Ice Chart Colour Standard Proposal

International Ice Charting Working Group

November 2001John Falkingham - Canadian Ice Service

Process to Date

• Ice services asked to provide colour proposals from which a short list of 6 options was prepared

• Ice services voted on these alternatives– 3 options were similar and all ranked equally high

• Ice Services prepared sample ice charts for each of these 3 options

• Following proposal is based on these samples considering comments provided by ice service experts

Some Basic Principles

• Majority said we should have only one international standard colour code and that it should be based on total concentration– proposal has a minor variation on this

• Colour code should be simple; all colours are acceptable

• Colours must be distinguishable even when produced on different media

Open Water (<1 tenth ice)

1-3 tenths ice

4-6 tenths ice

7-8 tenths ice

Ice Free255-255-255

150-200-255

000-255-000

255-255-000

255-150-050

9-10 tenths ice

Fast Ice150-150-150

255-000-000

New ice, dark nilas (If Total Concentration > 8/10)

Light nilas, grey ice (If Total Concentration > 8/10)

255-200-255

255-100-255

Colour Standard ProposalColour is based on Total Ice Concentration Only

except for Young Ice on Leads

Finland

Canada

Russia

86°86°

80°80°

75°75°

70°

70°

65°

65°

65°

65°

115°W100°W

80°W65°W55°W45°W

10°W

5°W

0°10

°E20

°E30

°E40

°E45

°E50

°E60

°E

75°E 95°E 105°E 115°E

140°E155°E

Danish Meteorological Institute

U.S. National Ice Center

Some Problems

• Proposed colour standard is not based on total concentration alone– violet colour for re-frozen leads violates this

principle– clear identification of re-frozen leads is important

to Baltic operators (similar issue exists for Gulf of St Lawrence)

• Is this a deal breaker or is there a compromise possible?

ExamplesFinland

ExamplesNIC

Some Problems (cont)

• Proposed colour standard does not handle Arctic conditions well– 9+/10 concentration is predominant

– differentiation of ice types is important• particularly Multi-Year vs First Year

• Solutions?– additional colour for Multi-Year ice as in Canadian code

– second, completely separate colour code based on ice types instead of concentration

Canadian Practice

86°86°

80°80°

75°75°

70°

70°

65°

65°

65°

65°

115°W100°W

80°W65°W55°W45°W

10°W

5°W

0°10

°E20

°E30

°E40

°E45

°E50

°E60

°E

75°E 95°E 105 °E 115 °E

140°E155°E

86°86°

80°80°

75°75°

70°

70°

65°

65°

65°

65°

115°W100°W

80°W65°W55°W45°W

10°W

5°W

0°10

°E20

°E30

°E40

°E45

°E50

°E60

°E

75°E 95°E 105 °E 115 °E

140°E155°E

Russian Practice

Next Steps• Agreement on colour proposal

• Each ice service produce all of their charts according to the proposed standard for the period January 1, 2002 to October 31, 2002 as internal products only

• Advise colour code working group of any difficulties encountered during this period

• Adjust as appropriate and adopt revised proposal at IICWG in 2002

• Submit to JCOMM Sea Ice Expert Panel for adoption as WMO standard