PDS APES 8th Period 2009-10

The air that we breathe is in the troposphere, the first level of air. This is where weather happens, global warming occurs, and where infrared rays are trapped.

The stratosphere is the second level of the air. The highest clouds are in this section, the climate is influenced by the upper troposphere and the lower stratosphere, and this is where the Ozone is located. It blocks UV radiation from reaching the troposphere.

Found at: http://www.williamsclass.com/EighthScienceWork/Atmosphere/EarthsAtmosphere.htm

So good air in the troposphere is made of:

78% Nitrogen (N2)– this is triple bonded so it is inert

21% Oxygen (O2)– used for cellular respiration

1% Other– Ar, Ne, He, H2, Xe (all of these are permanent gases) and H2O, CO2, CH4, N2O, O3 (all of these are variable gases that occur naturally, but they vary with human activity) and CFC (man made)

All of these gases are necessary to have healthy air, so we need to have them all. Without these warming gases, our Earth would be uninhabitable. Natural global warming is needed. These gases trap infrared radiation (heat). Note that UV radiation doesn’t cause heat.

Note: Air in the troposphere should have trace amounts of O3, which causes lung damage.

Recently, the Icelandic Volcano that erupted caused people to question the air quality in Europe. According to the World Health Organization, “Volcanic ash is composed of fine particles of fragmented volcanic rock. The main component of the ash that could be expected to have health effects is fine particulate matter (PM). Being less than 10 microns in size, particles can reach the lower respiratory airways. Analysis of the ash is ongoing and so far it is estimated that about 25% of the particles are less than 10 microns in size. People with chronic respiratory conditions such as asthma, emphysema or bronchitis may be more susceptible to irritation if ash is in the lower atmosphere in high concentrations.

As long as the volcanic ash remains in the upper atmosphere, there will be no increase in people’s exposure and no risks for health. If it reaches the ground due to vertical movement of air masses, there is a risk of an increase in respiratory symptoms, but the increase is expected to be low and in the range observed without this unusual event. Rains may wash the ash without causing health risks.

The ash cloud might slowly reach other European countries and the eruption might last for days to weeks or more. The European Air Quality Monitoring Network includes hundreds of stations all over Europe that are located in cities, allowing an up-to-date assessment of air pollution on the ground. The European project CITAIR provides daily updates on the quality of air in cities across Europe. Until the evening of Friday 16 April, no increase in European air pollution levels has been observed.

The WHO Regional Office for Europe is providing guidance to Member States on effective ways to address the situation from a public health standpoint, coordinating with partner agencies. WHO will continue to assess the situation and will provide updates as necessary.”

This article was found at: http://www.euro.who.int/air/NewsEvents/20100416_1

So, the volcanic ash isn’t affecting air quality levels in the troposphere.

Hey, I just need a bit of clarification. In class we discussed techniques that could be used to preserve macronutrients in the soil. We talked about planting legumes every other year and planting a cover crop, like clovers, to help replenish the soil. But I don’t understand how these would aid in soil conservation. Wouldn’t they still diminish the soil of important nutrients? Also, wouldn’t this constant tilling of land lead to more waterlogging and erosion? I just need to understand how alternating crops would actually help the soil.

Thanks.

Hey everyone. I have a question about temperate deserts. The book says that they get more precipitation than tropical deserts, but what about cold deserts? The concept of cold deserts is confusing to me, so I could just use a refresher on them. Thanks

In class on Wednesday, we learned about Human Demographics, the study of human population dynamics. Notice the word dynamics: this means that we as a population are constantly changing.

There are a few ways to study human demograpics:

-Age Structure

-Population Density

-Gender

-Size of population

-Spatial Distribution

-Growth Rates

Here are a few statistics that we talked about in class that we need to know:

-The Total World Population is 6.7 billion (6.7 x 10^9 in scientific form)

- The top five countries with the largest populations are: 1. China with 1.3 billion people; 2. India with 1.1 billion people; 3. USA with 300 million people; 4. Indonesia with 225 million people; 5. Brazil with 180 million people

These five countries alone carry half of the world’s population! Is this a problem? (We will discuss potential issues regarding the population and our resources in the future).

Now for the top five largest countries (largest surface areas): 1. Russia; 2. Canada; 3. China, 4. USA; 5. Brazil

*Notice that India isn’t there!

We finished up the lesson by discussing our population’s current growth rate. According to graphs, we are growing exponetially, but will our growth rate stay constant, like the graph suggests, or will it increase or decrease?

Here is a cartogram- a population map that records the population within countries on an even scale

http://odtmaps.com/detail.asp_Q_product_id_E_PopMap-35x52

We brushed over the topic of indicator species in class, but on the study guide D. Will. sent out, he said to know what they are and some examples. I know that indicator species are organisms that, when they are affected by seomthing in their habitat, will delineate, therefore tipping off to biologists that there’s something wrong in that habitat, but I’m wondering what are some examples of animals that were affected by temperature (global warming) or disease?