1. Aerosols : Refers to small suspended particals in a gas. Aerosols usually range of size from 1nm molecules on up to 100um pollen grains, a difference in size of over 100,000times. Often these suspended particles are liquids, referred to collectively as Hydrosols. In the stratosphere tha aerosols are often crystal groupings of water molecules around a sulfate or nitrate molecule. Stratospheric nitrate and sulfate concentration is a major factor in the formation of polar stratospheric clouds which are implicated in the formation of the antarctic ozone hole.

2. Arctic hole : because the arctic ice sheet sits on top of water, is ''heated''by the relatively warmer seawater (temperatures not much below zero). A 'arctic polar vortex' does circle the north pole during the arctic spring, but it is weaker and fewer polar stratospheric clouds form. The spring of 1993 saw significant stratospheric ozone depletion, 10-20%, but not nearly as large as depletions seen in the antarctic.

3. Atmospheric giant analogy Say that you have grown to a gigantic height, such that your little toe is now about one kilometer high. As you stand barefooted, rainclouds would hover about your toenails and Mount Everest would come no higher than the ball of your ankle. 90 % of the earths atmosphere is below this point! Just above the ball of your ankle is the tropopause, the boundry layer below which is the troposphere. Between your ankle and knee is the stratosphere,which contains the ozone layer . Between your knee and hip is the outer-most layer of our atmosphere, the mesosphere.

4. "d" as a symbol for change: in science the lower case greek letter delta, looking like a small triangle, is used as a symbol for change. For example a watch measures 'delta-time' and a speedometer measures 'delta-speed'. In mathmatics, or specifically calculus, writing an equation which reflects the change of a value is accomplished by taking its derivitive. For example speed is the distance an object travels divided by the change in time so an equation for calculating speed would be : speed = distance/ dt , where dt stands for the derivitive of the time.

5. Logarithmic scale : there are two types of logarithms used in science; in this file "base ten" logarithms are used. A base ten logrithm of a certain value is the power to which you must raise ten to obtain that value. For example:
   • 100,000 is 10multiplied by itself 5 times, expressed as 10 to the 5th power or 10e5. The logarithm of 100,000 is 5, log 100,000 = 5
   • 210,000 is 2.1 multiplied by 100,000; the logarithm of 210,000 is 5.322. In otherwords 10 multiplied by itself 5.322 times is 210,000.
   One value of logarithms is that it allows the expression of very large values or very small values with a minimum of digits. For example:
   • the number of molecule of water in a drop of water, about 16,000,000,000,000,000 molecules; can be logged to 16.2.
   • the wavelength of a photon of violet light, about 0.00000042 meters can be logged to -6.38.
   Graphing with a logarithmic scale yields much the same benefit: the ability to show very small and very large values on the same graph. Starting at the origin (zero) and moving a certain distance would be one unit, moving the same distance again is 10 units and moving the same distance again is 100 units:
   • 0_1_2_3_4_5_6_7_8_9_10_20_30_40_50_60_70_80
     _90_100_200_300_ and so on.

6. Mixing between layers : Normally the rising of warm air and the falling of cooler air produces a great deal of vertical mixing in the atmosphere. But as certain compounds within an upper-atmospheric layer absorb a part of the solar energy, it causes that layer to warm. The warming gases expand, the density of the layer drops; suddenly warm, low-density gas from underlying layers are no longer able to easily enter this layer. Mixing of gases between the two layers now proceeds very slowly accross the boundary between the two layers, referred to as a "pause". For example, between the troposphere and the stratosphere is the boundary called the tropopause. One application of this fact is that it takes man-made CFC's between 15 to 30years to rise vertically to the ozone layer , although in areas such as antarctica mixing accross the tropopause much faster.

7. phytoplankton : plankton is a loose term used to refer to small (need a magnifying lens to see clearly) plants and animals that live in the upper layers of the ocean. phytoplankton refers to the plankton that use photosynthesis to make needed compounds. There are a range of pigments that different phytoplankton use, both to gather solar energy and to protect themselves from high-energy solar radiation.

8. Volatile : a term applied to compounds which evaporate easily.

9. Volume considerations: the general statement that 'decreasing the internal pressure decreases the volume' is true if the temperature and the amount of gas are kept constant , and the container has a volume which can be changed easily.

Author: Brien Sparling

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