Climate/Winds/Ocean Currents/El Nino

climate

The average weather in a certain area over a long period of time.

polar climate

A type of climate found in the areas around the north and south pole, where the weather is cold and dry. It has no true summer season.

temperate climate

A type of climate located between tropical and polar climates with four distinct seasons and temperature changes.

tropical climate

A type of climate found in the areas just north or south of the equator, where weather is usually hot. It has no true winter season.

factors that affect climate

ocean currents, latitude, mountains, water, elevation

wind

Moving air. Air moves because of differences in pressure. AIR MOVES FROM HIGH PRESSURE TO LOW PRESSURE.

doldrums

A low pressure belt at the equator. It means "foolish" because it would be foolish to sail your ship there because there is little wind.

horse latitudes

High pressure belts at 30o north and 30o south. There is very little wind here. They are called this because ships would have to throw the horses overboard to save resources.

Coriolis Effect

The curving of moving objects, such as wind, because of the rotation of the earth. In the Northern Hemisphere, winds curve to the right. In the Southern Hemisphere, the winds curve to the left.

global winds

Winds that move long distances and follow a certain pattern across the Earth. Example: trade winds

local winds

Winds that move short distances and blow in any direction. Example: sea breeze

trade winds

Global Winds that blow from the 30 latitudes to the equator. The early traders used these winds to sail west.

westerlies

Global Winds that blow from the 30 latitudes to the 60 latitudes in both hemispheres. They blow from the west and blow towards the poles.

polar easterlies

Global Winds that blow from the poles to the 60 latitudes. They blow from poles and from the east.

jet streams

Narrow belts of high speed winds that blow in the upper troposphere and lower stratosphere. The can greatly affect weather. They can help save fuel and time with flying.

sea breeze

A local wind that blows from the sea to the land. This occurs when the land is warmer than the sea. This creates a low pressure over the land and a high pressure of the sea. The wind blows from the high pressure over the sea to the low pressure over the l

land breeze

A local wind that blows from the land to the sea. This occurs when the sea is warmer than the land. This creates a low pressure over the sea and a high pressure of the land. The wind blows from the high pressure over the land to the low pressure over the

El Nino

Refers to the irregular WARMING in the sea surface temperatures from the coasts of Peru and Ecuador to the equatorial central Pacific. It is very unpredictable. Has global weather implications.

Reason for El Nino

The Trade winds WEAKEN/SLOW DOWN in the Central and Western Pacific.
The colder water that the trade winds usually bring up, stays lower in the ocean.
This makes the sea surface temperatures stay WARM.

La Nina

This is characterized by unusually COLD ocean surface temperatures in the Equatorial Pacific. Has global weather implications.

Reason for La Nina

The Trade winds STRENGTHEN/SPEED UP in the Central and Western Pacific.
The trade winds bring up more cold water.
This makes the sea surface temperatures stay COLD.

Ocean Currents

A cohesive stream of sea water that circulates through the oceans.

What affects Ocean Currents

winds, Coriolis effect, uneven heating of the Earth, location of continents

Gulf Stream

A warm ocean current that carries water from the tropics to higher latitudes. This runs along the south east coast of the U.S.

Surface Currents

Along the top several hundred meters.
Mainly moves water from east or west.
Winds affect these the most.
Continents and land masses can act as barriers and deflect the currents at the surface.

Deep Currents

Along the bottom of the ocean.
Mainly moves water from equator to poles.
Affected by the density of the water.
Temperature and salinity (how salty it is) affect the water's density.