Ijskaarten

Ijskaarten, or ijskaarten in Dutch, are graphical representations of sea ice conditions for a defined region and time. They depict the extent and concentration of sea ice, typically shown as ice cover in percentages or tenths, and may also indicate ice type and age. In addition to the ice edge, many plots include information about open water leads, and, when available, predicted ice conditions for future days.

Creation and data sources: Ijspi charts are produced by national meteorological and hydrological services and specialized ice centers, such as national weather services and oceanographic institutes. They rely on a blend of satellite observations (including passive microwave and synthetic aperture radar), aerial or ship reports, buoy data, and numerical weather and sea-ice forecasts. Experienced analysts interpret the data to delineate the ice edge and classify ice characteristics before publishing the final map. Ice charts can be distributed as static images, digital vector layers, or interactive web maps.

Contents and format: Typical features include the satellite-derived ice edge, ice concentration contours, and, when possible, information about the age or type of ice (for example, first-year versus multiyear). Some charts also indicate thickness ranges where measurement is available and highlight ice leads or areas of open water. The charts are released on a daily basis or more frequently in periods of rapid change and may be tailored to specific regions, such as Arctic seas or northern ocean routes.

Usage and purpose: Ijiskaarten are primarily used for navigation safety and route planning by mariners, port authorities, and offshore operators. They also support scientific research on sea-ice dynamics and are a key tool in meteorological and climatological monitoring of polar regions.