed on temperature, the surface-to-bottom round-trip acoustic-travel-time associated with reflections between the PIES and the air-sea interface is an excellent proxy for heat content in the intervening water column. Furthermore, since reflections from seawater-ice interfaces are also detected when ice is present, PIES also provide a means to characterize the ice component in high-latitude systems. The PIs propose to develop these methods with existing PIES data collected in a 1-year test deployment in Sermilik Fjord in eastern Greenland and with observations to be collected in a 2-year deployment of three PIES in the fjord and on the nearby shelf.