Nelson Science 10 Section 13.9 Nelson Science 10 Section 13.9 (525)(525)Weather Dynamics UnitWeather Dynamics UnitScience 10Science 10Mrs. S. Pipke-PainchaudMrs. S. Pipke-Painchaud

Weather and OceansWeather and Oceans

Oceans are very important in creating Oceans are very important in creating global weather patterns.global weather patterns.– Occupy a large portion of the earth’s Occupy a large portion of the earth’s

surfacesurface– Most land masses are found at 45* northMost land masses are found at 45* north

What does this mean? What does this mean? – There is a lot of water at the equator to absorb There is a lot of water at the equator to absorb

the sun’s rays.the sun’s rays. What is the purpose of ocean currents?What is the purpose of ocean currents?

– Distribute the energy around the worldDistribute the energy around the world (Nelson Science 10 525)(Nelson Science 10 525)

http://www.oceansonline.com/ocean_currents.htm

Red = warm currents / Black = cold currents / Orange = water of 20°C or more

http://www.starfish.ch/reef/ocean.html

http://www.studyofplace.com/ActivityContent/M2_A3_S02b.html

Ocean Currents (top)

Wind Patterns (Bottom)

~ Do you notice any similarities or differences?

Iceland and Iceland and Norway are Norway are located at located at what what latitude?latitude?

What climate would you expect them to have based on their similarity to the same Canadian latitude?

Norway and Iceland have harbors that remain Norway and Iceland have harbors that remain ice free all winter. Why??ice free all winter. Why??

http://www.bigelow.org/shipmates/hc_currents_lg.gif

Because of the Gulf Stream, which Because of the Gulf Stream, which transports warm water from the Gulf of transports warm water from the Gulf of MexicoMexico

Ocean currents transport energy stored Ocean currents transport energy stored in the water from one part of the world in the water from one part of the world to other parts (warm to cold)to other parts (warm to cold)

Cold currents flow toward the equator Cold currents flow toward the equator and warm as they travel through the and warm as they travel through the region.region.

(Nelson Science 10 525)(Nelson Science 10 525)

Causes of Ocean Causes of Ocean CurrentsCurrents Convection currentsConvection currents WindWind Earth’s rotationEarth’s rotation Shapes of the continentsShapes of the continents Heat capacity of waterHeat capacity of water Amount of salt in waterAmount of salt in water

Warm water travels North or South Warm water travels North or South from the equator.from the equator.

Cold water is oppositeCold water is opposite Warm water is less dense; Cold water is Warm water is less dense; Cold water is

denserdenser The sun’s energy is most intense at the The sun’s energy is most intense at the

equator equator starts convection currents starts convection currents– Water warmed by the sun’s rays at the Water warmed by the sun’s rays at the

surface moves north or south, the cold surface moves north or south, the cold water from the bottom moves up to the water from the bottom moves up to the surface.surface.

(Nelson Science 10 526) (Nelson Science 10 526)

Edges of the continents:Edges of the continents:– Currents follow this like a river wouldCurrents follow this like a river would

Earth rotates eastwardEarth rotates eastward– Currents on the West side of the oceans Currents on the West side of the oceans narrow narrow

and faster (6.5 km/h)and faster (6.5 km/h)– Currents on the East side Currents on the East side wider and slower (1.1 wider and slower (1.1

km/h)km/h) What is the only current that travels around What is the only current that travels around

the world without running into any continents?the world without running into any continents?– Antarctic CircumpolarAntarctic Circumpolar

(Nelson Science 10 526) (Nelson Science 10 526)

Water ~ Heat SinkWater ~ Heat Sink

Remember that water takes a Remember that water takes a long time to heat up and a long long time to heat up and a long time to cool off. time to cool off.

SaltSalt– As warm water evaporates it leaves As warm water evaporates it leaves

behind saltier currents.behind saltier currents.– Saltier water is more dense Saltier water is more dense sinks sinks

deep water currents deep water currents (Nelson Science 10 526) (Nelson Science 10 526)

Effects of Ocean Effects of Ocean CurrentsCurrents Remember the warmer the air the Remember the warmer the air the

more moisture it can hold.more moisture it can hold. If a cold ocean current runs by a If a cold ocean current runs by a

coastal areas, then the air is coastal areas, then the air is cooler and drier (may cause a cooler and drier (may cause a desert).desert).– Peru current is cold = cold, dry air = Peru current is cold = cold, dry air =

Atacama DesertAtacama Desert

http://digilander.libero.it/luigipizzi/Atacama.jpg

http://www.universetoday.com/am/publish/printer_atacama_desert_space.html

“Bounded on the west by the Pacific and on the east by the Andes, the Atacama Desert only knows rainfall between two and four times a century. . . There are some parts of the desert where rainfall has never been recorded. The only moisture available comes from a dense fog known as camanchaca, formed when cold air associated with ocean currents originating in the Antarctic hits warmer air. This fog is literally harvested by plants and animals alike, including Atacama's human inhabitants who use 'fog nets' to capture it

for drinking water” (Universe Today).

Warm currents cause water to Warm currents cause water to evaporate evaporate clouds clouds large amounts large amounts of precipitationof precipitation– Ex. Brazil RainforestsEx. Brazil Rainforests

http://www.bugbog.com/gallery/brazil_pictures/brazil_pictures_1.html

Red shows logging

http://www.aaas.org/news/releases/2005/1021scipak.shtml http://

en.wikinews.org/wiki/Category:South_America

Ocean Currents and Ocean Currents and ClimateClimate Coastal regions are warmer in the Coastal regions are warmer in the

winter and cooler in the summer.winter and cooler in the summer.– i.e. Ottawa vs Newfoundlandi.e. Ottawa vs Newfoundland

Ottawa has a 30 degree difference Ottawa has a 30 degree difference between winter and summerbetween winter and summer

Newfoundland (further north) has only Newfoundland (further north) has only an 18 degree difference.an 18 degree difference.

High Heat Capacity of High Heat Capacity of WaterWater Our warmest months are June, Our warmest months are June,

July and August even though we July and August even though we have more solar energy in May, have more solar energy in May, June and July. Why?June and July. Why?– Water takes a while to warm upWater takes a while to warm up– Same effect in the winterSame effect in the winter

Less daylight in November, December Less daylight in November, December and January, but we are colder in and January, but we are colder in December, January and February.December, January and February.

Global Weather ModelGlobal Weather Model

Please refer to page 536Please refer to page 536– Read through the info presentedRead through the info presented

Discuss the following text Discuss the following text questions together.questions together.– Questions on page 527Questions on page 527– 1 (b,c,d), 4, 5, 61 (b,c,d), 4, 5, 6

Resource Sites:Resource Sites:

University of MiamiUniversity of Miami– http://oceancurrents.rsmas.miami.edhttp://oceancurrents.rsmas.miami.ed

u/u/ Ocean Planet – SmithsonianOcean Planet – Smithsonian

– http://seawifs.gsfc.nasa.gov/OCEAN_http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/oceanography_currentPLANET/HTML/oceanography_currents_1.htmls_1.html

SourcesSources

Nelson Science 10 Textbook Nelson Science 10 Textbook – Section 13.9Section 13.9

Universe Today – Atacama DesertUniverse Today – Atacama Desert– http://www.universetoday.com/am/http://www.universetoday.com/am/

publish/publish/printer_atacama_desert_space.htmlprinter_atacama_desert_space.html