Oceanography Lecture Notes

These flashcards cover key concepts in oceanography related to seawater properties, currents, marine ecosystems, and atmospheric interactions.

What is the chemical formula for water?

H₂O.

What are the two hydrogen atoms and one oxygen atom in water molecule classified as?

Atoms.

What type of molecule is water?

Polar molecule.

What property of water allows it to create surface tension?

Cohesion.

What is adhesion in relation to water?

The tendency of water molecules to stick to other substances.

What is specific heat?

The ability of a substance to give up or take in a given amount of heat.

What is heat capacity?

The quantity of heat required to produce a unit change of temperature in a material.

How many calories are required to freeze water?

80 calories.

What happens during the melting of ice?

It absorbs 80 calories.

What is the primary source of ocean water?

Outgassing.

How does erosion contribute to ocean salinity?

It introduces minerals and inorganic ions into seawater.

What is the salinity of seawater?

The total concentration of dissolved minerals and inorganic ions in seawater.

Is the ocean becoming saltier over time?

No, it is in chemical equilibrium.

What layers are present in the ocean regarding density?

Surface zone, pycnocline, deep zone.

What characterizes the thermocline?

Middle ocean zone where temperature changes rapidly with depth.

What is the main properties of seawater that affect marine systems?

Cohesion, adhesion, temperature, salinity.

Why is the ocean blue?

Because of light refraction, absorption, and reflection.

What happens when seawater absorbs more CO2?

It forms carbonic acid, lowering pH and increasing acidity.

What is a major consequence of increased CO2 in the ocean?

Ocean acidification.

What is the Redfield ratio?

The relative molar abundance of key nutrients in marine organic matter, C:N:P = 106:16:1.

Why are coral reefs considered biodiversity hotspots?

They support over 25% of all marine life despite covering less than 1% of the ocean floor.

What impact does ocean acidification have on corals?

It reduces carbonate ion availability for calcification.

What is a significant source of atmospheric CO2?

Burning fossil fuels.

How do nutrients cycle in relation to ocean acidification?

Acidification disrupts ammonia and phosphorus cycling, impacting biological productivity.

What happens at convergence zones in the ocean?

Surface water moves together, leading to downwelling and oxygen-rich water sinking.

What is the primary source of energy that drives ocean currents?

Wind.

Describe the relationship between surface and deep ocean currents.

Surface currents are wind-driven, while deep currents are driven by density differences.

What is the primary consequence of ocean circulation for climate?

It redistributes heat globally.

Explain what thermohaline circulation is.

A type of ocean circulation driven by temperature and salinity differences.

Describe how gyres form in the ocean.

Gyres form when trade winds blow water westward and the Coriolis effect deflects the flow.

What are the five major gyres of the world?

North Pacific, South Pacific, North Atlantic, South Atlantic, Indian Ocean.

What is the Ekman spiral?

The spiral of ocean currents caused by wind stress and Coriolis effect.

What effects do storm surges have during hurricanes?

They cause dangerous rises in sea level leading to coastal flooding.

What is a hurricane's eye?

The calm center of the storm surrounded by the eyewall.

What are the categories of hurricanes based on wind speed?

Category 1 (74-95 mph) to Category 5 (over 155 mph).

What state of the atmosphere is responsible for severe weather like hurricanes?

Low-pressure systems.

What does the term 'albedo' refer to?

The reflective capacity of a surface.

What is the primary cause of seasonal changes in wind patterns?

Seasonal variations in temperature and pressure.

How do ocean currents influence marine ecosystems?

They transport nutrients and organisms, affecting food webs.

Describe what is meant by 'Coriolis effect'.

The apparent deflection of moving fluids due to Earth's rotation.

How does ocean salinity vary with depth?

Salinity increases at high latitudes and decreases at low latitudes.

What is the role of phytoplankton in ocean ecosystems?

They serve as primary producers, forming the base of the marine food web.

What are the effects of increased CO2 in ocean waters?

Increased acidity and reduced carbonate ions for marine organisms.

What phenomenon occurs due to temperature inversions in oceans?

Formation of mixed layers with varying temperature and salinity.

What are thermal upwelling zones?

Areas where nutrient-rich water rises to the surface, supporting high biological productivity.

What is the function of the Gulf Stream?

It transports warm water from the Caribbean towards Europe.

What is the impact of coastal upwelling?

It brings nutrient-rich waters to the surface, boosting productivity.

Explain the influence of urbanization on hurricane impacts.

Increased population density and development raise risk of damage and casualties.

What do Langmuir cells do in surface waters?

Enhance surface mixing and oxygen exchange.

What are the primary drivers of ocean surface currents?

Wind stress and Coriolis effect.

How does the Earth's rotation affect ocean currents?

It causes the deflection of currents to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

What is the main climatic event associated with changes in sea surface temperature?

El Niño.

What defines the mixed layer in ocean stratification?

It is the top layer actively mixed by winds and convection.

How does temperature influence density in seawater?

Density increases as temperature decreases.

What is the primary effect of ocean stratification on nutrient cycling?

It limits vertical mixing of nutrients, affecting marine productivity.

What happens in the pycnocline?

A steep gradient in density separates the mixed layer from deeper waters.

What ecological significance does the ocean's thermocline have?

It traps heat and nutrients, influencing biological productivity.

What is the impact of barrier layers in the ocean?

They reduce vertical exchange of heat and momentum.

What is the role of the Antarctic Circumpolar Current?

It links all ocean basins, facilitating global nutrient and heat transport.

What is the effect of freshwater input from the Arctic Ocean?

It influences North Atlantic deep-water formation.

Describe the relationship between ocean circulation and climate regulation.

Ocean circulation redistributes heat and nutrients, regulating global climate patterns.

What defines the halocline in ocean stratification?

A rapid change in salinity with depth.

How does ocean acidity affect marine life?

It hinders calcification in shell-forming organisms like corals.

What is marine biodiversity?

The variety of life forms in marine ecosystems.

Explain the term 'ocean acidification'.

A decrease in pH of ocean waters due to absorption of CO2.

What is ocean temperature's impact on storm intensity?

Higher temperatures increase storm energy and intensity.

What areas of the ocean are most productive?

Coastal upwelling zones and regions with high nutrient flow.

How often do El Niño events occur?

Every 3 to 7 years.

What is a key characteristic of high-pressure areas in the ocean?

They lead to clear skies and low precipitation.

Define the term 'marine ecology'.

The study of interactions between marine organisms and their environment.

What influence do gyres have on weather patterns?

They can redirect atmospheric circulation and affect precipitation rates.

What is the significance of coral reefs?

They provide vital habitats and resources for marine life.

What does the term 'biogeochemical cycles' refer to?

The movement of chemical elements and compounds between living and nonliving components of the environment.

Why are temperature inversions significant in meteorology?

They can prevent vertical mixing, trapping pollutants near the surface.

How are hurricanes affected by sea surface temperatures?

Warmer oceans can fuel more intense hurricanes.

Explain what thermohaline circulation maintains.

It maintains global heat and nutrient distribution in oceans.

What factor primarily affects global wind patterns?

Uneven heating of the Earth by the sun.

What is meant by 'wind-driven currents'?

Currents generated mainly by the friction between wind and the ocean surface.

Name one factor that contributes to the biodiversity of coral reefs.

Complex structures that provide various ecological niches.

Describe how ocean currents can impact fisheries.

Currents affect nutrient transport, influencing fish populations and distribution.

Why is ocean stratification important for marine ecosystems?

It affects nutrient availability and biological productivity.

What is meant by 'upwelling'?

The process where deep, cold, nutrient-rich water rises to the surface.

What are the primary industries affected by ocean health?

Fisheries, tourism, and coastal protection.

Define the term 'air-sea interaction'.

The exchange of heat, moisture, and momentum between the atmosphere and the ocean.

How does the Earth's orbit affect ocean heating?

Variations in Earth's orbit can alter solar radiation received by oceans.

What drives seasonal changes in ocean currents?

Thermal and atmospheric changes related to seasons.

What do benthic organisms rely on for nourishment?

Detritus and nutrients settling from the water column.

How does urban development exacerbate ocean pollution?

Increased runoff carrying pollutants into marine environments.

What phenomenon occurs due to large scale ocean circulation?

El Niño–Southern Oscillation (ENSO).

What is a major climate consequence of melting Arctic ice?

It contributes to rising sea levels and alters oceanic currents.

What role do mangroves play in coastal ecosystems?

They provide nursery habitats for marine species and protect shorelines.

Why are nutrients cycling critical in oceanic contexts?

They support primary productivity and influence food web dynamics.

Describe the influence of monsoon winds on ocean currents.

They drive seasonal reversals in surface current directions.

What is the significance of the Great Pacific Garbage Patch?

It highlights the problem of marine debris accumulation.

How does tropical storm intensity correlate with ocean temperatures?

Higher temperatures lead to more intense storms.

What ecological role do estuaries play?

They serve as nurseries for numerous marine species.

Define the term 'ocean heat content'.

The total amount of heat stored in the ocean.

What do phytoplankton require for photosynthesis?

Sunlight, carbon dioxide, and nutrients.

What drives seasonal thermocline changes?

Seasonal heating and cooling of ocean surface waters.

What geophysical phenomenon affects ocean currents significantly?

Coriolis effect.