Pg. 30 RTW: What do you already know about El Niño? Objective: I will be able to understand how currents effect the world’s climate Agenda: –Current/El Niño Notes pg. 33 Homework: None Homework: None Wednesday, October 12 th

Ocean Currents

Surface Currents Represent large scale horizontal movement of water Occur in regions where winds blow over ocean w/ constancy of direction & velocity

Major ocean currents of the world. On this illustration red arrows indicate warm currents, while cold currents are displayed in blue.

Gulf Stream Average speed- 8 km/hr Surface temperature- 24ºC Responsible for the climate of England & Ireland

Wind Belts Trade winds-near 15ºN latitude, blow from NE to SW Westerlies- in the middle latitudes, blow from W-SW

Polar easterlies- at very high latitudes, blow from E to W All have a mirror image counterpart in the S. Hemisphere

Some currents transport more than 100X the volume of all earth’s rivers combined. –This greatly affects the distribution of marine organisms

Coriolis Effect Water does not move parallel with wind direction The spinning of the earth causes the winds & water to move in a clockwise direction in Northern Hemisphere

Water is deflected –Northern Hemisphere-Right –Southern Hemisphere-Left Gyres-giant circles caused by continents deflecting currents

Vertical H 2 0 Movement Produced by sinking & upwelling Break down the vertical stratification established by the Thermocline Deep ocean circulation may take hundreds to thousands of years

Caused by increased density Higher latitudes Highly Oxygenated Sinking

Upwelling Brings deeper nutrient-rich waters to the surface Cause for the areas of high productivity Several of the world’s important fisheries are in these regions

El Niño Changes in ocean surface winds and water temperatures On a 5-7 year cycle Responsible for the decline of coastal marine population

Trade winds from the east relax Movement of water to the west decreases Upwelling is blocked During severe years, fish and bird populations disappear

Typical

Reversed Conditions

Pg. 30 RTW:? Objective: I will be able to understand how currents effect the world’s climate Agenda: The GLOBE Earth Systems Activity Day 1 Homework: Study for Current Test next week Thursday, October 13 th

Pg. 32 GLOBE Activity Day 1 1.Study your image, looking for information 2.Write down as many observations as you can about your image on pg. 32  Remember: no observation is too small or obvious! 3.Once your group is finished, take turns explaining your observations and sharing your image 4.Assign 2 spokespersons to tell the class the info.

Pg. 32 Guiding Questions: 1.What variables did you examine and what is the range of values shown on the scale bars? 2.Where in the world did you find the highest and lowest values(extremes) of data in your image? 3.Why do these locations experience the extremes and not other locations? 4.Are any patterns in the data noticeable? Are patterns different on different continents? Different over water than over land? Explain these patterns.

Pg. 30 RTW:? Objective: I will be able to understand how currents effect the world’s climate Agenda: The GLOBE Earth Systems Activity Day 2 Homework: Study for Current Test next week Friday, October 14 th

Pg. 32 GLOBE Activity Day 2 Order images chronologically (Jan.  Dec.) 1.What changes do you see through the year? What explanations can you suggest for these patterns? 2.Choose a location or region. During which months do the extreme highs and lows occur? What explanations can you suggest for the timing of those extremes? 3.Which regions experience both the extreme highs and lows? Which regions don’t experience the extremes? Why do you think this happens? 4.What differences, if any do you find between the year’s variations over the oceans versus them over the continents? 5.Are there regions that remain relatively unchanged over the year? Why do you think this happens?