1 00:00:00,000 --> 00:00:09,480 How does the amount of aerosols in the atmosphere affect the Earth's weather condition? 2 00:00:09,480 --> 00:00:15,120 The atmosphere consists primarily of oxygen and other gases like nitrogen and water vapor, 3 00:00:15,120 --> 00:00:16,360 hydrogen. 4 00:00:16,360 --> 00:00:21,680 But did you know that the air we breathe also consists of tiny little particles called aerosols? 5 00:00:21,680 --> 00:00:24,400 Aerosols are very important for lots of reasons. 6 00:00:24,400 --> 00:00:29,780 For example, aerosols are thought to be important in climate by changing the properties of clouds. 7 00:00:29,780 --> 00:00:34,100 If you didn't have an aerosol, it would be very difficult for a cloud droplet to form. 8 00:00:34,100 --> 00:00:39,060 In the air, water molecules attach themselves to aerosols, and as they condense, a cloud 9 00:00:39,060 --> 00:00:40,940 droplet is formed. 10 00:00:40,940 --> 00:00:45,860 The aerosols act as seeds to start the formation of the cloud droplets. 11 00:00:45,860 --> 00:00:50,540 In any location, the amount of aerosols in the atmosphere can change how far we can see, 12 00:00:50,540 --> 00:00:56,420 the frequency of clouds in the sky, the thickness of clouds, and even the rainfall amount. 13 00:00:56,420 --> 00:01:00,900 Some aerosols are naturally occurring in the atmosphere, like sea salt, pollen, and 14 00:01:00,900 --> 00:01:04,660 particles produced by volcanic eruptions. 15 00:01:04,660 --> 00:01:09,820 Other aerosols are human-made, like factory pollutants, automobile exhaust, and smoke 16 00:01:09,820 --> 00:01:12,420 from biomass burning. 17 00:01:12,420 --> 00:01:14,980 Can aerosols affect the temperature here on Earth? 18 00:01:14,980 --> 00:01:16,640 Sure they can. 19 00:01:16,640 --> 00:01:21,380 When aerosols like smoke and dust and pollen float in the air, the air becomes hazy. 20 00:01:21,980 --> 00:01:26,940 If this haziness reflects sunlight back to space, the effect is going to be a cooling 21 00:01:26,940 --> 00:01:28,460 of the atmosphere on Earth. 22 00:01:28,460 --> 00:01:32,840 But if this haziness absorbs energy, well then the net effect is going to be a warming 23 00:01:32,840 --> 00:01:36,440 of the atmosphere here on Earth. 24 00:01:36,440 --> 00:01:40,860 After getting tons of information from Dr. McCormick, we drove to NASA Langley in Hampton, 25 00:01:40,860 --> 00:01:45,700 Virginia, to talk with Dr. Russell DeYoung, an atmospheric scientist in the chemistry 26 00:01:45,700 --> 00:01:46,700 and dynamics branch. 27 00:01:46,700 --> 00:01:47,700 Hi, I'm Ben. 28 00:01:47,700 --> 00:01:50,180 Hi, glad to meet you. 29 00:01:50,180 --> 00:01:51,380 What brings you two here today? 30 00:01:51,380 --> 00:01:55,340 Well, it all started when Van's car failed inspection. 31 00:01:55,340 --> 00:01:57,580 It's because his emission levels were too high. 32 00:01:57,580 --> 00:02:01,620 Yeah, I can't believe I got rejected when there's so many other things in the atmosphere 33 00:02:01,620 --> 00:02:02,780 to worry about. 34 00:02:02,780 --> 00:02:06,580 Can my van's little emissions really affect the huge atmosphere above us? 35 00:02:06,580 --> 00:02:07,580 Okay, good. 36 00:02:07,580 --> 00:02:11,060 You've got a lot of good questions, and I think I can get some answers for you all. 37 00:02:11,060 --> 00:02:15,400 Here at NASA Langley in Hampton, Virginia, and NASA Goddard in Greenville, Maryland, 38 00:02:15,400 --> 00:02:19,020 we study how natural and man-made aerosols affect the atmosphere. 39 00:02:19,020 --> 00:02:23,020 You have one vehicle, every family on your block has at least one vehicle, your city 40 00:02:23,020 --> 00:02:27,380 is full of vehicles, in the U.S. alone there are millions of vehicles, all burning fossil 41 00:02:27,380 --> 00:02:28,380 fuels. 42 00:02:28,380 --> 00:02:33,540 Altogether, these vehicles emit huge amounts of particles called aerosols that are carried 43 00:02:33,540 --> 00:02:35,740 long distances by the wind. 44 00:02:35,740 --> 00:02:41,540 Did you know that in 1991, Mount Pinatubo, a volcano in the Philippines, erupted, releasing 45 00:02:41,540 --> 00:02:44,740 massive aerosol concentrations into the air? 46 00:02:44,740 --> 00:02:48,860 These aerosols were immediately dispersed into the upper atmosphere. 47 00:02:48,860 --> 00:02:53,860 Three months later, these same aerosols could be found all over the Earth. 48 00:02:53,860 --> 00:02:58,940 Okay, your van is a small polluter, but think about this. 49 00:02:58,940 --> 00:03:02,980 Think about the combined effect of all the exhaust of all the cars in the world on the 50 00:03:02,980 --> 00:03:03,980 Earth's atmosphere. 51 00:03:03,980 --> 00:03:07,100 Wow, that's definitely something to think about.