Weather Currents

Unit 7- Earth's Atmosphere & Oceans

Wind & Ocean Currents

​Wind is air in Motion...

​You cannot see the wind, but you can see how is energy can move objects. the energy in wind moves more than tree branches and leaves. It also moves the water at the surface of the ocean.

...the air over that surface also heats up.

​

As Earth's surface heats up...

The warmer the Earth's surface is,

the warmer the air above it becomes.

​

​Uneven heating...

​​...because of differences in air density (cold air/warm air)

​causes wind...

​As air heats up...

​

gas molecules in the air move faster and farther apart.

​

So, the air becomes less dense (lighter) & takes up more space (spread out)

​How?...

Multiple Choice

How are the convection currents in the student's model different from the convection currents in Earth's atmosphere and oceans?

• A

• B

• C

• D

​When the Sun shines, land areas heat up faster than bodies of water. So air over the seashore becomes warmer than air over the ocean.

​After the Sun sets, the land cools faster than the water.

Wind blows from ocean to land...

Wind blows from land to ocean...

​Did you know?

​Convection...

​...the transfer of heat from one region to another by circulation of a fluid (water or air)

Wind and Convection Drive Ocean Currents

​How do ocean currents happen?

​Winds push on ocean water and makes it move.

Multiple Choice

Major surface currents of the ocean are shown in the diagram.

Ocean currents affect weather patterns by --

• F.

  regulating when tides occur in costal areas

• G.

  trapping heat at the equator to regulate the global climate

• H.

  distributing heat from the uneven absorption of solar energy

• J.

  increasing the rate of evaporation to transport water to areas experiencing droughts.

​These currents are caused by convection, due to differences in the density of ocean water.

​Cold, salty water is denser than warmer, less salty water.

Like air, the warmer less dense water rises, and colder denser water replaces it.

​This difference in density causes deep ocean currents to flow in a circular pattern.

​both surface currents and deep ocean currents affect weather.

Dropdown

Low Pressure area: ​​

Select answer

Cold air sinks: ​

Select answer

Dropdown

High Pressure area: ​​

Select answer

Warm air rises: ​

Select answer

Multiple Choice

What is the primary source of the energy that drives winds?

• Mechanical energy of ocean waves

• Light energy from the sun

• Chemical energy of air molecules

• Thermal energy from deep inside Earth

Weather

​If you walk outside...

​and it is sunny but the clouds make you think it might rain, you're predicting the weather.

​Weather is the condition of the atmosphere at a particular time and place.

​Distant winds and ocean currents can affect local weather, even in places that are far from the ocean

​Air Masses are large bodies of air that have the same temperature and moisture throughout.

Winds cause air massess to move.

Where two air masses meet, that's called a front.

Fronts bring changes in weather.

​Cold Front

Warm Front

Multiple Choice

• A

• B

• C

• D

Interpreting a Weather Map

Multiple Choice

• A

• B

• C

• D

​Cold Front

​After:

• Warmer Temps

Before:

• Colder Temps

• Thunderstorms

​Warm Front

​After:

• Cloudy Skies

• Light Rain

Before:

• Warmer Temps

• More Humidity

Multiple Choice

• A

• B

• C

• D

Multiple Choice

• A

• B

• C

• D

Match

Match the each term to its definition:

• Weather

• Weather map

• cold front

• air mass

• warm front

The condition of the atmosphere at a particular time and place

An illustration of current weather conditions and the location of air masses and fronts

A boundary that forms when a cold air mass moves under a less dense warm air mass

A large body of air that has the same temperature and moisture throughout

A boundary that forms when a warm air mass moves over a denser cold air mass

• The condition of the atmosphere at a particular time and place

• An illustration of current weather conditions and the location of air masses and fronts

• A boundary that forms when a cold air mass moves under a less dense warm air mass

• A large body of air that has the same temperature and moisture throughout

• A boundary that forms when a warm air mass moves over a denser cold air mass

Open Ended

What's a front?

Multiple Choice

Which forecast gives the most likely temperature for Point X or Point Y after the front passes?

• Point Y will be 14℃

• Point X will be 21℃

• Point X will be 3℃

• Point Y will be 32℃

Oceans and Weather Systems

Multiple Choice

• A

• B

• C

• D

​Hurricane Formation

One severe kind of wether that forms over ocean water is a hurrican. Hurricanes are large, powerful, rotating storm systems with high-speed winds.

​Hurricane in the Northern Hemisphere

Dropdown

A hurricane is formed from ​

Select answer

that is generated by ​

Select answer

ocean water.

Multiple Choice

Which condition is most important to the formation of a hurricane?

• Rapid changes in water temperature

• High-pressure systems

• Strong ocean winds

• Warm ocean temperatures

Multiple Choice

• A

• B

• C

• D