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Hot summer, cold topic

Aug 15, 2012

For most folks in the continental U.S., 2012 has featured one of the hottest summers on record. So it may seem a little unusual at this time of year to focus on the topic of sea ice. It is important to remember, though, that the season for icebergs in the North Atlantic runs from the spring through the summer, and that there are other areas open to ocean voyagers where ice is a concern at all times of the year.

Figure 1

The most famous of all ice-related maritime disasters, the sinking of Titanic, gave rise to the International Ice Patrol, which is responsible for monitoring the ice conditions for the major shipping lanes of the Atlantic to the east and southeast of Newfoundland. Originally, the only reports came from ships which were required to report any sightings of ice after the Titanic sinking. In more recent years, though, the region is regularly patrolled by aircraft, and satellite data is also used to provide a more comprehensive picture of the ice conditions.

The International Ice Patrol is administered by the U.S. Coast Guard, but ice conditions are also monitored by other governments with interests in maritime navigation in waters prone to ice. In particular, the Canadian Ice Service monitors all of their coastal waters from the Maritime Provinces through their Arctic regions. In fact, the Canadian Ice Service and the International Ice Patrol collaborate to issue a single, daily ice chart under the moniker of the North American Ice Service (Fig. 1).

The Canadian Ice Service issues many other ice charts covering their vast coastal regions prone to ice. Each of these charts shows in detail all the areas of ice, giving information about the concentration and types of ice. The World Meteorological Organization’s “egg code” is used on the charts to display this information, and there is a separate document which provides the information necessary to decode the data. Fig. 2 is an example of a Canadian Ice Service chart.

Figure 2

The Canadian Ice Service also provides information for the Great Lakes, but there is a U.S source for this information as well. The National Oceanic and Atmospheric Administration’s National Ice Center provides Great Lakes information along with information for ice in other U.S. coastal waters, and for icebergs around Antarctica. Ice information for the Bering Sea and other North Pacific areas prone to ice can be accessed from the National Ice Center as well.

The government of Norway provides charts for ice conditions in the high latitudes of the eastern Atlantic from Greenland east to Scandinavia including the waters around Iceland. An example of one of their charts is shown in Fig. 3.

Ice is of concern to mariners for many reasons, including the obvious reason that vessels can be damaged by running into it, perhaps to the point of losing the vessel. There are other consequences of the presence of ice, including a greater frequency of fog where ice is present since the ice will cool the lower portion of the atmosphere, and when warm and moist air moves over ice, this will result in the air cooling to its dew point and the development of fog. Therefore if fog is sighted at a distance in ice-prone waters, it may be a sign that the concentration of ice in that direction is greater. The presence of ice will also tend to reduce waves and swell since the wind will not be able to act on the surface of the water. This means that downwind of areas where a good deal of ice is present, sea states are likely to be less than they otherwise would, and this can be a sign to an observant mariner that significant ice may be present to windward.

Figure 3

Note that all of the charts accompanying this newsletter are fairly current at the time of its writing (early August 2012). This is an indication that ice is often still present at this time of year, and in fact one of the reasons for my choice of this topic at this time is that I have a client currently voyaging on the Davis Strait whose itinerary has been altered by the presence of ice along the coast of Baffin Island.

If you are looking for an ocean voyage to escape from the summer heat, you have options!

Websites of interest:

International Ice Patrol:

Canadian Ice Service:

National Ice Center (NOAA):

Norwegian Meteorological Institute ice page:

Egg Code (Canadian Ice Service version can also be found on NOAA site):

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