Properties of Sea Water Flashcards
What makes water special?
- Physical propety: water has great heat capacity
- Chemical property: very good solvent
- Implications for Earth and ocean, directly affect chemitsry of seawater and how the ocean moderates Earth’s temperature
Other important aspect of water: density, light, pH, gases
- Density changes as a result of chanegs in temp and changes in salinity –> ocean circulation
- Light does not travel far in the ocean, but sound does –> life in the ocean
- the pH of seawater is relatively constant, 8.2 –> life in the ocean
- gases (oxygen, carbon dioxide) dissolve easily in sea water –> climate
Thermostatic properties
Properties that act to moderate changes in temp
* high heat capacity - amount of heat needed to produce a unity change in temp
* high latent heat - amount of heat that can be absorbed when it changes state
* strong thermal inertia - ability to hold onto stored energy
How to change states of matter?
Change in heat/energy
Temperature
The property of the water that changes as heat is added or removed
Heat
A measure of the amount of energy contained in a volume of water
Heat capcity
The amount of energy (or heat) required to raise the temperature of 1 g of a substance by 1 degree C (measured in calories per gram per degree)
Latent heat
- Energy is being added, but the temperature does not chaneg (the energy is “hidden away” in the water)
- Certian amount of heat need to be added to chaneg temp of water. releases or absorbed heat during phase change
How to exchange energu between low and high latitudes?
Evaporation and condensation
Water density
Mass / volume
kg / m^3 or g / cm^3 or g / mL
Controlled by temperature and salinity (and pressure)
Desnity of pure freshwater and seatwater
1000 kg / m^3 = 1 g / m^3
1022 to 1030 kg / m^3
Why does water become less dense as it freezes?
- Water is packed less desnly is ice
- Change in density comes from change in volume
Effect of salinity on density
Salinity
The total amount of dissolved inorganic solids in the water
* Average salinity is 3.5% = 35 ppt
* Open ocean 33-38%
How does salinity impact ocean
- Increases the density
- Lowers the freezing point of water from 0 C to -1.9 C
- Increases pH of water from 7 to 8.1