Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea...
Transcript of Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea...
![Page 1: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/1.jpg)
Sea iceSébastien Barrault
Safety Course
January 2008Content
• UNIS & Sea ice
• Ice location & Dynamics
• Sea ice physics
• Scale and Ice feature
• Sea ice extent around Svalbard
• Decay
• Useful links
![Page 2: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/2.jpg)
Sea
ice & UNIS
Barrault Haig
• Cruises on
research
vessels
• Snow
scooter driving on
ice
![Page 3: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/3.jpg)
Sea
ice in the northern
hemisphere
![Page 4: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/4.jpg)
Ice dynamics
![Page 5: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/5.jpg)
•
Triple point –
3 phases are in equilibrium: T = 273.16 K, p = 611.7 kPa•
H2
O expands on freezing•
Other examples: Silicone, germanium•
The crystals reveal the hexagonal symmetry of the crystal lattice of ice (0°C< Ih
<-
80°C) •
Basal plane with
hexagonal
symmetry
and c-axis
Continuous
molecular
structure
(Løset et al., 2006)
![Page 6: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/6.jpg)
Initial discs, size ≈1 mm Stellar ice crystals
Growing
of isolated
crystals
(Løset et al., 2006)
![Page 7: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/7.jpg)
New ice Recently formed ice:Frazil ice Grease iceSlushShuga
Nilas Dark nilas < 5 cm thick. Light nilas > 5 cm thick.
Pancake ice Circular pieces of ice 0.3-3 m in diameter, up to about 10 cm in thickness.
Young ice Ice in the transition stage between nilas
and first-year ice, 10-30 cm thick.Grey ice 10-15 cm thick. Grey-white ice 15-30 cm thick.
First-year ice Developing from young ice, thickness 0.3 m –
2 m.Thin FY ice: 0.3-0.7 m thickMedium FY ice: 0.7-1.2 m thick.Thick FY ice: over 1.2 m thick.
Old ice Second year ice: < 2.5 m thick. Multi-year ice: up to 3 m or more thick
Ice growth: definition
Barrault Barrault Barrault
![Page 8: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/8.jpg)
• No snow
• No radiation
• No heat transfer from the ocean, qocean
= 0
• A linear temperature profile through the ice sheet
• qice = -kΔT/ Δ
z
• qlatent = qice = qsurface
l –
latent heat of fusion (333.4 kJ/kg)
ρ –
density of ice (917 kg/m3)
k –
thermal conductivity (2.2 W/m°C) i
sfice h
TTkq
−−=
dtdhlq i
latent ρ=
qocean = 0
qsurface
Ta
Ts
ice
air
water
T
hi
dhi
z
Freezing
Degree
Days [°Cdays]
Ice growth: Stefan’s
law
Tf
![Page 9: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/9.jpg)
l –
latent heat of fusion (333.4 kJ/kg)
ρ –
density of ice (917 kg/m3)
k –
thermal conductivity (2.2 W/m°C)
Ice growth: Stefan’s
law
Ts
= -10C
C. E. Bøggild (2007)
tH ∼
![Page 10: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/10.jpg)
Structure of sea year sea ice
(Løset et al., 2006)
![Page 11: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/11.jpg)
1000 g of
sea
water contains:
23.5 g NaCl
4.5 g MgCl23.9 g Na2
SO4
1.1 g CaCl2
+ rest
34.5 g of
salt
Sea
ice
language
: 34.5 psu or ppt
Chemical
composition
of sea
ice & Freezing
point
Tf = -
1.86°C
Freezing point vs
salinity:
Tf (°C) = -0.0539 ⋅ S(psu)
![Page 12: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/12.jpg)
Salinity
profile
C -
shape
-70
-60
-50
-40
-30
-20
-10
00 1 2 3 4 5 6 7 8
Salinity [psu]
dept
h[c
m]
dept
h[c
m]
![Page 13: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/13.jpg)
-1,3-1,2-1,1
-1-0,9-0,8-0,7-0,6-0,5-0,4-0,3-0,2-0,1
00,10,20,30,40,50,60,70,80,9
11,11,2
-25 -20 -15 -10 -5 0
Temperature (Deg C)
Dep
th (m
)
Temperature
profile
![Page 14: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/14.jpg)
Scales
in sea
ice research
•
microscale
10-4
- 10-1
m
physics
•
local
scale
10-1
- 101
m
engineering
•
floe
scale
102
- 103
m
•
mesoscale
104
- 105
m
geophysics
•
large
scale
106
m
geophysics
Moslet
Barrault
Barrault
Løset
![Page 15: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/15.jpg)
Ice Ridge, NW Barents Sea –
drift ice
Ice floes – drift ice Iceberg, Franz Josef Land – drift ice
Landfast
ice, Franz Josef Land
Marchenko
Løset Marchenko
Ice features
![Page 16: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/16.jpg)
FY ice ridge
wind
sail
keel
Ice blocks, Ridge Sail
Ice rubble-blocks, Ridge KeelShafrova
![Page 17: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/17.jpg)
Ice ridge
FY
SY MY
![Page 18: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/18.jpg)
Ice cover zones of different dynamic character:
• Landfast
ice• Shear zone• Marginal ice zone (MIZ)• Central pack
Ice floes in MIZ zone
0
10
20
30
40
50
0 20 40 60 80Distance from the ice edge (km)
Mea
n flo
e si
ze (m
)
Transition zone Interior Edge
(Løset
et al., 1989)
Drift ice divided as:
Description
of drift
ice
(Løset
et al., 2006)
![Page 19: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/19.jpg)
Sea
ice extent
around
Svalbard
DNMI data (IDAP report, 1994)USSR Atlas of the Oceans, 1980
August, September(USSR Atlas of the Oceans, 1980)
April September
![Page 20: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/20.jpg)
Sea
ice extent
around
Svalbard
in 2004
7 Dec
2003
12 Jan 2004
17 Feb
2004 27 May 2004
13 May 2004
14 Apr
200422 Jun 2004
11 Aug
2004
6 Sep 2004
![Page 22: Sea ice - UNIS · Sea ice Sébastien Barrault Safety Course. January 2008. Content • UNIS & Sea ice • Ice location & Dynamics • Sea ice physics • Scale and Ice feature •](https://reader034.fdocuments.net/reader034/viewer/2022042315/5f043e137e708231d40d034b/html5/thumbnails/22.jpg)
Norwegian
Meteorology
Institute•
http://met.no/kyst_og_hav/iskart.html
(ice
maps)Also on:
W:\COURSE MTR & DATA StudentsReadOnly\Common DataLibraryUNIS entrance
•
http://polarview.met.no/cgi-bin/highres_arkiv.pl
(ice maps archive)•
http://conman.met.no/sathav-is/svalbard_forecast.html
(ice
forecast)
University of
Bremen•
http://www.seaice.de•
http://iup.physik.uni-bremen.de:8084/amsr/amsre.html
ESA financed
program•
http://www.polarview.org•
http://www.seaice.dk/test.N
Sea
ice maps
for Svalbard
and Fram
Strait