Sea Ice Observations during Southern Ocean GLOBEC
Sea ice observations on the Southern Ocean GLOBEC cruises were conducted according to standardized protocols developed and utilized by members of the Antarctic Sea Ice Processes and Climate working group (co-sponsored by SCAR and GlOCHANT).
Related datasets:
ice properties, ice thickness, snow pits
More details regarding methodology can be found at http://www.scar.org/GLOCHANT/ASPeCt/seaiceobs.htm or by contacting Dr. C.H. Fritsen at cfritsen@dri.edu.
OPEN WATER (OpnWtrCode):
Code --- Description
0 --- No openings
1 --- Small cracks
2 --- Very narrow breaks, <50m
3 --- Narrow breaks, 50-200 m
4 --- Wide breaks, 200-500 m
5 --- Very wide breaks, >500 m
6 --- Lead/coastal lead
7 --- Polynya/coastal polynya
8 --- Water broken only by small scattered floes
9 --- Open sea
ICE CONCn (IceCon): to be expressed in tenths.
ICE TYPE (ITypeCode):
Code --- Description
10 --- Frazil
11 --- Shuga
12 --- Grease
20 -- Nilas
30 --- Pancakes
40 --- Young grey ice, 0.1-0.15 m
50 --- Young grey-white ice, 0.15-0.3 m
60 --- First year, 0.3-0.7 m
70 --- First year, 0.7-1.2 m
80 --- First year, >1.2 m
85 --- Multiyear floes
90 --- Brash
95 --- Fast ice
SEA ICE (IThkns) AND SNOWTHICKNESS (SnoThkns): to be expressed in centimetres.
FLOE SIZE (FloSzCode):
Code --- Description
100 --- Pancakes
200 --- New sheet ice
300 --- Brash/broken ice
400 --- Cake ice, <20 m
500 --- Small floes, 20-100 m
600 --- Medium floes, 100-500 m
700 --- Large floes, 500-2000 m
800 --- Vast floes, >2000 m
SNOW TYPE (SnoTypCode):
Code --- Description
0 --- No snow observation
1 --- No snow, no ice or brash
2 --- Cold new snow, < 1 day old
3 --- Cold old snow
4 --- Cold wind-packed snow
5 --- New melting snow (wet new snow)
6 --- Old melting snow
7 --- Glaze
8 --- Melt slush
9 --- Melt puddles
10 --- Saturated snow (waves)
11 --- Sastrugi
TOPOGRAPHY (TopoCode):
| Code |
Description |
| 100 |
Level ice |
| 200 |
Rafted pancakes |
| 300 |
Cemented pancakes |
| 400 |
Finger rafting |
| 5xy |
New, unconsolidated ridges (no snow) |
| 6xy |
New ridges filled with snow or a snow cover |
| 7xy |
Consolidated ridges (no weathering) |
| 8xy |
Older, weathered ridges |
| x values |
Areal Coverage |
| 0 |
0-10% |
| 1 |
10-20% |
| 2 |
20-30% |
| 3 |
30-40% |
| 4 |
40-50% |
| 5 |
50-60% |
| 6 |
60-70% |
| 7 |
70-80% |
| 8 |
80-90% |
| 9 |
90-100% |
| y values |
Avg. Sail Height |
| 1 |
0.5 m |
| 2 |
1.0 m |
| 3 |
1.5 m |
| 4 |
2.0 m |
| 5 |
3.0 m |
| 6 |
4.0 m |
| 7 |
5.0 m |
The following weather observation codes and descriptions are from the "National Weather Service Observing Handbook No. 1", Marine Surface Weather Observations, August 1995. U.S. Department of Commerce, Silver Spring, MD.
VISIBILITY (visib):
Code --- Visibility in m/km
90 --- less than 50 m
91 --- 50 but less than 200 m
92 --- 200 but less than 500 m
93 --- 500 but less than 1000 m
94 --- > 1 but less than 2 km
95 --- > 2 but less than 4 km
96 --- > 4 but less than 10 km
97 --- > 10 but less than 20 km
98 --- > 20 but less than 50 km
99 --- > 50 km or more
TOTAL CLOUD COVER (cldcvr): to be expressed in eighths; -1 = Sky obscured by fog, snow or other met. phenom.
PRESENT WEATHER (wx):
| Code |
Description |
| |
Change of sky during past hour |
| 0 |
Cloud development not observable |
| 1 |
Clouds dissolving or becoming less developed |
| 2 |
State of the sky on the whole unchanged |
| 3 |
Clouds generally forming or developing |
| |
Phenomena in past hour but not at time of obs |
| 28 |
Fog (in past hour, but not at time of obs.) |
| |
|
| 36 |
Slight or moderate drifting snow, low (below eye level) |
| 37 |
Heavy drifting snow, low (below eye level) |
| 38 |
Slight or moderate drifting snow, high (above eye level) |
| 39 |
Heavy drifting snow, high (above eye level) |
| |
Fog at the time of observation |
| 41 |
Sky visible
Fog in patches (visibility may be greater than 1/2 nm) |
| 42 |
Sky visible
Fog has become thinner in past hour |
| 43 |
Sky invisible
For has become thinner in past hour |
| 44 |
Sky visible
Fog, no change in past hour |
| 45 |
Sky invisible
Fog, no change in past hour |
| 46 |
Sky visible
Fog has begun or thickened in past hour |
| 47 |
Sky invisible
Fog has begun or thickened in past hour |
| |
Drizzle |
| 50 |
Intermittent
Slight drizzle |
| 56 |
Slight
Freezing drizzle |
| |
Rain (Not falling as showers) |
| 60 |
Intermittent
Slight rain |
| |
Solid precipitation not falling as showers |
| 70 |
Intermittent
Slight snow in flakes |
| 71 |
Continuous
Slight snow in flakes |
| 72 |
Intermittent
Moderate snow in flakes |
| 73 |
Continuous
Moderate snow in flakes |
| 74 |
Intermittent
Heavy snow in flakes |
| 75 |
Continuous
Heavy snow in flakes |
| 76 |
Diamond dust (with or without fog) |
| 77 |
Snow grains (with or without fog) |
| |
Solid precipitation in showers |
| 85 |
Slight
Shower of snow |
| 86 |
Moderate or heavy
Shower of snow |
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