WEBVTT 1 00:00:03.439 --> 00:00:07.719 Welcome to Bedtime Astronomy. Explore the wonders of the cosmos 2 00:00:07.759 --> 00:00:12.279 with our soothing Bedtime Astronomie podcast. Each episode offers a 3 00:00:12.359 --> 00:00:16.320 gentle journey through the stars, planets, and beyond, perfect for 4 00:00:16.399 --> 00:00:20.239 unwinding after a long day. Let's travel through the mysteries 5 00:00:20.239 --> 00:00:22.440 of the universe as you drift off into a peaceful 6 00:00:22.480 --> 00:00:26.760 slumber under the night sky. 7 00:00:26.920 --> 00:00:28.920 Welcome to the deep Dive. We're here to help you 8 00:00:28.960 --> 00:00:33.320 get a handle on complex science and understand those invisible 9 00:00:33.359 --> 00:00:35.240 forces really shaping our world. 10 00:00:35.359 --> 00:00:37.280 And today we're tackling something vital. 11 00:00:37.520 --> 00:00:41.359 Absolutely, we're diving into Earth's magnetic field, you know, our 12 00:00:41.399 --> 00:00:44.840 planet's primary shield. It's fundamental, really, it's. 13 00:00:44.679 --> 00:00:48.640 What makes life possible, blogging, harmful cosmic rays, charge particles 14 00:00:48.679 --> 00:00:50.880 from the Sun, all that stuff exactly. 15 00:00:51.000 --> 00:00:54.159 Without it, our tech in orbit and eventually well us, 16 00:00:54.719 --> 00:00:55.960 we'd be in serious trouble. 17 00:00:56.159 --> 00:00:59.039 And we've got some incredible data to dig into. We're 18 00:00:59.079 --> 00:01:04.480 looking at what a eleven years of continuous, really precise measurements. 19 00:01:04.000 --> 00:01:07.239 Right mostly from the European Space Agency's Swarm mission, those 20 00:01:07.280 --> 00:01:08.120 satellites up there. 21 00:01:09.319 --> 00:01:11.959 And our goal today is to go beyond just the headlines. 22 00:01:12.000 --> 00:01:14.599 Want to unpack what this decade of data tells us 23 00:01:14.879 --> 00:01:18.200 about the field strength, it's weaknesses which seem to be growing. 24 00:01:18.560 --> 00:01:21.359 And you know what's driving these changes deep inside the Earth. 25 00:01:21.359 --> 00:01:23.000 And we have to start with the big story here, 26 00:01:23.079 --> 00:01:26.439 the one the data really flags, this huge expansion of 27 00:01:26.480 --> 00:01:28.319 the weak spot over the South. 28 00:01:28.120 --> 00:01:30.840 Atlantic South Atlantic Anomaly or SAA. 29 00:01:31.079 --> 00:01:33.719 Yeah, the SAA, it's grown a lot, and the data 30 00:01:33.719 --> 00:01:36.640 suggests the weakening is actually speeding up in some places. 31 00:01:36.719 --> 00:01:39.439 It's not theoretical anymore. This is a measurable shift in 32 00:01:39.439 --> 00:01:41.680 our planet's defenses happening right now. 33 00:01:41.799 --> 00:01:44.959 So let's get into it. The swarm data shows this 34 00:01:45.239 --> 00:01:50.280 SAA expansion and acceleration is kind of the dominant thing happening. 35 00:01:50.000 --> 00:01:53.120 Right It's certainly a major focus, yes, but the field 36 00:01:53.200 --> 00:01:57.120 is dynamic everywhere. Still, the ESAA changes are dramatic. We 37 00:01:57.159 --> 00:01:59.120 need to look at the effects, sure, but also the 38 00:01:59.200 --> 00:02:01.280 cause a down in the Earth's core. 39 00:02:01.400 --> 00:02:04.840 Okay, let's start deep down then, like three thousand kilometers 40 00:02:04.879 --> 00:02:07.599 beneath our feet. What's actually generating this field? Most people 41 00:02:07.680 --> 00:02:10.319 picture like a simple bar magnet right. 42 00:02:10.240 --> 00:02:14.879 Right, the textbook picture, but the reality is much messier, 43 00:02:15.080 --> 00:02:18.000 more chaotic. Think heat, pressure, fluid. 44 00:02:17.639 --> 00:02:19.680 Motion down in the outer core exactly. 45 00:02:19.759 --> 00:02:24.080 Whatever the geodynamo, it's mostly generated by this vast ocean 46 00:02:24.439 --> 00:02:27.120 of molten liquid irons swirling. 47 00:02:26.680 --> 00:02:28.960 Around an ocean of liquid metal, a huge one, and 48 00:02:29.000 --> 00:02:29.439 it's moving. 49 00:02:29.639 --> 00:02:31.879 It's a conducting fluid, so as it flows, it generates 50 00:02:31.919 --> 00:02:35.639 electrical currents. These currents in turn create the magnetic field like. 51 00:02:35.599 --> 00:02:38.199 A giant dynamo, a generator sort of. 52 00:02:38.280 --> 00:02:41.000 Yeah, that's the basic idea, like a bicycle dynamo, but 53 00:02:41.159 --> 00:02:45.000 you know, on a planetary scale and way more turbulent. 54 00:02:45.159 --> 00:02:47.800 It's less a neat machine and more like a huge, 55 00:02:47.879 --> 00:02:50.439 self sustaining, very messy power plant. 56 00:02:50.520 --> 00:02:53.520 So the movement creates current current creates the field that 57 00:02:53.639 --> 00:02:56.520 reaches into space. But you mentioned complexity. 58 00:02:56.919 --> 00:02:59.599 Why isn't it simple, Well, it's a turbulence. This liquid 59 00:02:59.599 --> 00:03:03.080 iron is flowing smoothly. Earth's rotation stirs it up the 60 00:03:03.080 --> 00:03:06.800 Coriolis effect. Plus there's heat rising from the innercore, driving 61 00:03:06.840 --> 00:03:08.960 convection and even chemical. 62 00:03:08.639 --> 00:03:11.280 Changes, so it's churning basically immensely. 63 00:03:11.319 --> 00:03:15.080 It creates these huge swirling eddies and streams, not a 64 00:03:15.199 --> 00:03:18.000 uniform flow at all, and that means the magnet field 65 00:03:18.000 --> 00:03:22.080 it produces isn't smooth or symmetric. Either it's lumpy, it 66 00:03:22.240 --> 00:03:26.639 changes direction locally. It's incredibly difficult to model accurately over time. 67 00:03:26.479 --> 00:03:30.199 Which is why you need constant, really precise measurements exactly. 68 00:03:30.400 --> 00:03:33.759 Which brings us to SWARM right, the tool that's giving 69 00:03:33.840 --> 00:03:36.360 us these insights tell us about this mission. It's not 70 00:03:36.439 --> 00:03:37.639 just one satellite, is it. 71 00:03:37.919 --> 00:03:42.080 No, And that's key. SWARM is an EESA Earth Explorer 72 00:03:42.120 --> 00:03:45.879 mission part of their future EO program. It's actually a 73 00:03:45.879 --> 00:03:50.919 constellation of three identical satellites launched back in November twenty thirteen. 74 00:03:51.000 --> 00:03:52.759 So over eleven years of data. 75 00:03:52.520 --> 00:03:57.000 Now three identical ones. Why three wouldn't one super precise 76 00:03:57.039 --> 00:03:58.159 satellite do the job? 77 00:03:58.400 --> 00:04:02.560 Ah, good question. It's about separating the signals. One satellite 78 00:04:02.560 --> 00:04:06.280 tells you the field strength right here, right now. But 79 00:04:06.439 --> 00:04:10.039 Earth's magnetic field comes from multiple sources. Well, the main 80 00:04:10.080 --> 00:04:12.439 one is the core, the dynamo we just talked about, 81 00:04:12.560 --> 00:04:15.080 but there are also magnetic signals from the Earth's crust, 82 00:04:15.199 --> 00:04:18.040 from the mantle, even from electrical currents in the oceans, 83 00:04:18.319 --> 00:04:20.800 the ionosphere, the magnetosphere way out in space. 84 00:04:20.800 --> 00:04:23.439 Wow, Okay, lots of layers contributing precisely. 85 00:04:23.680 --> 00:04:25.759 And if you want to understand the core behavior the 86 00:04:25.800 --> 00:04:28.600 source of the SAA problem. You need to filter out 87 00:04:28.639 --> 00:04:29.879 all that other magnetic noise. 88 00:04:30.079 --> 00:04:31.959 So how did the three satellites help with that? 89 00:04:32.279 --> 00:04:35.399 They fly in a specific formation. Two fly close together 90 00:04:35.480 --> 00:04:37.920 side by side at a lower altitude around four hundred 91 00:04:37.920 --> 00:04:40.759 fifty kilometers up. The third one flies higher, and. 92 00:04:40.720 --> 00:04:42.240 The altitude difference is the trick. 93 00:04:42.560 --> 00:04:46.199 Yes, the lower pair can measure the finer details the 94 00:04:46.240 --> 00:04:49.480 smaller scale magnetic structure is coming from the core and crust. 95 00:04:50.279 --> 00:04:52.920 By comparing the readings from the lower pair with the 96 00:04:53.000 --> 00:04:56.639 higher satellite taken at the same time, scientists can effectively 97 00:04:56.680 --> 00:05:00.480 distinguish between the signals originating deep inside the Earth and 98 00:05:00.519 --> 00:05:04.319 those coming from external sources like the ionosphere or solar 99 00:05:04.360 --> 00:05:05.040 wind effects. 100 00:05:05.279 --> 00:05:08.439 Okay, so it's like using triangulation almost to pinpoint the 101 00:05:08.439 --> 00:05:09.319 source in a way. 102 00:05:09.439 --> 00:05:12.680 Yes, it gives you that separation. It's like having multiple 103 00:05:12.680 --> 00:05:16.040 microphones in a noisy room to isolate one specific voice. 104 00:05:16.199 --> 00:05:18.560 Swarm isolates the voice of the Earth's core. 105 00:05:19.040 --> 00:05:22.199 That level of detail is crucial then to figure out 106 00:05:22.199 --> 00:05:25.759 why the field is weakening in the SAA or strengthening elsewhere. 107 00:05:26.079 --> 00:05:28.839 You're mapping the entire magnetic finger press exactly. 108 00:05:29.120 --> 00:05:32.639 Without this long term, high precision multipoint data, we just 109 00:05:32.639 --> 00:05:36.360 be making educated guesses about what's happening three thousand kilometers down. Yeah, 110 00:05:36.399 --> 00:05:38.079 SWARM gives us the hard evidence. 111 00:05:38.319 --> 00:05:40.199 Okay, so let's use that evidence. Let's look at the 112 00:05:40.199 --> 00:05:44.199 primary symptom everyone's talking about, the South Atlantic Anomaly. How 113 00:05:44.279 --> 00:05:47.399 much has it actually changed since SWARM started watching. 114 00:05:47.680 --> 00:05:51.519 Well, THEESSAA itself isn't new. Scientists first noticed this dip 115 00:05:51.560 --> 00:05:54.639 and field strength southeast of South America way back in 116 00:05:54.639 --> 00:05:55.560 the nineteenth century. 117 00:05:55.600 --> 00:05:58.680 But it's become a much bigger issue now, right, especially 118 00:05:58.680 --> 00:05:59.959 for satellites. 119 00:05:59.600 --> 00:06:04.079 Definitely, and the SWARM data, particularly the analysis covering twenty 120 00:06:04.079 --> 00:06:08.160 fourteen to twenty twenty five quantifies this change pretty starkly. 121 00:06:08.519 --> 00:06:10.360 How big are we talking? Give us a sense of 122 00:06:10.399 --> 00:06:11.000 the scale. 123 00:06:11.120 --> 00:06:14.399 Since twenty fourteen, the total area defined as the SAA 124 00:06:14.920 --> 00:06:18.000 the region of significant weakness, has expanded by an area 125 00:06:18.360 --> 00:06:20.399 roughly half the size of continental Europe. 126 00:06:20.439 --> 00:06:22.480 Half of Europe. That's huge, it is. 127 00:06:22.759 --> 00:06:27.199 Imagine the magnetic shield over an area likes a Portugal, Spain, 128 00:06:27.439 --> 00:06:32.000 France and Germany combined getting significantly weaker, all in just 129 00:06:32.079 --> 00:06:35.160 over ten years. It's a major structural change. 130 00:06:35.199 --> 00:06:38.560 That's a massive chunk of our planetary shield becoming less effective. 131 00:06:38.680 --> 00:06:41.720 Is the weakening uniform across this new larger area, No, 132 00:06:41.800 --> 00:06:42.879 it's not, And. 133 00:06:42.879 --> 00:06:45.759 This is where swarm's precision really comes into play. While 134 00:06:45.800 --> 00:06:48.360 the overall area grew steadily, the data pinpoint at a 135 00:06:48.360 --> 00:06:52.000 specific zone southwest of Africa, in the Atlantic Ocean, where 136 00:06:52.199 --> 00:06:56.639 the weakening has accelerated, especially since twenty twenty. The magnetic 137 00:06:56.680 --> 00:06:59.279 field strength there is dropping even faster than in the 138 00:06:59.319 --> 00:06:59.959 rest of the essay. 139 00:07:00.399 --> 00:07:03.319 So it's not just strutting out. It's getting deeper, more 140 00:07:03.360 --> 00:07:04.759 intense in certain. 141 00:07:04.480 --> 00:07:08.240 Spots exactly, it's becoming more lopsided. Professor Chris Finlay, one 142 00:07:08.240 --> 00:07:10.439 of the researchers, noted, the SAA is not just a 143 00:07:10.519 --> 00:07:14.160 single block. The way it's behaving near Africa is different, 144 00:07:14.360 --> 00:07:17.240 more intense than how it's behaving near South America. 145 00:07:17.360 --> 00:07:20.079 That asymmetry must be a clue about the cause, right, 146 00:07:20.240 --> 00:07:23.680 which we'll get to. But first the so what why 147 00:07:23.680 --> 00:07:26.759 should someone listening care about a weak magnetic spot over 148 00:07:26.800 --> 00:07:29.000 the ocean? How does it affect us? 149 00:07:29.319 --> 00:07:33.040 The immediate impact is on technology in lower th orbit EOO. 150 00:07:33.519 --> 00:07:38.199 That's where thousands of satellites operate for communications, whether GPS, Earth. 151 00:07:38.000 --> 00:07:41.519 Observation, the workhourses of our space infrastructure. 152 00:07:40.959 --> 00:07:43.720 Right, and the SAA is the place where the magnetic 153 00:07:43.720 --> 00:07:47.120 field provides the least protection from incoming high energy particles 154 00:07:47.519 --> 00:07:50.720 think protons, heavy ions blasted out by the Sun or 155 00:07:50.839 --> 00:07:52.240 arriving as cosmic rays. 156 00:07:52.360 --> 00:07:55.240 Because the shield is weakest there, these particles can get 157 00:07:55.240 --> 00:07:56.600 closer to Earth, much. 158 00:07:56.480 --> 00:07:59.639 Closer than anywhere else. It acts like a phenel. And 159 00:07:59.680 --> 00:08:04.519 when the these high JV particles hit sensitive satellite electronics, well, 160 00:08:04.879 --> 00:08:05.839 bad things can happen. 161 00:08:05.959 --> 00:08:06.800 What kind of bad thing? 162 00:08:06.879 --> 00:08:11.879 Two main types. First, there are single event upsets or SEUs, 163 00:08:12.439 --> 00:08:15.040 A particle z app's a memory bit or a logic 164 00:08:15.120 --> 00:08:17.160 gait causing a temporary. 165 00:08:16.639 --> 00:08:19.360 Glitch like a computer crashing sort of. 166 00:08:19.959 --> 00:08:22.839 You could be corrupt a data, a system reboot, a 167 00:08:22.920 --> 00:08:27.360 temporary malfunction. Satellite operators actually planned for these scheduling reboots 168 00:08:27.399 --> 00:08:29.079 sometimes when passing through the SAA. 169 00:08:29.240 --> 00:08:32.600 Okay, annoying, but maybe manageable. What's the second type? 170 00:08:32.679 --> 00:08:35.320 That's total dose effects. This is more serious. It's the 171 00:08:35.399 --> 00:08:39.519 cumulative damage from radiation exposure. Over time, the particles physically 172 00:08:39.519 --> 00:08:41.679 degrade the semiconductor materials. 173 00:08:41.399 --> 00:08:42.840 Like sunburn for electronics, it. 174 00:08:42.879 --> 00:08:46.879 Pretty good analogy. Yeah, it leads to permanent damage, components failing, 175 00:08:47.080 --> 00:08:50.320 reduced performance, and eventually maybe the whole satellite just dies 176 00:08:50.519 --> 00:08:51.519 a total blackout. 177 00:08:51.600 --> 00:08:54.720 So every time a satellite flies through this expanding SAA, 178 00:08:55.000 --> 00:08:57.639 it takes a radiation hit that shortens its life span. 179 00:08:57.879 --> 00:09:01.279 Essentially, Yes, and they cross it hundreds even thousands of 180 00:09:01.279 --> 00:09:05.159 times over their mission life. So operators have to take precautions. 181 00:09:04.600 --> 00:09:07.000 Like putting the satellite into a safe mode. 182 00:09:07.159 --> 00:09:10.440 Often, yes, they might shut down sensitive instruments, power down 183 00:09:10.480 --> 00:09:14.679 non essential systems, or enter a protective standby mode just 184 00:09:14.720 --> 00:09:15.960 for the SAA transit. 185 00:09:16.080 --> 00:09:18.000 And if the SAA is now half the size of 186 00:09:18.000 --> 00:09:22.360 Europe bigger, that means more downtime, less operational time for 187 00:09:22.360 --> 00:09:23.360 these datag exactly. 188 00:09:23.440 --> 00:09:28.120 It impacts efficiency, mission duration, and costs. The swarm data 189 00:09:28.159 --> 00:09:31.399 is absolutely critical for updating the models used for mission planning, 190 00:09:31.519 --> 00:09:34.600 for designing shielding, and for predicting when these protective measures 191 00:09:34.639 --> 00:09:35.000 are needed. 192 00:09:35.000 --> 00:09:37.879 Okay, that makes the risk very clear. So let's go 193 00:09:38.000 --> 00:09:42.360 back underground. We see the symptom, the expanding, intensifying SAA. 194 00:09:42.399 --> 00:09:45.519 What's the root cause? You mentioned the core mantle boundary. 195 00:09:45.240 --> 00:09:47.799 Right, the boundary between the liquid outer core where the 196 00:09:47.799 --> 00:09:51.279 field is generated and the rocky mantle above it. This interface, 197 00:09:51.360 --> 00:09:55.720 the CMB is key. The specific mechanism driving the SAA 198 00:09:55.799 --> 00:09:58.320 seems to be these things called reverse flux patches. 199 00:09:58.399 --> 00:10:01.639 Reverse flux patches sounds intuitive, what are they okay? 200 00:10:01.679 --> 00:10:04.919 Think about the normal field in the southern hemisphere, we 201 00:10:04.960 --> 00:10:08.279 expect the magnetic field lines generated in the core to 202 00:10:08.360 --> 00:10:09.559 point outwards. 203 00:10:09.159 --> 00:10:11.320 From the Earth like arrows coming out of the South 204 00:10:11.320 --> 00:10:11.919 Pole region. 205 00:10:12.159 --> 00:10:15.039 Generally, yes, that's the configuration that gives us our shield. 206 00:10:15.559 --> 00:10:18.759 But under the SAA, something different is happening in the 207 00:10:18.799 --> 00:10:20.120 core fluid dynamics. 208 00:10:20.240 --> 00:10:22.840 The turbulence again, yes, the. 209 00:10:22.720 --> 00:10:26.320 Flow in certain localized spots is creating magnetic field lines 210 00:10:26.559 --> 00:10:29.759 that point in the opposite direction. Instead of pointing out, 211 00:10:29.879 --> 00:10:31.320 they point back into the core. 212 00:10:31.759 --> 00:10:36.240 Whoa, so patches of reverse polarity deep inside the Earth. 213 00:10:36.320 --> 00:10:40.200 That's essentially it. These reverse pointing field lines rise up 214 00:10:40.200 --> 00:10:42.879 to the core mantle boundary. When they get there, they 215 00:10:42.879 --> 00:10:46.360 meet the normal outward pointing field lines originating nearby, and 216 00:10:46.399 --> 00:10:49.720 they cancel each other out effectively. Yes, they interact and 217 00:10:50.120 --> 00:10:54.279 partially neutralize each other. This cancelation drastically weakens the total 218 00:10:54.320 --> 00:10:58.000 magnetic field strength. Directly above that patch, and that weakened spot, 219 00:10:58.080 --> 00:11:00.399 that leak in the shield is what we have at 220 00:11:00.399 --> 00:11:03.279 the surface and in orbit as the South Atlantic anomaly. 221 00:11:03.440 --> 00:11:07.159 So the core is basically fighting itself in these specific locations. 222 00:11:07.480 --> 00:11:10.919 In a sense, yes, it's an internal cancelation process. 223 00:11:11.000 --> 00:11:13.639 Which means if we can track where these reverse flux 224 00:11:13.679 --> 00:11:16.039 patches are and where they're going, we. 225 00:11:16.080 --> 00:11:19.679 Can understand and maybe even predict how the SAA will evolve. 226 00:11:20.240 --> 00:11:24.200 And swarm Stata has been absolutely crucial for tracking the movement, 227 00:11:24.320 --> 00:11:26.440 the dynamics of these patches. 228 00:11:26.279 --> 00:11:28.519 And what has swarms shown about their movement. 229 00:11:28.639 --> 00:11:32.000 The analysis confirms that the accelerated weakening we see southwest 230 00:11:32.000 --> 00:11:34.799 of Africa is directly tied to the migration of one 231 00:11:34.799 --> 00:11:37.480 of these patches. We can see a prominent reverse flux 232 00:11:37.519 --> 00:11:42.320 patch moving westward underneath the African continent westward. Why westward, 233 00:11:42.480 --> 00:11:45.480 It's consistent with a known phenomenon called the westerly drift 234 00:11:45.799 --> 00:11:49.279 of the magnetic field. It suggests the overall large scale 235 00:11:49.360 --> 00:11:53.440 rotation of the liquid outer core. This slow turbulent churning 236 00:11:53.879 --> 00:11:55.440 carry these patches along with it. 237 00:11:55.480 --> 00:11:59.159 So we're literally watching via swarm the deep Earth currents 238 00:11:59.200 --> 00:12:02.639 shift and seeing the direct consequence and a growing hole 239 00:12:02.679 --> 00:12:04.480 in our magnetic shield above Africa. 240 00:12:04.720 --> 00:12:08.200 That's the picture emerging. Yes, we're observing dynamics three thousand 241 00:12:08.240 --> 00:12:12.279 kilometers down manifesting is a clear and present danger to satellites. 242 00:12:12.600 --> 00:12:15.840 How sure are scientists that this westward patch migration is 243 00:12:15.840 --> 00:12:19.399 the main driver, especially for that intense spot near Africa? 244 00:12:19.759 --> 00:12:21.080 Could other things be involved? 245 00:12:21.240 --> 00:12:24.399 The link between the patches and the localized weakening, especially 246 00:12:24.519 --> 00:12:28.399 the post twenty twenty acceleration near Africa, seems very strong 247 00:12:28.600 --> 00:12:31.679 based on the data. These patches appear to be the 248 00:12:31.679 --> 00:12:36.159 primary cause of where and how intensely the field is weakening, but. 249 00:12:36.120 --> 00:12:38.039 Maybe not why the patch is formed there in the 250 00:12:38.039 --> 00:12:38.559 first place. 251 00:12:38.679 --> 00:12:42.399 Exactly what triggers the core flow to generate these reverse 252 00:12:42.440 --> 00:12:45.879 patches in the specific region is still a big research question. 253 00:12:46.480 --> 00:12:48.759 It might be related to how heat flows across the 254 00:12:48.799 --> 00:12:51.759 core mantle boundary may be influenced by structures in the 255 00:12:51.759 --> 00:12:55.279 deep mantle itself. Swarm shows us the what and where 256 00:12:55.600 --> 00:12:58.200 the why is the next frontier for geodynamo modeling. 257 00:12:58.360 --> 00:13:00.919 Okay, so the ESSAA is clearly a major focus, but 258 00:13:01.000 --> 00:13:04.120 you mentioned the entire field is dynamic. Let's broaden the view. 259 00:13:04.679 --> 00:13:07.440 What else did SWARM reveal about global changes? 260 00:13:07.559 --> 00:13:10.519 This is crucial because focusing only on the SAA misses 261 00:13:10.559 --> 00:13:13.639 half the story. The Earth's field is constantly changing shape 262 00:13:13.679 --> 00:13:16.240 and strength globally, and it's definitely not symmetrical. 263 00:13:16.360 --> 00:13:19.120 We talked about the simple bar magnet idea being wrong. 264 00:13:19.200 --> 00:13:21.840 Right, It's much more complex. Non dipolar is the term 265 00:13:21.879 --> 00:13:25.480 often used. We need satellites like SWARM to map this 266 00:13:25.679 --> 00:13:27.840 intricate shifting structure properly. 267 00:13:27.919 --> 00:13:30.000 So where are the strong points of the field the 268 00:13:30.080 --> 00:13:32.399 opposite of the SAA globally? 269 00:13:32.440 --> 00:13:35.919 The analysis shows two main areas of high intensity, both 270 00:13:35.960 --> 00:13:39.360 in the northern hemisphere. There's one centered roughly over Canada 271 00:13:39.399 --> 00:13:40.440 and another one over. 272 00:13:40.320 --> 00:13:44.159 Siberia, the twin pillars of the Northern Shield, you could say. 273 00:13:44.279 --> 00:13:46.960 A good way to put it. But Swarm's data over 274 00:13:47.000 --> 00:13:50.720 the last decades shows these pillars are behaving very, very differently. 275 00:13:50.720 --> 00:13:52.440 There's a major asymmetry developing. 276 00:13:52.559 --> 00:13:54.240 Okay, how so well, the. 277 00:13:54.200 --> 00:13:57.879 Magnetic field over Siberia has actually gotten stronger since SWARM 278 00:13:57.960 --> 00:13:59.080 launched in twenty thirteen. 279 00:13:59.559 --> 00:14:02.759 Consider stronger stronger while the SAA weakens. 280 00:14:02.919 --> 00:14:07.080 Yes, And that Siberian strong region has physically grown in 281 00:14:07.200 --> 00:14:09.879 surface area by about zero point four to two percent 282 00:14:09.960 --> 00:14:11.279 of the entire Earth's surface. 283 00:14:11.399 --> 00:14:13.919 Okay, point four to two percent. What does that translate 284 00:14:13.919 --> 00:14:14.799 to in real terms? 285 00:14:14.840 --> 00:14:16.799 It's an area comparable to the size of Greenland. 286 00:14:17.200 --> 00:14:22.039 Wow, so Siberia's magnetic pillar has gained Greenland size territory. 287 00:14:22.240 --> 00:14:23.840 What about the Canadian one. 288 00:14:23.600 --> 00:14:26.840 It's doing the exact opposite. The strong field region over 289 00:14:26.919 --> 00:14:31.000 Canada has weakened significantly and it is shrunken area by 290 00:14:31.039 --> 00:14:34.399 about zero point six five percent of Earth's surface. 291 00:14:34.519 --> 00:14:36.360 And point sixty five percent. 292 00:14:36.159 --> 00:14:37.559 Is roughly the size of India. 293 00:14:37.600 --> 00:14:41.279 Good grief. So let me get this straight. In the north, 294 00:14:41.720 --> 00:14:45.639 the Siberian strong spot gains a Greenlands worth of area, 295 00:14:46.000 --> 00:14:48.639 while the Canadian spot loses in India's worth. 296 00:14:48.840 --> 00:14:51.960 That's the dynamic swarm has measured. We're seeing this massive 297 00:14:52.039 --> 00:14:56.559 eastward shift, a transfer of magnetic dominance from Canada towards 298 00:14:56.600 --> 00:14:58.679 Siberia in the northern hemisphere. 299 00:14:59.080 --> 00:15:02.039 What are the implications of this, this magnetic tug of 300 00:15:02.080 --> 00:15:04.639 war in the north combined with the SAA in the south. 301 00:15:04.759 --> 00:15:07.600 The most immediate consequence relates to the position of the 302 00:15:07.600 --> 00:15:08.480 magnetic north. 303 00:15:08.320 --> 00:15:10.960 Pole, right the point your compass needle actually points. 304 00:15:10.679 --> 00:15:13.679 To exactly Because the Canadian field is weakening and the 305 00:15:13.679 --> 00:15:17.399 Siberian one is strengthening. The magnetic North poles drift towards 306 00:15:17.399 --> 00:15:21.080 Siberia has accelerated quite dramatically in recent years, and. 307 00:15:21.000 --> 00:15:23.399 That matters for navigation, doesn't it hugely. 308 00:15:23.840 --> 00:15:27.600 Think about the World Magnetic Model the WMM. It's the 309 00:15:27.639 --> 00:15:32.120 standard map of Earth's magnetic field used by well practically everyone, 310 00:15:32.440 --> 00:15:36.639 military navigation, aviation, maritime shipping, even the compass app on 311 00:15:36.679 --> 00:15:37.399 your smartphone. 312 00:15:37.440 --> 00:15:39.879 They all rely on knowing where magnetic North is, and. 313 00:15:39.840 --> 00:15:43.240 The WMM has to be updated regularly, typically every five years, 314 00:15:43.679 --> 00:15:46.840 to account for the pole's natural drift. But the core 315 00:15:46.919 --> 00:15:50.440 dynamics this rapid shift driven by the Canada Siberia changes 316 00:15:50.480 --> 00:15:54.240 that swarm measured made the drift so fast and unpredictable that. 317 00:15:54.120 --> 00:15:56.240 The five year updates weren't enough precisely. 318 00:15:56.519 --> 00:15:58.840 For the first time ever, scientists had to issue an 319 00:15:58.840 --> 00:16:02.080 emergency out of sight update to the WMM in early 320 00:16:02.159 --> 00:16:05.399 twenty nineteen. The magnetic poll was moving away from the 321 00:16:05.399 --> 00:16:06.919 model faster than expected. 322 00:16:07.159 --> 00:16:09.879 An emergency update to the world's magnetic map that really 323 00:16:09.879 --> 00:16:12.919 brings home how dynamic this system is. The core is 324 00:16:13.000 --> 00:16:15.320 literally rewriting the map faster than we plan for. 325 00:16:15.679 --> 00:16:19.080 It underscores why continuous monitoring with SWARM is so vital. 326 00:16:19.399 --> 00:16:23.039 If our navigation models become outdated too quickly because the 327 00:16:23.039 --> 00:16:28.360 core is being well uncooperative, then accuracy degrades, especially at 328 00:16:28.399 --> 00:16:32.480 high latitudes where the field lines converge. This shifting balance 329 00:16:32.519 --> 00:16:35.320 is making the poles dand faster, and SWARM is keeping 330 00:16:35.360 --> 00:16:36.879 our maps in sync with reality. 331 00:16:37.000 --> 00:16:40.559 It's amazing how physics three thousand kilometers down directly impacts 332 00:16:40.600 --> 00:16:43.440 technology we use every single day. There really is so 333 00:16:43.480 --> 00:16:45.919 looking back. SWARM has been up there over eleven years now, 334 00:16:46.360 --> 00:16:48.840 that's quite a run. What's its legacy? 335 00:16:49.279 --> 00:16:51.840 I think the longevity and the sheer consistency of the 336 00:16:51.919 --> 00:16:55.480 data record are incredible. It's the longest continuous set of 337 00:16:55.559 --> 00:16:58.519 high precision magnetic field measurements we've ever had from space. 338 00:16:58.919 --> 00:17:00.840 That alone is a mind mental achievement. 339 00:17:00.960 --> 00:17:03.320 It started as more of a tech demonstrator, right. 340 00:17:03.159 --> 00:17:05.920 It did, yeah, part of the Earth Explorer program designed 341 00:17:05.920 --> 00:17:09.599 to pioneer new observation techniques, but it's completely surpassed that 342 00:17:09.640 --> 00:17:10.279 original goal. 343 00:17:10.400 --> 00:17:11.400 It became foundational. 344 00:17:11.640 --> 00:17:15.559 Absolutely. These Explorer missions often perform way beyond their design life, 345 00:17:15.799 --> 00:17:19.200 but SWARM has become indispensable. It feeds data into critical 346 00:17:19.240 --> 00:17:21.160 operational systems used worldwide. 347 00:17:21.480 --> 00:17:25.519 We talked about the navigation models. What other real world 348 00:17:25.640 --> 00:17:28.119 uses does the SWARM data have right now? 349 00:17:28.440 --> 00:17:32.240 Well beyond the magnetic models. It's crucial for understanding space. 350 00:17:32.000 --> 00:17:34.279 Weather how the Sun affects us exactly. 351 00:17:34.759 --> 00:17:37.599 By tracking how the solar wind, that stream of particles 352 00:17:37.599 --> 00:17:41.759 from the Sun interacts with and distorts our magnetosphere, SWARM 353 00:17:42.000 --> 00:17:45.759 helps improve forecasts for geomagnetic storms. 354 00:17:45.640 --> 00:17:48.319 Which can affect power grids and things on Earth. 355 00:17:48.440 --> 00:17:53.640 Yes, power grids, pipelines, communications, satellite operations themselves. SWARM gives 356 00:17:53.720 --> 00:17:56.720 us this comprehensive view from the deep core, through the 357 00:17:56.839 --> 00:17:59.759 crust and mantle, the oceans, the atmosphere, all the way 358 00:17:59.759 --> 00:18:02.279 out to space. It connects all these layers, and. 359 00:18:02.240 --> 00:18:05.240 The satellites themselves are still going strong. What's the future 360 00:18:05.240 --> 00:18:06.000 hope for the mission? 361 00:18:06.319 --> 00:18:09.799 According to ESA's mission manager and just Strom, Yes, the 362 00:18:09.839 --> 00:18:14.039 three satellites are remarkably healthy and still delivering excellent quality data. 363 00:18:14.119 --> 00:18:16.920 That's great news, it is, and it fuels the big 364 00:18:16.960 --> 00:18:20.680 hope scientifically speaking, to extend the mission well beyond its 365 00:18:20.680 --> 00:18:22.720 current timeline, ideally past twenty thirty. 366 00:18:22.839 --> 00:18:25.480 Is there a specific reason for targeting past twenty thirty. 367 00:18:25.839 --> 00:18:29.039 Yes, it relates to the Sun's activity cycle. The Sun 368 00:18:29.079 --> 00:18:32.839 goes through roughly eleven year cycles of high and low activity. 369 00:18:32.880 --> 00:18:36.319 Extending swarm beyond twenty thirty would mean collecting data through 370 00:18:36.319 --> 00:18:39.400 the next predicted solar minimum, a period when the Sun 371 00:18:39.480 --> 00:18:40.839 is relatively quiet. 372 00:18:40.839 --> 00:18:44.279 Less solar wind, less noise from external magnetic sources. 373 00:18:44.400 --> 00:18:48.400 Exactly during solar maximum, the intense solar activity creates a 374 00:18:48.400 --> 00:18:52.880 lot of magnetic disturbances in the ionosphere and magnetosphere. It's harder, 375 00:18:53.039 --> 00:18:57.039 though not impossible, to perfectly isolate the signal coming purely 376 00:18:57.039 --> 00:18:58.200 from the Earth's core. 377 00:18:58.720 --> 00:19:01.519 So a solar minimum divides a cleaner window into the 378 00:19:01.559 --> 00:19:02.599 core's behavior. 379 00:19:02.759 --> 00:19:06.680 Precisely. Collecting this ultra precise data during a solar quiet 380 00:19:06.680 --> 00:19:09.839 period would give scientists the clearest possible view of the 381 00:19:09.880 --> 00:19:14.079 internal geodynamal processes, the ones creating those reverse flex patches 382 00:19:14.480 --> 00:19:17.799 and driving the global field shifts with minimal interference from 383 00:19:17.799 --> 00:19:18.079 the Sun. 384 00:19:18.200 --> 00:19:22.079 Getting almost two full decades of continuous data would be unprecedented. 385 00:19:22.119 --> 00:19:25.599 Then it would be revolutionary for the field of geomagnetism. 386 00:19:26.279 --> 00:19:28.359 It would allow us to study these changes with the 387 00:19:28.440 --> 00:19:31.400 level of detail and over a time span that simply 388 00:19:31.440 --> 00:19:34.559 hasn't been possible before. We're really just starting to scratch 389 00:19:34.599 --> 00:19:37.599 the surface of understanding these deep earth dynamics. 390 00:19:37.640 --> 00:19:40.440 Okay, this has been fascinating. Let's try to quickly wrap 391 00:19:40.559 --> 00:19:43.640 up the key takeaways for everyone listening based on this 392 00:19:43.839 --> 00:19:45.240 amazing swarm data. 393 00:19:45.400 --> 00:19:49.240 Right, So, the big ones are first the South Atlantic anomaly. 394 00:19:49.559 --> 00:19:52.839 That weak spot is definitely expanding. It's grown by an 395 00:19:52.880 --> 00:19:55.720 area about half the size of Europe since twenty fourteen. 396 00:19:55.480 --> 00:19:58.079 Driven by those reverse flex patches deep in the core, 397 00:19:58.200 --> 00:19:59.960 canceling out the field exactly. 398 00:20:00.160 --> 00:20:03.720 And the weakening seems to be accelerating in a specific 399 00:20:03.799 --> 00:20:07.319 zone southwest of Africa, linked to a westward moving patch. 400 00:20:07.839 --> 00:20:09.640 This is a direct risk for satellites. 401 00:20:09.680 --> 00:20:12.000