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Manual of Ice (MANICE)

Chapter 3: Observed Ice Charts

This chapter deals with basic procedures for preparing and transmitting ice charts. Ice charts are of importance to icebreaker captains, commercial shipping interests and fishing vessels to assist them in finding the easiest passage through the ice or to avoid the ice when feasible to do so. The data on the chart is of vital importance to ice forecasters, serving as the basis for:

  • ice hazard warnings
  • preparation of daily ice analysis chart
  • short- and long-range ice forecasts and seasonal outlooks
  • preparation of regional ice charts

 

3.1 Preparation of Ice Charts

Time and care are necessary to prepare ice charts. Details and precision are of the utmost importance.

3.1.1 Drawing Procedures

Ice charts are drawn directly on a computer screen using Geographical Information Systems software. This software has been developed specifically for the Coast Guard to allow precise observation and quick transmission of data.

It is beyond the scope of this manual to describe this particular software in detail. It is sufficient to know the precision of observation is greatly increased by the use and integration of the Global Positioning System (GPS). The usefulness of the data is enhanced by the automatic verification of all coding and final preparation of charts.

Data will generally be transmitted in the form of electronic files and distributed by Canadian Ice Service to clients. Maps of observed data will also be produced by Canadian Ice Service and made publicly available.

3.2 Dissemination of Aerial Ice Charts

Data (in the form of electronic files or charts) is of special importance to the ice forecasters and analysts and ships operating in or near the areas observed during the reconnaissance mission. Files are updated continuously while airborne and sent frequently. Partial files, rough copies and final copies of charts may be sent in-flight to the Canadian Ice Service, the appropriate Coast Guard ice offices and Coast Guard ships as necessary.

After the termination of the reconnaissance mission, the Ice Service Specialist will transmit the completed and corrected data to the Canadian Ice Service for distribution.

3.3 Dissemination of Shipboard Ice Charts

 

An Ice Service Specialist serving on icebreakers equipped with appropriate communication equipment should relay their ice information (even if incomplete) before 1800 UTC to Canadian Ice Service. Upon completion of the duty day, a second transmission is recommended. The data should be sent in the form of an electronic file via cellular phone, landline or satellite link depending on what is practical and available.

If it is not possible to transmit an electronic file, then a map could be printed and send by facsimile.

3.4 The Egg Code

The basic data concerning concentrations, stages of development (age) and form (floe size) of ice are contained in a simple oval form. A maximum of three ice types is described within the oval. This oval and the coding associated with it, are referred to as the "Egg Code". To indicate ice observations interpreted from radar imagery, the oval shall be omitted.

In the following figures and tables where ranges are shown for thickness, floe sizes or other dimensions, a report coinciding with the end point of a range shall be coded as the higher value.

The following is a summary diagram of the Egg Code. This code conforms to international convention and shall be used in coding all visual sea ice and lake ice observations without exception.

Diagram of the components of the egg code: total and partial concentration, stage of development and forms of ice. See description below for details.

The symbols CaCbCc and FaFbFc correspond to Sa Sb Screspectively.

There are some minor additions to the egg code symbology that are Canadian practice. In Canada, to enable the reporting of additional ice classes, especially during freeze-up and break-up, Cd Se and Fe can be used. This should not be a common occurrence.

The following pages describe the specific details and rules for completing each level of information within the egg.

3.4.1 Concentration (C)

Diagram of the egg code indicating the location of concentration of ice. See description below for details.

Total concentration (Ct ) of ice in the area reported in tenths and partial concentrations of thickest (Ca), second thickest (Cb), third thickest (Cc) and fourth thickest (Cd) ice in tenths.

Notes:

  1. Less than 1/10 (i.e. traces) shall not be reported within the oval except to describe open water (see Example 1, section 3.8).
  2. Cd shall only be included when Sd and Seare reported (see Example 2, section 3.8).
  3. When Sd is used and Cd is omitted, Cd equals Ct-(Ca+Cb+Cc) (see Example 3, section 3.8).
  4. When only one ice type is present, the partial concentration shall not be indicated (see Example 4, and Example 5, section 3.8).
  5. When one ice type is present with a trace of a thinner type, only total concentration of the major ice type shall be indicated (see Example 5, section 3.8 ).

3.4.2 Stage of Development (S)

Diagram of the egg code indicating the location of stage of development. See description below for details.

Stage of development of thickest (So), second thickest (Sa), third thickest (Sb) and fourth thickest (Sc) ice and the thinner ice types Sd and Se, of which the concentrations are reported by CaCb Cc Cdrespectively.

Notes:

  1. Reference to thicker ice should be understood to mean older ice and conversely, thinner ice to mean younger ice types.
  2. Ice is designated as Sea, Lake or River Ice depending on where it forms. In Canada, the practice is to use lake-ice coding to report ice in the Great Lakes and the St. Lawrence Seaway. Elsewhere, including the St. Lawrence River east of Montreal, sea-ice coding is used for stages of development.
  3. Sa, Sb and Sc shall have concentrations of at least 1/10, except when Ct is zero (see Example 1, section 3.8).
  4. Reporting of Sa, Sb and Sc should generally be restricted to a maximum of three significant classes. In exceptional cases further classes may be reported as follows:
    • So- Stage of ice development thicker than Sa, but having a concentration less than 1/10 (see Example 6, section 3.8).
    • Sd- Stage of development of the thickest remaining ice types (if more than one type remains). It is the fourth stage present after Sa, Sb and Sc.
    • Se- Shall only be reported when a thinner ice type remains after Sd. Partial concentration of Se is obtained by subtracting partial concentrations (CaCbCcCd) from total concentration (Ct) (see Example 2, section 3.8).
  5. When Se is not present,Sd may be a trace of ice (see Example 6, section 3.8).
  6. Concentration shall not be indicated for So and Se(see Example 2, section 3.8, and Example 6, section 3.8).
  7. Concentration shall not be indicated for Sd when Seis not present (see Example 3, section 3.8, and Example 5, section 3.8).

 

Table 3.1: Coding for Sea-Ice Stages of Development (SoSaSbScSdSe)

DescriptionThicknessCode
New ice< 10 centimetres1
Nilas, Ice rind< 10 centimetres2
Young Ice10 - 30 centimetres3
Grey Ice10 - 15 centimetres4
Grey-white ice15 - 30 centimetres5
First-year ice>= 30 centimetres6
Thin first-year ice30 - 70 centimetres7
First stage thin first-year30 - 50 centimetres8
Second stage thin first-year50 - 70 centimetres9
Medium first-year ice70 - 120 centimetres1·
Thick first-year ice> 120 centimetres4·
Old ice-7·
Second-year ice-8·
Multi-year ice-9·
Ice of land origin- Ice of land origin symbol
Undetermined or unknown-X·

 

Table 3.2: Coding for Lake-Ice Stages of Development (SoSaSbScSdSe)

DescriptionThicknessCode
New lake ice< 5 centimetres1
Thin lake ice5 -15 centimetres4
Medium lake ice15 - 30 centimetres5
Thick lake ice30 -70 centimetres7
Very thick lake ice> 70 centimetres1·

 

Notes for Tables 3.1 and 3.2:

  1. On the horizontal line giving SoSa Sb Sc Sd, only one dot (·) shall be placed to indicate the distinction between classes of ice. Every coded figure to the left of the (·) is understood to have the (·) as part of its code (see Examples 2, 3 and 6, section 3.8).
  2. Codes 3 and 6 shall only appear on Canadian charts if the Ice Service Specialist cannot confidently determine the stages of the ice in the area observed.
  3. Codes 8 and 9 shall only appear when measurements have been taken.
  4. Codes 8·and 9·shall normally appear on Canadian charts only from 01 October to 31 December, but if the Ice Service Specialist is confident of the report, it may be used throughout the year, otherwise 7·is used.
  5. The symbol Ice of land origin symbol shall only be used within the egg and when the concentration of ice of land origin is 1/10 or more.
  6. The symbol X (meaning "undetermined") shall be used to designate stages of development or forms of ice only if it is impossible to specify otherwise.

 

3.4.3 Form of Ice (F)

Diagram of the egg code indicating the location of forms of ice. See description below for details.

Floe Size corresponding to SaSbSc Sd and Se (when Sdand Seare greater than a trace).

Notes

  1. World Meteorological Organization International procedures also permit reporting of Fpand Fs as the primary and secondary forms of all the ice without reference to stage of development.
  2. It is Canadian practice to report FaFb Fc as predominant floe sizes of Sa SbScrespectively. This makes it necessary, when only Sa and Sbare present, that Fa and Fbshall be followed by a dash (-) where Fc would normally appear (see Example 7, section 3.8)

 

Table 3.3: Coding for Forms of Ice (FaFb Fc Fd Fe)

DescriptionWidthCode
Pancake ice-0
Small ice cake, brash ice, agglomerated brash< 2 metres1
Ice cake2 - 20 metres2
Small floe20 - 100 metres3
Medium floe100 - 500 metres4
Big floe500 - 2,000 metres5
Vast floe2 - 10 kilometres6
Giant floe> 10 kilometres7
Fast ice-8
Icebergs, growlers or floebergs-9
Undetermined, unknown or no form-X

 

Notes for Table 3.3

  1. Width refers to the maximum horizontal extent.
  2. At least one code 8 must be used for fast or consolidated ice. Other ice types embedded may retain their floe size (see Example 9, section 3.8).
  3. Occasionally the stage of development of fast ice cannot be determined. The area shall be blackened-in to denote fast ice (see Table 3.9).
  4. New sea ice does not have a definite form; therefore, when this stage of development occurs as Sa, Sb or Sc, the symbol X shall be used to designate floe size (see Example 4, section 3.8).
  5. Floe size is not included for So, Sd and Seif the concentration of these ice types is less than 1/10. Otherwise floe sizes for Sd and Se are optional.
  6. If there is a significant variation in floe sizes in an area containing only one particular ice type, the ISS may enter the applicable floe-size Categories in the lowest part of the oval reserved for floe size. The largest floe-size category shall be put on the left side within the oval, followed by the other applicable floe sizes. In this case, the partial concentrations listed (Ca Cb CcCd) would match the partial concentration of floe sizes, instead of different ice types.

 

3.4.4 Coding and Symbology for Strips and Patches

The Strips and patches symbolsymbol, placed at the bottom of the oval in the section reserved for Form of Ice, indicates that the ice is in strips and patches; the concentration within the strips and patches is represented by C.(see Example 11, section 3.8).

When strips and patches are observed in open-water areas, the symbol shall be placed to denote the position of the strips and patches. If the ice in the strips and patches is of the same composition as that inside an adjacent ice edge, no oval is required. If the ice in the strips and patches is of a different composition, an oval shall be used with an arrow or arrow(s) to the strips-and-patches symbol(s). To avoid confusion, the strip symbol must be included with the total concentration (see Example 10, section 3.8).

In an area where the ice is arranged in strips and patches and the ice floes are medium or greater, the floe size shall be indicated by using two ovals. The floe sizes are indicated as normal in the first oval, with the Strips and patches symbolsymbol placed between the first and second ovals. The Strips and patches symbolsymbol is repeated in the second oval beside the total concentration of the strips and patches (see Example 12a, section 3.8).

An alternate way of reporting the same situation as above:

In an area where the ice is arranged in strips and patches and the ice floes are medium or greater, the floe sizes shall be indicated as normal. Both the total concentration and the concentration within the strips will be placed in the space reserved for Ct, with the Strips and patches symbolsymbol between them. When this option is used, Ca Cb Cc and possibly Cd refer to the total concentration and not the concentration within the strips. For example, Ct can be reported as 2Strips and patches symbol9 meaning the total concentration is 2 tenths with strips of 9 tenths and the partial concentration(s) shall equal 2 tenths (see Example 12b, section 3.8).

In an area of ice where some thicker ice type(s) is (are) embedded as strips and patches, these shall be indicated by the use of two ovals. The overall partial concentrations of the ice types are indicated in the first oval and the concentrations within the strips and patches are indicated in the second oval. The Strips and patches symbolsymbol shall be placed between the two ovals and along with the total concentration in the second oval (see Example 13, section 3.8).

 

3.4.5 Coding for Brash

Diagram of the egg code indicating the location of brash coding. See description below for details.

If 1 tenth or more of brash is present, it will always be Ca .

If brash is present, Sa will always be a dash (-), otherwise the normal table is to be used.

Brash is already indicated in the table as 1, therefore Fa= 1 confirms the dash (-) for Sa.

Four digits (VKMT) shall be added below the oval to indicate the thickness concentration breakdown of the brash that is present. Table 3.4 (below) shows the thickness Categories for agglomerated brash. The breakdown shall be entered going from right (T) to left (V). In the case where there is no thickness for thin but there are entries for medium, thick and very thick a zero (0) shall be placed in the thin column. This also holds true for medium (M) and thick (K) regardless of the combination (see Example 14, to Example 17, section 3.8).

Table 3.4: Thickness Categories for Brash (VKMT)

DescriptionThickness
Very Thick (V)> 4 metres
Thick (K)> 2 - 4 metres
Medium (M)1 - 2 metres
Thin (T)< 1 metres

3.5 Symbols Used on Ice Charts

3.5.1 Symbols for Dynamic Processes

Symbols for Dynamic Processes

ProcessSymbol

Compacting

  1. Slight compacting (optional)
  2. Considerable compacting(optional)
  3. Strong compacting(optional)
 Compacting symbol
Diverging Diverging symbol
Shearing Shearing symbol
Drift Drift symbol
Indicate drift speed in tenths of knots
(e.g. 15 = 1.5 knots)
 Drift symbol

 

3.5.2 Symbols for Openings in the Ice

Symbols for Openings in the Ice

ProcessSymbolDescription
Crack Symbol for cracksThis symbol indicates the presence of cracks in the area.
Crack Symbol for crack at a specific location.This symbol represents a crack at a specific location.
LeadLead symbol
or
Lead symbol
The width in nautical miles may be specified.
Frozen lead Frozen lead symbolThe orientation of the crosslines may be varied to distinguish them from other hatching lines.

 

3.5.3 Symbols for Topographical Features

Symbols for Topographical Features

ProcessSymbolDescription
Ridges/Hummocks

Symbol for Ridges/Hummocks

or

Symbol for Ridges/Hummocks

Optional:

Optional symbol for Ridges/Hummocks

C - Concentration or area coverage in tenths.

f - Frequency in numbers per nautical miles (f is an alternative for C).

h - Mean height expressed in decimetres and included when known.

hx - Maximum height expressed in decimetres and included when known.

Rafting Rafting symbolC: concentration in tenths
Jammed brash barrier Jammed brash barrier symbol 

 

3.5.4 Symbols for Ice Thickness

Symbol for thickness measured in centimetres

tE= thickness measured in centimetres

Symbol for thickness estimated in centimetres

tE= thickness estimated in centimetres

Examples:

Example of ice thickness (measured and estimated in centimetres)

When more than one measurement has been taken, both mean and maximum thicknesses are reported, as shown below:

30/40

 

3.5.5 Coding for Stage of Melting

Stage of melting

Melting symbol

Table 3.5: Coding for Stage of Melting (ms)

DescriptionCoverageCode
No melt-0
Few puddles1-3/101
Many puddles>3/102
Flooded ice-3
Few thaw holes1-3/104
Many thaw holes> 3/105
Dried ice-6
Rotten ice-7
Few frozen puddles-8
All puddles frozen-9
Undetermined or unknown-X

 

3.5.6 Coding and Symbology for Snow Cover

Coding and Symbology for Snow Cover

SymbolDescription
 Snow cover symbol

C - concentration (or area coverage) in tenths

s - snow depth, according to Table 3.6

 Snow depth symbolThe orientation of the symbol with an arrow can show the direction of sastrugi

 

Table 3.6: Coding for Snow Depth (s)

DescriptionCode
no snow0
1- 5 centimetres1
6- 10 centimetres2
11- 20 centimetres3
21- 30 centimetres4
31 -50 centimetres5
51 -75 centimetres6
76- 100 centimetres7
> 100 centimetres8
unknown9

 

3.5.7 Coding and Symbology for Ice of Land Origin

Triangular symbol shown:

Symbol for ice of land origin

nn=number, see following Table 3.7
yy=day of month of sighting

Table 3.7: Number of Bergy Bits/Growlers or Icebergs (nn)

NumberCode
None00
101
202
303
404
505
606
707
808
909
1010
1111
1212
1313
1414
1515
1616
1717
1818
1919
1-920
10-1921
20-2922
30-3923
40-4924
50-9925
100-19926
200-49927
500 or more28
Undetermined99

 

Table 3.8: Symbology for Ice of Land Origin

DescriptionOneMany
Growler Symbol for one growler Symbol of many growlers
Bergy bit Symbol of one bergy bit Symbol for many bergy bits
Iceberg (size unspecified) Symbol for one iceberg of unspecified size Symbol for many icebergs of unspecified size
Small iceberg Symbol for one small iceberg Symbol for many small icebergs
Medium iceberg Symbol for one medium iceberg Symbol for many medium icebergs
Large iceberg Symbol for one large iceberg Symbol for many large icebergs
Very large iceberg Symbol for one very large icebergs Symbol for many very large icebergs
Ice island Symbol for ice island 
Ice of sea origin (floeberg) Symbol for ice of sea origin (floeberg) 
Radar target (suspected berg) Symbol for radar target (suspected berg) 

Notes

Tabular iceberg indicated by adding a horizontal line through any of the symbols as shown in the following example. These symbols can be combined with a number, if exact numbers are known.

Example: Tabular iceberg symbol

For further detail on reporting ice of land origin, see Chapter 4.

 

3.5.8 Symbols for Defining Limits

Symbols for Defining Limits

DescriptionSymbol
Limit of Undercast Limit of Undercast symbol
Limit of Radar Observations Limit of Radar Observations symbol
Limit of Visual Observations Limit of Visual Observations symbol
Observed Edge or Boundary Observed Edge or Boundary symbol
Ice Edge or Boundary from Radar Ice Edge or Boundary from Radar symbol
Estimated Edge or Boundary Estimated Edge or Boundary symbol

 

3.5.9 Supplementary Coding for Radar Observations

Relative Roughness

Lightup to 1/10L
Medium2/10 - 3/10M
Heavy4/10 - 10/10H

Relative Roughness

Note:

Areas showing no radar return shall be indicated NIL ECHO.

3.6 Supplementary Procedures for Indicating Total Concentration

In order to facilitate readability of the chart, ice-covered areas may be hatched according to total ice concentration. The hatching symbology (developed by World Meteorological Organization) may be applied to all areas of ice concentration or only to some of them. Whenever hatching is applied, the hatching symbols as shown in Table 3.9 shall be used. No International Rules are given for the thickness of the hatching lines; the thickness may be the same throughout all hatched areas or may vary in the sense that the thickest lines are used for areas of thicker ice. It is Canadian practice not to hatch ice charts except for total concentrations less than 1/10th.

Table 3.9: World Meteorological Organization Symbols For the Hatching of Total Concentration of Ice

DescriptionHatching
Fast Ice Symbol for fast ice
10/10 Consolidated ice, Compact ice and 9-9+/10
Very close pack/drift ice
 Symbol for consolidated ice
7-8/10 Close pack/drift ice Symbol for 7-8 close packed ice
4-6/10 Open drift ice (Line spacing is twice
that of Close pack/drift ice)
 Symbol for open drift ice
1-3/10 Very open drift ice Symbol for very open drift ice
Open water (less than 1/10 sea ice, no ice
of land origin)
 Symbol for open water
Bergy water (less than 1/10 sea ice may be present
and total ice concentration is less than 1/10)
 Symbol for bergy water
Water with Radar Targets (less than 1/10 sea ice may be present and
total ice concentration is less than 1/10)
 Symbol for water with radar targets
Ice free (no ice present) Symbol for ice free

Note

Presence of new ice can be indicated by the following symbols scattered throughout area affected:

Symbol for presence of new ice symbol

3.7 Colour Coding Ice Charts

3.7.1 Introduction

For several years, the Ice Service Specialists have been applying a colour code to ice information charts for the Canadian Coast Guard operations in the St. Lawrence River and the Gulf of St. Lawrence. This has proven to be quite beneficial to individuals making transportation decisions based on these information products. More recently, we have modified and expanded this colour code for application in all coastal waters of Canada, including the Arctic.

3.7.2 The Colour Code

This colour code is intended to assist navigation decisions in ice infested water. It is loosely based on the concept of a traffic light where green represents proceed, yellow represents caution and red represents danger. The objective of the colour code application is to enable a person to quickly assess general ice conditions. A ship sailing in a given area can easily assess the general ice conditions and hence qualify the difficulty or ease to either navigate through easily, or to reduce speed or to stop the ship.

However, this does not consider the other variables such as winds, currents or ship design which are important considerations in any ice navigation decision. The most detailed ice information continues to reside in the ice egg codes.

3.7.3 How to Interpret the Code

The following text is intended to assist an individual interpret the colour presentation.

Open or Bergy Water

Areas of open water or bergy water are coloured blue.

Blue
Open or bergy water

Presence of Ice

For ice concentration of one tenth or greater, the ice type must be separated into two categories: less than 15 centimetres and greater than 15 centimetres thickness:

Ice Types Thicker than 15 centimetres

The colour for a given ice area will be determined by the total concentration of the ice types thicker than 15 centimetres and is represented by the following list:

Colour code for ice types thicker than 15 centimetres

ColourDescription
 Green1 to 3 tenths of ice > 15 centimetres
 Yellow4 to 6 tenths of ice > 15 centimetres
 Orange7 to 8 tenths of ice > 15 centimetres
 Red9 to 10 tenths of ice > 15 centimetres

 

Presence of Old Ice

The presence of old ice (multi-year ice) is indicated by the colour purple, and is represented by the following list:

PatternDescription
 Dashed linesIndicates the presence of 1 to 4 tenths of old ice
 PurpleIndicates the presence of 5 tenths or more of old ice

 

Presence of Fast Ice

The presence of fast ice, regardless of the thickness is always black or grey.

Black or Grey

 

Ice Types Thinner than 15 centimetres - No Colour Assigned in Background

Ice less than 15 centimetres in thickness is indicated by a star code and the colour of the stars is determined by the predominance between grey ice (10 to 15 centimetres) and new ice (0 to 10 centimetres), and is represented by the following list:

PatternDescription
 Blue starPredominance of ice thinner than 10 centimetres
 Red starPredominance of ice thickness between 10 and 15 centimetres

 

Ice Types Thinner than 15 centimetres - Colour Assigned in Background

Secondary ice types with less than 15 centimetres in thickness are indicated by a star code and the colour of the stars is determined by the predominance between secondary grey ice (10 to 15 centimetres) and secondary new ice (0 to 10 centimetres), and is represented by the following list:

PatternDescription
 Blue Stars with colored backgroundPredominance of secondary ice thinner than 10 centimetres
 Red Stars with colored backgroundPredominance of secondary ice thickness between 10 and 15 centimetres

The star code is placed over top of the background colour. In the case of 9 to 10 tenths of ice (red background) and predominance of ice thickness between 10 and 15 centimetres (red stars), there is only one colour which can be represented: red. The result of red stars on a red background is red.

3.8 Examples of the Use of the Egg Code

3.8.1 Various Ice Type and Concentration Combinations

Example 1

Image of an egg with less than one tenth of ice to show open water; some thick first-year in small floes. See description below for more details.

Description:

Less than one tenth of ice to show open water. Some thick first-year in small floes; new ice is also present and has no floe form.

Example 2

Image of an egg with 9+/10 total ice concentration; 3/10 old ice in small floes; 2/10 thick first-year ice in medium floes; 1/10 thin first-year ice in small floes; 2/10 grey-white ice in small floes. See description below for more details.

Description:

9+/10 total ice concentration. 3/10 old ice in small floes, 2/10 thick first-year ice in medium floes, 1/10 thin first-year ice in small floes, 2/10 grey-white ice in small floes, and the remaining 2/10 is new ice with no floe form.

Example 3

Image of an egg with 8/10 total ice concentration; 3/10 old ice in small floes; 2/10 thick first-year ice in medium floes; 1/10 thin first-year ice in small floes; 2/10 grey-white in small floes.

Description:

8/10 total ice concentration. 3/10 old ice in small floes, 2/10 thick first-year ice in medium floes, 1/10 thin first-year ice in small floes and 2/10 grey-white in small floes.

Example 4

Image of an egg with 6/10 of new ice with no floe form.

Description:

6/10 of new ice with no floe form.

Example 5

Image of an egg with 4/10 of old ice in medium floes; new ice is also present with a concentration of less than 1/10.

Description:

4/10 of old ice in medium floes. New ice is also present with a concentration of less than 1/10.

Example 6

Image of an egg with 5/10 total ice concentration; 2/10 thick first-year ice; 2/10 medium first-year ice; 1/10 thin first-year ice. All in small floes. See description below for more details.

Description:

5/10 total ice concentration. 2/10 thick first-year ice, 2/10 medium first-year ice and 1/10 thin first-year ice. All in small floes. Old ice and grey-white ice with a concentration of less than 1/10 are also present.

Example 7

Image of an egg with 5/10 total ice concentration; 2/10 thin first-year ice in small floes; 3/10 grey ice in medium floes.

Description:

5/10 total ice concentration. 2/10 thin first-year ice in small floes and 3/10 grey ice in medium floes.

Example 8

Image of an egg with 9+/10 total ice concentration; 3/10 old ice in big floes; 4/10 first-year ice in medium floes; 3/10 young ice with floes undetermined. See description below for more details.

Description:

9+/10 total ice concentration. 3/10 old ice in big floes, 4/10 first-year ice in medium floes and 3/10 young ice with floes undetermined. Horizontal lines with no egg shell indicates that data has been interpreted from radar

Example 9

Image of an egg with fast grey ice with 3/10 multi-year ice in small floes embedded.

Description:

Fast grey ice with 3/10 multi-year ice in small floes embedded.

3.8.2 Strips and Patches

Example 10

Image of an egg with open water with strips and patches of old and thick first-year ice in small floes.

Description:

Open water with strips and patches of old and thick first-year ice in small floes.

Example 11

Image of an egg with 3/10 total ice concentration; 2/10 old ice; 1/10 thick first-year ice. All ice is concentrated in strips and patches of 9+/10.

Description:

3/10 total ice concentration. 2/10 old ice and 1/10 thick first-year ice. All ice is concentrated in strips and patches of 9+/10.

Example 12a

Image of an egg with 3/10 total ice concentration in strips and patches of 9+/10; 6/10 old ice in vast floes; 4/10 thick first-year ice in big floes. See description below for more details.

Description:

3/10 total ice concentration in strips and patches of 9+/10. 6/10 old ice in vast floes and 4/10 thick first-year ice in big floes. These floe sizes are significant and warrant the use of two ovals.

Example 12b

Image of two eggs with an alternate way to describe the same conditions: 3/10 total ice concentration in strips and patches of 9+/10; 6/10 old ice in vast floes; 4/10 thick first-year ice in big floes. See description below for more details.

Description:

An alternate way to describe the same conditions with 3/10 total ice concentration in strips and patches of 9+/10. 6/10 old ice in vast floes and 4/10 thick first-year ice in big floes. These floe sizes are indicated because they are significant.

Example 13

Image of two eggs with 9+/10 total ice concentration comprised of 1/10 thick first-year ice; 1/10 medium first-year ice; 8/10 new ice and old ice with a concentration of less than 1/10. See description below for more details.

Description:

9+/10 total ice concentration comprised of 1/10 thick first-year ice, 1/10 medium first-year ice, 8/10 new ice and old ice with a concentration of less than 1/10. The old and thick first-year ice are distributed throughout the area in strips and patches made up of 3/10 old and 7/10 thick first-year ice. All ice types in the second oval must be included in the first oval.

Example 14

Image of an egg with 8/10 total ice concentration; 3/10 of brash; 2/10 grey-white ice in medium floes; 3/10 grey ice in small floes; 1/10 of the brash is medium while 2/10 is thin. See description below for more details.

Description:

8/10 total ice concentration. 3/10 of brash, 2/10 grey-white ice in medium floes, 3/10 grey ice in small floes and 1/10 of the brash is medium while 2/10 is thin. There is no thick or very thick brash present.

3.8.3 Brash

Example 15

Image of an egg with 9/10 total ice concentration; 2/10 brash; 4/10 grey ice in medium floes; 3/10 nilas in small floes. See description below for more details.

Description:

9/10 total ice concentration. 2/10 brash (1/10 very thick brash, 1/10 thick brash and a trace of medium and thin brash), 4/10 grey ice in medium floes and 3/10 nilas in small floes.

Example 16

Image of an egg with 5/10 total ice concentration. See description below for more details.

Description:

5/10 total ice concentration. All brash with 2/10 thick brash, 1/10 medium brash and 2/10 thin brash.

Example 17

Image of an egg with 6/10 total ice concentration; 4/10 brash; 2/10 nilas in small floes. See description below for more details.

Description:

6/10 total ice concentration. 4/10 brash (1/10 medium, 1/10 thick and 2/10 very thick) and 2/10 nilas in small floes.

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