Chemical And Physical Feat Of The World Ocean Flashcards
Water (H2O)
- Water molecules has slight positive (hydrogen) and negative (oxygen) electrical charges
- slight electrical charges creat attraction among water molecules, hydrogen bonds (polar)
Ice (water solid form)
- as liquid water cools, water molecules move more slowly
- forms 3D crystal structured around hydrogen bonds. In Ice crystals water molecules are farther apart than in liquid form which causes water to expand when it freezes: ice is less dense than liquid water (hence why it floats)
-IMPORTANT because if ice was more dense than liquid water, bottom of the ocean would be solid ice! Hence this means we have life all the way in the challenger deep!
Evaporation (water vapor)
- hydrogen bonds are relatively weak so as temp increases so does the speed of movement of water molecules. Moves fast enough to break all its hydrogen bonds it will enter the gaseous phase as water vapor
Water density
Liquid water cools it becomes more dense to a point, at 4°C it reaches it’s highest density
From 4°C to 0° it will start to decrease in density! Because the volume decreases without changing the mass the water gets denser
Latent heat of melting & heat capacity
Lots of energy is needed to melt ice and to form it as well (time to freeze and to melt)
Lots of heat to raise the temp of water, having a high heat capacity
Latent heat of evaporation & evaporative cooling
Water also has a high latent heat of evaporation, the heat absorbed when water evaporates
Only fats moving molecules can break their hydrogen bonds to enter the gaseous phase leaving behind the slow ones
Water as a Solvent
Known as “universal” solvent, can dissolve more solutes than any other natural solvent
Source of Seawater
Weathering of rock on land and carried to the ocean via rivers
Hydrothermal vent
Substances in atmosphere from volcanoes enter the ocean via perception
Salinity and measurement
The total dissolved salt in seawater
Can be measured in grams left behind after water evaporates or ion conductivity which is equivalent to %
Salinity, temp, and density
- seawater density changes with BOTH temperature and salinity, density increases as water gets colder and saltier
- cold water sinks underneath warmer water
Seawater and ice
Floating ice insulates the water underneath so that it does not freeze, allowing aquatic organisms to thrive
Gas exchange
Occurs between seawater and the atmosphere, with critical implications for land and ocean animals, earth climate, global distribution of pollutants
Temperature and Dissolved Gases
- amount of dissolved gases is altered by organisms photosynthesis and respiration rate
- colder water holds more dissolved gases than the same volume of warmer water
- there is more dissolved oxygen near poles and in deep water
Pressure
Pressure increases with death at rate of 1 atmospheres (ATM) for every 10 m depth
What is earth’s energy budget
Input: almost all solar (light and heat), ~47% absorbed by earths surface
Output: some solar energy reflected and rest is lost into atmosphere and then space
Albedo unit
0 = black or perfect absorber
1 = white or perfect reflector (ice caps act as reflectors)
Surface circulation
Driven by winds and surface currents
How is wind formed?
Flow towards the equator as heat energy from sun make are less dense, causing it to rise, causing are from higher latitudes to flow in to replace
