week two - ocean circulation, tides, waves

Why does is solar intensity greater at the equator in comparison to the poles?

Solar radiation hits the equator directly, compared to the poles which are at a rounded surface area making the distance between solar rays and the affected area greater and thus more spread out

What is the Coriolis Effect?

The Coriolis effect is the apparent deflection of moving objects like wind and ocean currents due to the Earth's rotation.

How does solar radiation drive climate?

Solar radiation drives climate by heating Earth's surface, which in turn causes differences in air temperature and pressure that create winds and weather patterns. This is because solar radiation heats the earth unevenly, where the equator suffers the most heat intensity and the poles suffer the least.

Does the Coriolis Effect affect ocean movement?

Yes. The Oceans are moving across the surface of a spinning Earth

What is the Ekman Spiral?

The Ekman spiral is a theoretical model that describes how a wind-driven current in the ocean creates a spiral of water motion with depth, caused by the Coriolis effect and friction. As the wind moves the surface layer of water, it drags the layer below it, which is then deflected by the Coriolis effect to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. Each successive layer of water moves more slowly and is further displaced, creating a spiral pattern where the water motion gets progressively slower and more angled with depth. 

What is Ekman Transport?

Ekman transport is the net movement of ocean water caused by wind, resulting in a transport of water at a 90-degree angle to the wind direction due to the Coriolis effect. This net movement is to the right of the wind in the Northern Hemisphere and to the left in the Southern Hemisphere. This phenomenon is a critical factor in generating ocean upwelling and downwelling, which are vital for ocean ecosystems. 

What is coastal upwelling?

Coastal upwelling is a process where winds push surface water away from the coast, causing cold, nutrient-rich water from the ocean depths to rise to the surface. This happens because winds blow along the coast, and the Earth's rotation (Coriolis effect) causes the surface water to be transported offshore

What is Equatorial upwelling?

Equatorial upwelling is a process where strong trade winds push surface water away from the equator in opposite directions, causing cold, nutrient-rich deep water to rise and replace it. This occurs because the Coriolis effect deflects surface currents to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, creating a divergence at the equator

What is Downwelling? 

Downwelling is the process where surface water sinks to deeper ocean layers, often driven by winds pushing water together or cooling and increasing its density. This sinking motion is crucial for global ocean circulation, as it transports oxygen-rich surface water and heat to the deep ocean, which can reduce biological productivity in the surface waters and contribute to the formation of intermediate water masses. 

What is a Gyre?

circular motion of water in the major ocean basins

How does Ekman transport result in water mounding?

The ocean gyres move clockwise in the Northern Hemisphere and Counter-clockwise in the Southern Hemisphere

What is the Eularian method of tracking ocean circulation? 

Measuring fluid movement around a fixed point

What is the Langrangian method of tracking ocean circulation?

Measuring fluid movement by following particles in the fluid. (global drifter array)

What do currents influence?

Currents influence global climate, local conditions, and distribution and abundance of organisms

What are eddies?

Swirling of a fluid and reverse current when fluid flows past an obstacle (can be large or small)

How do eddies form?

They form from water interacting with water/land

What is a bight?

A bight is a bend in the coastline

What is thermohaline circulation?

Thermohaline circulation is a large-scale ocean current system driven by differences in water density, which is determined by temperature and salinity. It is often called the "global ocean conveyor belt" and involves both surface and deep-water currents that distribute heat around the planet

What is the “global conveyor belt”?

The global conveyor belt is a large-scale ocean circulation system that moves warm and cold water around the planet, regulating climate by distributing heat.

Is Thermohaline circulation an example of a convection cell?

yes/no*

How will reduction of sea ice impact global ocean circulation?

**

When are tidal bulges the largest?

They are largest during full and new moons, when the sun and moon are pulling tides parallel to each other.

When are tidal bulges the smallest?

They are smallest during quarter moons, when the sun and moon are pulling perpendicular to each other.

What are semidiurnal tides?

When there are 2 high tides and 2 low tides in a day

What are mixed semidiurnal tides?

when there are two high tides of different heights in a day

What are diurnal tides? 

when there is one high tide and one low tide in a day. this is less common.

What type of waves are wind-generated waves?

Wind-generated waves are progressive waves because they travel across the sea surface.

What determines the type of wave generated by wind?

wind velocity, wind duration, and fetch

what is fetch?

fetch is the distance which over the wind blows

what are wind waves?

wind waves are shorter period waves that result from local winds

What is swell?

Swell are longer period waves that build over large water bodies as a result of major weather patterns (i.e. winds very far away)

What types of waves are progressive waves?

Wind waves and Swell

What are wave refractions?

What types of waves are tidal waves?

Tidal bore and Tsunami waves

What is tidal bore?

tidal bores are waves that surge upriver with an incoming tide

what are tidal waves?

waves that are generated by tides

what are tsunami waves?

tsunami waves are waves generated by tectonic activity or extraterrestrial impacts