Application of collected data
Presentations at the DBCP Technical Workshop
Buenos Aires, Argentina, 17-18 October 2005

Theme 3: Vision and Possibilities / Technological Developments

16. A Novel Ice-Drifting Platform for Deployment During the International Polar Year 

Author: David Meldrum

Abstract: The International Polar Year in 2007-8 is giving birth to a number of large international programmes aimed at better understanding the cryosphere and its interaction with climate change. Within the UK, we have proposed a basin-wide study of the Arctic Ocean, using a large Canadian icebreaker as the vehicle for a number of experiments and deployments. A key component of this work will be the deployment of a number of autonomous CTD and ice mass balance stations. The free-drifting stations, tracked by GPS, will make observations of key environmental parameters above, within and immediately below the ice, and will feature a novel autonomous CTD package for making full-depth hydrographic measurements. In addition to meteorological and solar radiation measurements, thermistor chains will be frozen into the ice: one to measure the diffusive heat flux within the floe, the other two to infer the position of the ice-water and ice-air interfaces respectively. These latter chains will also be operated in a 'hot-wire anemometer' mode to estimate boundary layer water and air speeds. Daily CTD profiles will be performed using a sensor package attached to an autonomous winch. The winch will lower the CTD from just below the ice to full ocean depth, using knowledge of its GPS position to consult a bathymetric look-up table. Data transfer between the CTD and the surface will be accomplished using an infra-red transceiver suspended below the ice. These measurements will be used to support oceanic heat flux determinations and to provide information on the halocline and deeper ocean. The equipment will be powered for up to two years using conventional alkaline cells backed up by solar panels and lead-acid batteries. A webcam at each site will record twice-daily images of surface conditions. Data, commands, image 'thumbnails' and diagnostics will be transmitted in near real time via the Iridium satellite system, with the option to request full-resolution images as required.