Questions to ponder...and answer by the end of the class How is earth a system of systems? Specifically, what are some examples of spheres, systems, and/or cycles related to earth? First, list as many as you can. Then, pick two and describe them briefly. What is the reason that we (in Massachusetts) have such different seasons throughout the year? Why might our piles of snow melt faster now than in January? What is Weather? How are weather and climate different from each other? What's an example of a current that has an effect on climate and weather? | Good News: As a group, you were able to answer all of these questions by the end of class. Congratulations! As you read this over, can you remember the answers? |
Resources for today's class:
Handouts for image sorting
Online articles/videos about three major currents -- to go with the printed readings and question prompts:
Global Weather Machine; about El Niño (Carlos, Carmen)
A five day view of the Jet Stream (Kim, Nkemji)
What causes the Gulf Stream? (Ingrid, Florine)
Handouts for image sorting
Online articles/videos about three major currents -- to go with the printed readings and question prompts:
Global Weather Machine; about El Niño (Carlos, Carmen)
A five day view of the Jet Stream (Kim, Nkemji)
What causes the Gulf Stream? (Ingrid, Florine)
What made sense from the Celestial Islands article on earth system science?
| Unknown words
Questions
|
Demonstrations & Models done in class The earth (ping pong ball on a stick) and the sun (large lamps): to demonstrate the different amounts of sunlight on earth as earth both rotates (around its axis) and revolves (around the sun) A flashlight, sand, paper and pencil: to demonstrate the difference between sunlight in summer and winter A glass baking dish, vegetable oil, dried herbs, two mugs, and a lit candle: to demonstrate the effect of heat on creating a convection current | As you review this, recall how each of these models or demonstrations worked. What was it trying to show? Can you explain it now? |
From Scientific American:
https://www.scientificamerican.com/article/seawater-science-model-ocean-currents-in-your-kitchen/
Key concepts
Ocean currents
Fluids
Density
Salinity
Movement
Heat
Introduction
Under the waves the world’s oceans have currents that can move massive amounts of warmer or cooler water from off the coast of one continent to that of another. These currents have profound effects on the continental climates, especially those regions bordering on the ocean. For example, the Gulf Stream (a warm current that flows up from the Gulf of Mexico into the North Atlantic Ocean) likely makes northwestern Europe much warmer than it would otherwise likely be. Have you ever wondered what causes these important currents? In this science activity you will model the behavior of these “rivers” of warm and cold water within the ocean to find out how temperature affects the direction and speed of the currents.
Background
Ocean currents profoundly affect weather and climate, marine transportation and the cycling of nutrients. Deep-ocean currents are driven by differences in the water's density, which is controlled by temperature (cold water is denser than warm water) and salinity (salty water is denser than freshwater).
How does the varying density of the ocean's waters create the global currents? To understand the deep-ocean currents, it's easiest to look first at Earth's polar regions. Water flowing into the these regions becomes cold, which increases its density. As ice forms when the water freezes, freshwater is removed from the ocean (it has turned into ice), making the ocean water saltier. The cold water is now denser, due to its lower temperature and the additional salt, so it sinks toward the ocean bottom. Surface water then moves in to replace the sinking water, creating a current.
A global “conveyor belt” is set in motion when dense water forms in the North Atlantic, sinks, moves south, circulates around Antarctica and then moves northward to the Indian, Pacific and Atlantic basins. This conveyor belt moves lots of water—it is a huge circulation pattern that transports about 100 times more water than the Amazon River!
Although ocean currents depend on temperature and salinity to move, in this activity you will see how temperature alone can create currents in a liquid.
https://www.scientificamerican.com/article/seawater-science-model-ocean-currents-in-your-kitchen/
Key concepts
Ocean currents
Fluids
Density
Salinity
Movement
Heat
Introduction
Under the waves the world’s oceans have currents that can move massive amounts of warmer or cooler water from off the coast of one continent to that of another. These currents have profound effects on the continental climates, especially those regions bordering on the ocean. For example, the Gulf Stream (a warm current that flows up from the Gulf of Mexico into the North Atlantic Ocean) likely makes northwestern Europe much warmer than it would otherwise likely be. Have you ever wondered what causes these important currents? In this science activity you will model the behavior of these “rivers” of warm and cold water within the ocean to find out how temperature affects the direction and speed of the currents.
Background
Ocean currents profoundly affect weather and climate, marine transportation and the cycling of nutrients. Deep-ocean currents are driven by differences in the water's density, which is controlled by temperature (cold water is denser than warm water) and salinity (salty water is denser than freshwater).
How does the varying density of the ocean's waters create the global currents? To understand the deep-ocean currents, it's easiest to look first at Earth's polar regions. Water flowing into the these regions becomes cold, which increases its density. As ice forms when the water freezes, freshwater is removed from the ocean (it has turned into ice), making the ocean water saltier. The cold water is now denser, due to its lower temperature and the additional salt, so it sinks toward the ocean bottom. Surface water then moves in to replace the sinking water, creating a current.
A global “conveyor belt” is set in motion when dense water forms in the North Atlantic, sinks, moves south, circulates around Antarctica and then moves northward to the Indian, Pacific and Atlantic basins. This conveyor belt moves lots of water—it is a huge circulation pattern that transports about 100 times more water than the Amazon River!
Although ocean currents depend on temperature and salinity to move, in this activity you will see how temperature alone can create currents in a liquid.