WEBVTT 00:00:00.000 --> 00:00:02.000 Alright! Let me start the recording. 00:00:02.000 --> 00:00:07.000 So Dean wanted me to introduce him because he didn't want to introduce himself. 00:00:07.000 --> 00:00:27.000 But first I'd like to say that if you have questions of clarification, please put them in the chat, and we'll say I will read them off to Dean, or point at you to read them off yourself. 00:00:27.000 --> 00:00:38.000 But save questions of discussion until the very end, and then we'll we'll open it up more talk. 00:00:38.000 --> 00:00:45.000 So the days Sto seminar, in A. Is by W. 00:00:45.000 --> 00:00:54.000 Dean, Pezell. He's the project scientist of the Solar Dynamics Observatory he's studied the sun, sun grazing comets, variable stars. 00:00:54.000 --> 00:00:58.000 The sunners. Connection. Quantum mechanics and neat ears and planetary atmospheres. 00:00:58.000 --> 00:01:03.000 He received his Phd. In 93, from the University of Florida. 00:01:03.000 --> 00:01:09.000 After a postdoc at the University of Colorado, and a visiting professorship at New Mexico State University. 00:01:09.000 --> 00:01:22.000 He formed nomad research, Incorporated in 1,995, and did scientific contracting he joined NASA in 2,005 as the project scientist of Sto. 00:01:22.000 --> 00:01:32.000 He likes to use music, to describe physics, or even listen to data talking about the sun is fun, because almost anyone can study it. 00:01:32.000 --> 00:01:33.000 Right. 00:01:33.000 --> 00:01:38.000 And teams, title. It is the Rise of Sdos, Second Sunspot Cycle. 00:01:38.000 --> 00:01:40.000 Take it away. Dean. 00:01:40.000 --> 00:01:46.000 Alright thanks for the introduction, Frank. Thanks for everybody coming out for this talk. 00:01:46.000 --> 00:01:54.000 The goal of today's talk is to describe what's happening in solar cycle 25. 00:01:54.000 --> 00:02:02.000 And then the latter part is going to be. Whether or not the prediction that we did was correct. 00:02:02.000 --> 00:02:14.000 So let's get started. Our first X-class flair in solar cycle 25 was about a year and a half or so into. 00:02:14.000 --> 00:02:18.000 So what's like? So here it is. It's right on the limb over on the right. 00:02:18.000 --> 00:02:33.000 Here. If there's a whole series of of flares that take place with a an X point one at the end, the largest, so far. 00:02:33.000 --> 00:02:47.000 Where has be? It was just a couple of weeks ago. Excuse me, it was a year ago, and it was down in this region down here, and we see that the large flares of solar cycle, 25. 00:02:47.000 --> 00:02:54.000 Are all occurring off the limb, and so they'd be great if Russie was still alive. 00:02:54.000 --> 00:03:08.000 There's also, if you watch. I left this run for the entire day, because there's a kind of a nice coronal dimming that takes place towards the end of the calibration maneuver in this region here. 00:03:08.000 --> 00:03:14.000 So we're seeing all the usual stuff in solar cycle 25. 00:03:14.000 --> 00:03:29.000 The irriances have recovered, they went into a minimum in in the 2020 area time, and now they've come back up and there're showing both the increased heights. 00:03:29.000 --> 00:03:32.000 Or size, and they've also show the increased fluctuations that come with being near solar maximum. 00:03:32.000 --> 00:03:49.000 And my favorite is the iron 3 35 here, which has a very nice, greater than an order of magnitude of variation over the course of the solar cycle. 00:03:49.000 --> 00:03:57.000 Oh, the magnetic fields of solar cycle 25 is not the same yet as solar cycle 24. 00:03:57.000 --> 00:04:05.000 So here's 25. This is an average of synaptic maps from Stanford over all of solar cycle 25. 00:04:05.000 --> 00:04:19.000 And if we compare that with the same done for all of the synaptic maps over sort of like a 24, we can see that solar cycle 25 is still at higher latitudes. 00:04:19.000 --> 00:04:28.000 So the activity has not progressed down towards the equator as yet, and that there's also it definite white. 00:04:28.000 --> 00:04:35.000 Or outgoing field in the north, definite black or inward directed magnetic field in the South. 00:04:35.000 --> 00:04:50.000 Whereas we look at Cycle 24. It averaged over the sign Change, and by and large the field in the north averages to fairly close to 0 over the entire cycle. 00:04:50.000 --> 00:05:00.000 Probably disappoint most of the pointing is, we continue to have our droughts of geomagnetic storms. 00:05:00.000 --> 00:05:05.000 We do have storms, but here are storm days, and I've defined storm days to be a day with the Df. 00:05:05.000 --> 00:05:14.000 T. Index to be below minus 25. And this is actually quite a small storm. 00:05:14.000 --> 00:05:31.000 Minus 100, is considered to be a large storm, and you can see that over the course of each 27 day Bartel's rotation that we're only typically having we're having fewer than 10 days that have major storms, whereas if we 00:05:31.000 --> 00:05:42.000 look back into the eighties and nineties. We were having 10 or 15 days with a major storm, and then. 00:05:42.000 --> 00:05:53.000 But the real thing, the one of the things that got me thinking about doing this talk was this film interruption that occurred back in February, and this I'm pretty sure, is a polar crown filaments. 00:05:53.000 --> 00:06:00.000 I have been watching for them to form an issue. 00:06:00.000 --> 00:06:09.000 Corona had studied these as a and they're really with coronavities back in solar cycle to 24. 00:06:09.000 --> 00:06:12.000 But we didn't have anyone really actively watching them. 00:06:12.000 --> 00:06:19.000 Here for solar cycle 25. And so when someone has asked about this film interruption, I said, Oh, it definitely looks like a full of ground filament. 00:06:19.000 --> 00:06:31.000 It's pretty high up right there. There's a cabinity over here, sure enough, and it looks like it rips all along the do. They? 00:06:31.000 --> 00:06:43.000 Possibly even you can imagine it goes around on the backside a little bit, and I measured it, and it's going across the limb here at about 72 degrees. 00:06:43.000 --> 00:06:49.000 Wow! That's if that's the polar Crown filament, and we're almost at solar maximum. 00:06:49.000 --> 00:06:55.000 So? Are there any other ways to test that possibility? 00:06:55.000 --> 00:07:06.000 So how close are we to? So our maximum now, back in the fifties, some people named Babcock noted that the polar field reversed. 00:07:06.000 --> 00:07:09.000 Here's a north Pole going from outward to inward. 00:07:09.000 --> 00:07:13.000 Here's the South Pole kind of just looking about. 00:07:13.000 --> 00:07:27.000 As it goes from in word to outward. And then here are the latitudes of filaments, and this is sometimes called a rush to the poles, as the filaments go up towards the poll. 00:07:27.000 --> 00:07:38.000 Here in the north, and here down in the south, and this region in here is once we start heading into the solar maximum time over the solar cycle. 00:07:38.000 --> 00:07:43.000 So let's go look at another indicator or a more modern indicator. 00:07:43.000 --> 00:07:44.000 So our cycle 25. Now the polar fields. 00:07:44.000 --> 00:07:50.000 But here is the polar field from the Wilcox Observatory. 00:07:50.000 --> 00:07:51.000 They've been measuring this since about 1970. 00:07:51.000 --> 00:08:02.000 5. And I use this in my work on predicting Solar Cycle. 00:08:02.000 --> 00:08:09.000 So it's nice to introduce it, and when I gave a talk about a month ago, I looked like they were going through 0. 00:08:09.000 --> 00:08:21.000 But you can see that the variations caused by the of the sun mainly, or the tilt of the sun to the ecliptic, or actually kind of messing up. 00:08:21.000 --> 00:08:26.000 They're acting their aliasing the variations. 00:08:26.000 --> 00:08:40.000 A month or 2 ago. It's a little easier to see what's happening now, and we can see here the Hmi polar field, which is an average over a different parts of the a different area of the sun. 00:08:40.000 --> 00:08:44.000 So there approximately the same. But they're not exactly comparable, and we can see that both of them are starting to approach 0. 00:08:44.000 --> 00:09:10.000 But they have not gotten there yet. But let's look at the Wilcox one, and a little bit more detail, and we can see here that the South, if if you look at these, are the obliquity, the variations caused by the tilt of the sun with respect to the 00:09:10.000 --> 00:09:11.000 ecliptic, and you can see that the North Pole. 00:09:11.000 --> 00:09:22.000 It looks like it may have actually gone through 0. And in this the difference between these is at least approaching. 00:09:22.000 --> 00:09:28.000 Z. In the near we're getting close to Solar, Max. 00:09:28.000 --> 00:09:33.000 This is not a surprise. 00:09:33.000 --> 00:09:39.000 This is not a surprise. The soda prediction. 00:09:39.000 --> 00:09:57.000 For this cycle was that it would peak in 2024, but 2024.6, which is roughly July of 2024, and have a peak of about a 125, and so here's what we're trying to predict so let's talk about these predictions 00:09:57.000 --> 00:10:03.000 for just a minute. Here is the record that we have. 00:10:03.000 --> 00:10:11.000 This is the version 2 sunspot number has been developed by a variety of people, and it's supposed to be more accurate than the previous version. 00:10:11.000 --> 00:10:27.000 But we do still have to wonder whether it's a complete history, or is it a continuous representation of the variation of solar activity? 00:10:27.000 --> 00:10:33.000 Or are there sampling issues that occur throughout the record, anyway? 00:10:33.000 --> 00:10:38.000 Why do we wanna predict solar activity? There's a couple one is. 00:10:38.000 --> 00:10:42.000 NASA has to build and fly spacecraft. That's our job. 00:10:42.000 --> 00:10:44.000 It's in the law that started NASA. 00:10:44.000 --> 00:10:45.000 It's in the law that continues to fund NASA. 00:10:45.000 --> 00:10:56.000 They have to renew at every so often and they pretty much copy that part in there that we're supposed to build and operate spacecraft in space. 00:10:56.000 --> 00:11:03.000 The major concern that we have is orbital decay for low Earth orbit, satellites, and then the second concern is radiation, exposure, and damage. 00:11:03.000 --> 00:11:13.000 And I'm going to talk mostly about orbital decay for a minute. 00:11:13.000 --> 00:11:19.000 I, founder. I I've had this figure for a long time, but I couldn't remember where I got it from. 00:11:19.000 --> 00:11:21.000 I finally found it again. This is the lifetime of an orbit, probably a circular orbit. 00:11:21.000 --> 00:11:31.000 If you launch a spacecraft that has a ballistic, coefficient. 00:11:31.000 --> 00:11:44.000 Of certain values and the ballistic coefficient is rolling the column mass density of the spacecraft presented along the velocity of the spacecraft. 00:11:44.000 --> 00:11:49.000 So it's the mass divided by the volume, and in times. 00:11:49.000 --> 00:12:03.000 But yeah, I'm not gonna give you an exact. So the variations from 20 to 200 nicely incorporate things like the Hubble and the Iss. 00:12:03.000 --> 00:12:04.000 These are typical things that we worry about because they're bu hubble. 00:12:04.000 --> 00:12:26.000 We kept in orbit with boosts from the space shuttle for many years, and the Iss is simply an advanced array of equipment in orbit that is boosted by a much smaller spacecraft, and so you want to get as much light 00:12:26.000 --> 00:12:46.000 out of these satellites as you can, and and so, if we look, here's the Hubble started out of a higher altitude, and here's the Iss, and you can see they have lifetimes that are starting out in the in the half in the 3 to 5 year kind of range so that means 00:12:46.000 --> 00:12:53.000 you really need to boost them to keep them the extend their life. 00:12:53.000 --> 00:13:12.000 And if there's more solar activity, the upper atmosphere of the earth, it expands, it heats, expands, or roll drag is increased at all altitudes, and the lifetime of any mission is reduced. 00:13:12.000 --> 00:13:13.000 So they want us to predict F, 10 and 10.7 is what they like to predict. 00:13:13.000 --> 00:13:27.000 S. Is, they're willing to live with. The predictions have to be believable, and even if they're not physically correct, and there's a lot of predictions that aren't actually physically correct. 00:13:27.000 --> 00:13:40.000 They're simply a time series analysis, some correlation function that someone found actually seemed to work, that doesn't give them a physical model. 00:13:40.000 --> 00:13:58.000 That tells them why the the prediction is correct. But the people that do these calculations just one something that's accurate, and the sort of index that we have developed has been one that's actually worked pretty well. 00:13:58.000 --> 00:14:22.000 We had an excellent example of the problems of satellite track earlier I believe it was last year, early last year, when Spacex launched a tranche of their starlink constellation, and they lost 40 odd spacecraft because of some unanticipated at least on their 00:14:22.000 --> 00:14:28.000 part, the satellite drag, caused by a geomagnetic storm. 00:14:28.000 --> 00:14:45.000 So I to you know we can complain all we want about starling, but they do launch them at a relatively low altitude, and then, if the spacecraft doesn't fire up and is considered dead, then they don't raise the the energy and apoge up to 00:14:45.000 --> 00:14:56.000 the 600 kilometer working orbit. And so that means that the ones that don't pass the startup, or at least the orbit, they don't put them on orbit and allow them to become junk. 00:14:56.000 --> 00:14:57.000 But, on the other hand, it is fun to watch things come back down. 00:14:57.000 --> 00:15:06.000 So here is a starlink spacecraft coming down as a result of the access drag from. 00:15:06.000 --> 00:15:12.000 I believe it's February third, 22 launch. 00:15:12.000 --> 00:15:16.000 Now we didn't have a whole lot of data until recently. 00:15:16.000 --> 00:15:26.000 Space based requirements, the development of microwave technology after World war. 00:15:26.000 --> 00:15:43.000 2, has given us many other indicators of solar activity, but the one we've had the longest measure with, or the greatest experience with, is the sun, spot, number and there have been several quotes that say, the wolf's on spot. 00:15:43.000 --> 00:15:48.000 Number so the version one was the most analyzed data set in history. 00:15:48.000 --> 00:15:55.000 Yeah. So that's says something that a data set whose only only advantage was that it had everything. 00:15:55.000 --> 00:16:07.000 Was in such demand for people trying to develop these prediction methods that we continue to try and use today. 00:16:07.000 --> 00:16:12.000 There are, of course, at least 67 predictions of solar cycle, 25. 00:16:12.000 --> 00:16:20.000 Sitting out there. The average of previous cycle maximum is this, like 1 80. 00:16:20.000 --> 00:16:25.000 Unlike the previous cycle, cycle 24. We don't have. 00:16:25.000 --> 00:16:32.000 Is that a uniform spread? We actually have most of the prediction for below average. 00:16:32.000 --> 00:16:36.000 Here's so much like the 24, which was also below average. 00:16:36.000 --> 00:16:43.000 So we I don't know if we learned something from the previous solar cycle. 00:16:43.000 --> 00:16:46.000 Did we get better at predicting that? 00:16:46.000 --> 00:16:52.000 There's still a pretty good spread of predictions here, so I think we still have a ways to go. 00:16:52.000 --> 00:17:00.000 But let's talk about what can some of the methods that have been developed for auto regressive analysis which was actually invented? 00:17:00.000 --> 00:17:12.000 To study the sun. Spot number for your wavelet, analyze predictions based on the motions of the solar center of mass. 00:17:12.000 --> 00:17:30.000 So this is the planets going around the sun and the Barry center of the solar system actually moves in and out of the sun, and the idea is that that is what's causing a title motions and drive selectivity people will come up with an explicit dynamo 00:17:30.000 --> 00:17:46.000 model. Some of them are numeric, some of them are highly simplified, so there's only 3 equations, but in nonetheless state they have a non-linearity that allows them to treat them as a an explicit dynamo. 00:17:46.000 --> 00:17:53.000 But almost all these methods have a poor record of predicting the amplitude of solar cycles, and I have. 00:17:53.000 --> 00:17:56.000 I analyze that back in 2016, this is really what we want to understand. 00:17:56.000 --> 00:18:08.000 We want to understand is the magnetic field and Dave Hathaway keeps updating this really nice plot of the longitudinally average line of sight magnetic field. 00:18:08.000 --> 00:18:20.000 And it shows the information that we were lacking by constrating on the sun spot. 00:18:20.000 --> 00:18:24.000 Number alone. If we look, here are the Sunday. Roughly speaking, this region. 00:18:24.000 --> 00:18:33.000 This is where the sun spots, and if we only have sun spot numbers, then we're missing the well. 00:18:33.000 --> 00:18:40.000 For one thing, we're missing the poll. The whatever the poll is doing, we're missing completely, but it's more. 00:18:40.000 --> 00:18:48.000 This interacting addiction of field into the polls is also being missed because sunsplats don't track that. 00:18:48.000 --> 00:19:00.000 So in reality is, we've seen more things can be used to understand solar activity, but unfortunately, we don't have the time scale. 00:19:00.000 --> 00:19:03.000 This also goes only back to 1975. 00:19:03.000 --> 00:19:12.000 We have from about 1995, we have a helio seismic measurements that also show this. 00:19:12.000 --> 00:19:34.000 Like the trend to go from higher latitude down towards the equator, and you can see that here in this band of torsional oscillations that are headed down from higher latitudes down towards the equator, and this a polar extension that goes from from a 00:19:34.000 --> 00:19:44.000 latitude here, up into the polls, so we have a lot more information that it'd be nice to be able to put that to use in predicting solar activity. 00:19:44.000 --> 00:19:51.000 The model that we're often guided by is a very physically intuitive model. 00:19:51.000 --> 00:19:56.000 That magnetic field at the poin regions of the sun. 00:19:56.000 --> 00:20:06.000 Is there at Solar Minimum. It gets wrapped up by the convection zone and then it gets wrapped up. 00:20:06.000 --> 00:20:15.000 If it's a strong field in the polar regions, then it has many active regions. Emerge. 00:20:15.000 --> 00:20:22.000 If it's a relatively weak field in the Pole regions, and you have few and that's really nice. 00:20:22.000 --> 00:20:26.000 But it doesn't really tell us how we get from strong to one Pollar field. 00:20:26.000 --> 00:20:36.000 So we've kind of changed the problem from how we go from a week activity to strong activity and into weak activity again and spotify number. 00:20:36.000 --> 00:20:39.000 We changed it to. How do we go from week polar field the strong public field to weak polar field? 00:20:39.000 --> 00:20:51.000 So we've simply add, well, double the number of things we have for sure. 00:20:51.000 --> 00:20:52.000 Okay. 00:20:52.000 --> 00:20:53.000 There's a clarification question, hey? She asks. 00:20:53.000 --> 00:21:01.000 What depth is that plot? By Rachel showing for the. 00:21:01.000 --> 00:21:02.000 I think this is very close to the surface. 00:21:02.000 --> 00:21:09.000 If I remember correctly. But don't quote me on that. 00:21:09.000 --> 00:21:15.000 This one just was a nice illustration that other depths they would look roughly the same. 00:21:15.000 --> 00:21:24.000 But the details would be different. They they still tend to show the same it quite a word drift at the lower latitudes. 00:21:24.000 --> 00:21:34.000 I'm not sure if they still have the polar extension at the lower depths. 00:21:34.000 --> 00:21:35.000 Yeah, I would say it was about point 9 5. 00:21:35.000 --> 00:21:38.000 But. 00:21:38.000 --> 00:21:42.000 Hey! 00:21:42.000 --> 00:21:47.000 Okay. 00:21:47.000 --> 00:21:51.000 It gives a phone number. 00:21:51.000 --> 00:21:56.000 Alright! So here is the polar field again. Now what to do? 00:21:56.000 --> 00:21:57.000 Our precursor, we take this for our field, and we have to do some filtering. 00:21:57.000 --> 00:22:09.000 It's got that to the variations due to the those have to be removed. 00:22:09.000 --> 00:22:18.000 We typically filter it to annual averages and then take, this is not done here. 00:22:18.000 --> 00:22:24.000 This is simply the data. And then we take the new minus the South, and that gives us something like a dipole moment, almost of the sun. 00:22:24.000 --> 00:22:41.000 And this has had much of the variation removed. And so it's a more reasonable thing to use as a precursor. 00:22:41.000 --> 00:22:47.000 We take that value which is the polar field. It's this guy right here. 00:22:47.000 --> 00:22:51.000 We square it, and then we added to the square of F. 00:22:51.000 --> 00:23:07.000 10.7, and we get this kind of an envelope of solar activity where the the the 11 year period has been greatly reduced in amplitude, and I was pretty happy. 00:23:07.000 --> 00:23:11.000 We developed this back in 93, we did a lot of 4 year transforms to reduce the 11 year cycle. 00:23:11.000 --> 00:23:23.000 And we haven't had to change the numbers we derived, even though we have added we more than double the length of the data stream. 00:23:23.000 --> 00:23:28.000 And we've had quite a change from the higher activity here down to the lower activity. 00:23:28.000 --> 00:23:34.000 But we're still using the same numbers. To combine, and I did not. 00:23:34.000 --> 00:23:42.000 I went through and tried reanalysing it, and those numbers were still pretty good. 00:23:42.000 --> 00:23:43.000 It's so. Here are the predictions made by these polar fueled precursor predictions. 00:23:43.000 --> 00:23:53.000 I like to show this because it's got 2 things you need to. 00:23:53.000 --> 00:23:58.000 One, is, they're not perfect. The predictions here is, it's too high. 00:23:58.000 --> 00:24:04.000 But you know we catch it. Within the it's within the error bar. 00:24:04.000 --> 00:24:08.000 But you know that's a thickness of the error bar and lying thing there. 00:24:08.000 --> 00:24:16.000 This one, you know it was. It had 2 peaks, and so it's and I have to. 00:24:16.000 --> 00:24:19.000 If you and get rid of the 2 peaks, and that looks actually pretty good. 00:24:19.000 --> 00:24:24.000 This one was pretty nice. This is the current prediction. 00:24:24.000 --> 00:24:32.000 You'll notice that the the increase over the beginning of the cycle was following the predicted line fairly well. 00:24:32.000 --> 00:24:42.000 There was a burst of activity at the beginning of this year, that is, as we as coming back down. 00:24:42.000 --> 00:24:57.000 And this is kind of the same amplitude as other bursts that we've seen throughout the record and so that would say that we're probably up around here at this point, depending on what this does this year and the peak here. 00:24:57.000 --> 00:25:01.000 And F 10.7 is at a 24.7, so that would be about August. 00:25:01.000 --> 00:25:10.000 Of this of next year. Here's the same information, but now done in sunspot number. 00:25:10.000 --> 00:25:14.000 There is no predicted. 00:25:14.000 --> 00:25:16.000 Peaks back in here but once again it's got the annual average data. 00:25:16.000 --> 00:25:26.000 It's got the 87 and 81 day average drawn on top of that. 00:25:26.000 --> 00:25:28.000 So once again, you can see the variability around the top. 00:25:28.000 --> 00:25:35.000 And here is the the current data with the predicted. 00:25:35.000 --> 00:25:36.000 Now it would be at it's a month earlier. 00:25:36.000 --> 00:25:38.000 And S. Because the shapes of the 2 of the 2 curves are slightly different. 00:25:38.000 --> 00:25:52.000 So the pk would be a a one month earlier, and and the peak of S would be about 125. 00:25:52.000 --> 00:25:57.000 And one thing I'd like to in this is vertical. 00:25:57.000 --> 00:26:07.000 Lines are at least successful. A set tests or large, a set tests or large Asap tests. 00:26:07.000 --> 00:26:08.000 Here's one from United States, where they shot down. P. 87. 00:26:08.000 --> 00:26:22.000 I believe it was called. These are some others that took place before, so like 20 fourfour, and also there was a collision of satellites. 00:26:22.000 --> 00:26:27.000 But the funny thing is, he's a he's an anti satellite test. 00:26:27.000 --> 00:26:37.000 Seem to take place. And so our minimum. Come on, people, you should do those things at solar maximum when the debris will be knocked down as quickly as possible. 00:26:37.000 --> 00:26:45.000 This was an Indian test, I think, and then one of these is the spacex. 00:26:45.000 --> 00:26:48.000 The Orbit Institute. 00:26:48.000 --> 00:26:54.000 So what can we learn from the time series? Analysis, even if they're ineffective, that they don't work? 00:26:54.000 --> 00:26:59.000 If we gotta build something from them and so here's an example of a time series analysis. 00:26:59.000 --> 00:27:03.000 This is a Morelett wavelets of order. 8. 00:27:03.000 --> 00:27:08.000 Applied to the sun. Spot number, which is shown in blue down here. 00:27:08.000 --> 00:27:17.000 This is the transform. This is scale. So this is the 11 year period here, and this is a 120. 00:27:17.000 --> 00:27:18.000 And we're getting and the these are the zones of exclusion. 00:27:18.000 --> 00:27:31.000 So data that extends into the left of this line into the right of this line are contaminated by edge effects and are not believable. 00:27:31.000 --> 00:27:43.000 So you can see that here where the 10, the 1011 years, like amplitude, is dying away because we're less than 10 years from the end of this record. 00:27:43.000 --> 00:27:48.000 And here is of the sum of the wavelet power. 00:27:48.000 --> 00:28:12.000 By summing this way and then plotted with an actual 4 year, transform the more jagged line is the actual 4 year transform the wavelet really averages over every the frequency space, and so you can often see where it has power associated with the peaks 00:28:12.000 --> 00:28:20.000 before you transform. But they're totally washed out and here's the peak at 10 years in both of them. 00:28:20.000 --> 00:28:21.000 And here is the data with the line. It's in background is the power summed now over scale. 00:28:21.000 --> 00:28:37.000 So summed down, and you can see that that is a very nice kind of representation of the data. 00:28:37.000 --> 00:28:59.000 And if we do that for a bunch of different wavelets, the Gaussian Nepal, and the Morelet I just showed earlier, you can see that they all kind of represent the sun spot number, but they get rid of the 11 year period by and large the poll is the best for finding 00:28:59.000 --> 00:29:06.000 frequency. So the and the more lit is the one best at finding the amplitudes. 00:29:06.000 --> 00:29:09.000 So you know, the more or less probably the one you want to use. 00:29:09.000 --> 00:29:12.000 But the cool thing is, I'm a variable star, Guy. 00:29:12.000 --> 00:29:25.000 Excellent. I'm a variable star, theoretician, and when I was learning my trade from Jean Valjean and John Perdin, we were looking for invariants. 00:29:25.000 --> 00:29:30.000 We wanted things that adiabatic in variance that we could, that had some slow variation in in the model. 00:29:30.000 --> 00:29:45.000 So we could track things more precisely. The period change of a Cepheid, the amplitude change of a you wanted these things to have some kind of invariance. 00:29:45.000 --> 00:30:03.000 So I kind of went looking for invariance in the solar activity, and lo and behold, if we draw that soda index that's the war, jagged line here and we draw the amplitude of the wavelets and all i've done here is 00:30:03.000 --> 00:30:04.000 to make sure they got to the same scale, because they're not. 00:30:04.000 --> 00:30:11.000 They don't have the same unit. So I have to do a unit conversion. 00:30:11.000 --> 00:30:28.000 But you can see that they actually work pretty well the soda index is is kind of doing a pretty good job of getting the envelope of solar activity, and you can see that just by comparing it with a waiver. 00:30:28.000 --> 00:30:31.000 Okay, so you have to be careful with you're looking at large values of the Daily Index. 00:30:31.000 --> 00:30:46.000 Here's why. Here is the smooth yes, the in blue, and here is a daily sun spot. 00:30:46.000 --> 00:30:58.000 Number minus that smooth data, you'll notice that the values, the daily values are often similar to the actual. 00:30:58.000 --> 00:31:03.000 Buy to the smooth value it's a 100%. 00:31:03.000 --> 00:31:14.000 And so, during a given epic in the Solar cycle, the solar activity can appear to be getting quite high, but a lesson keeps it high for months. 00:31:14.000 --> 00:31:23.000 Then in the annual average that we actually do the prediction of it doesn't count it it's just a fluctuation about that annual average. 00:31:23.000 --> 00:31:28.000 And here's a different way to look at the data. 00:31:28.000 --> 00:31:33.000 This is a fit in this case. I've done assigned S. 00:31:33.000 --> 00:31:49.000 Where I you changed the sign of the Sun spot number as you go through in the even an odd sun spot number counts, and then I fit a trig series to that you have to do that, because fitting a trigonometric function to the actual sounds by number. 00:31:49.000 --> 00:31:58.000 It is tough, because the fluctuations don't aren't quite what sline functions should represent. 00:31:58.000 --> 00:32:00.000 The zeros in S. Spot number become Max, become extrema in the trigonometric fit, and that's not what you want. 00:32:00.000 --> 00:32:17.000 So if you put the the sign S into the analysis, you get this really nice trigonometric fit, and then once again I took the the difference between S. 00:32:17.000 --> 00:32:32.000 Prime. In this case the signed sun's by number, and you can see that even here there's often times where we, even with the smooth data where you get residuals that are quite large. 00:32:32.000 --> 00:32:36.000 So the next step should be predicting the residuals. 00:32:36.000 --> 00:32:58.000 We give the soda index a relatively large error bar, because that error bar is used to kind of estimate the residual, the to essentially estimate these residuals when people do Monte Carlo for long term solar orbital 00:32:58.000 --> 00:33:05.000 decay. Then you need to make sure they're putting big enough residuals in to the analysis. 00:33:05.000 --> 00:33:10.000 They're not thinking that it's a very tightly constrained sunset number. 00:33:10.000 --> 00:33:15.000 It's actually, there's quite a lot of variability that you have to allow for. 00:33:15.000 --> 00:33:20.000 In the daily and even monthly values. Oh, these indices! 00:33:20.000 --> 00:33:21.000 The latest thing that we've been working on has been. 00:33:21.000 --> 00:33:29.000 Thankfully. These were used by Canada back in 93, with Neil Sheila's work and Andre's was actually done. 00:33:29.000 --> 00:33:47.000 A great deal of work, taking Neil's data and making it more consistent as a data set, and then adding the Mdi faculty. 00:33:47.000 --> 00:33:59.000 You know how well and we've been looking at the Hmi polar facial line to understand what's going on in the polar regions and faculty are good for the polls. 00:33:59.000 --> 00:34:06.000 That's one of the few polar phenomena that can be measured from the ecliptic. 00:34:06.000 --> 00:34:10.000 We still have terrible problems because of the tilt to obliquity. 00:34:10.000 --> 00:34:11.000 But you know, we can actually see something at the polls. 00:34:11.000 --> 00:34:17.000 That's we see as well at the polls as we see at any other point. 00:34:17.000 --> 00:34:24.000 Around the limb of the sun. So these are pretty cool, and I've had a couple of students that have been working on it. 00:34:24.000 --> 00:34:31.000 And here's one of the movies we make. And you're also supposed to say the sun's rotating in the wrong sense. 00:34:31.000 --> 00:34:43.000 But that's because this is the South Pole, and we just made it book this way, and each of those colored regions has been identified as a faculty in in the sun. 00:34:43.000 --> 00:34:51.000 And we're hoping that we can use the presence and movements of frankly to track plasma motions in the polar regions. 00:34:51.000 --> 00:34:58.000 So solar power precursors are provided pretty good forecast for sunspot cycles. 00:34:58.000 --> 00:35:03.000 What do we need to improve on them, or to make better predictions? 00:35:03.000 --> 00:35:07.000 But just it could be worse. These poor guys! He's hand radios. 00:35:07.000 --> 00:35:09.000 So I was like a 24 was the worst cycle for propagation in the history of Hf radio and solar cycle. 00:35:09.000 --> 00:35:23.000 25 is not clinic, and so we're almost at the maximum with. So it's like a 25. 00:35:23.000 --> 00:35:34.000 It'll happen next year. I think we all kind of got off track, because of the pandemic next year. I think we all kind of got off track because of the pandemic, and we've kind of lost 2 years, and we all still think we're at the beginning of the rise solar 00:35:34.000 --> 00:35:38.000 maximum. The solar polar reason should be a primary goal of future reach. 00:35:38.000 --> 00:35:47.000 So research basically because we've got a huge amount of information and long-term studies of the active region parts of the sign. 00:35:47.000 --> 00:35:54.000 But we should now try and constrate on the other side the other half of solar activity. 00:35:54.000 --> 00:35:58.000 I did not present anything about the port grown a whole. 00:35:58.000 --> 00:36:09.000 We haven't really done much this this cycle, and it's almost believe it or not. It's almost time to start thinking about predicting solar Cycle 26. 00:36:09.000 --> 00:36:13.000 So thank you very much, and I will take questions. 00:36:13.000 --> 00:36:18.000 Okay, what's first? Thank your speaker with claps in the chat or on your reactions. 00:36:18.000 --> 00:36:34.000 I've got a couple of questions, but there, there's been at least one in the chat that has generated quite a bit of discussion in the chat. 00:36:34.000 --> 00:36:37.000 If you haven't been paying attention, being okay. 00:36:37.000 --> 00:36:39.000 I have not been paying attention. I'm not the chair. 00:36:39.000 --> 00:36:52.000 The seed question. Well, Shay, asking about whether the lack of major storms in this solar cycle was due to the global solar field configuration. 00:36:52.000 --> 00:36:59.000 And Barbara responded that there have been a lot of, or quite a few major storms. 00:36:59.000 --> 00:37:05.000 They just haven't hit earth. But do you wanna join in on the discussion? 00:37:05.000 --> 00:37:17.000 Well, I would have to agree that we we see essentially all all, all the sun spots to show up on our side of the sun. 00:37:17.000 --> 00:37:30.000 We see. But if you think about all the filament eruptions and the Cmes, we don't necessarily see all of them, because the way we see a Cme. 00:37:30.000 --> 00:37:33.000 Us is to measure it when it hits the error, or when it hits one of the stereo spacecraft. 00:37:33.000 --> 00:37:42.000 Now, so we terribly under count. The number of large. 00:37:42.000 --> 00:37:45.000 I'll add in that we're also measuring. 00:37:45.000 --> 00:37:52.000 Cmes at Mars, with Navin. 00:37:52.000 --> 00:37:53.000 Yeah. 00:37:53.000 --> 00:37:54.000 Right. But that's a relatively recent thing. I'm thinking more. 00:37:54.000 --> 00:38:03.000 Back to 57. What? We've and even the thirties when they first started measuring Ap. 00:38:03.000 --> 00:38:10.000 On the fifties, I think, was Dst, and you know even the the late 18 hundreds, when they started doing the other Ap. 00:38:10.000 --> 00:38:17.000 And Aa indices. You're still reliant on the Cme. 00:38:17.000 --> 00:38:18.000 Right. 00:38:18.000 --> 00:38:21.000 Hitting New York, and so you probably terribly under count. 00:38:21.000 --> 00:38:28.000 The number of large geomagnetic storm, possible geomagnetic storms. 00:38:28.000 --> 00:38:33.000 So I'll ask, what am I first questions for? 00:38:33.000 --> 00:38:49.000 My first of 2 questions. So in your predictions, you show that big spread, that plot with the the big spread, and I've seen that plot for this solar cycle and for the last solar cycle. 00:38:49.000 --> 00:38:57.000 And my question is, are the methods. 00:38:57.000 --> 00:38:58.000 Like this to me like this one? 00:38:58.000 --> 00:39:04.000 Hey? No! The the one with the big scatter of all the published predictions. 00:39:04.000 --> 00:39:05.000 Oh! Oh! Oh! 00:39:05.000 --> 00:39:08.000 You know keys. 00:39:08.000 --> 00:39:09.000 The piano plan. 00:39:09.000 --> 00:39:23.000 Yeah, that one, that one. Yeah. So that one you've done that for the previous solar cycle to, and are the ones that are correct, consistent between the 2 solar cycles. 00:39:23.000 --> 00:39:25.000 So, I haven't done that comparison yet, and there are a few people. 00:39:25.000 --> 00:39:35.000 It's probably a dozen people that have done both. Oh, a dozen is not 60. 00:39:35.000 --> 00:39:36.000 Right. 00:39:36.000 --> 00:39:40.000 So it's a matter of trying to match up people. 00:39:40.000 --> 00:39:41.000 Intercept. Yeah, the intersection of the sets of predictions. 00:39:41.000 --> 00:39:45.000 Isn't that large? 00:39:45.000 --> 00:39:49.000 Yeah, I mean, there is some overlap. There are people that made both. 00:39:49.000 --> 00:39:57.000 But the you know, the polar, the ones that I've concentrated on have been the polar precursor ones, because in the I did not show that slide. 00:39:57.000 --> 00:40:10.000 But in the previous cycle only the polar precursor predictions had a positive skill score. 00:40:10.000 --> 00:40:11.000 Okay. Yeah. 00:40:11.000 --> 00:40:17.000 So every, all, all the other classes have negative skill. Scores. 00:40:17.000 --> 00:40:24.000 Okay. My other question is from an email I got from spacewater.com. 00:40:24.000 --> 00:40:36.000 Talking about Scott, Mcintosh's latest paper he's predicting a So cycle peak of later. 00:40:36.000 --> 00:40:45.000 This year, rather than next year for 25, and he's basing this on his Arnold Schwarzenegger Terminator method. 00:40:45.000 --> 00:40:48.000 What are your thoughts on that prediction? 00:40:48.000 --> 00:40:51.000 So so I believe this is the plot you're referring to. 00:40:51.000 --> 00:40:52.000 Yup! 00:40:52.000 --> 00:41:03.000 This was, I copy this from spacewater.com earlier today, I suppose I should copy it from Scott's org. 00:41:03.000 --> 00:41:10.000 The problem here is why you have to make it earlier. 00:41:10.000 --> 00:41:19.000 So the sort of prediction I showed would agree that the maximum is going to happen next year. 00:41:19.000 --> 00:41:23.000 Halfway through next year. 00:41:23.000 --> 00:41:30.000 So, you know there's no need to have to modify. 00:41:30.000 --> 00:41:33.000 My prediction to do that I did have to shift it. 00:41:33.000 --> 00:41:49.000 The original one would have was in early 2025 and we had to move it back a little over half a year to account for the time of minimum. 00:41:49.000 --> 00:41:52.000 So we did a maximum to maximum prediction. 00:41:52.000 --> 00:41:56.000 For the first prediction, and then we once minimum, passes. 00:41:56.000 --> 00:41:57.000 We shifted to, so it has the right minimum value. 00:41:57.000 --> 00:42:06.000 The timing of these things is the most difficult part of the prediction, and so we would. 00:42:06.000 --> 00:42:13.000 I would say that if you did look and. 00:42:13.000 --> 00:42:29.000 At this guy right here, you would see there's the scatter is such that it's actually doing pretty good at representing the the time variation, the sense. But number. 00:42:29.000 --> 00:42:37.000 So you're saying that the faster rise is just means it's a slightly bigger. 00:42:37.000 --> 00:42:38.000 Hi! Cool! 00:42:38.000 --> 00:42:41.000 Yes, it's probably gonna be a little bigger than what we predicted. 00:42:41.000 --> 00:42:42.000 Right. 00:42:42.000 --> 00:42:57.000 But it's not gonna be substantially larger. And if you're only basing the rise on the on the somebody's prediction, it said it should be a year from a 2 years from now instead of a year from now then, yes, you are going to get it be substantially larger. 00:42:57.000 --> 00:43:13.000 But I think that it should be based on the fact that it's a prediction predicted. Ample prediction. Maximum is the middle of next year. 00:43:13.000 --> 00:43:14.000 Daddy. Not a quarter year after that. 00:43:14.000 --> 00:43:20.000 There's a a comment in the chat about dynamo models. 00:43:20.000 --> 00:43:26.000 Do you wanna ask a question? 00:43:26.000 --> 00:43:49.000 Sure it is the first question I asked with, are are you aware of any studies that kind of give you a correction factor for the historical sunspot series based on in order to correct for spots that we might have missed which we're born and died of the far side of the sun? 00:43:49.000 --> 00:43:52.000 Well, we since we only measure the spot, number on one side. 00:43:52.000 --> 00:44:05.000 That's not a that's not a bias. 00:44:05.000 --> 00:44:06.000 Hmm! 00:44:06.000 --> 00:44:15.000 So, if there are many problems with the observations, some spot number, but one of them isn't that we now see the whole, we've always only seen one side of the sun, so we're only we're only talking about the sun's 00:44:15.000 --> 00:44:17.000 bus that appear, that are visible from. 00:44:17.000 --> 00:44:21.000 Yeah, that's true. But when we model the sun in dynamo models they model the whole sun. 00:44:21.000 --> 00:44:40.000 Not just the visible side. So when we try to match the models to the sun spot number that we've constructed only by viewing one half of the sun, if are you just aware of any statistical studies that give you like a correction factor for to correct the sun spot number 00:44:40.000 --> 00:44:45.000 to represent the whole sun, instead of just the one half. 00:44:45.000 --> 00:44:46.000 Well, it's your typical observation problem. 00:44:46.000 --> 00:44:53.000 You have a model. It models the whole sun and their sun spots around the whole sun. 00:44:53.000 --> 00:45:01.000 But if you wanted to produce an artificial sun spot number, you would only measure those that are on one side. 00:45:01.000 --> 00:45:14.000 You would have, you would have to pick out a rotating coordinate system that matched the viewpoint of the earth and sun, and then only sample that to generate your artificial sunsbot number. 00:45:14.000 --> 00:45:27.000 Right? Yeah. And the other thing was just a comment based on the dynamo model predictions for cycle 25 seem to converge and think. 00:45:27.000 --> 00:45:29.000 Depend to head a paper about that. 00:45:29.000 --> 00:45:42.000 Right? Yeah. So I I have not delved into cycle 25 is as much as I did in cycle 24. 00:45:42.000 --> 00:45:51.000 So only to the point of looking up the predictions. So far. 00:45:51.000 --> 00:45:56.000 But still doesn't mean that they're right, because they could all be wrong at the same time. 00:45:56.000 --> 00:45:58.000 Yeah, we learned that with total solar radians. 00:45:58.000 --> 00:46:03.000 Yeah, there it is. Yeah, we're not. We're not so. 00:46:03.000 --> 00:46:18.000 So remember what I said. The the prediction only has to be usable, and and the people that use it have to find it acceptable, and the solar polar precursor has done that for 4 cycles. 00:46:18.000 --> 00:46:37.000 Now, and so that when the flight dynamics people wanna do orbital decay, that's the one they look at and they even in the past cycle they did this excellent study where they did a Monte Carlo hey? It it was generated it was for the Hubble. 00:46:37.000 --> 00:46:44.000 The big question back then was whether Hubble would need a boost just to get over solar Cycle 24. 00:46:44.000 --> 00:46:48.000 Would it dework in during slower cycle? 24. 00:46:48.000 --> 00:46:52.000 And they did quite a substantial study, and my! 00:46:52.000 --> 00:46:59.000 It was nice to see that the error bars and things that we gave them seem to work pretty well. 00:46:59.000 --> 00:47:03.000 Nariaaki's got a question. 00:47:03.000 --> 00:47:09.000 Is there solar cycle dependence of the strength of heliospheric, eg. 00:47:09.000 --> 00:47:15.000 One au magnetic field. How systematically has this been studied! 00:47:15.000 --> 00:47:24.000 So I would defer that to life I I would encourage you to talk with life. He's the one that's really big on. 00:47:24.000 --> 00:47:34.000 Relating Aa in the season, a variety of other magnetic indices to the magnetic field. 00:47:34.000 --> 00:47:38.000 No, I I would encourage them to do that. 00:47:38.000 --> 00:47:39.000 That discussion outside of outside of this. 00:47:39.000 --> 00:47:41.000 You want to see the floor to life, and there's like on a respond, okay? 00:47:41.000 --> 00:47:42.000 But that's I think life is thought about that a lot. 00:47:42.000 --> 00:47:52.000 Maryaki, and and I, would I I you should talk privately with him. 00:47:52.000 --> 00:47:55.000 Okay. 00:47:55.000 --> 00:47:58.000 I see. Shay. Yes, he's online, I see. 00:47:58.000 --> 00:48:11.000 Shay asked about. Yes, the science versus operational and Ken and I are trying to be scientific, but in reality we've gotten paid for, it, or he's gotten paid for it. 00:48:11.000 --> 00:48:13.000 For making an operating. 00:48:13.000 --> 00:48:35.000 So I have to say that I'm very happy. When I was a post, Doc, at what was then Space Environment lab in the early nineties. 00:48:35.000 --> 00:48:36.000 Right. 00:48:36.000 --> 00:48:39.000 All of the solar cycle predictions and analysis they were doing was based on frequency, analysis, and numerology, recurrence and throwing, checking bones on the floor and reading them. And it's great. 00:48:39.000 --> 00:48:47.000 To see that there's actually some physical processes behind a lot of the predictions. 00:48:47.000 --> 00:48:48.000 Now and whether they're right or wrong, that doesn't make a difference. 00:48:48.000 --> 00:48:57.000 It means that we're doing real science. 00:48:57.000 --> 00:49:00.000 Well, what are the tests that I use? 00:49:00.000 --> 00:49:04.000 And I once again, I have not really done the analysis of so like the 25. 00:49:04.000 --> 00:49:07.000 But it's almost like a 24. 00:49:07.000 --> 00:49:23.000 I would go back and find somebody who did an analysis for 23 and 24, and then I would look at their correlation fit that they derived, and whether they got the same numbers in their correlation fit, hey! 00:49:23.000 --> 00:49:41.000 And by and large they commonly did not, so they would have this variable and that variable, or, you know, some variable in the amplitude of the cycles, and they would derive a correlation fit, and then they would use that as the predictor the correlation, fit and if you went back and 00:49:41.000 --> 00:50:00.000 left at their previous solar cycle. So they've added 1 point to their fit, and the numbers would change outside the airports, which means that there the correlation fit that they're driving does not have a physical reason for existing. 00:50:00.000 --> 00:50:06.000 It's nice. It's sampling the noise of the problem to give a solution. 00:50:06.000 --> 00:50:21.000 But the next time they do it, you know, the slope changes, and the one nice thing about the soda index is we've not changed the numbers in the soda index since I derived them in 93 so we've done 2 more cycles. 00:50:21.000 --> 00:50:29.000 Since then, and I have tried to update the numbers and the it's not any better. 00:50:29.000 --> 00:50:38.000 The power. The 4 year power and 11 cycles does not decrease substantially by another side. 00:50:38.000 --> 00:50:45.000 So that gives me some confidence that something's happening that is not just noise based. 00:50:45.000 --> 00:50:48.000 And when we do the analysis. 00:50:48.000 --> 00:50:58.000 Are there any other questions from anybody in the audience? 00:50:58.000 --> 00:51:04.000 Not see any raised hands or anything more. Oh, still, sir, says yes. 00:51:04.000 --> 00:51:07.000 You wanna unmute and ask a question or? 00:51:07.000 --> 00:51:28.000 Oops! 00:51:28.000 --> 00:51:29.000 Right. 00:51:29.000 --> 00:51:35.000 I can't type fast enough. I noticed that your plot, the that had the nice solid colors that you can see the doubles double site, double peak cycles sort of out in that, and every other one is double peaked in that plot, and 00:51:35.000 --> 00:51:45.000 this one isn't, and I'm wondering if you think it's it's actually a valuable thing to notice. 00:51:45.000 --> 00:51:48.000 So that's really a second order effect. 00:51:48.000 --> 00:51:56.000 Because that's probably the song behaving with some difference from one hemisphere to another. 00:51:56.000 --> 00:52:08.000 It's not precisely that both hemispheres are changing, but the 2, the double peak, seem to have one that has more northern spots in the other, with more southern spots. 00:52:08.000 --> 00:52:09.000 But it's clearly 00:52:09.000 --> 00:52:27.000 So we were assuming the sun is is as a whole, not too hands. So we don't predict that we can only get a smooth average with single peak for the amplitude in prediction. 00:52:27.000 --> 00:52:28.000 I don't work. 00:52:28.000 --> 00:52:34.000 If you see a double peak, that's the actual data. That is not one of our predictions. 00:52:34.000 --> 00:52:44.000 Have the sunspots from this cycle so far been predominantly from one hemisphere. 00:52:44.000 --> 00:52:49.000 Actually, I was looking at A and my computer turned off. 00:52:49.000 --> 00:52:53.000 I was looking at some data earlier today. And I to be ready for that question. 00:52:53.000 --> 00:52:57.000 But the beautiful plot that I had is on a computer that has shut off. 00:52:57.000 --> 00:52:58.000 Okay. 00:52:58.000 --> 00:53:01.000 And so I would have to turn it, get it working again. 00:53:01.000 --> 00:53:02.000 But a group called the Stce. 00:53:02.000 --> 00:53:20.000 There's our terrestrial center of excellence, has some really nice plots that show, and up the it looks like it's updated weekly or so that show the North and South dominance of the sun spot number. 00:53:20.000 --> 00:53:24.000 So I can refer you to that cause. That's what I was gonna talk about, anyway. 00:53:24.000 --> 00:53:27.000 Okay. 00:53:27.000 --> 00:53:39.000 If there are no other questions, and because we are 1 min from the supposed to end time of this, why don't we thank Dean again? 00:53:39.000 --> 00:53:43.000 You can unmute and clap, or do the clap. 00:53:43.000 --> 00:53:45.000 Icon. 00:53:45.000 --> 00:53:54.000 And the reminder that the next seminar is May tenth. 00:53:54.000 --> 00:54:01.000 Penis. We'll talk about her work comparing Aia with solar orbiter measurements. 00:54:01.000 --> 00:54:07.000 It's actually quite nice. I saw some of it when I was out in Palo Alto. 00:54:07.000 --> 00:54:12.000 Well, it should be an interesting talk. 00:54:12.000 --> 00:54:13.000 Thanks for having me. 00:54:13.000 --> 00:54:17.000 Thank you, Dean.