(Previously) Current Topics in Earth Science
Weather fronts can be cold, warm, stationary or occluded. Fronts indicate that there is an interaction between two different types of air masses. The word "front" indicates that the interaction happens at the boundaries of air masses. The temperature and humidity are some common differences between air masses. What kind of front do you think the clouds in this picture indicate? What changes do you think might be happening to the air mass?
We have been learning (hopefullly) about changes in the Earth's atmosphere like wind direction, high and low pressure, humidity, dew point and other factors that determine weather. Although the weather may seem uninteresting to you in class, it affects your life every day and shapes your behavior in ways that you are not aware. Did you know that men are 4 times more likely to be struck by lightning than women? There is evidence that wind is responsible for a change in human behavior, as this quote suggests:
Wind
How often do you hear people say that the wind is driving them crazy! A persistent or noisy wind can lead to an increase in tiredness and irritability, or even a sudden decrease in mood. Some school teachers have noticed that children tend to be more irritable and that there are more playground 'upsets' when it is windy.
Seasonal winds are known as 'ill winds' in many cultures and have a variety of names such as the föhn (Alps), Mistral (southern France), Chinooks (western Canada and the USA) and the Sharav (Middle East). They are linked to feelings of anxiety, stress, depression and sleepless nights.
When these winds blow, temperatures can increase by up to 15°C in as little as two hours. As they are common in mountainous regions they are often responsible for avalanches. Studies have linked these winds to an increase in traffic accidents, crime and suicide rates, and they have even been taken into account during legal proceedings! A survey by Germany's Allensbach Institute found that a third of their respondents said that föhn-like weather affected their health.
The exact reason why these winds have such extreme effects is unknown, but it has been suggested that it may be the electrical charge of the air. When people are exposed to negatively charged air they report feeling positive and vice versa. Warm winds, such as those mentioned above are positively charged.
Homes and offices today are built to be airtight. Heating and air-conditioning depletes negative ions, leaving the positive ones to re-circulate and reduce our moods. As we spend less and less time outside due to pressures at work and home our bodies are also going to be less exposed and less adapted to different weather conditions.
But if you've ever wondered why the air feels so good after a heavy downpour - it's nature's way of creating negative ions, so get outside and soak them up!
The Earth's atmosphere is divided into five distinct layers. Weather happens mostly in the troposphere or the layer closest to the Earth's surface. This is where we live. The ozone layer is part of the stratosphere Do you know what the ozone layer is and what important role it plays in our lives? Is it a form of pollution or a protective filter? Why do you think so?
California is in a crisis situation when it comes to supplying all of its residents with enough water. There is a proposal currently being considered to raise the level of Shasta Dam by 16 feet. This would serve an additional 900,000 California families with water for a year. Do you think this is a good idea? Consider this: Raising the water level of the Shasta Dam will also place the home of the Winnemem Wintu tribe underwater. The culture of this tribe of indians which once occupied the McCloud River basin would be wiped out, their home would no longer exist. For the 125 remaining tribe members, this would mean disaster. Do you think that is too high a price to pay for water or is it worth sacrificing a once dominant culture that has been diminishing steadily since the arrival of gold seekers to California in 1849?
Some other questions... Did you know that California is in a water crisis? Do you or your family conserve water? If you do conserve water, what do you do?
The Earth has been shaped in many ways by the forces of weathering and erosion. Arizona is home to some of the most beautiful and spectacular examples. The Grand Canyon was carved from thousands of years of erosion by the colorado river. The canyon in this example was formed by wind and water erosion. The rock this cave is made from is sandstone which is a composite of small grains of quartz and feldspar (remember when we studied minerals?). Can you think of any examples of erosion that you have seen. Where was it and what do you think caused it? Can you describe what it looked like?
Click on this link for more pictures of Antelope canyon.