Space Weather + Sub Cables | Shibaji Chakraborty, PhD

So you've all seen the Aurora Borealis, maybe in person if you're lucky, but certainly in a picture. This is a visual and beautiful example of what we call space weather. But did you know that space weather might take out service on submarine cables? I certainly did not have that on my radar, but in this special bonus episode in our submarine cable series, we're going to learn all about it.

So welcome to Telegeography Explains the Internet, the show that explores the business behind all of the ways humans stay connected around the world. I'm your host, Greg Bryant, and my guest today is Shabaji Chakuraborty. a research scientist at Embry-Riddle Aeronautical University. Shabaji and I will be discussing the fascinating topic that you may not have considered before, where first he'll explain just exactly what space weather is, the weather conditions in geospace.

starting around 100 kilometers above Earth. And that includes phenomenon like solar storms that can create powerful electric charges and magnetic fields. Then we'll dive into how this space weather can affect the critical metallic power feed cables that run alongside.

fiber optic lines to power repeaters on the ocean floor. We'll talk about how water depth and electrical properties of the Earth's crust can actually make certain cable sections particularly vulnerable to these magnetic fluctuations. Shibati shares historical examples of these. storms and discusses a lot of the ongoing research and industry collaboration needed to better understand, model, and mitigate these potential risks to submarine cables.

This was an entirely new layer of risk in my knowledge for our global connectivity that I really think. you need to hear about. So please first rate the show, subscribe, tell a friend to listen, and of course, find me on LinkedIn with any suggestions or feedback and enjoy the show.

Welcome to the show, Shabaji. Thank you, Greg. Thanks for having me. Yeah, absolutely. I think this is going to be a fun little bonus episode tacked on to our Submarine Cable episode. With this really interesting topic that you brought up to us, so thanks for that. Before we jump into it, could you just give us a brief background on yourself and your career and how you came to be a research scientist at Embry-Riddle?

So I'm a research scientist at Emory Little Aeronautical University. Prior joining Emory, I was in Virginia Tech, so where I graduated from as a space weather researcher under Superdome. Virginia Tech Superdome Lab. So there I started research on the space weather and electromagnetism. So I worked on the communication systems. prior to working on the submarine cable stuff. But my main motivation behind it is like after graduating as a as a PhD holder after like

from Virginia Tech. I started doing this study with one of the pioneers in the field, Dr. Bottler, David Bottler from Natural Resources Canada. He has this overarching structure of distributed source transmission line modeling systems. which is like modeling power systems or long long distance transmission lines across the globe so they they have these all these structure for pipelines and

long transmission lines like power feed systems, but they didn't have any structures or simplified code base for submarine cables, which is even larger. So I worked on that. I started working on those things. I mean, this fits in really well, like I said, as a capstone for our little series all about submarine cables. But before we talk about the submarine cable part, I think we've got to back up for our audience and just have you explain what is space weather.

yeah that that's probably the most uh pivotal point like based on which everything is so it is like a geospace so typically if space starts from if you go and google what is space it starts from approximately 100 kilometers sometimes it says 89.9 kilometer depending upon which book you are looking for and beyond that everything is space so the space weather is nothing but the weather condition over there

Just like the terrestrial weather, you have another thing called space weather. So the terrestrial weather typically defines by the atmospheric pressure, which is pressure differences in winds and pressure differences in...

Sorry, temperature differences across different locations. So instead of that, so those are all kind of true in space, but also there are additional stuff. For example, electrical charges and stuff like... magnetic fields so all these things commonly constitute as ionosphere and then magnetosphere where these are much more dominant forces Lorentz forces so you started observing again the pressure difference but in terms of voltages and magnets

The differences of voltages and differences of magnetic field and which can drive them and they can actually create circuitry within them. It's kind of distributed. not exactly like lumped sources like resistance and conductance so they started creating these current across different location on top of the earth and they can actually creates significant disruption because these currents are in the or the voltages are kilo volts and ampere kilo amperes Mega amperes like this order of magnitude

So to give us some concrete examples that listeners can work with, something like the Aurora Borealis is an example that we're all familiar with of space weather. Or we've heard about, you know, solar flare, EMPs that shut down electronics. yeah those are solar storms so the primary source is the sun and that actually create the this disruption in the geospace systems obviously yeah you mentioned i forgot to mention this aurora borealis is one of the primary right

like a visual representation of what can happen. You might not see it as a storm, but it's a fallout of storm, how we perceive it. So that's one thing and then the other solar storms the geomagnetic This is called coronal mass ejection that is actually coming from the sun. Sun throws out, it's called solar wind, it actually throws out stuff towards the earth and it can actually interact with this geospace environment.

And that can create or alter the space weather, which is like a dynamic system. I mean, this is really fascinating. Yeah. And when you think about it from a sort of geotechnology or geodescription, like... there's there's a fine line where where there's no more atmosphere it's not like there's a there's a clear you know bright line there's this gradient and things are happening different at different levels of the atmosphere now

That is super fascinating to me, but take it down to the very lowest level here, which is underneath the oceans. What impacts could these space phenomenon that you're talking about? actually have on submarine cables. Well, in short, it's like it can create induced EMF, just like in very layman terms. So all these different. So if you go back and check the Faraday's law, right, when if you have a. change in magnetic field that can induce a voltage in a conducting metal. It's very simple as that.

as so you can you can imagine like huge amount of current flowing through in our upper atmosphere which is like let's say around 100 kilometers sometimes even a few thousand kilometers depending upon where these currents are located as i mentioned it's not Clearly, depending upon what type of phenomena we are observing, there can be different. And these current can actually then induce magnetic fields.

on top of the surface of the earth and also underneath the ocean and as you can understand like the fiber optic cables needs the repeaters right at a specific different locations for example few hundreds of kilometers and those repeaters need power feed cables which are typically metallic and then those currents, those induced magnetic field and then can induce voltages in those currents.

typically what happens as i understand is like these cables these repeaters are feed by the stable voltage sources on the either side right of the of the cable submarine cables and then they have a fixed voltage with some maybe wiggle room in their voltage sources now when these currents are induced in the ionosphere and then followed by the magnetic field on the surface of the earth and underneath the ocean, they induce some sort of fluctuation on the base background voltage on these.

conducting metals and they can create then disruption on the signal that passing through these cables. That's really interesting.

All right. So there's a couple of places there, Shibaji, where I want to follow up. One would be, you know, when I first heard of this concept that you brought up, I was thinking that the danger would be largely to the landing stations. But you're saying that the ocean... doesn't necessarily shield from these sort of magnetic fluctuations that this can go into the actual repeaters like on the seafloor.

And then my second question is that it sounds like from what you're saying, the danger isn't so much to the... fiber optic cables themselves but to the the metal that is used to power them so the power the repeaters the shielding that sort of thing yeah so i'll answer the second question first yeah so

You are getting that right because the fiber optics, they are typically made out of some sort of a descendant of glass, as I understand, like some sort of a glass material. So they are not susceptible to these kind of scenarios. At least as I know of. I'm not completely 100% sure. Well, that's why we need to fund this research, right? Yeah. As I know of, that is not. But definitely the metals.

Anything metallic that is going to be impacted. So these things called GIC, geomagnetically induced currents. And now going back to the second, your first question. So can you repeat your first question?

Yeah, the first question was about that. So I was initially thinking that probably the primary danger was to the CLS, the cable landing station that's initiating the signals. But you're saying that there's actually a danger even under... you know, sort of kilometers of ocean above it, that the repeaters themselves that are sitting on the ocean floor can also be affected by this magnetic phenomenon.

Well, yeah, to answer your question, it's partially yes and no. To be honest, it is right. I mean, the water depth, it acts like a Faraday cage.

Right. Okay, that's what I'm getting at. It shields some part of it. But the problem is, as you can understand, the cage is made out of different holes, right? I mean, let's say if you are using a Faraday cage of some sort of a... boxes and those those metallic mesh are like let's say one square meter in size then anything less than one square meter of wavelength in terms of electromagnetic wave will pass it through so similar things happen over here as well and as you can understand it's not

It's not like a 0-1 scenario. It's like an attenuation that goes with the water depth. And as you go higher and higher water depth, then the attenuation is higher.

come out on the continental shelves when when it starts from one end let's say from west eastern part of usa to western part of Europe western side of Europe so the cable starts from somewhere Fredericksburg I'm taking a typical example Fredericksburg in Virginia right I mean that first maybe a few hundred kilometers is the water depth is between 100 meter to 500 meters and and the other side is the similar some somewhere in Germany is the water depth is around that

And they create, even if those are like few hundred kilometers long cable sections, they might be much more vulnerable together along with all this huge cable, which is like 8,000 kilometer transatlantic. that can create a significant total voltage fluctuation. Right.

Right, right. But yeah, I mean, if the last few kilometers of the cable are at least where there needs to be a repeater and the landing station are damaged, then the cable might be down altogether. Right. So, yeah. Yeah. Interesting.

Work through with me, Shibaji, the likelihood that something like this would happen. and affect a sort of broad area of submarine cables. So you brought up the transatlantic. That's a good example because there are dozens of cables there. Lots of places around the world have a concentration of cables. So if this... I assume this phenomenon has some sort of limit to the geographic extent is my sort of first question there. And then two, help us work out.

the balance of the likelihood of this versus the sort of level of problems that it could cause? Well, so I'll take the likelihood first. To be honest, it depends upon the grid of the geomagnetic storm. So if you go back and check the NOAA website, they provide a typical detailed outline of what... different types of geomagnetic storm typically can be it starts with g0 which is like no storm and then go up to g5 and this is a logarithmic scale so if g0 to g1 2 3 4 and 5 it's not linear

So G5 is a huge storm. And to be honest, these are based on the recorded data, which is probably going back to 1957 and probably early 19... 50s, let's say. So we don't have a very big data set to understand this frequency. To be honest, we do have some example of what might happen, what might not, and in terms of frequency, which is called the recall rate, let's say.

We do understand there are some sort of a recall rate. We have some studies that talks about one in a hundred year, one in a thousand year kind of typical strength of these events. Right. But to be honest.

those are typically modeled and some sort of a reconstruction of what people have recorded in a historically for example there are studies that talks about okay the auroral uh phenomena we observed near the equator so that's a very big event that is how people have described this historical event but to be honest we don't have a very clear understanding

Yeah, that's really fascinating. So you get a little multidisciplinary understanding there. You go to history, archaeology, things like that to look for evidence of these happening because they're so infrequent. um then then back to the sort of first part of my question is let's say there's something uh like very strong on that zero to five scale a three or above or whatever right

Does it have a limited geographic extent or is this happening to, you know, sort of one whole side of the globe? Take us through that a bit. So the first rule of thumb is like as you go up in the latitude where... I don't want to go too deep into the technicality. Sure. Yeah. Keep it for a general audience for sure. If you go up in the latitude, what happens is like typically you see this oral.

phenomena the aurora borealis and australis in the in the south pole and the north pole as you go up in the latitude the the typical understanding is uh it might have more impact on those latitude higher latitudes of the poll but having said that there is this phenomena so for going back to an example of 2024 may storm we typically call it some other mother's day storm or gannon storm

it can happen like you can observe aurora borealis near equator texas people have observed and there are reported events not only 2024 but going back to there is a recent storm which is called Halloween storm 2003 Halloween storm it happened November

started like 31st of october to maybe some during two to four days it stays and people observe near like guam yeah oh wow yeah yeah so they lit up suddenly the night sky lit up with these different colors and people have no idea then going back to 1989 storm and people Going back to some other, older literature, people describe like how submarine cable, early submarine cable, 1989 storm that actually...

showed like around 700 volt peak to peak fluctuation in the transatlantic cable, the similar location we discussed. And then there was a TAT-1 cable going back to 1958 storm. They observed three kilovolts, which is significant in terms of even people don't have that much of a leg room, I guess, for transatlantic level. Maybe, maybe not, but it is touching that limit.

Right, right. Really interesting. Yeah, as a matter of fact, my kids and I went out in Northern Virginia here and saw the 2024 storm. I mean, you could see it much better with your camera, but you could see it with your naked eye. It was incredible. Yeah. Okay. So we're still working out kind of the likelihood of this. We also are, it seems, working out.

the the degree of the impact though it's it's certainly possible that there would be an extensive impact particularly maybe for cables that are at a further north or further south latitude it's not really yes like cables in the very far south, but there's plenty in the north. So that's one thing, the latitude, which controls how much impact it can create from the extraterrestrial sources.

The second thing is like, which is I mentioned, this is called GIC, geomagnetically induced current and for current to flow. or induction to happens. There is another parameter that plays a very strong role, not only the water depth. but the different earth's crust and layers and what is their property in terms of electrical properties in terms of describing how capacitive or resistive they are. So that can actually create another.

level of impact and as you can understand it's not our earth is not homogeneous so it's it's very different and even if you go across the same latitude not all the parts across the different location of the earth is has the similar type of this resistive structure and that can create some sort of a differences across the latitude and latitude to latitude

And finally, I'll put this one, which is slightly scientific. This current structure in the magnetosphere and anosphere I was talking about, they have their own structure. It's not like even if you go through across the globe. they are uniform we observe these current systems that appear and disappears with time and space and they have sometimes very sharp

and very strong independent location dependence on how intensive they are. Interesting. And that can create, let's say, if you go... a very short length sometimes very short cables let's say there are some cables coming up on the great lakes canada it is higher in high slightly higher in latitude in terms of where the tat 8 cables are located probability but the length of the cables are short but i'm not exactly sure about the water depth of the great lakes right but

But the resistivity, what I understand, the resistivity of the crust and the mental structure of the earth is relatively higher on those locations. And that can create some sort of a... challenges in terms of what we perceive. Even if the cable length is shorter, we can have havoc. Not just for those big trans-oceanic sort of spans, but it's very interesting. And again, to sort of put a pin in what you're saying, that there are just differences.

geographically on on the the strength of this effect right so so it's might be difficult to to predict and understand exactly

where this would have the ability to take out a cable, where it might not really fully affect a cable? Is that what you're saying? Yes. We have some sort of modeling capabilities, but... with the amount of resource we have, we can't able to do it comprehensively for different locations. Obviously, it's cable to cable dependent. And another part we haven't touched upon, I might be

wrong, I might be right. I'm not exactly sure. We haven't tested the cable property in itself. Whatever we are discussing right now, we are discussing from the standpoint of geophysics and modeling what is the induction effect and everything. we haven't touched upon the cable design again if we wanted to perceive that money is one of the major source of limitation probably and resources in terms of people are whether people are interested in doing that

Yeah, I mean, that really sort of keys me up for my final couple of questions here. First, to your knowledge and where we've developed our understanding of this so far.

Is there a way that cable operators can currently sort of anticipate or mitigate these risks? Are we there yet? So first of all, even before, yeah, I mean, not... partially yes and true again it's not exactly we can we can't say like we can't have anything to do it's not like that but we we can't really um have complete protection from this it's it's like an

from from me it's like an analogy to earthquake it might happen you can you can redirect some part of it you can mitigate the risk by saving human not exactly human lives here but um something like that but you can't really move the whole city something like that so what we can do is we can actually provide for a specific standard of geomagnetic storm like g1 to g5 we can provide some sort of a standard fluctuation expected through a specific cable let's say for

transatlantic cable at this specific latitude we can provide some sort of a background sorry the wiggle room of the voltage it can expect for a g1 storm or maybe g5 storm so that if your cable if the cable operators or cable designers are designed a cable such a way like it is it is able to withstand 10 000 it is able to operate at 10 000 volts it can create let's say another 2000 volts wiggle room so that even the fluctuation goes around that it it did not trip or the repeaters does not

has any any any type of problem in there so that kind of things we can do second is like even if that can trips we can we can provide relatively stable latitudes where the impact be less we can provide those kind of understanding so that you can lay down one or two cables so that in a kind of a scenario where one of your cables get disrupted you can actually reroute your

traffic through other cables sort of things like that and finally where we are moving but to move like that location like where we can actually forecast right i mean maybe a day ahead or two day ahead so that you can you can have some sort of wiggle room to adjust your operations accordingly what you can do is like is like for that is like there are two or three different components here first component is uh to predict what sun is going to do

two or three days ahead of time so there are people who are like heliophysicists are doing that we we have made significant progress but again 50 years of data in terms of helioseismology is nothing. We're still facing that data gap. like this magnetosphere and atmosphere system is responding geospace space weather responding i i mean partially in that field so we are trying to predict those things given a specific scenarios and finally the final part is how

Even if we understand how these currents are located, how the cables are responding. And on top of all these things, whatever I just said, there is a very big missing link here is like. the magnetic field observations we need to understand or even like the ionospheric currents we don't have enough data points to actually find

what should happen along this cable. You can imagine all these cables are running through underneath the ocean and we don't have continuous monitoring what is happening in terms of magnetic field fluctuation. on top of the surface of the water or even underneath the water. So all these things are kind of limitations right now probably once some of them get addressed as we address some part of it.

the prediction capability will enhance yeah yeah absolutely excellent so so it sounds like um there's there's still a lot more research to be done, as you said, kind of across all these different areas in terms of the heliophysics, in terms of the physics of how it actually interacts with the submarine cable. all these kinds of things. How do you think that maybe the industry, the folks who are operating and using submarine cables might be able to support these efforts?

Well, first of all, they can provide the data. So the first thing is like because we have a capability called SCUVAS. It's a submarine cable upset by Aurora. uh streams and the full form of it so gotta have an acronym to make it official right so we can actually model it we started collaborating with the australia japan cable network and recently started working out some of the nds with meta and google probably will get some data so first of all get the data

and then test our model. We did pretty good when the historical event, for example, I mentioned 1989 storm, which was one of the legacy storm and then going back to 1958 storm which is again a legacy storm we call them these two storms as super storms as for very specific reasons but whatever happened last 20 years

there are a few other storms like these kind of we wanted to test and validate how good our model is doing to do that we need validation and then the final part of it it's not about the end-to-end voltage I always mentioned about driving voltage but also what the voltage is between the repeaters and that can because as as i mentioned right i mean there there can be a current systems that is very low

like just very centralized and located along on top of one cable section and it can fry only one or two repeaters. It might not affect the whole cable and that can happen. So providing the data, first of all, collaboration in terms of partnerships, then obviously supporting it from the perspective, if they provide us some sort of grant, that would be a very good.

uh money always helps with research right so yeah it's got to be part of your job as a researcher yeah the project has been funded through nsf but again um due to various sort of things we are limited by the funding source but yeah i mean these two are pretty good and the final thing is like again going back to the model again i mentioned the model

This model is typically driven from the perspective of geospace and from the perspective of geospace science, ileo science and the Faraday's law and stuff like those things. we have a limited understanding of this cable in structure itself. And that might play a significant role in terms of how it affects the overall cable. That is a part where engineers probably are more valuable than a scientist. Right. And so there you're saying you just need more collaboration with the industry to get a...

a better insider kind of understanding of exactly how the cables are operating. So, I mean, these seem like this is a good place to make this sort of call to action. So I appreciate that so that, you know, not just funding, but also data share and just. collaboration on the engineering so that you can relate what they actually do on the ground or under the sea, as it were, to your models that you've created based on these various physical...

model. So that sounds really interesting. All right. So on that note, Shubhaji, how can listeners who are interested in this topic keep up with you and your work at Embry-Riddle? I have a GitHub page, as simple as that. Of course, of course. If they want to contact me, they can just Google me. The School Bus, they can search for School Bus. It will pop up too many things in the Google.

Yeah, yeah. Scuba with space weather and submarine cable effect, probably with these three, four keywords if they search it. Otherwise, Emery Little sees our website.

they can find me i i have the email listed over there so yeah excellent all right yeah and we'll we'll we can put some in the show notes so excellent well this has been really fascinating yet yet uh you know very often on this show i run into things that are new to me but this was a a topic that it was entirely i didn't even know was a thing so i think that's really fascinating so thanks for well i i didn't even think about it

maybe four years going back when i was conducting the space weather but in terms of other stuff i didn't know it existed Yeah. Yeah. And yet certainly all the listeners here know how crucial this infrastructure is to the entire global economy. So it's definitely we're glad you're thinking about it. Excellent. Well, thank you. Thank you for having me. Yeah.

Thanks for listening. Telegeography Explains the Internet comes from the experts here at Telegeography. It's edited and produced by Jane Miller, and it's hosted by me, Greg Bryan. And I also wrote that theme song you're listening to right now. To learn more about our data, jump over to telegeography.com and we'll see you on the internet.