Remember, the Gulf StreamOcean Currentaffects us here on the south side of Cape Cod. The waters of Nantucket Sound and Buzzards Bay in summer are warmer than the cooler waters of Cape Cod Bay – remember this when you’re headed to the beaches this summer!
The precipitation of a location can be affected by either of two factors, as shown below when we used the Smartboard Maps.
Note the effects of the Prevailing Winds on the levels of precipitation. Global winds that blow across ocean areas bring moisture, such as the Trade Winds blowing into the Caribbean Islands and Southeast Asia. When the Trade Winds blow from south Asia onto northern Africa, they blow across land, bringing very dry winds and little rain into the Sahara Desert area.
The Westerlies blow across the North Atlantic Ocean bringing lots of moisture and rain to Ireland, England and Scotland!
Below is a diagram showing the effects ofMountainson the precipitation pattern of a location.
The side of the mountain facing the wind, the windward side, gets much more rain than the dry leeward side.
Effects of Mountains on Rainfall : Windward & Leeward
We have been studying the effects of unequal heating of the Earth’s surface, and the resulting wind patterns these cause. Land that is heated more directly absorbs more of the sun’s heat through radiation. The ground touches the air, and through conduction, heats the air – the air becomes less dense which causes it to rise. This creates an area of lower pressure in the atmosphere. As the air rises, it cools, becomes more dense, and then falls back to the earth, creating an area of higher pressure. The movement of the air creates a convection current.
AIR ALWAYS MOVESFROMAREAS OF HIGH PRESSURE TO AREAS OF LOW PRESSURE.
Moving air is called WIND.
The spinning of the Earth causes the winds to bend to the right as they move across the globe. We call this effect the Coriolis Effect. Global Winds are winds that move across large areas around the globe. There are three major Global Wind Belts – the Trade Winds, the Westerlies and the Easterlies. These wind belts are found in both the Northern and the Southern Hemispheres. There are also areas of calm winds, called the doldrums near the equator, and the Horse Latitudes nearthe 30 degrees latitudes. See the diagrams below.
The same convection currents that cause the Global Winds also affect the atmosphere at the local level, especially at the seacoast. Here on Cape Cod we experience these local winds during the summer. Cape Cod is kept cool, sort of a natural air-conditioning, by the local sea and land breezes. The hot summer sun heats the land on Cape, causing the air to rise (low pressure). Cooler descending air from the water (higher pressure) rushes in to take the place of the rising warm air on land, forming a cooling Sea Breeze. This keeps the Cape comfortable on most summer days. At night, the land cools down much faster, the warmer ocean water heats the air, causing the air over the water to rise. Cooler air from the land moves in to take the place of the rising are, creating a Land Breeze.
Study the diagram below, and then CLICK on it to see the animation!.
Both Global Winds and Local Winds are caused by the unequal heating of the Earth’s surface, creating differences in air temperatures and air pressures.
Air (wind) always moves from HIGH pressure to LOW pressure.
We are studying the Layers of the Atmosphere as we start our new unit. In our graphing lab activity we learned that the temperature of the air definitely changes as we go higher in altitude…but it does not always go down, as you may think! Each of the layers of the atmosphere is defined by a Change in the Temperature Direction. The chart below shows the changes as we graphed them in class.
Remember your Silly Sentence to recall the layers in order:
T S M T I E
The Sun Melts The Ice Everyday!
The Aurora Borealis, also know as the Northern Lights, are caused by the sun’s high energy radiation ‘charging’ the air molecules in the Ionosphere, causing them to glow. This happens near the North and South Poles, as the Electromagnetic Field is less strong at these points.
The Northern Lights are one of nature’s most spectacular visual sights, and in this speeded-up video from National Geographic Videos, they provide a breathtaking display of light, shape, and color over the course of a single night in Norway.
And finally, for some fun, here is the link to the Classroom JigSaw Puzzle we did today…
We have been studying the ways that heat can be moved form one substance to another…through the three types of Heat Transfer - Radiation, Convection and Conduction. For an animation review of what we did in class, click on the picture.
In the diagram below you can see how each of these types of heat transfer is represented in the picture of the boiling water. Radiationfrom the campfire travels through open space to heat the pot. The pot then conductsthe heat through direct contact (touch) to heat the entire pot and handle, as well as the water inside the pot. As the water, a fluid, gains heat energy, the molecules of water become more agitated and move more quickly, becoming less dense. The warmer water then rises to the top of the pot, where it hits the air, cools, and then contracts to become more dense. It then sinks to the bottom of the pan, where it is heated once again. This forms a convection current in the pan.
In the atmosphere, the same three types of Heat Transfer take place…Radiationfrom the sun heats the ground. The ground then touches the air, and through this direct contact, conduction, the air is then heated. As the warm air becomes less dense and molecules move farther apart, the warm air rises through convection. When it reaches the upper levels, the warmer air cools, contracts, becomes denser, and then sinks back to earth. It then gets heated by the ground one more time, and the repeated actions form convection currents.
In the darkest regions of deep space, the temperature is a chilly -450° Fahrenheit. Closer to our Sun, temperatures reach thousands of degrees Fahrenheit. What makes Earth’s climate so moderate? Separating Earth from the extreme and inhospitable climate of space is a 500-mile-thick cocoon of gases called the atmosphere.
All planets have an atmosphere, a layer of gases that surrounds them. The Sun’s atmosphere is made up of hydrogen, while Earth’s is made up primarily of nitrogen and oxygen. Carbon dioxide, ozone, and other gases are also present. These gases keep our planet warm and protect us from the direct effects of the Sun’s radiation. Without this regulation, Earth could not sustain life.
Today we will start to learn WHY the earth’s atmosphere is so important to life. We will also discuss the major gases in the atmosphere and learn why each of them is so important.
From here we will then do an online activity called AstroVenture!
And when you have finished the AstroVenture Assignment,
Processes at Earth’s surface and heat within Earth cause rocks to change into other types of rocks.
All rock started as magma. The rock cycle started with the cooling of the earth’s magma billions of years ago. But after that, it has no end. Rather, it is an ongoing cycle in which rock — driven by tectonic processes such as volcanoes and earthquakes, the surface processes of weathering and erosion, and compaction — is created and destroyed.
For this assignment, you will go to the following web site:
Open the Interactives Rock Cycle in a different window.
This interactive web site will help you to review the types of rocks and the processes that occur within the rock cycle. Instructions given on the web site will lead you through the different sections of material.
In this part of the tutorial, when you click on the rock sample, you will be provided with the name of the rock as well as information on how the rock forms and where it can be found. Make sure to add the rocks to your collection.
The next section, “Identify Rock Types”, will allow you to test your ability to recognize rock characteristics and types. Note: this section is timed (six minutes…more than enough time to complete the activity).
When you have completed this self-test, go on to the next section, which describes How Rocks Change. Be sure to view the animation sequences provided for each rock family!
At the end of this section, complete the self-test Transform the Rock to see if you can identify the processes that can change rocks from type to another.
This self-test is timed (six minutes); to complete the sequence, click and drag your answer into the appropriate box.
The next section describes the rock cycle and also includes a self-test Complete the Rock Cycle to see if you can name the different parts of the rock cycle.
The final activity at the web site is a Test Your Skills assessment to see how much you have learned.
Enter your first and last name in the space provided. When you have completed the assessment, print out your results. Make sure that you print out the complete results. Do not just print your score. You must show your teacher the printout with all of the graded questions to get credit.
This will then become your Study Sheet!
Alternate Assignment:Rocky’s Journey
You are now a well-educated geologic student of The Rock Cycle!
These are a few videos and presentation tools produced by last year’s 8th graders for their National Park Projects. We’ve been exploring different tools to use more of today’s Web 2.0 technology in our classroom work, and the park projects have created a great opportunity for many of you to explore and push yourselves. Hopefully the work below will motivate you to work with the tools this year!
Class Work: I'll try to give an overview of what we are doing in class :
We are beginning a new unit - Heat transfer in the Earth's System - which is basically a study of the earth's atmosphere. We will be studying the composition of the gases and the layers in the atmosphere, and the dynamics of heat transfer and its effect on our weather and climate.