In order to understand ice formation and the types of ice in the Great Lakes, the NOAA Great Lakes Environmental Research Laboratory (GLERL) and the U.S. Coast Guard use Synthetic Aperture Radar (SAR) data from the NOAA CoastWatch Great Lakes Node to monitor six different types of ice, ice thickness, and ice cover. This risk assessment tool is known as the Ice Condition Index (ICECON). The U.S. Coast Guard uses ICECON to identify areas that require ice breaking operations and ship transit assistance. These ice breaking operations allow government and commercial ships to travel through the Great Lakes unobstructed.
Satellite SAR Ice Type ICECON Scale
| ICECON Categories | Description Example Ice Types | Thickness | Color | Impacts to Vessels |
|---|---|---|---|---|
| 0 | Calm Water (or below noise floor) | 0″ | Blue | No Ice present or imminent. |
| 1 | New Lake Ice | <2″ | Green | Minimum ice concentrations and thickness, Does not present hindrance to commercial navigation. |
| 2 | Pancake Ice | 2″ – 6″ | Yellow | Light Ice conditions present. Still open water areas. May be some hindrance to less ice-capable ships. |
| 3 | Consolidated Flows | 6″ – 12″ | Orange | Light-to-moderate ice conditions present. Less ice-capable ships may need icebreaker assistance for transit and /or be at risk for damage. |
| 4 | Lake Ice w/patchy crusted snow Snow/SnowIce/LakeIce | Up to 28″ | Moderate-to-Heavy Ice conditions present. All Commercial ships may require ice breaker assistance for transit. | |
| 5 | Brash | >28″ Up to 9-11m | Red | Heavy-to-extreme ice conditions. All transits require icebreaker escort. Approaching or exceeds capabilities of light icebreaker assets. Increased risk of damage to vessels. |