SPRING 1999
SPRING 1999
An Introduction to Meteorology
THE EFFECTS OF WEATHER ON OUR ENVIRONMENT
Sometimes what you see in the media isn’t always true. To avoid being misinformed it is beneficial to use multiple sources. As we know, especially with the increase of methods of communication in the last 20 years, misinformation travels quickly.
Quick question: Where are you from in the United States? How many of you have seen an ice storm? What happened? No power, gas, or heat. What do you need? Electricity.
How many here watch CNBC? Recently, a meteorologist said, "Pretty soon everything will be a weather story."
Question to class: Where do you live? (Show of hands for different areas of country: local; northeast; midwest; New England; west coast)
Question to class: Who is affected by weather? Give me some examples of how weather affects the world.
This part of the course (with Mike Mogil and Jim O’Connor) will put spins on how weather, climate, geology and astronomy are all connected and have an important impact on our lives.
Question to class: How man have heard of global warming? (Show of hands) How many think it is real? Unreal? How many don’t care? (Show of hands --- most believe that it is real.)
Question to class: What is global warming? Answer given: It’s caused by a hole in the ozone layer.
Ozone breaks apart when sunlight hits its weak bonds. The ozone layer in the stratosphere depletes in the southern hemisphere summer, but comes back during the southern hemisphere winter.
Real reason for global warming: presence of certain gases trapped in the atmosphere, primarily CO2and water vapor. Water vapor acts like a blanket, trapping the earth’s radiation not allowing it to escape into space, but in turn letting all the suns rays in to penetrate the earth. Thus, we have a warming of the earth’s atmosphere. The effects of this could be devastating and the following events can occur:
Question to class: How does El Nino affect global warming? El Nino has nothing to do with global warming. It involves the phenomenon of the warming of the ocean temperatures near the equator. Most immediate effect is warming of Pacific Ocean waters off coast of South America. Drives away fish (which thrive better in cold water), thus affecting the economy of the western South America countries. However, effects of El Nino are felt worldwide: too much or too little rain; too hot or too cold; increased number of hurricanes; droughts in Africa. What is important to point out is that in weather society today, a lot of large changes in weather seemed to be attributed to El Nino and that may not necessarily be the case.
Also in the last couple of years, the concept of La Nina, the opposite of the phenomenon of El Nino has emerged. In a sense we see that it is difficult to predict some weather patterns.
Examples given by the class:
Weather terms:
Temperature
Geography terms:
Deep south
What we learn is the importance of knowing our geography in order to understand the weather patterns occurring at a give place during a given time.
In the next session, we will be talking about geography and climate zones.
Studying Meteorology and Geography
Class activity: View 4-5 minutes of a tape made of a recent broadcast of the Weather Channel. At its conclusion, class was asked to do the following: 1. Take a sheet of paper and draw a line down the middle.
2. Label the left column "Geography" and the right one "Weather Terms"
3. In a given time, write down as many items you can remember from the video that would fit into either of these categories.
Front
Precipitation
Houston
Snow
Nourtheast
Interstate 95
Houston
Outerbanks of NC
Topics Covered Today:
Question posed by student in class: Why is the sky sometimes red in the morning?
Why do we get colorful sunrises and sunsets?
Some background information you need to know. Sunlight has all colors of the visible spectrum in it. It also has other forms of radiation such as ultraviolet light, infrared rays, x-rays, gamma rays, etc. Most of the radiation we receive from the sun is in the visible spectrum because of the temperature of the sun (6,0000 C). That radiation hits the atmosphere and bumps into the air molecules. Because of the size of the air molecules the color blue gets scattered first. That’s why the sky is blue. If we had different molecules in air we may have red, green, or yellow skies. In the summer we have brown skies and that’s because of the polluting molecules in the atmosphere. All the colors are scattered as a result of having polluted skies.
Our earth is curved. So when the sun is low in the sky it has to go through a pretty good chunk of the atmosphere before the light hits the earth. During that process the blues get scattered out completely. The next most powerful colors left are the reds and yellows. If all the blues get scattered out then at sunset you are fortunate enough to see the reds and yellows. You won’t see these colors during the middle of the day because the sun is not at such a low angle; therefore light has less atmosphere to penetrate.
A bit of weather lore:
In the morning, sun comes up over the horizon and when there are no clouds where the sun is in the east but there are clouds to the west there will be a red sky in the morning. Remember that in our latitudes weather systems move from west to east. "Red Sky in the Morning Sailor
Take Warning." That means the sun’s rays are being scattered by clouds in the west so some type of weather system is approaching.
At sunset, sun is in the west and if clouds are to the east rolling away there will be a pink sky. "Red Sky at Night Sailor’s Delight".
Let’s Go Back In Time
Has the weather always been the same as it is now?
Things change over time including the weather.
What’s one thing that can change global weather drastically?
Volcanic Ash. The ash blocking the sun’s light results in lower temperatures.
Other thoughts? We had ice ages. We had glaciers throughout the United States.
How do we figure out what conditions were like in the distant past?
There weren’t video cameras. We can’t go back in time.
One solution presented by a student was drilling holes into ice cores . Measurements from this will provide some information on what conditions were like thousands to tens of thousands of years ago. The place where drilling ice cores has been most successful is in Greenland.
Besides ice cores what other things can we do to try and piece together the history of the earth and the weather that went along with it?
Class replies with several examples:
1.) Fossil Collection – isotope analysis, chemical analysis, etc. of these fossils to figure out what time these animal or plant fossils lived. The types of animals and plants that lived during a specific time will give an indication as to what the conditions were like.
2.) Different Layers in Rocks – their composition and where they come from will supply us with clues. If the layers are tilted, folded, bent, or intruding into other rocks will give indications as to the geology of the time and not as much to the climate. This type of information could tell us where oceans were once located if for instance a substantial amount of sedimentary rock was found. We may also learn about flooding that may have occurred or if there had been any erosion by the size of the particles in the rock.
3.) Ocean Floor – finding life that currently exists on the ocean floor may provide information on what past organisms may have been like.
To the west of Colorado Springs are petrified forests. There are about 27 petrified forests in the United States and a total of 31 other petrified forests in the world. Typically you only hear about the petrified forests in Arizona. What is a petrified forest? Fossilized trees. How? The wood of the tree has been replaced by the minerals in water, essentially the tree is made out of stone. You can buy portions of these trees for a modest to outrageous fee plus shipping. With respect to the petrified forests of Arizona something must have happened such that these petrified trees got buried in the soil and then fossilized. These types of fossils can tell you about erosion, where these trees came from, and the type of tree (its structure – big or little).
In the case of the petrified forests west of Colorado Springs the trees are still standing straight up! What might have covered them to cause them stand straight up rather than be washed away or buried? There was a volcanic eruption that covered the trees in ash and years later the trees became fossilized. These fossils provided us about a geological event that occurred in the past for which we have no written evidence.
Trees that grew on the east side of the Colorado Rockies were redwood trees. Typically redwood trees prefer to grow near the ocean, more specifically in Northern California by the Pacific Ocean. What is required is a marine environment where a cool fog catches on the needles of the redwood and nourishes the tree. Does the previously described environment exist on the east side of the Colorado Rockies today? It’s not even close, it’s a dry climate. Something had to be very different for redwoods to have grown in Colorado. One suggestion made in class was that the ocean at one time came further east meaning that California was once under water. Here’s a clue: the redwoods were growing on the east side of the Colorado Rockies. What wasn’t there millions of years ago was the Colorado Rockies!
Where do we get a large volume of oil from? The Middle East
Oil is formed from fossilized marine life. The Middle East today is a barren dessert so how can there be so much oil there? We also get oil from Texas and that is not a marine environment. Northern Alaska provides much of the oil we use and export. These facts tell us that at one time these areas presently rich in oil must have had a much different environment, one conducive to marine life.
The clues provided from the fossilized trees and the examples of regions rich in oil help us figure out what the conditions were like in the past (way in the past).
Recently the Washington Post reported that N. Korea is having a famine. Is this common? No, something has happened in the country within the last couple of years that is causing this. In the 1970’s the famine was in Africa. In the eastern United States we are having a snow famine. These events are short term.
The geological time of the planet earth is approximately 4.6 billion years. The time that humans have existed on the earth is realistically insignificant. The task in putting together a complete picture of the history of the earth is that we have not been around long enough to gather data so we must use clues provided to us by nature. For example, in trying to create a graph of the global climate for the past several billion years on earth will be an insurmountable task because we only have data (temperature & precipitation) for the last 200 years! At best this climate data is only for places that are heavily populated. We infer from geologic records, glacial records, fossils, rock layers, salinity of the ocean, carbon dioxide levels in the Ice Caps, and whatever else we can get our hands on to piece the earth’s geological and climate history together.
Climate varies from place to place even within a single state. We now take weather readings at Ronald Reagan National Airport instead of in the city as was done in the past years. That change of location will have a effect on temperature and precipitation readings because of the airport’s proximity to a body of water. Urbanization is a factor that lends to global warming. Temperatures will vary from a populated city to a rural area. So when we here statistics quoting that the temperature of the earth has increased one degree each year you need to be skeptical and take into account where and how this information was determined.
Looking at a graph of temperature based on tree ring analysis we see that the temperature before the 1900’s was fairly level. What’s happened since the 1900’s? Ford’s Model T was built and the Wright Brothers invited flight. The Industrial Revolution began in the 1830’s yet global warming didn’t happen until seventy years later. Does this information tell us that factories are the cause of global warming? With a seventy-year lag between a possible cause and effect we cannot be so sure. The effects could be cumulative. If one looks at the temperatures in the years 1000-1200 the temperatures were similar to those of today. Was there an Industrial Revolution occurring around this time? No. If we are going to say global warming is now a fact of our existence today what can we say was the cause of the temperature rise in the 1000’s? Burning of a lot of trees? Probably. Did we stop burning trees after the 1000’s? No. There is conflicting data in the global history record. One cannot attribute a single cause in the warming of temperature in one geological time period to another period’s temperature flux.
Volcanoes have more effect on the climate of the earth than any number of cars. Erupt four volcanoes at any one time and global warming will cease. If a meteor of substantial size hit the earth global warming will cease for the next 100 years. We’d probably drive our cars to try to initiate global warming.
Has the earth ever been warmer than it is now? Yes, something other than humans has the ability to increase global temperature. Some postulations that may be possible for temperature trends: the tilting of the earth at a different angle than 23 degrees, a different orbit around sun, the sun’s output of energy changes over time, etc. It is not a simple puzzle we’re solving here. There are many disciplines that are involved in trying to piece together this puzzle: astronomy, meteorology, climatology, biology, chemistry and others.
Oceans store an incredible amount of energy. Looking at isotherm data over the past thousands of years we can see that oceans have cooled and heated up and some have remained the same. Changes in water temperature have played a significant role in land temperature variation throughout time.
As we all know there is more water than land. At one time there was just a single landmass. Over time the continents started to split. How do we know this? The tip is that the shapes of the continents fit together like a puzzle. Later evidence came in the form of fossil records shared between continents once joined but now separated. An example is that the rock formations of England are an extension of the Appalachian Mountains in the northeast United States. As a result of the continents splitting mountain ranges were formed and some worn down. Oil that was in once place literally moved to another.
Later in the semester we will hunt for marine fossils that are 200ft above sea level! We are learning about the forces that are controlling the globe. Weather and climate are nice but they would be nothing without the geology, geography, and astronomy of the Earth.
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