Michael,+Juyon,+Juliana

SORRY IT TOOK ME LONGER THAN I THOUGHT TO MAKE COMMENTS, IF YOU WERE UNABLE TO MAKE CHANGES BASED ON MY COMMENTS DUE TO THE 1 DAY TURN AROUND YOU MAY PASS IN YOUR FINAL PAPER ON TUESDAY FOR NO LATE GRADE PENALTY. Juyon Lee, Juliana Lord, Michael Zhang Tan Class, Ms. Green
 * [|Jun 5, 2011 2:50 pm] ||= [[image:http://earthscienceirp.wikispaces.com/i/compare1.gif width="50" height="15" link="http://earthscienceirp.wikispaces.com/page/history/Michael%2C+Juyon%2C+Juliana#"]] || [[image:http://www.wikispaces.com/i/user_none_sm.jpg width="16" height="16" caption="guest" link="http://www.wikispaces.com/user/view/173.13.101.166"]][|guest (173.13.101.166)] was J.Y ||

 **The Effect of Cloud Type and Cloud Cover Percentage on UV-A and UV-B Rays **   The sun is the central part of our solar system, and it has a great impact on Earth. It radiates an immense amount of energy into space and toward Earth—some of this energy is in the form of ultraviolet radiation. UV radiation is electromagnetic waves between 100 to 400 nanometers. The smaller measurement of UV radiation, the greater amount of energy it has (8). In addition, UV rays are sub-divided into UV-C, UV-B, and UV-A rays in an order of the strongest ray with the shortest wavelength to the weakest with the longest wavelength (8). Because of its power and how the ozone works, almost all UV-C rays are absorbed by the ozone layer and broken down by the layer’s O3 molecules (8). UV-B radiation is able to break apart the ozone layer and thus be absorbed, but it also can pass through the ozone layer (8). Finally, UV-A radiation, being the weakest of the three types, cannot break apart the ozone and be absorbed. This means that the UV-A rays pass through unabsorbed and unfiltered (8). Therefore, there are larger traces of UV-A radiation on Earth while less amounts of UV-B and UV-C radiation can be found on the surface of Earth.Clouds are striking and noticeable features of the atmosphere and are categorized based on their shape and altitude. The three basic types of clouds are cirrus, cumulus, and stratus. Cirrus clouds are high, white, and thin clouds that exist in patchy layers and have a veil-like or feathery appearance (7). Cumulus clouds have rounded individual cloud masses in a cauliflower-like structure and appear in heaps (7). Stratus clouds are like sheets or layers of clouds that cover much or all of the sky where individual clouds cannot be seen as it blends together often varying in thicknesses (7). These clouds are sub-categorized into three levels of cloud heights: high clouds are above 6000 meters in altitude, middle clouds are between 2000 and 6000 meters in altitude, and low clouds are lower than 2000 meters in altitude. The three general categories of high clouds are thin, wispy cirrus clouds, fluffy cirrocumulus clouds, and flat cirrostratus clouds (7). The mid altitude cloud family consists of large, dense, round altocumulus clouds, and thin, white-to-grayish altostratus clouds (7). The low clouds are layered stratus and nimbostratus that bring some type of rain, along with stratocumulus clouds, which are similar to cumulus clouds (but with more spread out and slightly patchy feature) (7). Furthermore, there is one type of cloud with vertical development: the cumulonimbus cloud. This cloud has a base in the low cloud height range but is extended upward into the middle or high altitudes (7). When clouds cover the atmosphere they help preventing ultraviolet radiation from reaching to the surface of earth (5). There are many factors that affect the amount of radiation absorbed on Earth. Such factors are location, time of day, season, ozone levels, and clouds. In this experiment, all other factors beside cloud type and cloud cover are kept constant simply because the experiment takes in the same location (in front of Ms. Chang’s science class, by the windowsill), at the same time (after school 2:40pm-2:50pm), and in springtime (April and May). Also, water vapor in clouds and in the atmosphere absorbs narrow bands of radiation between 0.9 m to 2.1 m (1). While cloud cover can create a barrier to the penetration of the insulation if it is thick and complete enough, cloud type is also important because the amount of insulation reflected depends on the cloud cover and the cloud thickness (1). For example, complete overcast of cirrostratus can block out up to 50% of solar radiation while a complete overcast of stratocumulus clouds may block out up to 80% (1). UV-A has a relatively consistent intensity all year round (5). It penetrates the skin deeper than UV-B and causes skin aging, wrinkles, sunburn, and skin cancer (5). UV-B rays are stronger than UV-A and their intensity increases during the summer months, at higher altitudes and the closer you are to the equator (5). UV-B exposure can cause cataracts, skin aging, and sunburns (3). UV-C rays are the strongest rays and the most dangerous, however the ozone layer absorbs them, so they do not reach the Earth’s surface (3). UV radiation intensity is reduced when there is thick and widespread cloud cover and when there are scattered clouds, UV radiation rises and falls as the clouds pass in front of the sun (5). However, it is possible to get sunburn even on a cloudy day since some of the UV rays can still penetrate our atmosphere (6). The eyes are most sensitive to UV radiation from 210 nm to 320 nm (UV-C and UV-B) (3). Since maximum absorption by the cornea occurs around 280 nm, it would be dangerous if the radiation goes above 280 nm (3). **If water has some ability to block out ultraviolet radiation and clouds are made up of water vapor, then days with more cloud cover and heavy, dense clouds will be able to block out more UV radiation than days with less cloud cover and thinner clouds because denser clouds and high cloud cover means that there will be more water vapor in the air that will block out UV radiation. **
 * Introduction: **

**Materials & Methods:**  - UV-A Sensor - UV-B Sensor - LoggerPro 3.8.4 30-Day Trial Program - Laptop Computer - Excel Program

1) Go to the science wing on the first floor of Wellesley High School, just outside of room 193 on the windowsill. Make sure to do so at 2:40-2:50 each day. xxx <span style="color: black; display: block; font-family: 'Times New Roman',serif; font-size: 16px;">2) Record the type(s) of clouds using a "cloud reference" sheet from NOAA (clouds with high altitudes have the prefix "cirrus", clouds with mid altitudes have the preafix "alto", clouds with low altitudes have the prefix "stratus"; whispy clouds have the suffix "cirrus", round clouds have the suffix "cumulus", flat & sheet-like clouds have the suffix "stratus"). <span style="background-color: #ffffff; color: #ffffff; display: block; font-family: 'Times New Roman',serif; font-size: 16px; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; vertical-align: baseline;">xxx <span style="color: black; display: block; font-family: 'Times New Roman',serif; font-size: 16px;">3) Record the percentage of cloud cover based on how much of the sky has clouds in it versus how much of the sky is clear. <span style="background-color: #ffffff; color: #ffffff; display: block; font-family: 'Times New Roman',serif; font-size: 16px; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; vertical-align: baseline;">xxx <span style="color: black; display: block; font-family: 'Times New Roman',serif; font-size: 16px;">4) Take UV-A readings for two minutes using a UV-A probe connected to a computer and the program LoggerPro 3.8.4 (go to the toolbar, press "experiment", press "start collection", & hold the probe directly at the sun). Then, take the average of the thirty-one readings taken over the two-minute period and record it. (Do this by adding the data from the 31 readings and dividing the sum by 31.) <span style="background-color: #ffffff; color: #ffffff; display: block; font-family: 'Times New Roman',serif; font-size: 16px; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; vertical-align: baseline;">xxx <span style="color: black; display: block; font-family: 'Times New Roman',serif; font-size: 16px;">5) Take UV-B readings for two minutes using a UV-B probe connected to a computer and the program LoggerPro 3.8.4 (go to the toolbar, press "experiment", press "start collection", & hold the probe directly at the sun). Then, take the average of the thirty-one readings taken over the two-minute period and record it. (Do this by adding the data from the 31 readings and dividing the sum by 31.) <span style="background-color: #ffffff; color: #ffffff; display: block; font-family: 'Times New Roman',serif; font-size: 16px; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; vertical-align: baseline;">xxx <span style="color: black; display: block; font-family: 'Times New Roman',serif; font-size: 16px;">6) Repeat steps 1-5 for as many days as possible--always at the same time and in the same place--for maximum accuracy of the graphs. <span style="background-color: transparent; color: black; display: block; font-family: 'Times New Roman',serif; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;">
 * Results:**

Data Table1: The Effect of Cloud Type and Cloud Coverage on UV-A and UV-B Radiation <span style="background-color: transparent; color: black; display: block; font-family: 'Times New Roman',serif; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;"> <span style="background-color: transparent; color: black; display: block; font-family: 'Times New Roman',serif; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;">
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Date/Time(mm.dd.yy/00:00pm) || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Cloud Type || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Cloud Coverage (%) || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">UV-A Radiation (mW/m2) || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">UV-BRadiation (mW/m2) ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">04.25.11/14:45pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Cumulus & Stratus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">100% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">861.97 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">40.73 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">04.26.11/14:45pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Altocirrus & Cumulus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">13% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">5604.16 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">282.30 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">04.27.11/14:45pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Altostratus & Cumulus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">92% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">1409.59 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">76.49 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">05.02.11/14:50pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Altocumulus & Altostratus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">90% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">3776.45 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">108.06 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">05.05.11/14:45pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Cumulus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">80% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">895.52 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">39.37 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">05.09.11/14:45pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Altostratus & Cumulus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">66% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">3877.39 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">227.69 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">05.10.11/14:40pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Cumulus & Stratus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">97% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">1240.32 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">51.88 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">05.11.11/14:45pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Cumulus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">100% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">1889.65 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">91.24 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">05.12.11/14:45pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Cumulus & Cirrostratus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">94% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">1906.19 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">94.73 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">05.16.11/14:40pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Stratus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">99% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">535.90 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">30.42 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">05.18.11/14:40pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Stratus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">100% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">555.90 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">30.75 ||
 * <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">05.20.11/14:40pm || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">Stratus & Cumulus || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">100% || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">834.42 || <span style="display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">45.59 ||
 * 05.25.11/14:45pm || Altocumulus || 15% || 6339.94 || 337.50 ||
 * 05.26.11/14:45pm || Cirrocumulus || 20% || 5271.52 || 289.85 ||
 * 05.27.11/14:40pm || Altocumulus || 25% || 3792.06 || 246.22 ||

<span style="background-color: transparent; color: black; display: block; font-family: 'Times New Roman',serif; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;"><span style="background-color: transparent; color: #000000; display: block; font-family: 'Times New Roman'; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;">

<span style="background-color: transparent; color: black; display: block; font-family: 'Times New Roman',serif; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;">Graph 1) As cloud cover increases, UV-A radiation decreases (y = -51.124 + 6297.7). Every single data point on the graph of over 80% cloud cover had below a 2000 mW/m2 (milliWatt per square metre) UV-A level, except for one outlying reading with 90% cloud cover and 3776.45 mW/m2 of UV-A radiation, which is higher than the other data points with similar cloud cover.

Graph 2) As cloud cover increases, UV-B radiation decreases (y = -2.9544x + 345.07). Almost every data point on the graph of over 80% cloud cover has a measure of less than 100 mW/m2. A data point with 80% of cloud coverage and 39.37mW/m2 has lower UV-B radiation compared to points with 90% cloud coverage and 108.06 mW/m2 or 94% cloud coverage and94.73 mW/m2. It has even lower radiation than a data point with 100% coverage and 45.59 mW/m2. Graph 3) Judging from the graph of the effect of cloud type on UV-A radiation, different cloud types affect UV-A radiation differently. Based on the results, it can be said that stratus and stratocumulus clouds block out the most UV radiation, since they have mulitple readings under 1000 mW/m2. Cumulus clouds also had relatively low readings, all being under 2000 mW/m2. On the other hand, altocirrus, altostratus, altocumulus, and altocumulus clouds all bore higher readings of UV-A radiation, indicating that they did not block UV radiation as effectively. (The different colored bars are used only to show different readings)

<span style="background-color: transparent; color: #000000; display: block; font-family: 'Times New Roman'; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;">Graph 4) Judging from the graph of the effect of cloud type on UV-B radiation, different cloud types affect UV-B radiation differently. Based on the results, it could be said that stratus and stratocumulus clouds were able to block out the greatest amount of UV-B radiation which most results less than 50mW/m2, which only one stratocumulus measurement being 1.88 mw/m2 over 50. Similar to Graph 3, cumulus cloud readings were realtively low, being under 100 mW/m2. Again, the altostratus, altocumulus, altocirrus, and cirrocumulus clouds bore high readings of UV-B radiation. All, except for one reading, were above 100 mW/m2. (The different colored bars are only used to show different readings)

<span style="background-color: transparent; color: #000000; display: block; font-family: 'Times New Roman'; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;">There is a relationship between both cloud type and cover with both UV-A and UV-B radiation from the graphs. As cloud cover increases, UV-A and UV-B radiation decrease. In both the cloud cover graphs, there were irregularities. For example, when there was 80% cloud cover on May 5th, the UV-A radiation was measured at 39.37mW/m2 and the UV-B radiation was measured at 895.52mW/m2. These measurements are much lower than others near 80% cloud cover (an instance of this is when cloud cover was 90% measured at 3776.45mW/m2 for UV-A radiation and 108.06mW/m2 for UV-B radiation). <span style="background-color: transparent; color: #000000; display: block; font-family: 'Times New Roman'; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;"> <span style="background-color: transparent; color: #000000; display: block; font-family: 'Times New Roman'; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;"> <span style="background-color: transparent; color: #000000; display: block; font-family: 'Times New Roman'; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: left; text-decoration: none; vertical-align: baseline;"> **Discussion:**

<span style="font-family: 'Times New Roman','serif'; line-height: 150%;">The hypothesis “If water has some ability to block out ultraviolet radiation and clouds are made up of water vapor, then days with more cloud cover and heavy, dense clouds will be able to block out more UV radiation than days with less cloud cover and thinner clouds because denser clouds and high cloud cover means that there will be more water vapor in the air that will block out UV radiation” is supported by our results because in both UV-A and UV-B radiation data, there is a decrease in mW/m2 with the increase of cloud cover, and also there is a correlation with type (or types) of clouds in the sky (with thicker clouds being able to block out more UV radiation). The data has shown that there is no perfectly defined, linear relationship between UV radiation and either one of the variables because both cloud cover and cloud type affect radiation at the same time, and the sun’s radiation output varies uncontrollably from day to day. <span style="font-family: 'Times New Roman','serif'; line-height: 150%;">Under different circumstances, the data could have been put into graphs that isolated one variable (for example, measurements with stratus clouds and cloud cover above 50%). However, there was not enough data collected in this experiment to create such graphs. If data was collected over a longer period of time, these more exact graphs would have been possible to make.

<span style="font-family: 'Times New Roman','serif'; line-height: 150%;">Also, the type of cloud affects UV radiation just as much because there was more than one case where cloud cover was nearly the same but UV-A and UV-B radiation were not. For example, on May 2nd, there was 90% cloud cover. However, unlike most readings with similar cloud cover, the UV-A reading was taken at 3776.45 mW/m2. This is because the cloud type was altocumulus, which is less dense than other clouds such as stratus and stratocumulus.Although the findings fit the hypothesis that heavier, denser clouds and high cloud cover will block out UV-A and UV-B radiation, there may be some inaccuracy. One error could have been simple mis-positioning of the UV sensors—not pointing the UV sensor directly at the sun. Another factor that could have led to inexact results is the inconsistency of weather—over the period of time in which data was taken, the majority of the days were cloudy and overcast, which means that there were fewer readings that yielded high UV measurements. This would result in imprecise relationships between UV radiation and cloud cover/cloud type. Also, low clouds such as stratus and stratocumulus clouds are thick, which prevents sight of the sky above. This indicates that while the cloud type for a day may be marked “stratus”, it is possible that there were cumulus clouds above those stratus clouds. However, the data points taken still give an accurate idea of the relationships that were explored. Despite the possible inaccuracy, however, the data yields significant information regarding ultraviolet radiation. It is dangerous to expose one’s eyes and skin to all three types of UV radiation—UV-A, UV-B, and UV-C—and this data makes it easier to see which types of clouds and how much cloud cover result in high ultraviolet radiation and its ensuing physical consequences. For example, UV-A radiation results in premature skin aging (wrinkles and discoloring), sunburns, and mild skin cancer. UV-B radiation, having shorter electromagnetic waves, causes sunburns, mild to severe skin cancer, and cataracts. The data suggests that UV-A and UV-B radiation would cause almost no harm to the skin if there is more than about 85% cloud cover with denser clouds such as stratus or cumulus clouds. However, if there is either less cloud cover with heavy clouds or lighter, less dense clouds with a high percentage, the damage to skin will be increased. Pertaining to eye damage, there is almost always the chance of damage because eyes are extremely sensitive to radiation. Looking up at the sky, even when there are clouds, exposes the eyes to radiation. Doing this repeatedly can cause cataracts that can lead to blindness if the cataracts are severe and go untreated. Wearing sunglasses every day would be beneficial and applying sunscreen unless there is 100% cloud cover would prevent sunburns and possible long-term damage (3). In addition to wearing sunglasses and sunscreen, it’s important to determine a person’s exposure to UV rays by knowing a UV Index (10). Based on the number on a scale—one being lowest exposure and 11 and up being extreme exposure—and in combination with a person’s skin type—with fair-skinned meaning increased effect of UV radiation—it’s possible to measure a healthy exposure to the sun that will not cause various skin diseases and cancers (10).

<span style="color: black; display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">**Sources:** <span style="background-color: transparent; color: #000000; display: block; font-family: 'Times New Roman'; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: center; text-decoration: none; vertical-align: baseline;"><span style="color: black; display: block; font-family: 'Times New Roman',helvetica,sans-serif; font-size: 12pt; text-align: left;">(1) <span style="font-family: 'Times New Roman',helvetica,sans-serif;">Barry, R. G., and R. J. Chorley. //Atmosphere, Weather, And Climate//. New York: Holt, Rinehart And Winston, 1970. Print. (2) Calbó, Josep, David Pagès, and Josep-Abel González. //Reviews of Geophysics.// American Geophysical Union, 29 June 2005. Web. <[]>. (3) Canadian Centre for Occupational Health & Safety. //Canadian Centre for// //Occupational Health & Safety//. N.p., 27 July 2005. Web. 6 <[]>. <span style="background-color: transparent; color: #000000; display: block; font-family: 'Times New Roman'; font-size: 12pt; font-style: normal; margin-bottom: 0pt; margin-top: 0pt; text-align: center; text-decoration: none; vertical-align: baseline;"><span style="color: black; display: block; font-family: 'Times New Roman',helvetica,sans-serif; font-size: 12pt; text-align: left;">(4) <span style="font-family: 'Times New Roman',helvetica,sans-serif;">"Cloud Types." //WW2010//. University of Illinois, n.d. Web. 23 May 2011. [|http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/cldtyp/home.rxml]. (5) Healthscope. "UV Radiation." //Healthscope Medical Centres//. N.p., n.d. Web. <[]>. <span style="color: black; display: block; font-family: 'Times New Roman',serif; font-size: 12pt; text-align: left;">(6) NSF Polar Programs UV Monitoring Network. //National Science Foundation Polar// //Programs UV Monitoring Network//. N.p., n.d. Web. <[]>.(7) Tarbuck, Edward J., and Frederick K. Lutgens. "Sleet, Glaze, and Hail." //Earth Science//. Boston: Pearson Prentice Hall, 2009. 522. Print.// (8) <span style="font-family: 'Times New Roman',helvetica,sans-serif;">"Ultraviolet Radiation." //NSF Polar Programs UV Monitoring Network//. Biospherical Instruents Inc., n.d. Web. 23 May 2011. []////<span style="font-family: 'Times New Roman',serif; font-style: normal;">(9) <span style="font-family: 'Times New Roman',helvetica,sans-serif;">"UV and You: Sunshine and Safe Skin." //National Outdoor Leadership School//. Ed. Buck Tilton. NOLS Professional Training, n.d. Web. 23 May 2011. <http://www.nols.edu/wmi/articles/archive/uv.shtml>.// (10) //UV Student's Guide//. NSF, n.d. Web. 30 May 2011. <[]>. (11) <span style="font-family: 'Times New Roman',helvetica,sans-serif;">"What Is UV Radiation and How Much Does It Increase with Altitude?" //National// Weather Service Forecast Office Flagstaff, AZ//. National Oceanic and Atmospheric Administration, n.d. Web. 23 May 2011. <http://www.wrh.noaa.gov/fgz/science/uv.php?wfo=fgz>.//

<span style="font-family: Georgia,serif;">**Title** <span style="font-family: Georgia,serif;">This should tell me what the variables being investigated are and which is independent and which is dependent. <span style="font-family: Georgia,serif;">-Generally follows the format of the effect of (independent variable(s)) on (dependent variable) or which impacts (dependent variable) the most? (independent variable 1, independent variable 2, or independent variable 3)

<span style="font-family: Georgia,serif;">This section states the overall purpose and hypothesis of this <span style="font-family: Georgia,serif;">experiment. Background information is used to carefully explain this <span style="font-family: Georgia,serif;">hypothesis and provide the reader with a foundation <span style="font-family: Georgia,serif;">to understand the experiment.
 * <span style="font-family: Georgia,serif;">Introduction **

-Provides important scientific background information on the topic including important terms, variables that -might impact results and should therefore be held constant or accounted for in analysis, information about how to interpret results (such as what is “normal” or “hazardous”) -Most importantly, the information in the introduction leads to the reader agreeing that the hypothesis is logical and well supported by research into the behavior of the thing being investigated) -Communicates the anticipated results (hypothesis), often at end but if it is multiple it might fit better in pieces  at the end of each paragraph  -Hypothesis statement should be in bold and should be specific and measurable. It should be about the  relationship between the independent and the dependent variable in your experiminet.  -Cut out any repetitive or unnecessary information. Make sure the introduction flows logically.

<span style="font-family: Georgia,serif;">This section describes how the data in this experiment was collected. <span style="font-family: Georgia,serif;">All important procedures are outlined to ensure that the results <span style="font-family: Georgia,serif;">can be reproduced for verification.
 * <span style="font-family: Georgia,serif;">Materials and Methods **

-List the steps followed to complete the investigation in a #’d list, each step having its own #. Write in present tense, command form. -Describe any complicated equipment or set-ups using diagrams, maps and/or photographs, do not add diagrams or pictures unless they are needed. -All steps must be detailed, quantitative if necessary, and in order. Make sure you are specific to what you actually did. Do not say “choose a location” but describe the actual location you chose. -methods are well described and are a good design to test what you wish to test; they limit human and experimental error and are as efficient and quantitiative as possible -Details such as as “bring a pencil for writing down data, or “analyze data” are assumed and not part of the methods. “Take density data” is not specific enough!

<span style="font-family: Georgia,serif;">The Results section shows the data that was collected in an <span style="font-family: Georgia,serif;">experiment and what is done with this data. This could include tables, <span style="font-family: Georgia,serif;">graphs, and/or calculations. It should summarize the data from the experiments without discussing the implications or analyzing patterns.
 * <span style="font-family: Georgia,serif;">Results **

-The first thing in your results section should be your data table (s). Data tables with raw data present and follow the guidelines given for good data tables -Appropriate data analysis present including calculations, graphs and/or charts following guidelines for good graphs and showing the significant patterns in the data with the focus on the pattern indicated in hypothesis.

<span style="font-family: Georgia,serif;">In this section, the experimenter explains implications of the data and <span style="font-family: Georgia,serif;">analysis presented in the previous section. This will include background <span style="font-family: Georgia,serif;">information to support the hypothesis presented in the introduction.
 * <span style="font-family: Georgia,serif;">Discussion **

<span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">-Should begin by describing the major findings/patterns in data relative to the purpose of this experiment (is your hypothesis supported by the <span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">data or not?) making sure to reference the graphs in the results section in which this pattern is displayed. Use calculations! <span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">-Attempts to explain the significant findings using background information and answer the question; why did this <span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">happen?. <span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">-Be careful in the degree of certainty you give your explanations and findings (ex. suggests rather than proves). <span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">Be aware of systematic or specific errors that affected the overall results of your experiment and explain how/why <span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">-Describes any significant use these findings have. Why is this important to know, are your results <span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">generalizable? Focus on scientific understanding and/or human impact) for conducting the experiment <span style="font-family: Georgia,serif; font-size: 8pt; margin: 0in -40.5pt 0pt 0.25in;">-Makes recommendations for further study and improving the experiment.

**General Format Guidelines** <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">O -Never use “I” or “we”, you should write in a formal, scientific paragraph (except methods are #’d steps) style, <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">cut out unnecessary or repetitive sentences <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">OX -There will be 4 clearly labeled sections (Intro, Materials & Methods, Results, Discussion) The heading of each section <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">should be on its own line, in bold. The first line of each paragraph should be indented twice from the heading. <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">O - All the rest of the paragraph will be indented once. This makes the heading alone on the left margin. <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">-All pages should be numbered and sections MUST be in the correct order, all data must be after the heading <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">“Results” and before the heading “conclusion” not attached at end. <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">-Double space all except the methods. It is appropriate to single space methods but leave a space after each <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">step. 12 Font. <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">-Spell check, grammar check, typo check and edit for clarity as you would for any formal writing assignment. <span style="font-size: 8pt; margin: 0px -40.5pt 0px 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">The final draft shall be free of all such errors.