@article{3b91b499712a4eac837c29d6f0b4e91d,
title = "Cryoegg: Development and field trials of a wireless subglacial probe for deep, fast-moving ice",
abstract = "Subglacial hydrological systems require innovative technological solutions to access and observe. Wireless sensor platforms can be used to collect and return data, but their performance in deep and fast-moving ice requires quantification. We report experimental results from Cryoegg: a spherical probe that can be deployed into a borehole or moulin and transit through the subglacial hydrological system. The probe measures temperature, pressure and electrical conductivity in situ and returns all data wirelessly via a radio link. We demonstrate Cryoegg's utility in studying englacial channels and moulins, including in situ salt dilution gauging. Cryoegg uses VHF radio to transmit data to a surface receiving array. We demonstrate transmission through up to 1.3 km of cold ice-a significant improvement on the previous design. The wireless transmission uses Wireless M-Bus on 169 MHz; we present a simple radio link budget model for its performance in cold ice and experimentally confirm its validity. Cryoegg has also been tested successfully in temperate ice. The battery capacity should allow measurements to be made every 2 h for more than a year. Future iterations of the radio system will enable Cryoegg to transmit data through up to 2.5 km of ice.",
keywords = "Glacier hydrology, glaciological instruments and methods, subglacial processes",
author = "Prior-Jones, {Michael R.} and Bagshaw, {Elizabeth A.} and Jonathan Lees and Lindsay Clare and Stephen Burrow and Werder, {Mauro A.} and Karlsson, {Nanna B.} and Dorthe Dahl-Jensen and Chudley, {Thomas R.} and Poul Christoffersen and Wadham, {Jemma L.} and Doyle, {Samuel H.} and Bryn Hubbard",
note = "This work was funded by UK Engineering and Physical Sciences Research Council (EPSRC) New Investigator Award EP/R03530X/1, awarded to E.A.B. We thank all who assisted us in the field, in particular: Trevor Popp, Romain Duphil and the EastGRIP drill team; {\textquoteleft}Mickey{\textquoteright} MacKay, Eliza Dawson and Rob Law at the RESPONDER site; Lai Bun Lok, Jonathan Hawkins, the ETH Z{\"u}rich VAW Glaciology team and the Swiss Air Force at the Rh{\^o}ne Glacier site. Phil Anderson gave us the use of the RF test chamber. We are grateful for in-kind contributions of equipment from Quadro and Radiocrafts. We thank the team at DGF Engineering for the machining of the caseworks, Protronix EMS Ltd for the rapid production of the electronics, and Justin Johnson of InnovAntennas for the custom design of the receiving antenna. Miles Gould provided assistance with the algebra for Eqn (3). We thank our anonymous reviewers for their helpful contributions and suggestions. EastGRIP is directed and organised by the Center of Ice and Climate at the Niels Bohr Institute. It is supported by funding agencies and institutions in Denmark (A. P. M{\o}ller Foundation, University of Copenhagen), USA (US National Science Foundation, Office of Polar Programs), Germany (Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research), Japan (National Institute of Polar Research and Arctic Challenge for Sustainability), Norway (University of Bergen and Bergen Research Foundation), Switzerland (Swiss National Science Foundation), France (French Polar Institute Paul-Emile Victor, Institute for Geosciences and Environmental research) and China (Chinese Academy of Sciences and Beijing Normal University). B.H. acknowledges support for hot-water borehole drilling from HEFCW through a Capital Equipment Grant awarded to Aberystwyth University, and from the NERC through grant NE/K006126. The RESPONDER project is funded by a Consolidator Grant to P. C. from the European Research Council, under the European Union's Horizon 2020 research and innovation programme (Grant 683043). T.R.C. was supported by a Natural Environment Research Council Doctoral Training Partnership Studentship (Grant NE/L002507/1). ArcticDEM was created from DigitalGlobe, Inc., imagery and funded under National Science Foundation awards 1043681, 1559691 and 1542736. Publisher Copyright: {\textcopyright} The Author(s), 2021. Published by Cambridge University Press.",
year = "2021",
month = aug,
day = "1",
doi = "10.1017/jog.2021.16",
language = "English",
volume = "67",
pages = "627--640",
journal = "Journal of Glaciology",
issn = "0022-1430",
publisher = "Cambridge University Press",
number = "264",
}