WEBVTT - Weather Tech, Part 2 0:00:04.519 --> 0:00:13.480 Technology with tex Stuff from Hastuff. Hey there, and welcome 0:00:13.520 --> 0:00:16.400 to Tech Stuff. I am your host, Jonathan Strickland, and 0:00:16.440 --> 0:00:20.439 now I'm going to bring you the exciting conclusion about 0:00:20.640 --> 0:00:25.680 whether Technology Dylan has joined me for this episode. This 0:00:25.840 --> 0:00:28.120 was a show that we recorded all in one go, 0:00:28.320 --> 0:00:30.080 but it turned out to be too long for a 0:00:30.120 --> 0:00:33.120 single episode, so we've broken it up and that means 0:00:33.159 --> 0:00:36.760 we are now going to join the podcast already in progress. 0:00:38.640 --> 0:00:41.560 We were able to gather a lot of information once 0:00:41.640 --> 0:00:45.199 we had those basic tools available to us. But what 0:00:45.479 --> 0:00:50.720 really pushed meteorology forward is when we could stop relying 0:00:50.840 --> 0:00:53.400 upon the data that we can gather here on the 0:00:53.440 --> 0:00:58.520 ground and supplement that with information from the atmosphere itself. 0:00:59.080 --> 0:01:02.840 And that brings us to weather balloons. Weather balloons more 0:01:02.920 --> 0:01:07.160 than just fodder for your roswald uh concy right right, 0:01:07.440 --> 0:01:10.520 swamp gas and weather balloons and uh, you know, weather 0:01:10.560 --> 0:01:13.319 balloons do more than just act as a subplot in 0:01:13.360 --> 0:01:16.520 an X Files episode. Right, Yes, They're very important. Yeah, 0:01:16.600 --> 0:01:23.640 So they carry instrumentation that collects data about atmospheric conditions 0:01:23.720 --> 0:01:26.080 and weather balloons have been around for a long time, 0:01:26.240 --> 0:01:31.560 but more recently they typically carry instruments called radio SOND, 0:01:31.720 --> 0:01:34.400 which is a bettery powered device that can measure altitude, 0:01:34.440 --> 0:01:39.400 atmospheric pressure, temperature, humidity, wind speed. Sometimes there's a GPS 0:01:39.480 --> 0:01:41.960 element to it, so it can so people on the 0:01:42.000 --> 0:01:44.600 ground can track where the weather balloon is. Normally, the 0:01:45.000 --> 0:01:48.000 you tether these devices. You don't just release a weather 0:01:48.000 --> 0:01:51.480 balloon and say sia uh. But sometimes you know you 0:01:51.480 --> 0:01:55.280 need to have that GPS element there too. And getting 0:01:55.280 --> 0:01:57.760 this information from the atmosphere is really important because it 0:01:57.800 --> 0:02:00.760 can tell you about how conditions may soon change on 0:02:00.840 --> 0:02:06.200 the ground. Um. It's pretty interesting actually to ever if 0:02:06.240 --> 0:02:08.480 you've ever had a chance to to look at some 0:02:08.560 --> 0:02:12.240 of the data pulled from these because you you see 0:02:12.320 --> 0:02:15.480 how different conditions in the atmosphere are compared to what 0:02:15.560 --> 0:02:23.320 we experience here, including some pretty intense winds at higher altitudes. UM. 0:02:23.400 --> 0:02:27.880 So we've got all this information being collected. Uh. And 0:02:27.960 --> 0:02:30.640 before we get into space, because that'll be the next 0:02:30.720 --> 0:02:33.520 step outward, I wanted to talk a little bit about 0:02:33.520 --> 0:02:36.160 what we do with all that data. One of the 0:02:36.200 --> 0:02:39.880 things we do is we create databases that have all 0:02:39.880 --> 0:02:42.480 this information, so that let's say that we have a 0:02:42.600 --> 0:02:47.680 day with pretty nice weather, we collect all the information 0:02:47.720 --> 0:02:50.880 about that what was the atmospheric pressure, what was the temperature, 0:02:50.880 --> 0:02:53.160 how much humidity was in the air, what was the 0:02:53.160 --> 0:02:57.119 wind speed, were there any higher low pressure systems nearby? 0:02:57.360 --> 0:02:59.519 What were the what kind of front had just moved through? 0:02:59.560 --> 0:03:01.560 All this sort of information, we feed it all into 0:03:01.680 --> 0:03:05.280 a database. Collecting that over and over and over again 0:03:05.320 --> 0:03:09.960 allows us to build a better virtual understanding of how 0:03:10.040 --> 0:03:14.480 weather works, right um, and we can supplement that with 0:03:14.520 --> 0:03:17.920 more information as we learn more about the weather. Then 0:03:18.440 --> 0:03:21.880 we would end up using that to help us make 0:03:21.919 --> 0:03:24.440 some predictions about how weather weather it might be in 0:03:24.480 --> 0:03:27.280 the future. And we to do that, really we use 0:03:27.320 --> 0:03:32.280 computer models. Uh. Typically we would build what it's called 0:03:32.320 --> 0:03:39.800 a numerical weather prediction model, the NWP. So this is 0:03:39.960 --> 0:03:42.880 really a model that's made up of a bunch of 0:03:42.920 --> 0:03:46.920 different calculations that take all of the different variables into 0:03:46.960 --> 0:03:51.160 account and tell you, based upon all the variables available 0:03:51.200 --> 0:03:54.120 to us, here's what it looks like the weather is 0:03:54.160 --> 0:03:58.200 going to be like in X amount of time. Right. So, 0:03:58.280 --> 0:04:00.760 whenever we're talking about forecasts, obviously we have to worry 0:04:00.760 --> 0:04:03.520 about what are the current conditions and how far out 0:04:03.560 --> 0:04:07.760 are we trying to predict the weather? And on TV, 0:04:07.920 --> 0:04:10.839 you might see five or seven or even these days 0:04:10.880 --> 0:04:13.200 sometimes ten. Yeah. Like if you go to go to 0:04:13.280 --> 0:04:15.720 weather dot com, they have a ten day forecast, which 0:04:15.720 --> 0:04:18.960 I always think is hilarious. And the reason I think 0:04:18.960 --> 0:04:23.520 it's hilarious is here's how those predictions work. You take 0:04:23.560 --> 0:04:26.200 all the information available to you, You run it through 0:04:26.279 --> 0:04:30.839 your computer model, which factors in these different variables and 0:04:30.960 --> 0:04:34.960 gives you sort of a a percentage of probability of 0:04:34.960 --> 0:04:36.800 what your weather is going to be like in the 0:04:36.839 --> 0:04:40.960 next let's say hour. What if you want to look 0:04:41.000 --> 0:04:43.560 two hours ahead, Well, then what they do is they 0:04:43.560 --> 0:04:46.480 take the prediction that they made for an hour from 0:04:46.520 --> 0:04:52.880 now and extrapolate from there, saying, well, if in fact 0:04:53.000 --> 0:04:54.800 the weather is what we think it's going to be 0:04:54.880 --> 0:04:58.280 like in an hour, this is what should look like 0:04:58.400 --> 0:05:01.160 two hours from now. Well if you want to look 0:05:01.200 --> 0:05:03.400 at three hours from now, well let's take what the 0:05:03.440 --> 0:05:06.119 results were for two hours from now and extrapolate again, 0:05:06.200 --> 0:05:07.599 and that's what we think it's going to be three 0:05:07.600 --> 0:05:11.400 hours from now. Extend that out to ten days. Yeah, 0:05:11.400 --> 0:05:15.559 and it's going to become less and less reliable, Yes, 0:05:16.000 --> 0:05:20.279 because you're you're basing your predictions upon the results of 0:05:20.279 --> 0:05:24.680 a previous set of predictions, not upon a previous set 0:05:24.720 --> 0:05:30.200 of actual conditions. Right, So when you're tracing it all 0:05:30.200 --> 0:05:35.159 the way back and you're starting point is right now, like, well, clearly, 0:05:35.200 --> 0:05:38.520 the further out we look, the more unreliable the information 0:05:38.560 --> 0:05:42.080 is going to be, the more likely some other variable 0:05:42.120 --> 0:05:45.480 that we have not anticipated will play a larger role 0:05:45.680 --> 0:05:48.880 or a smaller role. Uh, and that is going to 0:05:48.960 --> 0:05:52.840 affect the overall outcome of the fourth of what will 0:05:52.880 --> 0:05:56.000 actually happen. The forecast is the same, but the actual 0:05:56.240 --> 0:05:59.160 thing we experience might be very different. Which is why 0:05:59.360 --> 0:06:02.559 if you're planning a picnic and you've got ten days 0:06:02.640 --> 0:06:04.880 out from it and you're looking at the weather and 0:06:04.920 --> 0:06:09.159 it says it's going to be absolutely perfect, don't bet 0:06:09.200 --> 0:06:12.200 the house on it. That's not necessarily true. Not to 0:06:12.279 --> 0:06:15.840 discredit numerical weather predictions, because a lot of science and 0:06:16.240 --> 0:06:20.960 time goes into it, but it's still you know, it's 0:06:21.000 --> 0:06:23.920 it's the way that my I see modern meteorology is 0:06:23.960 --> 0:06:28.200 that over time we have continually built upon basically what 0:06:28.320 --> 0:06:31.599 our ancestors did, and it's gotten it's gotten more scientific, 0:06:31.720 --> 0:06:35.000 we've gotten better instruments, uh, but it's still looking for 0:06:35.080 --> 0:06:39.479 patterns yeah, exactly right. So you might look at the 0:06:39.520 --> 0:06:43.240 patterns of when all of these conditions are in play. 0:06:44.400 --> 0:06:48.280 Out of the last hundred times that that happened, this 0:06:48.400 --> 0:06:51.400 is how the weather turned out. Uh, And we're gonna 0:06:51.440 --> 0:06:54.960 break it down. So maybe eighty days out of those 0:06:55.000 --> 0:06:58.280 one days where the conditions were similar to today's, it 0:06:58.320 --> 0:07:01.839 didn't rain at all. It was perfectly sunny, So eight 0:07:01.960 --> 0:07:04.960 out of a hundred it was lovely. The other twenty 0:07:05.080 --> 0:07:09.479 days it rained and it was just steady rain. And 0:07:09.840 --> 0:07:12.040 that's all there is to it. This is a super 0:07:12.160 --> 0:07:16.200 oversimplified version of what could happen. This is what would 0:07:16.240 --> 0:07:19.160 lead you to say there's a chance of rain, because 0:07:19.200 --> 0:07:22.040 he would say, all right, now, the last hundred times 0:07:22.120 --> 0:07:25.840 the weather was exactly like it is today, twenty of 0:07:25.840 --> 0:07:28.840 those times it rained, eighty of those times it did not. 0:07:29.360 --> 0:07:31.920 Therefore there is a twenty chance that it will rain. 0:07:32.320 --> 0:07:36.240 That again is oversimplifying the way it works, but generally speaking, 0:07:36.640 --> 0:07:40.240 that's kind of how they come to those determinations, and 0:07:40.280 --> 0:07:44.000 in fact that there are ways of bolstering the NWP 0:07:44.160 --> 0:07:48.200 by using something called model output statistics, which is I 0:07:48.280 --> 0:07:50.120 kind of just talked about a little bit. I'll just 0:07:50.160 --> 0:07:52.640 go ahead and touch on it right now. It's essentially 0:07:52.760 --> 0:07:55.160 doing what we were talking about, looking at a specific 0:07:55.240 --> 0:08:00.360 region and the specific outcomes of days that had emmeler 0:08:00.400 --> 0:08:03.480 conditions to the one you're looking at right now, and 0:08:03.520 --> 0:08:06.680 then you're kind of making an educated guess based upon 0:08:06.680 --> 0:08:11.520 a computer model and actual localized history. But that clear 0:08:11.560 --> 0:08:13.560 to something up for a lot of people. I sure 0:08:13.600 --> 0:08:16.360 hope so, because I've just kind of gone with it, 0:08:16.720 --> 0:08:19.160 you know, I've just seen chance of rain, okay, and 0:08:19.240 --> 0:08:22.920 never really thought about what goes into determining that well. 0:08:22.920 --> 0:08:25.720 And I know that there's some people who had, you know, 0:08:25.920 --> 0:08:28.440 when they saw chance of rain, they thought it meant, oh, 0:08:28.480 --> 0:08:32.120 it's going to rain over of the forecast area, which 0:08:32.120 --> 0:08:33.640 means that you know that that would be more like 0:08:33.679 --> 0:08:36.520 scattered showers. That's really what scattered showers means. When you're 0:08:36.520 --> 0:08:40.720 scattered showers, it means that parts of the forecast area 0:08:40.760 --> 0:08:43.280 are expected to get rain, but it will not necessarily 0:08:43.360 --> 0:08:47.640 rain over the entire forecast area. Um. But if you 0:08:47.679 --> 0:08:49.440 hear twenty percent chance of rain, it does not mean 0:08:49.480 --> 0:08:52.200 that of the forecast area is going to be dry 0:08:52.200 --> 0:08:53.720 and the other twenty percent is gonna be wet, Nor 0:08:53.800 --> 0:08:56.320 does it mean it will rain for twenty of the day. 0:08:56.559 --> 0:09:00.800 In fact, that's part of the problem, uh, a prediction 0:09:00.880 --> 0:09:05.960 of precipitation, the good old pop, the pop so pop 0:09:06.360 --> 0:09:10.080 that that requires a time element to it as well. 0:09:10.240 --> 0:09:12.800 It doesn't mean anything without a time element. So if 0:09:12.840 --> 0:09:15.320 you say there's a twenty percent chance to rain, you 0:09:15.360 --> 0:09:17.640 also need to have an element of time attached to 0:09:17.679 --> 0:09:20.600 that to make it meaningful. So chance to rain over 0:09:20.640 --> 0:09:23.760 the next six hours, then you know, all right. So 0:09:23.800 --> 0:09:26.360 it's not saying that's gonna be chance to rain or 0:09:26.360 --> 0:09:29.400 it's gonna not gonna rain of the day, just that 0:09:29.520 --> 0:09:31.640 for the next six hours there's a twenty percent chance 0:09:31.679 --> 0:09:35.560 it will be raining in the forecast area. So I 0:09:35.640 --> 0:09:38.719 hope that demystifies some of it. Also, we can talk 0:09:38.760 --> 0:09:41.560 about Radar, one of my favorite things to talk about. 0:09:42.040 --> 0:09:47.160 Radar is awesome, favorite character on nash Yeah, well, I 0:09:47.200 --> 0:09:50.520 think it's so adorable, right, It's hard not to feel 0:09:50.559 --> 0:09:54.080 for him, and the fact that he can anticipate everything 0:09:54.240 --> 0:09:58.640 his commanding officer wants, and he can even say what 0:09:58.679 --> 0:10:01.240 the commanding officer is saying for the commanding officer has 0:10:01.280 --> 0:10:07.320 finished a sentence. Obviously a key part of that operation 0:10:07.920 --> 0:10:11.520 um so, but we're talking about actual radar, using radar 0:10:11.600 --> 0:10:15.880 to detect weather. You've probably heard Doppler radar when looking 0:10:15.920 --> 0:10:17.400 at a weather report, like, well, let's look at the 0:10:17.400 --> 0:10:21.120 Doppler radar and see where the this, this precipitation is 0:10:21.160 --> 0:10:25.960 moving in. Doppler radar for weather is different from Doppler 0:10:26.080 --> 0:10:29.360 radar used by say, police officers who are trying to 0:10:29.400 --> 0:10:33.839 detect if you are speeding. The Doppler radar that meteorologists 0:10:33.920 --> 0:10:38.600 use actually shoots out radio waves in very short bursts 0:10:38.640 --> 0:10:43.360 called pulses, and then the radar listens for any echoing 0:10:43.400 --> 0:10:46.640 pulses coming back to the antenna, and the short pulses 0:10:46.679 --> 0:10:50.560 indicate not just the presence of something out there, but 0:10:50.679 --> 0:10:54.079 whether it's moving and which direction is it moving in? 0:10:55.280 --> 0:10:58.520 Um is it moving toward the radar station or away 0:10:58.520 --> 0:11:01.520 from it? If a Doppler radar receiver detect waves of 0:11:01.520 --> 0:11:05.839 a higher frequency, the precipitation particles are moving towards the 0:11:05.960 --> 0:11:10.280 radar exactly, and lower frequencies they're moving away. Yes, because 0:11:10.280 --> 0:11:13.960 what's happening is it's similar to a Doppler shift. And 0:11:13.960 --> 0:11:17.640 and anyone who's ever heard a vehicle with a siren 0:11:17.760 --> 0:11:21.280 go past is familiar with this. It's a higher pitch 0:11:21.360 --> 0:11:24.040 as the vehicles coming toward you and a lower pitch 0:11:24.120 --> 0:11:27.240 as it's moving away. What's actually happening is, as the 0:11:27.360 --> 0:11:30.280 vehicle is moving towards you, the sound waves it's emitting 0:11:30.280 --> 0:11:34.320 are being compressed. Now that compression creates a higher frequency, 0:11:34.360 --> 0:11:38.520 which means we detect a higher pitch. As the vehicle passes, 0:11:38.640 --> 0:11:43.360 those frequencies are elongated, which means a lower pitch. Same 0:11:43.360 --> 0:11:45.280 thing is true with the radar accept Instead of it 0:11:45.360 --> 0:11:47.599 being a pitch, it's a radio frequency. If so, a 0:11:47.679 --> 0:11:50.760 higher frequency will tell you, yeah, something's coming towards you, 0:11:50.960 --> 0:11:53.760 and a lower frequency will tell you something's moving away 0:11:53.840 --> 0:11:57.800 from you. And also the time between when the pulse 0:11:57.880 --> 0:12:00.400 goes out and when you detect it tells you the 0:12:00.440 --> 0:12:06.360 distance from the radar detection system and the precipitation. So 0:12:06.400 --> 0:12:10.559 you could even say there's a storm system that's five 0:12:10.679 --> 0:12:14.920 miles to the west, it's moving easterly at this speed 0:12:15.200 --> 0:12:18.240 because you've detected it through a series of pulses UH. 0:12:18.280 --> 0:12:21.400 If you have enough radar detections UH stations, you can 0:12:21.440 --> 0:12:25.760 even describe the shape of the weather system and talk 0:12:25.840 --> 0:12:29.680 about how some areas are more intense than others. You 0:12:29.679 --> 0:12:32.560 can get all of that information from this approach, and 0:12:32.640 --> 0:12:38.240 it's amazing how this thing works. First of all, it's 0:12:38.280 --> 0:12:43.040 super high power. Uh. These radar stations are are they're 0:12:43.200 --> 0:12:45.720 they're generating or they're transmitting I should say at four 0:12:45.800 --> 0:12:50.320 hundred fifty thousand watts. So your typical microwave oven is 0:12:50.320 --> 0:12:53.040 a thousand watts, So you need a four hundred and 0:12:53.080 --> 0:12:56.160 fifty of those to equal one of these radar systems. 0:12:57.080 --> 0:13:01.120 So four and fifty thou wats. And the pulse lasts 0:13:01.160 --> 0:13:05.440 so short as to be unimaginable. It is point zero 0:13:05.679 --> 0:13:11.800 zero zero zero zero seven seconds long, or one point 0:13:11.880 --> 0:13:14.560 five seven times ten to the minus six seconds. So 0:13:14.600 --> 0:13:17.800 if you hear the weather man on TV bragging about 0:13:17.840 --> 0:13:21.040 Doppler radar, there's a reason. It's very impressive. Yeah. I 0:13:21.080 --> 0:13:25.640 mean you're sitting at a a burst of radio signals 0:13:26.640 --> 0:13:29.560 at such a fraction of a second that it is 0:13:30.240 --> 0:13:34.000 again impossible to even imagine. Meanwhile, then it listens for 0:13:34.120 --> 0:13:37.040 a longer period, and by longer I mean relatively longer. 0:13:37.080 --> 0:13:39.480 It's still a fraction of a second. It's point zero 0:13:39.640 --> 0:13:45.280 zero zero four three seconds. So it shoots out a 0:13:45.360 --> 0:13:48.720 pulse listens for a little while, so I can detect 0:13:48.920 --> 0:13:51.880 when the pulse comes back and what frequency it's at, 0:13:51.880 --> 0:13:53.600 so it knows whether or not a body is moving 0:13:53.600 --> 0:13:56.040 toward it or away from it, and then it does 0:13:56.080 --> 0:13:59.240 it again. But that means with that amount of time 0:13:59.600 --> 0:14:03.480 and the the comparatively large amount of time of listening, 0:14:04.160 --> 0:14:09.480 for every hour of operation, the radio or the radar 0:14:09.520 --> 0:14:13.319 antenna is only shooting out signals for seven seconds out 0:14:13.320 --> 0:14:16.600 of an entire hour. That means for the fifty nine 0:14:16.600 --> 0:14:19.000 minutes fifty three seconds, it is not sending out a signal. 0:14:19.040 --> 0:14:24.960 It is listening. So for almost a full hour it's listening, 0:14:25.040 --> 0:14:28.160 and only for seven seven seconds is actively shooting out 0:14:28.160 --> 0:14:32.280 a signal. A conversation for someone who talks seven seconds, 0:14:32.320 --> 0:14:35.240 it would I any conversation with me would last like 0:14:35.280 --> 0:14:39.720 a decade before you could get a word in edgewise. Yeah, 0:14:39.880 --> 0:14:43.680 it's uh, it's pretty amazing. And you usually would have 0:14:43.760 --> 0:14:48.080 one of these stations shooting out these radio bursts at 0:14:48.240 --> 0:14:52.400 different angles of elevation. These are called elevation slices, and 0:14:52.480 --> 0:14:56.360 when you go through the entire range, you get what 0:14:56.480 --> 0:15:00.360 was called volume coverage pattern or vc P. That's what 0:15:00.440 --> 0:15:04.360 tells you what the activity is, not just at ground level, 0:15:04.640 --> 0:15:07.480 but up in the atmosphere as well. Toppler radar can 0:15:07.520 --> 0:15:11.880 also detect tornadoes. Yeah. Yeah, if if, if the particles 0:15:11.920 --> 0:15:16.800 switch from moving toward and then away over a small distance, uh, 0:15:16.840 --> 0:15:19.840 there's a good chance it could be a tornado. Yeah, 0:15:19.840 --> 0:15:22.080 we know a lot about those. Here in the southeast too. 0:15:22.240 --> 0:15:24.200 We get a lot of tornadoes, not as many as 0:15:24.240 --> 0:15:28.360 places in the uh, you know, like in the Midwestern States, 0:15:28.400 --> 0:15:30.640 things like you know, Oklahoma and stuff, and you guys 0:15:30.640 --> 0:15:33.920 get tornadoes even more frequently than we do, but we 0:15:34.000 --> 0:15:38.320 get them pretty seriously. Actually this year hasn't been too bad, 0:15:38.640 --> 0:15:41.160 but there was one in November, yeah, which is weird 0:15:41.200 --> 0:15:44.080 because typically we get them in the spring. Yes, um, 0:15:44.200 --> 0:15:47.080 usually between March and June. That's kind of like our 0:15:47.800 --> 0:15:50.640 let's play it easy. Yeah, but you don't waste that 0:15:50.720 --> 0:15:55.200 on anybody, So no, I have. I have been through 0:15:55.320 --> 0:16:00.280 a close call with a tornado while wearing Renaissance festival year. 0:16:01.000 --> 0:16:04.240 That sounds surreal. That was my final day when I 0:16:04.280 --> 0:16:08.640 did my first run at the festival in two thousand one. Yeah, 0:16:08.800 --> 0:16:11.360 we had a really massive thunderstorm and at one point 0:16:11.400 --> 0:16:15.000 someone said that there was a tornado a tornado watch, 0:16:15.160 --> 0:16:18.880 but not a tornado warning watch, being that the conditions 0:16:18.920 --> 0:16:23.000 for a tornado forming. Our present warning being that a 0:16:23.040 --> 0:16:26.840 tornado has actually been spotted in the region, in case 0:16:26.880 --> 0:16:30.880 you were wondering. So now let's talk about satellites and meteorology. 0:16:30.920 --> 0:16:33.200 So the computers are really good for building out those 0:16:33.240 --> 0:16:36.320 models and giving us predictions. The double radars really good 0:16:36.320 --> 0:16:40.920 at tracking precipitation. What do weather satellites do, Uh, well, 0:16:40.960 --> 0:16:45.720 they're they're keeping an eye on global weather patterns. But 0:16:45.920 --> 0:16:49.560 there are two different types of weather satellites and they 0:16:49.600 --> 0:16:53.040 do this in different ways. So one is the geostationary 0:16:53.080 --> 0:16:58.080 weather satellite. Now, geo stationary weather satellites maintain their relative 0:16:58.080 --> 0:17:01.560 position over a specific point on the Earth. They are 0:17:01.640 --> 0:17:06.320 at a very high orbit over the equator, and they 0:17:06.720 --> 0:17:09.439 they're always looking at the same thing because their orbit 0:17:09.560 --> 0:17:13.399 is at the same speed as Earth's rotation um not 0:17:13.480 --> 0:17:15.880 really the same speed, but relative speed because it's able 0:17:15.920 --> 0:17:18.960 to stay in that same point over that part of 0:17:19.000 --> 0:17:21.720 the Earth. And so they have to be on an 0:17:21.720 --> 0:17:23.920 equatorial orbit and they have to be at a particular 0:17:23.960 --> 0:17:26.880 altitude for this to work. It's great because it means 0:17:26.880 --> 0:17:29.080 they can keep an eye on a specific region. It's 0:17:29.160 --> 0:17:33.240 lousy because one they're really far away, so the instrumentation 0:17:33.280 --> 0:17:35.040 you have to put on the satellites has to be 0:17:35.160 --> 0:17:39.560 incredibly sophisticated in order to get good readings from that altitude. 0:17:40.160 --> 0:17:42.639 Plus they have a limited view, right, They're always looking 0:17:42.640 --> 0:17:44.479 at one part of the Earth. They can't see anything 0:17:44.480 --> 0:17:48.679 else outside of that view. So the other type you 0:17:48.720 --> 0:17:51.920 have are satellites they are in a polar orbit around 0:17:51.960 --> 0:17:55.359 the Earth. Polar orbits are interesting. So if you think 0:17:55.400 --> 0:17:59.040 of the Earth on its axis, the polar orbit is 0:17:59.040 --> 0:18:02.480 going parallel to the axis of the Earth. It's going 0:18:02.520 --> 0:18:06.040 perpendicular to the equator, so you would think of it 0:18:06.080 --> 0:18:08.960 as going from north to south and then south to 0:18:09.080 --> 0:18:12.320 north because once it crosses the south pole, you can 0:18:12.359 --> 0:18:14.840 only go north at that point, that's the only direction 0:18:14.920 --> 0:18:17.600 left to you. UM, and it goes in that circle, 0:18:17.640 --> 0:18:21.560 which means these satellites get a full view of the 0:18:21.800 --> 0:18:25.080 entire Earth because the Earth is rotating while it's going 0:18:25.080 --> 0:18:29.040 in this orbit north south orbit UM. But it also 0:18:29.080 --> 0:18:31.920 means that you only get a look at the same 0:18:31.960 --> 0:18:34.800 part of the Earth twice in a twenty four hour period, 0:18:35.000 --> 0:18:38.040 since once every twelve hours. UM. You can always put 0:18:38.040 --> 0:18:40.480 another satellite up there, and that way you could get 0:18:40.800 --> 0:18:43.960 you know, put it on the the opposite uh side 0:18:43.960 --> 0:18:46.040 of the Earth where it's in the same orbit, and 0:18:46.080 --> 0:18:48.520 then you get a look every six hours, just one 0:18:48.600 --> 0:18:51.359 from one satellite and then six hours later one from 0:18:51.400 --> 0:18:54.879 another satellite. But you also get to see everything on 0:18:55.000 --> 0:18:58.800 the planet. So there's your trade off is that you 0:18:58.840 --> 0:19:01.600 get you get a more conference of view, but you 0:19:01.640 --> 0:19:04.560 don't get a consistent view of any one part of 0:19:04.560 --> 0:19:06.439 the Earth with these kind of weather sellites. So a 0:19:06.480 --> 0:19:12.080 lot of of weather services depend upon both yeah, and 0:19:12.119 --> 0:19:17.080 typically they carry devices called radiometers, which usually have a 0:19:17.119 --> 0:19:20.840 small telescope or some sort of antenna, a scanning device 0:19:20.920 --> 0:19:23.399 of some sort, and one or more detectors that can 0:19:23.400 --> 0:19:26.960 pick up visible, infrared or microwave radiation, and they use 0:19:27.040 --> 0:19:29.439 that to take measurements of the Earth and send that 0:19:29.520 --> 0:19:33.399 down to the planet's surface so that weather stations around 0:19:33.400 --> 0:19:36.399 the world can take that data and crunch it and 0:19:36.440 --> 0:19:38.880 figure out what the heck is going out on out 0:19:38.920 --> 0:19:41.919 there when the frogs are raining from the sky. Apart 0:19:41.960 --> 0:19:46.720 from amphibious assault UM, and all of those measurements are 0:19:46.720 --> 0:19:50.359 actually done through little electrical voltages which then get digitized, 0:19:50.440 --> 0:19:53.960 so transformed into digital information before transmitted down to Earth, 0:19:53.960 --> 0:19:56.840 because you know, zapping electricity through space down to the 0:19:56.840 --> 0:20:00.520 planet's not the most efficient way of getting information across UM. 0:20:00.560 --> 0:20:02.080 And he certainly don't want to have a power chord 0:20:02.119 --> 0:20:04.080 stretch all the way there. That would just be such 0:20:04.119 --> 0:20:08.400 a pain. Yeahs with aircraft patterns, and if you don't 0:20:08.400 --> 0:20:11.360 have geostationary orbit, it gets wrapped up around the planet 0:20:11.359 --> 0:20:16.320 pretty quickly. Yeah, So how do meteorologists do things like 0:20:16.400 --> 0:20:19.679 predict temperature, like predict highs and lows and that kind 0:20:19.720 --> 0:20:22.479 of stuff. For this I went to a website that 0:20:22.560 --> 0:20:27.800 was written by a meteorologist named Jeff Haby And boy, howdy, 0:20:27.920 --> 0:20:30.840 did it suddenly dawn on me how much more complicated 0:20:30.880 --> 0:20:35.080 this was than I had even anticipated. But according to Haby, uh, 0:20:35.240 --> 0:20:41.400 he looks at everything from um thermal advection, wind speed, 0:20:41.520 --> 0:20:45.120 cloud cover, de point, and the number of daylight hours 0:20:45.119 --> 0:20:47.520 expected for that region in order to come up with 0:20:47.920 --> 0:20:49.760 the prediction for the high temperature of the day in 0:20:49.760 --> 0:20:52.280 the low temperature of the day. So, what the heck 0:20:52.320 --> 0:20:56.200 does all that mean? So thermal infection, what is that 0:20:56.200 --> 0:20:59.520 that refers to the transportation of heat by a moving fluid. 0:21:00.160 --> 0:21:04.280 So typically the stuff that affects the infection include the 0:21:04.320 --> 0:21:07.800 strength of wind, So how hard is the wind blowing 0:21:07.800 --> 0:21:11.639 in that region? The temperature gradient between the warmer and 0:21:11.680 --> 0:21:15.480 colder areas, So if one area is warmer than the other, 0:21:15.680 --> 0:21:18.199 is it warmer by like a couple of degrees or 0:21:18.280 --> 0:21:20.960 is it more significant than that, is, like ten degrees fahrenheit, 0:21:21.160 --> 0:21:25.520 That would be a much larger gradient, right, And the 0:21:25.600 --> 0:21:28.880 angle between the wind direction and the temperature gradient, If 0:21:28.920 --> 0:21:31.840 that angle is more narrow, you're going to see a 0:21:31.840 --> 0:21:36.399 greater thermal infection, meaning you'll see more temperature changes moving 0:21:36.440 --> 0:21:41.280 into an area from a different region. So that's just infection, 0:21:42.520 --> 0:21:45.200 that's all I play. Uh, the other one that you 0:21:45.440 --> 0:21:48.120 other term you might be a little confused by. I mean, 0:21:48.160 --> 0:21:51.200 wind speed makes sense, cloud cover makes sense, daylight hours, 0:21:51.240 --> 0:21:52.960 All of that makes sense. But what about do point? 0:21:53.880 --> 0:21:56.119 That refers to the temperature at which air must be 0:21:56.240 --> 0:22:00.480 cooled at constant barometric pressure for water vapor to and dense. 0:22:01.520 --> 0:22:04.400 So that temperature again has depended upon things like the 0:22:04.440 --> 0:22:08.560 actual air pressure right um, and so the dow point 0:22:08.640 --> 0:22:12.640 changes based upon those other factors as well. So all 0:22:12.680 --> 0:22:15.400 those have to be taken into account before a meteorologist 0:22:15.440 --> 0:22:17.439 can forecast what the temperature is going to be the 0:22:17.480 --> 0:22:20.320 next day. This is why we're so happy to have 0:22:20.400 --> 0:22:24.080 those complicated computers now, because if you were to keep 0:22:24.080 --> 0:22:27.800 track of this yourself, you probably go bonkers. And then 0:22:27.800 --> 0:22:31.080 we have like the idea of the the probability of precipitation, 0:22:31.080 --> 0:22:33.640 which we kind of talked about already, but generally speaking, 0:22:33.720 --> 0:22:39.680 there's some weather services that will only predict rainfall if 0:22:39.800 --> 0:22:42.480 it's expected to be over a certain amount, like point 0:22:42.520 --> 0:22:44.960 to five millimeters. If it's going to be less than 0:22:45.000 --> 0:22:49.520 point to five millimeters, it doesn't even register as rainfall 0:22:49.600 --> 0:22:52.439 in predictions. You would say there's a zero percent chance 0:22:52.600 --> 0:22:55.600 or or whatever, if that's what you think is going 0:22:55.640 --> 0:22:58.800 to be the the accumulation. Some other ones are like, 0:22:58.840 --> 0:23:03.480 no any rain at all counts. If it's one drop 0:23:03.520 --> 0:23:06.480 of rain it rained in that in that region. Um 0:23:06.760 --> 0:23:10.800 so it really depends upon the service. But uh that 0:23:10.920 --> 0:23:13.360 we already talked about the percentages and what those means, 0:23:13.400 --> 0:23:16.200 so hopefully that clears things up. And again that kind 0:23:16.240 --> 0:23:20.240 of goes into that concept of model output statistics, where 0:23:20.320 --> 0:23:25.400 you you correct for your predictions based upon past conditions 0:23:25.400 --> 0:23:29.159 for a particular region. All of this comes together to 0:23:29.320 --> 0:23:34.480 create the weather report that you see. So I think 0:23:34.560 --> 0:23:38.879 I think the real takeaway here is it's incredible the 0:23:38.920 --> 0:23:45.280 amount of of schooling and expertise a meteorologist has to 0:23:45.320 --> 0:23:47.400 have in order to do his or her job properly, 0:23:48.240 --> 0:23:50.600 right like, because you see how complicated this is, and 0:23:50.600 --> 0:23:53.720 you start to have an appreciation of all right, and 0:23:53.800 --> 0:23:56.159 they said it was a six chance of rain, I 0:23:56.200 --> 0:24:00.000