Download 1. - Density ice at 0 C less than density water at 0 C

1.
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Density ice at 0 C less than density water at 0 C
Strong hydrogen bonds
High heat capacity
Exists in all three forms
Many molecules remain bounded together in liquid state
2.
Volcanic eruptions, weathering of rocks on land and chemical reactions between
seawaters and hot, newly formed, crustal rocks (most important)
3.
Temperature change, phase constant : Heat required = Q = m*cp*∆T, where cp =
heat capacity
Temperature constant, phase changes: Heat required = Q = m*L, where L = latent
heat
Five steps: Ice -10 C Æ ice 0 C : Q = 2000*0.5*10 = 10.000cal
Ice 0 C Æ water 0 C: Q = 2000*80 = 160.000cal
Water 0 C Æ water 100 C: Q = 2000*1*100 = 200.000cal
Water 100 C Æ vapour 100 C: Q = 2000*539 = 1.078.000cal
Vapour 100 C Æ vapour 125 C: Q =2000*0.45*25 = 22.500cal
Q_total = 10.000+160.000+200.000+1.078.000+22.500 = 1.470.500cal = 1.47Mcal
4.
Two reasons : water has higher heat capacity AND heat is mixed in ocean in the
surface layer, whereas on land it stays near the surface
5.
Areas with excess precipitation have low salinity; areas with excess evaporations
have high salinity
6.
1: More warm water remains at west coast of South America (flatter ocean) . 2: No
more upwelling of cold water off coast of South America
7.
Ekman spiral: 3 crucial points: 1) spiral is wind-driven, 2) there is an angle
between surface wind and surface current, but also deflection between layers in the
ocean, 3) there is an energy transfer from upper layer to lower layer, but due to
viscous dissipation energy is lost during this transfer process, resulting in lower
speeds in deeper water.
Real ocean: wind not steady, inhomogeneous, other currents present in ocean,
boundaries, real ocean is more turbulent than laminar, etc.
8.
Subtropical gyres are always anticyclonic (direction of rotation opposite to
direction of rotation of Earth), i.e. clockwise on NH, and counterclockwise on SH.
On NH, water is transported to the right of the current, on SH to the left. This
results in net inward water motion in subtropical gyres on both hemispheres, giving
rise to hills in their centers. For subpolar gyres, there are counterclockwise on NH
and clockwise on SH, causing water to be deflected outward and the formation of
valleys in the centre
9.
Use formula: Time = distance/speed
Gulf Stream: T1 = 1.000.000/1 = 1.000.000s
NA current: T2 = 4.000.000/0.05 = 80.000.000s
Î 1.000.000 + 80.000.000s = 81.000.000s = 22.500hours = 2.57years
10. Coastal upwelling: along western boundary (on NH), net water movement offshore,
gives upwelling
Equatorial boundary: Coriolis changes direction at equator. Westward wind causes
water to be transported northward on NH and southward on SH. This results in
divergence at the equator, water up welled from below.