Manice - Chapter 5
5.4 Daily Iceberg Analysis Chart
5.4.1 Description
These charts are important to shipping and fishing vessels as well as the tourism industry. They assist them in determining the limit of all known icebergs on Canada's east coast.
5.4.2 Method of Production
Iceberg analysis charts are generated with the use of mapping software (GIS). The system allows the forecaster to model the position of icebergs and targets that were visually or remotely sited up to 40 days prior. The forecaster can use reports from ships, land stations, and radar satellites, but mostly relies on dedicated iceberg flights using fixed wing aircraft. The individual iceberg information is entered into the modelling database, where currents, wind and water temperature and other factors are applied to estimate the iceberg position and size at the time of the chart valid time.
5.4.2.1 Valid Time
The Iceberg Analysis charts have a valid time of 1200 UTC. The chart represents the iceberg conditions at 1200 UTC on the date that it is issued.
5.4.2.2 Corrections and Amendments
If a correction is warranted, then the chart is re-issued but with the same valid time as the original. There would be nothing on the chart to indicate that it is a correction. Amendments are not issued. If an iceberg is sited outside the iceberg limit, then a bulletin is issued to notify mariners. The chart will not be re-issued.
5.4.2.3 Chart Legend
A legend is used on the daily iceberg analysis charts to detail the valid date and time of the chart. When the International Ice Patrol (IIP) is in operation, there is a note that the iceberg limit and the distribution of icebergs in the vicinity of the limit south of 52N is estimated by the IIP. The initials of the forecaster who produced the chart will be in the bottom right corner of the legend.
5.4.2.4 Deadlines
The transmission deadline is 1700 UTC.
5.4.3 Dissemination of Charts
Daily iceberg analysis charts are disseminated electronically via a product delivery system. Clients may receive the chart via e-mail, fax or the internet.
5.4.4 Symbols used on the Daily Iceberg Analysis Charts
Iceberg Limit
Known icebergs in the Atlantic located landward (north and west) of the iceberg limit. |
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Iceberg Limit in the Gulf of St Lawrence
Known icebergs in the Gulf of St Lawrence are located east of this line. |
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Sea Ice Limit
Landward of this line is the location of sea ice of any concentration. Exception: Sea ice in the Gulf of St Lawrence is not usually depicted on the iceberg chart. |
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Known Data Limit
This line depicts the iceberg coverage of the most recent dedicated iceberg flight. This limit is moved southward with the icebergs as they drift. South of this line there is more confidence in the position and number of icebergs than to the north. |
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| This number represents the number of icebergs within that degree square. Growlers and/or bergy bits are not included in the count but may be present anywhere within the limit.
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5.4.5 Area of Coverage
The iceberg analysis chart covers icebergs located in waters east and southeast of Newfoundland and Labrador, as well as in the Gulf of St Lawrence. There are two chart extents. The northern extent is used most of the year and shows icebergs between about 45N and 61N. The southern extent is used when the International Ice Patrol (IIP) is in operation. It shows icebergs that are between about 40N and 57N. On rare occasions when the iceberg limit is south of 40N, then a text message on the chart will describe the latitude and longitude of the points not seen on the chart.
5.4.6 Notes on the Role of the International Ice Patrol (IIP)
The IIP was established after the sinking of the Titanic to monitor and report icebergs for Atlantic shipping. While CIS monitors icebergs year-round, IIP usually begins operations when icebergs cross 48ºN latitude. This is usually in the late spring. When IIP is in operation they are responsible for determining the iceberg limit south of 52N. At this time CIS uses the same iceberg limit as IIP for the daily iceberg chart and maintains the limit north of 52N.
