Manual of Ice (MANICE): chapter 4


Chapter 4: Iceberg Messages

This chapter describes the iceberg information depicted on the observed ice chart as generated from either a ship or an aircraft in a message format.

Since Canada is in the northwestern quadrant of the globe, please note that all latitudes and longitudes are degrees North and West respectively. Also note that all times are in Coordinated Universal Time.

4.1 Iceberg Coding and Message Preparation

An iceberg reporting code has been developed by the Meteorological Service of Canada and International Ice Patrol, to allow for exchange of digital iceberg information and to enable computer-assisted manipulation of volumes of iceberg observations into one complete iceberg analysis. The iceberg code follows standard coding practices and iceberg nomenclature of the World Meteorological Organization and supplements codes that exist in World Meteorological Organization. It provides for the reporting of all iceberg parameters, the area of surveillance and the factors that influence both visual and radar iceberg detection.

Listed below is the basic format for the iceberg message, with the following sections describing each component. Notes referred to in the code descriptions appear in Section 4.3 (following the Iceberg Coding Tables section).

Iceberg Message:

IBXXN CCCC YYGGgg
PPPP PtNrNrNrNr YYMMJJ

00000
QcLaLaLaLaL a LoLoLoLoLo ZGGgg 1CsAAA 2VIVI 3RlRlRlRrRrRr 4DsDsHsHs

11111
(SSSS) (IdIdIdId) CIGGgg LaLaLaLaLa LoLoLoLoLo 01CiSiSh
(1ClLEN 2ClWID 3ClHEI 4ClDRA 5ClDIR 6ClSPE)

22222
(SSSS) CIGGgg LaLaLaLaLa LoLoLoLoLo NtNtDrr nnCiSiSh (nnCiSiSh)

33333
CIGGgg LaLaLaLaLa LoLoLoLoLo LaLaLaLaLa LoLoLoLoLo nnnnD ( nnnnD)

44444
CIGGgg LaLaLaLaLa LoLoLoLoLo (1mamamomo) 2NtNtNtD nnCiSiSh (nnCiSiSh)

55555
(SSSS) CIGGgg LaLaLaLaLa LoLoLoLoLo (1DvDvVvVv) (2NvNvrr)

Note:

Note

Groups 00000 to 55555 can be repeated as often as necessary.

4.1.1 Iceberg Message Header

Sample iceberg message header:

IBXXN CCCC YYGGgg
PPPP PtNrNrNrNr YYMMJJ

This section is mandatory for all iceberg messages.

Table 4.1: Iceberg Message Header

Symbol Description Code Table
IB Indicator for an iceberg message  
XX Nationality of iceberg message Note 1
N Figure to indicate source of iceberg message Note 2
CCCC International call sign for the location from which the iceberg message was transmitted Note 3
YY Day of month that the message was transmitted  
GG Hour that the message was transmitted  
gg Minute that the message was transmitted  
PPPP 4 figure or 4 letter platform identifier Note 4
Note 13
Note 26
Pt Platform type Table 4.14
NrNrNrNr Consecutive iceberg message number from this platform Note 5
YY Day of the month that the message begins Note 6
MM Month of the year that the message begins Note 6
JJ Last digit of the year that the message begins Note 6

4.1.2 Track Information

Sample track information message:

00000
QcLaLaLaLaLa LoLoLoLoLo ZGGgg 1CsAAA 2VIVI 3RlRlRlRrRrRr 4DsDsHsHs

This section is mandatory for icebreakers and aircraft. (Note 7, p. 4-13).

Table 4.2: Track Information

Symbol Description Code Table
00000 Indicator that track information follows  
Qc Quadrant of the Globe (usually 7) Table 4.11
LaLaLaLaLa Latitude in degrees and minutes at the start of each leg Note 8
Note 9
LoLoLoLoLo Longitude in degrees and minutes at the start of each leg Note 8
Note 9
Z Time indicator  
GG Time in hours at the start of each leg  
gg Time in minutes at the start of each leg  
1 Indicator for general sea ice and altitude group  
Cs Code for general sea ice distribution Table 4.12
AAA Altitude of platform in hundreds of feet  
2 Indicator for visibility group  
VIVI Visibility left of track in nautical miles Note 10
VrVr Visibility right of track in nautical miles Note 10
3 Indicator for radar group  
RlRlRl Radar range to left of track in nautical miles Note 10
RrRrRr Radar range to right of track in nautical miles Note 10
4 Indicator for wave or swell group Note 11
DsDs Direction (to nearest 10 degrees) from which is generated the predominant wave or swell  
HsHs Height of predominant wave or swell in half metres  

4.1.3 Individual Observations

Sample of individual observation message:

11111
(SSSS) (IdIdIdId) CIGGgg LaLaLaLaLa LoLoLoLoLo 01CiSiSh
(1ClLEN 2ClWID 3ClHEI 4ClDRA 5ClDIR 6ClSPE
)

Table 4.3: Individual Observations

Symbol Description Code Table
11111 Indicator that iceberg observations by individual position follows Note 12
SSSS Optional group used by Ice Operations Centres and by the offshore industry Note 13
Note 26
IdIdIdId Optional groups used by offshore industry to report consecutive iceberg number Note 14
I Optional groups used by offshore industry to indicate iceberg mobility Note 14
CI Confidence level/Method of observation Table 4.13
Note 15
GG Time in hours that observation was made Note 16
gg Time in minutes that observation was made  
LaLaLaLaLa Latitude of the individual observation in degrees, minutes and tenths of a
minute
 
LoLoLoLoLo Longitude of the individual observation in degrees, minutes and tenths
of a minute
 
01 Indicator for single iceberg report  
Ci Concentration of sea ice immediately at the iceberg position Table 4.10
Note 17
Si Size of iceberg Table 4.8
Note 18
Sh Shape of iceberg Table 4.9
Note 18
1ClLEN
2ClWID
3ClHEI
4ClDRA
5ClDIR
6ClSPE

Optional groups to report iceberg length (LEN), width (WID), height
(HEI) and draft (DRA), in whole metres, direction (DIR) of iceberg drift
(toward) in whole degrees and speed (SPE) of iceberg drift in knots and
tenths. The confidence level (Cl), indicates whether these parameters are
measured (4) or estimated (5)
Note 19

4.1.4 Cluster Observations

Sample of cluster observation message:

22222
(SSSS) CIGGgg LaLaLaLaLa LoLoLoLoLo NtNtDrr nnCiSiSh (nnCiSiSh
)

Table 4.4: Cluster Information

Symbol Description Code Table
22222 Indicator that iceberg observations by cluster follow Note 12
Note 20
SSSS Optional group used by Ice Operations Centres and by the offshore industry Note 13
Note 26
CI Confidence level/Method of observation Table 4.13
Note 15
GG Time in hours that observation was made Note 16
gg Time in minutes that observation was made  
LaLaLaLaLa Latitude of the centre of the cluster in degrees, minutes and tenths of a minute  
LoLoLoLoLo Longitude of the centre of the cluster in degrees, minutes and tenths of a minute  
NtNt Total number of icebergs within the cluster, disregarding bergy bits and growlers Note 21
D Distribution of icebergs within the cluster Table 4.15
rr Radius of cluster in nautical miles  
nn Number of icebergs of each size and shape in the cluster Note 21
Ci Average concentration of sea ice in the cluster Table 4.10
Si Size of icebergs reported in the cluster Table 4.8
Note 21
Sh Shape of icebergs reported in the cluster Table 4.9
Note 21
nnCiSiSh Sufficient 5 figure groups to describe the numbers of each size and shape within the cluster Note 21

4.1.5 Grid Observations

Sample of grid observation message:

33333
CIGGgg LaLaLaLaLa LoLoLoLoLo LaLaLaLaLa LoLoLoLoLo nnnnD ( nnnnD
)

Table 4.5: Grid Observations

Symbol Description Code Table
33333 Indicator that iceberg observations by grid follow Note 22
CI Confidence level/Method of observation Table 4.13
Note 12
GG Time in hours that observation was made Note 16
gg Time in minutes that observation was made  
LaLaLaLaLa Latitude at the start point of the grid in degrees, minutes and tenths of a minute  
LoLoLoLoLo Longitude at the start point of the grid in degrees, minutes and tenths of a minute  
LaLaLaLaLa Latitude at the end point of the grid in degrees, minutes and tenths of a minute  
LoLoLoLoLo Longitude at the end point of the grid in degrees, minutes and tenths of a minute  
nnnn Number of icebergs within the grid Note 23
D Location of the grid Table 4.15
Note 22
nnnnD Group required if both left and right of track grids reported  

4.1.6 Zone Observations

Sample of zone observation message:

44444
CIGGgg LaLaLaLaLa LoLoLoLoLo (1mamamomo) 2NtNtNtD nnCiSiSh (nnCiSiSh
)

Table 4.6 Zone Observations

Symbol Description Code Table
44444 Indicator that iceberg observations by zone follow Note 24
CI Confidence level/Method of observation Table 4.13
Note 15
GG Time in hours that observation was made Note 16
gg Time in minutes that observation was made  
LaLaLaLaLa Latitude at the southwest corner of the zone in degrees, minutes and tenths of a minute  
LoLoLoLoLo Longitude at the start point of the grid in degrees, minutes and tenths of a minute  
1 Indicator for optional group to specify non-standard zone  
mama Whole minutes of latitude  
momo Whole minutes of longitude  
2 Indicator for total number of icebergs group  
NtNtNt Total number of icebergs disregarding bergy bits and growlers Note 21
D Distribution of icebergs within the zone Table 4.15
nn Number of icebergs of each size and shape in the zone Note 21
Ci Average concentration of sea ice in the zone Table 4.10
Si Size of icebergs reported in the zone Table 4.8
Note 21
Sh Shape of icebergs reported in the zone Table 4.9
Note 21
nnCiSiSh Sufficient 5 figure groups to describe the numbers of each size and shape within the zone Note 21

4.1.7 Ship Locations

Sample of ship location message:

55555
(SSSS) CIGGgg LaLaLaLaLa LoLoLoLoLo (1DvDvVvVv) (2NvNvrr
)

Table 4.7 Ship Locations

Symbol Description
55555 Indicator that ship position follow
SSSS Optional ship identifier
CI Confidence level/Method of observation (Code Table 4.13)
GG Time in hours of reported ship location
gg Time in minutes of reported ship location
LaLaLaLaLa Latitude of reported ship/cluster centre location in degrees, minutes and tenths of a minute
LoLoLoLoLo Longitude of reported ship/cluster centre location in degrees, minutes and tenths of a minute
1 Indicator for first optional group to specify ship speed and direction
DvDv Optional ship direction (01-36) in tens of degrees
VvVv Optional ship speed in knots
2 Indicator for second optional group to specify a cluster of ships
NvNv Total number of ships within the cluster
rr Radius of cluster in nautical miles

4.1.8 Plain Language Remarks

REMARKS (Note 15, p. 4-15)

END (*Mandatory end of message)

4.2 Iceberg Coding Tables

Table 4.8: Size of Iceberg (Si)

Description Height Length Code
Growler < 1 metre < 5 metres 1
Bergy Bit 1- < 5 metres 5- < 15 metres 2
Small Iceberg 5- 15 metres 15-60 metres 3
Medium Iceberg 16- 45 metres 61- 120 metres 4
Large Iceberg 46- 75 metres 121-200 metres 5
Very Large Iceberg > 75 metres >200 metres 6
Not Specified - - 7
Radar Target - - X

 

Table 4.9: Shape of Iceberg (Sh)

Description Code
Tabular 1
Non-Tabular 2
Domed 3
Pinnacled 4
Wedged 5
Drydocked 6
Blocky 7
Ice Island 8
Not Specified 0
Undetermined (Radar) X

 

Table 4.10: Concentration of Sea Ice (Ci)

Description Code
No Sea Ice 0
Trace of Sea Ice /
1/10 1
2/10 2
3/10 3
4/10 4
5/10 5
6/10 6
7/10 7
8/10 8
9/10,9+/10 or 10/10 9
Undetermined X

 

Table 4.11: Quadrant of the Globe (Qc)

Latitude Longitude Code
North East 1
South East 3
South West 5
North West 7

 

Table 4.12: Distribution of Sea Ice (Cs)

Description Code
No Sea Ice 0
Trace of Sea Ice /
Very Open Drift 1
Very Open Drift in strips and patches 2
Open Drift 3
Open Drift in strips and patches 4
Close Drift/Pack 5
Very Close Drift/Pack 6
Consolidated 7
Undertermined X

 

Table 4.13:Confidence Level/Method of Observation (Cl)

Description Code
Radar position with visual confirmation 1
Radar (Side-Looking Airborne Radar/Forward-Looking Airborne Radar) only 2
Visual only 3
Measured (only used in iceberg dimension) 4
Estimated (only used in iceberg dimension) 5
Satellite - High Confidence 6
Satellite - Medium Confidence 7
Satellite - Low Confidence 8

Note:

A "Z" found in the Ship Location section of older messages is treated as code 3.

 

Table 4.14: Platform Type (Pt)

Description Code
Fixed wing aircraft 1
Helicopter 2
Icebreaker including helicopter 3
Other ship 4
Oil rig 5
Shore station 6
Satellite 7

 

Table 4.15: Iceberg Distribution (D)

Description Code
Evenly (both sides of track) 1
Left of track 2
Right of track 3

 

Table 4.16: Source of Iceberg Message (N)

Description Code
Meteorological Service of Canada/International Ice Patrol 1
Icebreaker 2
Ice Operation Centre 3
Offshore Industry 4
Canadian Ice Service / International Ice Patrol 5

4.3 Notes on Iceberg Coding Procedures

  1. Nationality of originator of iceberg message is indicated by CN for Canadian and US for American.
  2. To facilitate turn-around of iceberg data, messages are designated by source:
    • Aerial reconnaissance by Meteorological Service of Canada and International Ice Patrol
    • Canadian Coast Guard icebreakers
    • Commercial ships, land stations and miscellaneous reports input by Ice Operations Centres
    • Offshore industry
    • Miscellaneous iceberg reports input by the Canadian Ice Service
  3. When transmitted from or through a land station, CCCC is the four-letter identifier, but when transmitted directly from an icebreaker or an aircraft, CCCC becomes the four-letter or four-figure identifier of the ship or aircraft.
  4. Normally a reconnaissance is conducted from one platform and the PPPP code for the identifier is in brackets e.g., icebreaker Henry Larsen (CGHL), MSC Dash-7 (GCFR) and US Coast Guard C130 (1504). Messages from Ice Operations Centres may be comprised of reports from several commercial ships and PPPP becomes (SHIP) or if the message is an assortment of reports from shore stations PPPP becomes (LAND). Messages from the offshore industry will usually include reports from rigs and supply vessels and PPPP is coded as (RIGG).
  5. Consecutive iceberg message numbers shall commence January 1st each year.
  6. Since reconnaissance missions may extend through two days, YYMMJ refers to the date on which the mission began or in the case of a message from industry or Ice Operations Centres the date of the first sighting.
  7. A track is made up of one or more legs defined by position, time and parameters. There are as many legs (lines of code) as required to describe all turning points or any change of parameters, e.g., general sea-ice description, aircraft altitude, visibility, radar range and sea state. Although complete detail is required to reproduce a plot as if it was drawn by the observer, complicated tracks should be redrawn to give a simpler track with appropriate visibility and radar ranges to outline the area of coverage. Variable parameters could be averaged to keep the message to a reasonable length. The last track line must only contain the latitude, longitude and time parameters.
  8. If a mission starts or ends at a shorebase, the first and last position becomes the international call sign of the shorebase. An aerial mission may start or end at any position. For example, a mission from Iqaluit to observe icebergs in Hudson Strait and then sea ice in Hudson Bay, would end iceberg reporting in western Hudson Strait. In this same example, if the mission re-entered Hudson Strait to continue iceberg reporting, the endpoint of the first iceberg reconnaissance would be joined to this restart point by a straight line with all parameters coded as X's. Track legs over stretches of land may have all parameters coded as X.
  9. Each leg start position is, by default, the end position of any previous leg; consequently, the last line of the track is always position and time. For stationary icebreakers, these two positions are the same.
  10. For icebergs, visibility or radar limits are defined by the distance from the ship or aircraft that the observer feels confident that he/she can see or get a radar return for all small icebergs. This does not preclude the observation and reporting of icebergs beyond these limits. the radar visibility must have a minimum of 2 digits and a maximum of 3 digits on either side.
  11. Experienced Ice Services Specialist may estimate the wave or swell group visually or by radar from an aircraft or report XXXX for "undetermined". Icebreakers should report the group.
  12. The individual-position method of iceberg and target reporting should be used in areas near the iceberg limit, areas of offshore drilling activity, the approaches to the Strait of Belle Isle and in all other areas where icebergs are evenly distributed and their numbers permit. When numbers increase or when icebergs are concentrated in small areas, a combination of cluster and individual methods can be used. When numbers become unmanageable, zones and grids should be incorporated.
  13. Messages from the offshore industry and from Ice Operations Centres consist of iceberg reports from individual sources such as commercial ships, rig supply vessels, land stations, etc. If the iceberg message contains only one individual source, the message is coded with PPPP in the second line of the header information and is coded as the first four letters (or figures) of the call sign of the single source. However, if the iceberg message contains iceberg reports from more than one source, the optional group SSSS is used to indicate the call signs of the individual sources.
  14. The offshore industry usually tracks icebergs through their area of interest. Icebergs entering the area are assigned a consecutive number which is maintained until the iceberg exits from the area. The optional group IdIdIdIdI is used by the offshore industry to code the assigned number of the iceberg and to indicate if the iceberg is freely drifting (D), grounded (G) or is under tow (T).
  15. The degree of confidence in an iceberg's observed position and related parameters is expressed by CI. The highest confidence (Code 1) is a radar position with visual confirmation. There should be an attempt to consolidate visual and radar data to produce high confidence levels. Radar-only targets (Code 2) will not appear in areas visually searched, unless there is some doubt about the visual capability which should be expressed in the REMARKS section.
  16. The time of observation is the time at which an individual iceberg, the centre of a cluster, the southwest corner of a zone or the start point of a grid becomes abeam of the track. Times may be rounded off to the nearest 15 minutes but they must be within the time frame of the track leg from which the observations were made.
  17. The concentration of sea ice is a factor which affects iceberg drift and which provides the user with some degree of confidence in iceberg detection, especially if the detection is made by radar. There shall be an attempt to describe the ice cover to the nearest tenth immediately adjacent to the iceberg. However, when the concentration varies from side to side, the recorded concentration will be an average of the conditions around the iceberg. Open water areas or trails caused by the iceberg will be disregarded.
  18. Sizes refer to the portion of the iceberg above water. If height and length of a berg in metres (m) fall into a different size classification, use the larger size. Dimensions (in kilometres) of a tabular berg or ice island may be indicated beneath the symbol. Iceberg size and shape parameters are important in the process of re-identification of icebergs and as inputs to iceberg deterioration and drift models. These parameters shall be reported along the limit of icebergs, in areas of offshore drilling activity, in the approaches to the Strait of Belle Isle and in all areas where the work load permits. When icebergs are more numerous, shape parameters should be simply tabular or non-tabular. When icebergs become too numerous, use code 7 for unspecified size and code 0 for unspecified shape. X's will only be used for radar information.
  19. The optional groups (1ClLEN 2ClWID 3ClHEI 4ClDRA 5ClDIR 6ClSPE) shall be used when any of the length, width, height, draft, direction and speed iceberg parameters are available. The confidence level in this group shall only be measured (Code 4) or (Code 5).
  20. Accurate determination of the positions and radii of clusters is essential so that the circles do not overlap other clusters, zones or grids, overlap land or extend beyond the applicable radar or visual limit. Normally observations by individual position will not be included inside a cluster. However a visually confirmed iceberg through a hole in the clouds could be included in a radar cluster and in this case the total number of icebergs reported in the cluster would not include the individual iceberg.
  21. If there are no bergy bits or growlers present, nn equals NtNt for clusters or NtNtNt for zones. Si is coded as 7 for not specified and Sh is coded as 0 for not specified. However, when the workload permits, the code allows specifying the numbers of different sizes and shapes within the grid or zone. For example, in a cluster free of sea ice which has 1 very large tabular iceberg, 3 medium icebergs, 5 small icebergs and 2 bergy bits which are all evenly distributed within a radius of 5 nautical miles,NtNtDrr nnCiSiShnnCi SiShnnCiSiShnnCiSiS hwould be coded as: 09110 01061 03040 05030 02020.
  22. Grids are defined by the confidence level (whether radar and visual, radar only or visual only), by two positions along the track, by the visibility or radar limits as coded in the track part of the message and by the iceberg distribution (left of track, right of track or both sides of track). A visual and radar or a visual-only grid extends from the track line to the visibility limit. A radar-only rid extends from the track to the radar limit or if there is a visible limit, the grid extends from the visibility limit to the radar limit. Two lines of code are required to encode both visual and radar grids with the same endpoints. Clusters will not be reported inside grids and normally individual icebergs should be excluded. However, individual icebergs which are considered significant because of ize, shape or other parameters which can assist in reidentification may be positioned inside of the grid. The time assigned to the grid associates it with the correct visibility and/or radar limits coded in the track leg, so it is essential that the time refers to the right leg. Grids will not extend beyond one track leg.
  23. An accurate count of iceberg numbers in grids, clusters and zones is desired. However, when numbers are too large, report an estimate and explain in the REMARKS section.
  24. Zones are areas usually one degree latitude by one degree longitude defined by the latitude and longitude of the southwest corner. The optional group 1mamamomo permits the use of nonstandard zones. Zones should not overlap other zones, grids or clusters, or extend beyond the appropriate visibility or radar limit. As with clusters and grids, individual icebergs should not normally appear in zones.
  25. Factors, such as turbulence, drift angle, precipitation and sea state, that can effect radar; and variable visibilities or breaks in the undercast that effect visual capabilities shall be included.
  26. The platform identifier group PPPP, found in the Iceberg Messae Header, and the optional ship identifier group (SSSS), coded in the observation reports can be extended to contain up to 7 alphanumeric characters.

4.4 Examples of Coded Iceberg Reports

Example of a chart from March 6, 2014 produced by the iceberg patrol. Chart identifies iceberg locations around the Northeast coast of Newfoundland.
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