The atmosphere that surrounds our Earth is like a huge ocean of gas! Our "thin" atmosphere of gas protects us from solar winds: The atmosphere on Mars has been eroded away by solar winds. We are lucky that the composition of gases that surround our Earth have been able to withstand these winds. Our magnetic field is one way protons from sunlight are deflected and reflected away from the atmosphere... Because our Earth receives unequal amounts of heat in certain areas "domes" of dense air are created. These domes of high pressure travel across Earth because the Earth spins and revolves around our Sun. When we increase temperature...(think about cramming 50 sixth graders in the elevator and being stuck inside), the temperature inside the elevator is going to increase really fast. Same thing happens in the "dome" of high pressure. LOTS of air is crammed together and the temperature rises. Low pressure air masses are cooler, the gases are not as tightly packed together and are higher in altitude. As the air gases become cooler and move more slowly and clump together they sink and mix with warmer air particles that are rising and condensation occurs. What a mess! A barometer actually measures air pressure simply. At sea level the air pressure averages around 29.92 inches. When high pressure air masses move in the barometer will rise to 30 inches. If low pressure air masses move over the barometer, it may drop to 28 inches. Not very dramatic changes... Ten to twenty tons of air pressure sits on top of the average adult! We should be so relieved that air pressure is stable and doesn't fluctuate...how do we survive under twenty tons of pressure??? The largest hurricanes atmospheric pressure are recorded around 28 inches, and the driest air pressure over a desert has been recorded at 31 inches. Atmospheric pressure is stable and it is the tiny changes in that pressure that tells us that HUGE things will be happening. If the barometer tells us the pressure is 29 inches in the morning and by afternoon the barometer shows us it has fallen 0.25 inches, this may mean when you go outside the wind is blowing 35 miles per hour! It's all about the CHANGE in pressure, not the "Rainy, Cloudy, Fair" settings. We are looking for change, even the tiniest changes can bring big consequences when it comes to air pressure.
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Mrs. TaylorI love science! Everything about the world is interesting and never boring. I love to study plants, animals, insects, and people. My favorite subjects are my students who are the most unique organisms on the planet! Categories |