Module lV: Climate,Cultures and Oceans

We are the water planet. Seventy percent of our earth is water. Water is able to absorb and release tremendous amounts of heat energy. The amount of heat released or absorbed by our atmosphere and ocean affects our weather and climate. If changes take place on our planet that change the heat distribution our weather patterns and ocean circulation will change. At this time we are seeing changes taking place in our climate. Native Inupiats living in the arctic also see these changes taking place. Living in the midwest the changes at this time do not have an

affect on our lifestyle. We read about global warming and the scientific research going on the study climatic changes. In the arctic the Inupiats see the changes firsthand. They have observed the thinning ice, warmer temperatures, and changes in seasonal weather. All of these changes will effect how they hunt whales, and other animals for food to survive. Their lifestyle is changing. This is a great example of native science observations vs western perspectives of science. The native people see and experience climatic changes while western scientists gather data to try and understand the causes of the changes taking place. This module also shows how heat energy is an interdisciplinary topic. Changes in heat distribution on our planet has an impact on the atmosphere, hydrosphere, lithosphere, biosphere and cryosphere. Our students need to understand the basic principles that cause the seasons, how the ocean is a heat sink, that ocean circulation through currents disperses heat, and the hydrologic cycle is in reality an energy cycle.

Heat is an energy that is created by the motion of particles. As heat is absorbed the molecular particles of a substance move faster and if heat energy is released the molecular particles move slower. With the addition or removal of heat energy changes of state in matter occur. These changes of state are the foundation of the hydrologic cycle. Through the processes of evaportion and condensation heat energy if moved through the atmosphere. Different substances absorb and release heat at different rates this is called specific heat capacity. The specific of a substance is the amount of heat need to raise on gram of a substance one degree Celcius. Water has a high specific heat and can absorb large amounts of heat. Water will absorb heat slowly and release heat slowly. Land or the beach has a low specific heat. Land will heat up quickly and cool off quickly. During the day the beach sand can feel hot and the water cool. At night the water feels warm and the beach sand cool. Why? Differences of heat capacity. A great way to show this concept is to boil water in a paper cup. Fill a paper cup with water, place it under a lit bunsen burner until the water boils. This is a great discrepant event.

Fall in Iola, Wisconsin Oct. 25--------------------------------Fall in Barrow, Alaska Nov. 4

Why are the seasons so different at different latitudes? The sun is the same distance away and gives off the same amount of energy. Both locations are in the Northern Hemisphere. The difference is latitude. Iola is about 44 degrees N and Barrow about 71 degrees N. Since the earth is a curved surface the angle of incidence of sun's rays in Iola and Barrow are different.

Iola recieves rays at a lower angle so the energy is more intense, in Barrow the angle is higher so the energy is dispersed over a larger area. The other difference is the altitude of the sun. As the earth revolves around the sun it's postion in space changes. During the summer the axis of the earth points towards the sun and in the winter away from the sun. As the earth moves from summer to winter the vertical rays of the sun start to migrate south. Again due to the curve of the earth the altitude of the sun changes at each latitude. The higher the latitude the lower the sun in winter and less solar or heat energy is recieved. Iola in winter has about 6hr of day while in Barrow there is about 3 months with no sun or solar energy.

Winter in Iola,WI in Feb. above left. Winter Wainwright,Ak Feb. above right. Christmas noon Wainwright lower right.

In summer the axis points towards the sun. The sun is higher in the sky and the solar energy is more intense. Also we have longer daylight hours. In the arctic the solar energy is not as intense as in the lower latitudes. Although there are 24 hr of sunlight the angle of incidence is still low so the solar energy is spread over a large area and summers remain cool.

Since we know that water has a high specific heat capacity the ocean is able to absorb large amounts of heat energy. Due to unequal heating of the earth the air in the atmosphere is put into motion. This moving air or wind blows across the ocean causing motion in the water. The currents created transport heat around the world. The ocean currents carry heat from warm places to cold. The currents that flow from the equator move to the higher latitudes. As the heat is released the water cools at the higher latitudes and sinks. The cool/cold water sink and the currents return the water to the equatorial reigions where heat energy is again absorbed. Many scientific concepts combine to create wind and currents. The direction of planetary winds and flow of ocean currents depends on several factors. Some factors are the Coriolis Effect, the concept of density and landforms. The Coriolis Effect is the deflection of air and water due to the rotation of the earth. In the northern hemisphere the wind and currents are deflected to the right and in the southern hemisphere to the left. An excellent way to demonstrate the Coriolis Effect is to use an old turntable or phonograph player. Cut out paper in a circle to fit the turntable. Place the circular paper on the turntable and draw a line from the center of the paper to the edge. Turn on the turntable and while the paper is spinning again draw a line from the center of the paper to the edge. Compare the results. This model shows how air and water are defected due to rotation. Density is the concept that compares mass and volume. Density explains why ice floats and not sinks. Saltwater is more dense than freshwater. Make several solutions of saltwater with different amounts of salt dissolved. Meaure equal volumes of the saltwater and determine the mass of each sample. Using the formula D=M/V determine the density. To show differences in densitys of liquids make a density tower using different liquids like water, cooking oil, rubbing alcohal, syrup and saltwater. Carefully pour the liquids into a cylinder and create the density tower. Changes in temperature also change the density by changing the volume. This explains why warm air rises , cool air sinks, and warm water is on the surface and cool/cold water sinks and is on the bottom. The waters of the ocean are in layers of different densities. The least salty water is the top layer and most salty form the bottom layers. The movement of water due to density differences, prevailing winds and the Coriolis Effect create a global current system. The waters of the ocean act as a large conveyer belt transporting heat, losing heat at the higher latitudes and then the cooler water sinking to return to the equator. If the salinity or amount of freshwater entering the ocean system changes, the currents can also change. As ice sheets melt more freshwater is added to the system. As more ice forms salt is added to the system. In cold climates the cold salty water sinks creating the deep ocean currents that moves the water back to the equator.

Ocean currents through the transportation of heat energy regulate the climate. If the ocean temperatures change weather patterns change, ocean circulation could change and cultures
that depend on steady ocean patterns will change. Changing the ocean system could result in different locations of food sources. If food sources change migration routes of whales could change causing native arctic cultures serious problems in hunting. If seasonal weather changes the plants on the tundra will change forcing animals to seek different locations for their food. This also would effect the arctic natives. We live in a world were all things are connected. The atomosphere, the ocean, solar energy and the seasonal changes are all connected. If you change one there is a ripple effect and the other systems will adjust and change. Past cultures have vanished like the Anasasi. They thrived in the southwest. They understood the significance of the seasons . At the Chaco Canyon National Historical Monument Fajada Butte ( shown above right) has on it a sprial carved into a stone(shown above left). Only on the day of the summer solstice a shaft of light pierces the center of the spiral. This culture depended on seasons. The Anasasi Indians vanished. Only their ruins exist today. Did the climate change which caused the disappearance? Cultures of the past and today depend on the seasonal cycles and ocean currents. As our planet and climate change whether man-made or natural cultures will also change.