S/V TARA (FRA) is attempting a single-season Arctic Circumnavigation counterclockwise (West-to-east)...
S/V TARA departed Tuktoyaktuk to the east on the 21st of September 2013, knowing that the Northwest Passage was blocked with 5/10 to 9/10 sea ice concentration at multiple locations which did not leave another eastern route out of the Arctic unless one or more of these choke-points opened before hard freeze-up around October 15th.
TARA has made it through Bellot Strait last night and is northbound in Prince Regent Inlet attempting to find a route through what is reported to be 9/10 sea ice concentration.
The World Meteorology Organization (WMO) system for sea ice symbology is more frequently referred to as the "Egg Code" due to the oval shape of the symbol.
Ct - Total concentration of ice in area, reported in tenths. May be expressed as a single number or as a range, not to exceed two tenths (3-5, 5-7 etc.)
Ca Cb Cc - Partial concentration (Ca, Cb, Cc) are reported in tenths, as a single digit. These are reported in order of decreasing thickness. Ca is the concentration of the thickest ice and Cc is the concentration of the thinnest ice.
Sa Sb Sc - Stages of development (Sa, Sb, Sc) are listed using the code shown in Table 1 below, in decreasing order of thickness. (NOTE: If there is a dot (.), all stages of development codes to the left of the dot (.) are assumed to carry the dot (.)) These codes correspond directly with the partial concentrations above. Ca is the concentration of stage Sa, Cb is the concentration of stage Sb, and Cc is the concentration of Sc.
So Sd - Development stage (age) of remaining ice types. So if reported is a trace of ice type thicker/older than Sa. Sd is a thinner ice type which is reported when there are four or more ice thickness types.
Fa Fb Fc - Predominant form of ice (floe size) corresponding to Sa, Sb and Sc respectively. Table 2 below shows the codes used to express this information.
|Stage of Development|
for Sea Ice
|Stage of Development|
for Fresh Water Ice
|New Ice-Frazil, Grease, Slush, Shuga (0-10 cm)||1||New Ice (0 - 5 cm)|
|Nilas, Ice Rind (0 - 10 cm)||2|
|Young (10 - 30 cm)||3|
|Gray (10 - 15 cm)||4||Thin Ice (5 - 15 cm)|
|Gray - White (15 - 30 cm)||5||Medium Ice (15 - 30 cm)|
|First Year (30 - 200 cm)||6|
|First Year Thin (30 - 70 cm)||7||Thick Ice (30 - 70 cm)|
|First Year Thin - First Stage (30 - 70 cm)||8||First Stage Thick Ice (30 - 50 cm)|
|First Year Thin - Second Stage (30 - 70 cm)||9||Second Stage Thick Ice (50 - 70 cm)|
|Medium First Year (70 - 120 cm)||1.||Very Thick Ice (70 - 120 cm)|
|Thick First Year (>120 cm)||4.|
|Old - Survived at least one season's melt (>2 m)||7.|
|Second Year (>2 m)||8.|
|Multi-Year (>2 m)||9.|
|Ice of Land Origin|
|Forms of Sea Ice||Code|
|Forms of Fresh Water Ice|
|~F||Belts and Strips symbol|
followed by ice concentration
|New Ice (0-10 cm)||X|
|Pancake Ice (30 cm - 3 m)||0|
|Brash Ice (< 2m)||1|
|Ice Cake (3 - 20 m)||2|
|Small Ice Floe (20 - 100 m)||3|
|Medium Ice Floe (100 - 500 m)||4|
|Big Ice Floe (500 m - 2 km)||5|
|Vast Ice Floe (2 - 10 km)||6|
|Giant Ice Floe (> 10 km)||7|
|Fast Ice||8||Fast Ice|
|Ice of Land Origin||9|
|Undetermined or Unknown|
(Iceberg, Growlers, Bergy Bits)
Tara was escorted several hours yesterday by Canadian Coast Guard Ship LOUIS S. ST-LAURENT.