Input variables: Meteorological

Table 5 Summary of environmental variables. Shaded blocks indicate vari-

ables used in NSRSIM01.

Apr

Jun

Aug

Oct

Sea Ice

Ridges

Fog

Icing

1

Snowstorms

1, 4

Permanent Ocean

Currents

Wind induced

Height

Waves

Frequency

1

Winds

Temperature

2

Diurnal

4

Tides

Storm surge

2, 4

Darkness

3

Notes: 1. Insufficient data.

2. Impact accounted for by other factors.

3. 24 hours of daylight assumed for June.

4. Not a significant factor at most data points.

visibility (as affected by fog, rain, snowstorm, and

Input variables: Meteorological

Table 5 shows the environmental parameters

duration of daylight).

that were considered when we designed NSRSIM01.

Wind

Shaded cells indicate those variables that are cur-

rently used, and the notes explain why others were

The available wind regime information was not

not used.

adequate to make a statistical description of the

Three major meteorological phenomena that can

wind speed and direction. We therefore used a

impede commercial navigation are addressed in

geostrophic wind model (Gill 1982) to simulate

the wind regime over the Arctic Ocean with a space

the model. These are wind (both speed and direc-

resolution of about 50 km. Simulations of wind

tion), vessel topside icing (due to the combined

were initialized and started from rest on 1 January

influences of cold air and water temperatures, di-

rection and speed of the wind, direction and speed

1946, and run for 43 years until 31 December 1988,

of the ship, and state of the sea), and horizontal

using daily surface atmospheric pressure data from

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