1 00:00:00,000 --> 00:00:04,940 Hi, I'm Dr. Jennifer Olson. I'm one of the treehouse detectives. We're trying to learn more about wind 2 00:00:04,940 --> 00:00:09,120 We want to know if volcanic ash can blow all the way from the Pacific Ocean to Virginia 3 00:00:09,120 --> 00:00:13,820 I'm looking at some data in the cave right now. Would you like to step in with me and take a look? 4 00:00:13,820 --> 00:00:18,820 I've heard of the cave. Sure. Let's go. First. You'll need to take off your shoes and put on the glasses 5 00:00:21,580 --> 00:00:26,940 Wow, this is neat. We're looking at wind vectors over the Pacific Ocean in the US 6 00:00:27,880 --> 00:00:29,240 What's a wind vector? 7 00:00:29,240 --> 00:00:31,240 Do you see the yellow arrows? 8 00:00:31,240 --> 00:00:33,240 Yeah, lots of them. 9 00:00:33,240 --> 00:00:39,240 Those are wind vectors. They show which direction the wind is blowing. Their size tells you how fast the wind is blowing. 10 00:00:39,240 --> 00:00:43,240 The longer the arrow is, the faster the wind speed is. 11 00:00:43,240 --> 00:00:45,240 What about the wind vectors way up there? 12 00:00:45,240 --> 00:00:51,240 These vectors are up at 12 miles over the Earth's surface. That's well above the weather. 13 00:00:51,540 --> 00:00:57,540 It looks like all those arrows are pointing in the same direction. Is that normal for high altitudes? 14 00:00:57,540 --> 00:01:05,540 Yes, it is. Notice that these arrows are mostly pointing from the west toward the east. That's a zonal direction in the global wind pattern. 15 00:01:05,540 --> 00:01:07,540 How fast are they blowing? 16 00:01:07,540 --> 00:01:15,540 At 12 miles up, most wind speeds are between 40 and 50 miles per hour. At these altitudes, there's also something that we call a jet stream. 17 00:01:15,540 --> 00:01:19,540 Oh, you mean the white stuff that comes out the back of a jet we see? 18 00:01:19,840 --> 00:01:25,840 Yes, but the jet stream is a river of very fast-flowing air, where speeds can reach several hundred miles per hour. 19 00:01:25,840 --> 00:01:27,840 That's as fast as a major tornado. 20 00:01:27,840 --> 00:01:30,840 Let's step outside and go to my computer lab. 21 00:01:30,840 --> 00:01:32,840 Okay. 22 00:01:32,840 --> 00:01:35,840 So what's the second thing that affects how far wind can transport particles? 23 00:01:35,840 --> 00:01:37,840 It's the lifetime of a particle. 24 00:01:37,840 --> 00:01:42,840 Scientists have a tremendous amount of data available to them to study things like lifetimes of gases and particles, 25 00:01:42,840 --> 00:01:45,840 and much of that data is stored here at the Atmospheric Science Data Center. 26 00:01:45,840 --> 00:01:47,840 I didn't know particles had a life. 27 00:01:48,140 --> 00:01:52,140 Yes, lifetime refers to how long the particle stays in the atmosphere. 28 00:01:52,140 --> 00:01:58,140 For a particle near the surface, ash and dust will be rained out of the atmosphere within a matter of days. 29 00:01:58,140 --> 00:02:00,140 So volcanic ash would not have a very long lifetime. 30 00:02:00,140 --> 00:02:02,140 Not necessarily. 31 00:02:02,140 --> 00:02:10,140 If the ash were injected up in the atmosphere, near the stratosphere, its lifetime could be very long, in the order of weeks or months. 32 00:02:10,140 --> 00:02:13,140 Would zonal winds then be able to carry the ash to Virginia? 33 00:02:13,440 --> 00:02:14,440 Yes, it could. 34 00:02:14,440 --> 00:02:16,440 If a volcano injected particles into the stratosphere, 35 00:02:16,440 --> 00:02:21,440 it could be transported for very long distances by the very fast wind speeds of the jet stream. 36 00:02:21,440 --> 00:02:23,440 Yeah, but the Pacific Ocean is so far away. 37 00:02:23,440 --> 00:02:25,440 That would take forever. 38 00:02:25,440 --> 00:02:27,440 Let's do a quick calculation. 39 00:02:27,440 --> 00:02:30,440 It's about 7,000 miles from here to Mount Luminous. 40 00:02:30,440 --> 00:02:35,440 If we take a typical atmospheric wind speed of about 40 miles per hour, 41 00:02:37,440 --> 00:02:38,440 what do you get? 42 00:02:38,440 --> 00:02:39,440 175 hours. 43 00:02:39,740 --> 00:02:43,740 175 hours to transport the dust to Virginia. 44 00:02:43,740 --> 00:02:45,740 That's about a week. 45 00:02:45,740 --> 00:02:50,740 In fact, the dust plume could be transported completely around the globe in about a month. 46 00:02:50,740 --> 00:02:52,740 The sky is so deep red. 47 00:02:52,740 --> 00:02:54,740 Is there anything about this eruption that is different? 48 00:02:54,740 --> 00:02:55,740 Yes, there is. 49 00:02:55,740 --> 00:03:00,740 I read that this volcano also injected a lot of sulfur dioxide and water vapor into the stratosphere. 50 00:03:00,740 --> 00:03:04,740 These two gases react together to form tiny sulfuric acid particles. 51 00:03:04,740 --> 00:03:08,740 We learned from Dr. Poluski that particles scatter the blue light. 52 00:03:09,040 --> 00:03:10,040 That's right. 53 00:03:10,040 --> 00:03:14,040 And these particles are small enough that they act with the molecules in the atmosphere 54 00:03:14,040 --> 00:03:17,040 to scatter even more of the blue light from the sun's rays. 55 00:03:17,040 --> 00:03:18,040 Thanks, Dr. Olson. 56 00:03:18,040 --> 00:03:19,040 Sure.