SDSU Ocean 100 Exam 2

What is the basic structure of a water molecule?

Two oxygen (-) and one hydrogen (+) in a “mickey mouse” shape

What is so particular about a water molecule?

It’s a polar molecule meaning it attracts both negatively and positively charged atoms

What kind of bonds are found in water molecules

Covalent bonds

What kind of bonds are found in water that bonds multiple water molecules together?

Hydrogen bonds

What do these strong bonds in water lead to?

Cohesion

Why is water a polar molecule?

It has both negatively charged and positively charged atoms, hydrogen (+) oxygen (-)

What do we call water as a result of it being a polar molecule?

Universal solvent

What happens to salt in water?

Salt dissolves as hydrogen takes the Cl- and oxygen takes the Na+ slowly dissolving it

What are the three phases of water?

Ice, water, vapor

How does water change from one phase to another?

Adding or removing heat

What happens to the hydrogen bonds during the phase change to ice?

Hydrogen bonds are all bonded

What happens to the hydrogen bonds during the phase change to water?

Most hydrogen bonds are bonded

What happens to the hydrogen bonds during the phase change to vapor?

None of the hydrogen bonds are bonded

What is the heat capacity of water?

High heat capacity

What does it mean to have a high heat capacity?

It takes a lot time to heat up or cool down and it absorbs a lot of energy and releases lots of energy

What is the heat capacity of sand?

Low heat capacity

What does it mean to have a low heat capacity?

It takes little time to heat up and cool down, it absorbs little energy and releases little energy

What influences the coastal climate?

Water influences the coastal climate because of its high heat capacity

How does salinity affect density?

Increase salinity means increases density and vise versa

What happens to cold, salty water (thermal contraction)?

Sinks as it has higher density

What happens to warm brackish water (thermal expansion)?

It rises as it has a low density

What does water do at the poles?

Cold water sinks and goes to warmer areas and the cycle continues and keeps temperatures moderate (ocean doesn’t freeze up)

What does water do at the equator?

Warm water rises and goes towards cooler areas and cycle continues and keeps temperatures moderate (ocean doesn’t boil over)

What is the temperature of the max density of water?

4* C

How does the density of water change when freezing?

It decreases in density due to less volume in the same amount of mass, it takes a honeycomb like shape allowing air to fill in the same (less dense than water)

What is salinity?

Amount of dissolved solids in water

What is the average salinity in the world’s ocean?

35 parts per thousands

What are the most abundant salt ions?

Na+Cl-

How is the surface salinity at the equator?

Moderate salinity

How is the surface salinity at the subtropical regions?

High salinity

How is the surface salinity at polar regions?

Low salinity

What are the evaporation latitudes?

30* and at the equator

What are the precipitation latitudes?

60* and at the equator

Salinity of the Mediterranean Sea

Has high salinity

Salinity of the Baltic Sea?

Has low salinity

What are the most abundant sources of salt?

Volcanoes, erosion, runoffs, thermal vents

What is the surface layer?

Makes up 2%, receives lots of sunlight, due to this it’s quite warm

What is the thermocline?

Makes up 18%, last layer that receives sunlight, progressively getting colder, found in tropical regions

What is the deep zone?

Makes up 80%, deep, dark, cold, receives no sunlight, NOT found in tropical regions

Define thermocline

Change in temperature

Where are the places where seawater sinks to the bottom?

Polar regions

Where is solar radiation least absorbed?

Polar regions

Where is solar radiation most absorbed?

Equator

What is the flashlight example?

A flashlight is being shined directly, the light is bright (representing the heat being direct), while if you shine the flashlight at a low angle the light is more spread out representing the heat being less direct 

What distributes heat around Earth?

Wind and currents

What is relevant about the troposphere?

Only sphere where weather occurs

What does air moving from H to L pressure means?

Wind

Describe Hadley Cell

• 30* Latitude: cold, dry air which causes it to sink because high density, high pressure, it compresses and warms up and goes back to 0* and continuing the cycle

• 0* Latitude: warm humid air rises, not dense and low pressure, expands which causes it to cool down and condenses and turns into clouds and goes to 30*

What are the two major winds in America?

Westerlies and Easterlies

What latitudes are the winds found in the US are located?

30*-60*

What does the Coriolis affect do to the Northern and Southern hemispheres?

Causing veering to the right in the Northern hemisphere and in the Southern hemisphere veering to the left

How does the Coriolis affect the prevailing winds?

Affects prevailing winds by causing things to veer off to the right or to the left depending on what hemisphere you are in

How does the Coriolis effect affect cyclones and anticyclones?

Allows them to occur, at the equator no Coriolis affect causes no cyclones or anticyclones, cyclones cannot cross the equator

What is a cyclone?

Are low pressure and they spin counterclockwise in the Northern hemisphere 

What is an anticyclone?

 Are high pressure and they spin clockwise in the Northern hemisphere

What are hurricanes?

Tropical cyclones, they spin fast and counterclockwise in the Northern hemisphere and clockwise in the Southern hemisphere, they form in tropical regions 

When is hurricane season?

September to November

Why don’t hurricanes form during the summer?

High heat capacity of water leads to it absorbing a lot of energy from the Summer and releasing it in September to November

What are the conditions for hurricanes to form?

Winds must be moving 120 km/hr, seawater is 26*C, warm moist air (tropical regions), weak wind shear

What damage do hurricanes cause to the coastlines?

Erosion, flooding, destroying coastal homes

What are storm surges?

Ocean water being picked up by the storm and being pushed onto land

Why are storm surges deadly?

It causes a lot of flooding and high turbulent seas 

Why was Hurricane Katrina so deadly?

It caused severe flooding, destroying many homes, since New Orleans (primary city affected) is below sea level and its dominated by delta (flat), 80% of the city was flooded 

What is a surface current?

It’s driven by prevailing winds

What is a deep ocean current?

Driven by density and occur at polar regions 

What are the characteristics of the Western Boundary Current?

ex. Gulf Stream, warm, flows west of ocean basin, gets warmth from tropical regions/equatorial regions, deflects North by continents, makes the climate warm and humid

What are the characteristics of Eastern Boundary Currents?

ex. California Current, cold, flows east, gets cold from sub-polar regions, deflected South by continents, makes the climate cold and dry 

What powers gyres?

Winds and Coriolis effect

How to gyres move in the ocean?

Circular like motion

What is Ekmen transport?

Moving to the right of the wind in the Northern Hemisphere because of Coriolis affect 

What is upwelling?

Deep waters coming up, brings nutrient rich water to the surface of the ocean

How does upwelling relate to life in the ocean?

It provides rich nutrients to the surface causing sea life to thrive

How does El Nino effect currents, winds, and the conditions it causes?

Thermocline lowers, trade winds go back to east, reverses their direction towards Americas, warm waters flow to America, more rain & low pressure systems, low productivity (sea life) and less upwelling

How does La Nina effect currents, winds, and the conditions it causes?

Warm and dry conditions in South, Trade winds are strong pushing to Asia, cold waters in America 

What are we going through right now? El Nino or La NIna?

El Nino

What type of weather should be expect soon because of El Nino?

Humid weather with lots and lots of rain

Where do deep currents originate?

Polar regions

Where do deep currents go?

Into the thermohaline circulation belt

What is the driving force of deep currents?

Density of waters

What is notable about the Antarctic waters in regards to thermohaline circulation?

Bottom waters, most dense and cold out of the two sources of currents

What are the two sources of deep currents?

North Atlantic and Antarctic

What is notable about North Atlantic in regards to thermohaline currents?

Deep waters, less dense compared to the other source of deep currents

Why don’t sea water sink at the equator?

Warmer water, less dense therefore doesn’t sink, plus Equator lacks a deep zone (where it would occur)

What are waters like at the Poles?

Cold, dense water