1 00:00:00,000 --> 00:00:09,360 Merci Dr. Tonray. Well, now that you are experts on aerosols, let's head to Collège Cantolando, 2 00:00:09,360 --> 00:00:15,240 located in Bordeaux, France, for Part 2 of this program's hands-on activity, the Globe 3 00:00:15,240 --> 00:00:16,240 Aerosol Protocol. 4 00:00:16,240 --> 00:00:27,240 Bonjour! Nous sommes des élèves du Collège Cantolando CESTAS à Bordeaux, en France. 5 00:00:27,240 --> 00:00:30,920 NASA Connect nous a demandé de présenter la deuxième partie de ce programme de travaux 6 00:00:30,920 --> 00:00:31,920 pratiques. 7 00:00:31,920 --> 00:00:37,920 In this activity, called Aerosols Protocol, you will use a sun photometer to measure the 8 00:00:37,920 --> 00:00:44,240 aerosol optical thickness of the atmosphere, or how much of the sun's light is scattered 9 00:00:44,240 --> 00:00:49,720 or absorbed by particles suspended in the air. Remember, you can download a copy of 10 00:00:49,720 --> 00:00:54,520 the educator guide containing directions and list of materials from the NASA Connect 11 00:00:54,520 --> 00:00:55,520 website. 12 00:00:55,520 --> 00:01:00,280 When you are ready to go outside, put your sun photometer in an insulated bag to keep 13 00:01:00,280 --> 00:01:05,720 it at room temperature. Putting your sun photometer in a bag will help minimize any temperature 14 00:01:05,720 --> 00:01:07,680 sensitivity problems. 15 00:01:07,680 --> 00:01:12,200 To begin taking measurements with your sun photometer, flip the power switch on and then 16 00:01:12,200 --> 00:01:17,880 select the green channel. Hold the instrument in front of you about chest high. Point the 17 00:01:17,880 --> 00:01:23,880 sun photometer at the sun and then find the spot made by the sun as it shines through 18 00:01:23,880 --> 00:01:29,520 the front alignment bracket. Remember, guys, never look directly into the sun. Use the 19 00:01:29,520 --> 00:01:35,480 mark on the rear alignment bracket as a guide to align the sunspot until it rests on the 20 00:01:35,480 --> 00:01:36,480 color dot. 21 00:01:36,480 --> 00:01:42,960 It is normal for the readout to fluctuate within a few millivolts. Record only the highest 22 00:01:42,960 --> 00:01:48,960 reading that you see over a period of about 15 seconds. Record the value on the data sheet 23 00:01:48,960 --> 00:01:52,400 and the time of the reading to within 15 seconds. 24 00:01:52,400 --> 00:01:58,240 Now take the dark voltage reading. Cover the two holes on the sun photometer. Record 25 00:01:58,240 --> 00:02:04,560 the value of the dark voltage reading on the data sheet. Switch to the red channel. Record 26 00:02:04,560 --> 00:02:10,400 the maximum voltage and the time just as you did with the green channel. Then take the 27 00:02:10,400 --> 00:02:16,200 dark voltage reading again just like before. You need to repeat the process for the green 28 00:02:16,200 --> 00:02:22,280 and red channels two more times, giving you a total of three data points for each channel. 29 00:02:22,280 --> 00:02:28,360 Next, using your cloud chart as a guide, observe and record cloud conditions. Determine 30 00:02:28,360 --> 00:02:34,240 what types of clouds are in the sky. Record your observation on the data chart. Next, 31 00:02:34,240 --> 00:02:39,240 determine the percentage of cloud cover and record the value on the data sheet. Now you 32 00:02:39,240 --> 00:02:46,280 need to observe the sky conditions. What is the sky color? Is the sky clear or hazy? Is 33 00:02:46,320 --> 00:02:53,320 the sky obscured by fog, smoke, or haze? Record these observations on the data sheet. Finally, 34 00:02:54,360 --> 00:02:59,320 record the current temperature. When you get back into your classroom, log on to the following 35 00:02:59,320 --> 00:03:05,560 website. You will record all your data into the database. The database will automatically 36 00:03:05,560 --> 00:03:10,720 convert your voltage readings to aerosol optical thickness. To learn more about assessing a 37 00:03:10,720 --> 00:03:13,720 sun photometer, check out the NASA Connect website.