Who: Environment and Climate Change CanadaWhat: Collect lake ice thickness and composition data including white ice, black ice, on ice snow depth and hydrostatic water level. Work is completed by a team of a 2 to 3 people using an ice auger and measurement stick. Sample location latitude and longitude geocoordinates from previous years ice survey are identified using a handheld GPS Global Positioning System. Lake is accessed by snowmobile.Why: Climate change is projected to cause significant change to arctic aquatic ecosystems. Changes in the thickness and composition of arctic lake ice covers will produce second order impacts on lake biological productivity and ecology. The most important effects are likely to result from changes in temperature (ice growth) and precipitation (ice cover composition). While a number of models have been developed to model these changes, their validation has been stalled by lack of relevant field data.Annual surveys obtain in situ measurements of lake ice including the depth of white ice (i.e. slush ice, snow ice, grey ice) and black ice (i.e. blue ice, clear ice, congelation ice). Also collected will be the depth of snow on the ice. Measurements will occur during a single visit to the lake sites at approximately the time of peak ice thickness and prior to significant pre-breakup melt and decay. To obtain a representative sample across the latitudes of Canada, this project includes annual surveys at lake sites in the Northwest Territories, Manitoba and Ontario. The annual data is uploaded to government of Canada open data portal.Where: Lower Dumbell Lake, Alert, Ellesmere Island and Lake Hazen, Quittinirpaaq National Park, Ellesmere IslandWhen: Lower Dumbell Lake data is collected during Canadian Ice Service weekly ice thickness measurements from March to then end of the ice season. Lake Hazen data is collected by Parks Canada staff within the May-June period. Work is scheduled to continue for year 2025 onwards. Data has been collected since 2009 and is available on the Government of Canada open data portal Lake Ice Database: https://open.canada.ca/data/en/dataset/05d08819-75b8-4f77-8688-aca5e7cce8ad(copy also attached at .docx)