Skip to main content

tv   Hurricanes and Tornadoes  CSPAN  August 22, 2017 2:43pm-3:50pm EDT

2:43 pm
those areas. those are the ways you have to keep your mind active, especially somebody like myself where i have to go from appropriations to issues, and then when he get on the airplane to fly from laredo to houston, from houston to washington, a lot of time on the plane, this is when you use some of those apps to make sure you keep your mind active, but you are constantly learning at the same time. know whattv" wants to you're reading. send us your summer reading list via twitter, instagram, are posted to our facebook page. c-span2," on television for serious readers. >> next, a discussion on climate change and the effect on hurricanes. author and geographer james
2:44 pm
elsner says increasing ocean warmth is making hurricanes stronger and that tornadoes are becoming stronger and more frequent. from florida state university, this is just over an hour. >> hello, thanks a lot. actually, i only wear one hat, also. i really think of myself as a scientist. really, that is all i do. but if you do science for a long enough time, they put you in positions like being the chair of a department. so it is not something that you seek out, but it is something that happens because you do a lot of science. so i like to think of myself as a person who just focuses on one thing. actually, two things, hurricanes and tornadoes. i focus on two things, but they are connected in that they are these violent windstorms that cause lots of damage and
2:45 pm
casualties. so we have to think about what might happen in the future. what i do, and this is this idea of just wearing one hat, i spend all of my time thinking about what hurricanes and what tornadoes might be like in the future. so you are going to see a lot of science today in the sense that you are going to see a lot of graphs. ok, we use a lot of graphs the cause that is the way we make comparisons. science is about comparing this with that. this is not a science class. i am not going to apologize, because i think that is the window of understanding science. but i want you to know that these are my graphs. these are not graphs i got off the internet. is is not someone else's argument about what has happened, and there are a lot of arguments and a lot of opinions. what you will hear today from me
2:46 pm
is what i do and what i think about on a daily basis. i would like to thank felicia for inviting me to do this. i got a chance to tour the facility with doreen this afternoon to wonderful facility. this is really an outstanding facility that i think you should be very proud of. and folks associated with fsu should know more about this fsu coastal and marine lab. a large part of the reason for that is because of what has been done over the last decade. i chair the department of geography, not a very big department. we have about 10, 12 faculty, depending on how you count. but it is very dynamic, and it is increasingly associated with what folks do down here at the lab. hurricane center native -- i will start out with hurricanes.
2:47 pm
if you kind of drift off on this part, and you might, when i get to tornadoes, you know i am about halfway done. we are going to talk about hurricanes to start out. you are obviously familiar with hurricanes in a generic sense. we can track them and look at them from space, and they are these powerful things. so we know it hurricanes are certainly like today. in fact, last year we had a hurricane come very close to so theyt of the world, are in our consciousness constantly. where, how often -- these are things we know about, especially if you live know the coast. but what about the future? are we in for a greater risk of these storms? unfortunately, there is no simple way to get answers to these questions. they are very important. there is just no simple way. why is that? why can't we just do some kind of calculation on the back of
2:48 pm
the envelope and work it out? well, first of all, the theory is very limited it we do not have a theory of climate. theoryone said this is a of how climate works, it is nonsense and we have parts of theories of how things work, but we do not have a general theory of how climate works. and we certainly do not know everything about what drives a hurricane to besides basic stuff, so theory is limited. models, which are good at forecasting where a hurricane might go, given that there is one out there, they do not really represent the atmosphere way,e ocean in an adequate at least on the scale of climate. finally, we do not have enough data. we do not have a way to look back in the prehistoric times. it is very difficult to look back. we just do not have enough data. and the data that we do have
2:49 pm
kind of very and quality -- kind of vary in quality. of course, social media is not going to help us out or do you will get a lot of opinions and a lot of bickering. what is the solution? how does jim elsner spend his days figuring out this problem? well, i try to put things together. i put the theory together with the models in the data. i will talk about two theories. these are the two theories that allow us to get some answers about what hurricanes might be like in the future. you probably are not physicists or statisticians, so i will not go that deep, but these are the deep structures and which we can hang our hats on to try to understand what might it be like in the future. we will start with thermodynamics.
2:50 pm
this is my thermodynamics slide from popular mechanics, which basically describes how a hurricane operates. all you have to keep in mind is a couple prepositions, ok? the first one is in. the second one is up. the third one is out. in, up, and out. that is the circulation of a hurricane, which you are probably not aware of it you think of circulation like this, these things that are spinning. that is the wind that will destroy your home, produce the surge, slide your house. but that is not the circulation that drives the hurricane. it is the in, up, and out. if you leave from here with those three prepositions, i have done my job. the in part is where the air comes in at low levels, near the ground, near the ocean's surface. up is heat and we stood. in the center of the
2:51 pm
hurricane and also the other thunderstorms surrounding the hurricane. it exhausts at higher levels. temperaturesn high and exhausts the heat at much lower temperatures. it is kind of, not even kind of, it is almost exactly opposite of your refrigerator. cold inw things day your refrigerator, you are exhausting at a high temperatures. here you are exhausting at low temperatures. this is what you call a heat engine. it is an extremely efficient heat engine. these describe a hurricane that has a heat engine, a way of converting the heat and moisture of that motion into the winds that you feel circulating. in, up, and out. and it is a theory, based on thermodynamics that was worked out in the 18th century,
2:52 pm
and it is called the carnot heat engine. with that heat engine theory, with that theory, we can work out how strong a hurricane can get. i will use this mpi to abbreviate how strong can those winds actually rotate, right? 60 miles per hour, 80 miles per hour, 100, 100 50 -- that is what i will call maximum potential intensity, the speed. that is just related to how warm the ocean is. that is an abbreviation we use for how warm that ocean is. the warmer the ocean, the hider -- hired the intensity of the storm. they are proportional. more motion, more energy. this is a basic theory. this was worked out by a good friend of mine at m.i.t. he worked out this theory of how hurricanes and tens of i and how
2:53 pm
they get strong and their maximum potential, when energy is derived directly from how warm the water is to it so if you go summing in the ocean tomorrow and you feel that heat, that is that heat, because of this carnot engine theory, that drives the hurricanes. you think, that is kind of symbol, you can figure out how warm it will be and we can figure out intensity storms will be. if you are thinking ahead, you are thinking, why is this so complicated? warmer oceans, more energy. first, you have this thing done here, the denominator. that is the upper level. so the colder it is, so that his downstairs, colder it is, also the stronger the storm can be. aloft, strong storm. colder aloft, you can get a very strong hurricane. you can get arctic hurricanes. if this is cold enough, even if this is not that warm.
2:54 pm
you say, ok, he has everything there, why does he need -- he has his theory here, his friend can work this out. but here is the problem right here. fluxes --ary layer the thing here is that the hurricanes start to makes up the ocean and produce all kinds of sea spray, so there's a lot of complexity going on. it is not clear how much this is going to go up given this. we know the oceans are warming up. they are warming up, primarily due to greenhouse gases. they are warming up, you should get stronger storms. how much longer? who knows, because of this be it we cannot work it out because of these boundary layer fluxes. ok, so that is one theory. bring in the second theory.
2:55 pm
the first one again to review. in, up, and out, the theory of how storms intensify through the heat engine. your car has an engine, and it works as a similar idea, not nearly as efficient as a hurricane. the other theory is from statistics. this might even be farther from your experience. let me see if i can humor you a little bit. it was worked out in the mid-20th century, about 1955. for example, we record the highest wind speed in 10 consecutive hurricanes. so there is a hurricane out there now, let's say, and after two days it is gone, but we know how strong it got. let's say it got to 34.5 meters per second. why am i using meters per second? because i am a scientist.
2:56 pm
i apologize for that, but that is what we use. if you need to convert, you just double that. that is miles per hour, so about 60 miles per hour. your how fast you go in car, 70 miles per hour. this was the first hurricane, how strong it got. the next one, let's say, hit puerto rico and then died some and it had a maximum intensity of 44.2. you can imagine doing this for each hurricane. simply tell me how strong it got. i am going to put all those strengths down here. some get stronger than others. so this is the set of 10 wind speeds for the last 10 hurricanes. we can order these. this is how they occurred in time. this is more interesting from a statistical point of view. this was the weakest. this was the strongest.
2:57 pm
this tells us that 20% of the hurricanes of these last 10 have winds that exceeded 61 meters per second. these two in red exceeded that amount of wind speed. 10% exceeded this amount. so we have percentages and threshold wind speeds. those two things make statisticians drool because they can connect the dots through this extreme value theory. so we can work up the spirit ago highest -- so we can work up these theoretical highest wind speeds. this gives a limiting intensity from the data. so from the theory from dynamics, you can work of the intensity, andal from statistics, you can work out the limited intensity.
2:58 pm
ok, so we have this limiting intensity as indicated by this red line. ok, overur hurricanes, the last set of years, and we can look at how strong the got. this is how fast they were rotating in meters per second. and we can plot them and fit a curve through their. -- a curve through there. the black dots represent that curve. they start to flatten out. level here for this set of storms is right at 75 meters per second. that is what i mean by limiting intensity. that is a brilliant statistical theory. it tells us about the maximum you can get given the set of values you have. think about that, folks. think about it. people are in
2:59 pm
this room right now, and if i measured the height of every one of you and then ranked them from shortest to tallest, i would have a single tall person in this room, but i would not say that that is the tallest person that could ever be in this room, right? but i want to know that. i want to know what would be the tallest, so i would have another lecture next week and would get another 25 people, a different group of people, and i would get another tall person. now i have two tell people. that is what i do here. i'm getting all the set of tall people and then fitting a curve through that, and i can then extrapolate to get the possible tallest person. wonderful theory. it is embedded in the mathematics of statistics. so i got to about things going on here. this limiting intensity, a statistical quantity that we can use to compare with emmanuel's theory of maximal -- maximum potential intensity. hopefully you are still with me.
3:00 pm
i have this maximum digital intensity from theory. statistical limited intensity from statistics. how should we make that comparison? it turns out that the limiting intensity is the absolute limit, that is that the tallest person is not that important, it is how limiting intensity changes with the ocean temperature. that is the key component here. how do we get at this? it turns out hurricanes, of course, occur over oceans where the temperatures are not uniform. so maybe if you pay attention to hurricanes, you will recognize this season. this is a plot of all the hurricanes in one season. i did not label which season it was. as a professor, i want to test my students. what season is this, if you remember? it was a pretty active season. >> [inaudible] >> close, very close to 2005.
3:01 pm
2004 is an excellent guess. they look very similar. had lots of hurricanes and got hit a couple times here in florida. but you notice underneath the track, each of these white lines, actually, they are a series of hourly dots of where that hurricane was, at least the center of it. underneath those tracks are the ocean temperatures. they do not all of her over the same temperature, right? so what we can do is use space -- as felicia said, i was trained as a scientist, but i really became a scientist when i became a geographer. science ismospheric an important discipline for understanding how the atmosphere works, younger fee a lousy to put pieces together. it allows you to leverage space. it allows you to think about things spatially.
3:02 pm
when you start leveraging space, you can get a lot more bang for your buck. let me show you what i mean. domain.rid up the this is our atlantic basin. we recognize florida here. this is where our hurricanes form. we can look at two hurricanes, one here and one here. ay the hurricane hours are gre until he gets into one of those hexagons, and then it turns black. i should say it is not a hurricane until it gets to black, but that is about hurricane intensity. so it is a weak storm that becomes a hurricane. i can count how many hurricanes occurred in each of the boxes, each of the hexagons. this is another key component of besides the three prepositions, which hopefully
3:03 pm
you do not forget. i want you to keep in mind the difference between the frequency of storms and the intensity of storms. this is a key idea of trying to understand what might happen in the future. i am going to count them right here. these boxes had one, these had two, the others had no hurricanes. do that for all the hurricanes that have occurred over many years. this is a 50-your plot. you can see were hurricanes are most common. in this box here, just off the north carolina coast, and then this box here. this one here,ly comes as somewhat of a surprise to you. this is where more hurricanes occur than here, more than here, more than here. more hurricanes out here and here than there are in here.
3:04 pm
2010. hurricanes number of set have occurred in these boxes over that period of time. the darker blue indicates more hurricanes, the lighter blue, fewer hurricanes. simple. i will point to two, c and d. hexagons, c and d. i can tell you how strong each hurricane was. i am getting back to the theory. each hurricane gets to have one value when he goes through that hexagon. i will take his highest value. this plot probably looks more familiar to you. this is where the storms are strong.
3:05 pm
this is where they are frequent. this is where they are strong. fewer, buts fewer, stronger. fewer, stronger. more. less. less intense. more hurricanes, not as strong. ok? that is the key to this puzzle. fewerture might be about but stronger. ok? and i know that does not sound like he is going to tell you whether my house is going to get -- i do not work at that scale. what i work at is the scale of trying to understand how the climate aspires to create hurricanes in this aggregate. so this is how i work it out. i have these two boxes, and i can say, for example, for box c, where there is fewer of them, i get a stronger limiting intensity. and for d, were there are fewer
3:06 pm
where there -- i getre but less intense, a lower limiting intensity. i am halfway done. sorry about that, only halfway done with the hurricane. i have the limiting intensities now. i have this nice special geographic -- a meteorologist would never think of this, but geographers would think about this all the time. is blank space to understand how things are happening over time. i have my limiting intensity, so i can put a limiting intensity for age of my boxes, and i also have my ocean temperatures. ah-ha. no i have what i need, the limiting intensity and ocean temperature, and together i get this beautiful plot. here are my ocean temperatures. here is how strong storms can get. and that slope represents the
3:07 pm
sensitivity, the sensitivity of hurricane intensity to ocean warms. -- to ocean warmth. that is exactly close to eight 16ers per second -- about miles per hour for every degree celsius warming or two degrees fahrenheit of warming. strongerow much hurricanes we can expect to get, just based on combining the theory with the data. that is a beautiful result, because it has never been worked out before how to get that sensitivity. it is a fundamental component of how the atmosphere works and produces. why is this important? ok, eightell,
3:08 pm
meters per second, plus our minus one. what is that important? turns out that hurricanes are getting stronger by one meters per decade. it does not sound like a lot, but we can see the strongest storms, so for every year i can group the storms by their intensity. this is the medium intensity, and that is changing much but these upper quartiles are going up and going up at about one meter per second or decade. decade. this is where it gets interesting, because the losses increase by -- here is your economic damage in billions of dollars. these indicate how much more damage we can expect for every meter per second increase in the wind speed. so this is important, folks, nextse it maps onto the aggregation of the next 20, 30,
3:09 pm
50, 100 years more of hurricanes that we will see this kind of change. forget about the fact that we're going to may be billed with stuff. -- that we will maybe build more stuff, have more stuff in the way. the is completely based on theory of how hurricanes operate, so extremely important. ok, just a real quick summary. we can understand my hurricanes might be like in the future by combining the theory with the data. out, heat, up, and engines. looks like the strongest hurricanes are stronger by about eight meters per second per degree of ocean warming. you can take that to the bank. this amounts to about one meters per second per decade, which translate to about a 5% increase in losses per decade, independent of how much we are exposing.
3:10 pm
exposing more, of course you will get more. the keeping exposure constant, that is the increase. of course, you will say, well, there are lots of other factors. you take one factor. you are right, that affects sensitivity, share, upper level, etc. if we put those in our model, and we have done this, it is not very strong. it is not really affect it here it but there could be something i am missing. as a scientist, you always reserve the right to be wrong and to be found wrong. that is part of our job. but because it is part of our job, we think about this all the time. about tornadoes. then we will stop and you can ask me questions. maybe tornadoes a somewhat mysterious to you compared to hurricanes. that as a scientist, to me, it is the same idea, this idea that the atmosphere produces these
3:11 pm
eventsisodic and extreme , whether it is the hurricane or the tornado. tornadoes are much smaller from an ominous -- much smaller phenomenon, but winds blow faster and do much more damage, on average, in hurricane -- and then hurricanes. generally, this focuses on looking at the annual counts. if you look at the number of ef one plus tornadoes, we rate the for judahs on scale -- we rate these traders on the frujita scale. about an 80 mile per hour hurricane or stronger, you do not really see any trend in the number of storms.
3:12 pm
this does not imply that the tornado climate is stationary. we find that the number of days with tornadoes provide additional information about tornadoes and their occurrence. we do not have any theory to hang our heads on with regard to what 20 does might be like in the future. -- what tornadoes might be like in the future. we do have something to go on with the data. unfortunately, we have become much better at observing when it is then in the past. if you look at the long record of tornadoes, there is generally an increase in the numbers, but that is because we probably are able to communicate what we see and there are just more people paying attention. we have a population bias. this graph clearly shows this population bias. this is distanced to nearest
3:13 pm
city center. this is the number of tornado inorts scaled by an area square kilometers. so this is within 10 square kilometers, a function of distance from a city, every city. this is every city. and you see a higher rate, tornadoes, and 1.4 per 10 square kilometers and near the city to less than one, about .8 from the city. if you want to go out and say cities cause tornadoes, you can get front-page headlines, right? but am clearly, you probably want to step and say, is that the causal mechanism? maybe i have this backwards. it is likely that this is due to the fact that there's people say that the cities are will people can report it, and efficient
3:14 pm
mechanism of getting observations into record books. so that is what we are seeing here. the what is really interesting, i did the same thing and 10-year periods, starting with 1961 to 1970, going to decades in one year at a time. ast do you see in this plot you go down? a couple things. very interesting. ok? to me, i will call this a snake plot. snakesike these snakes, that have been alerted to you. what is happening to those snake plots over time? maybe it is hard to see this bottom one. it is starting to flatten out. we do not see much of an urban effect relative to a rule affect today than we did back here. it is higher. those are the two main points of the plot. beautiful. clearly, it is not the cities
3:15 pm
that are causing the hurricanes, because this would not go flat if that was the case. i just bring this up, folks, not because i like to look at snake plots, but i do spend a lot of time making nice plots, ok, but that is how i think, the way i tried to put the pieces together. i say, well, if i did it this way, i should see that. if i do not, i am surprised. here is your number of tornadoes over time since about 1954. this is only the stronger tornadoes. it bounces around from year-to- year, sometimes as many as 900. 2011 was a big year. but there is no real trend. asre seeing more tornadoes the climate is warming up, clearly the climate has warmed,
3:16 pm
but we're not seeing more tornadoes, not seeing fewer tornadoes. but we are seeing fewer tornado days. so the same number of tornadoes but they are occurring on fewer days. this is work i did with my wife. she is sitting in the audience. she was instrumental in trying to get me to make these plots. days witheeing fewer tornadoes, and that is the key, folks. suppose i count the number of days, number of days with at least 10 tornadoes. i told you i would have lots of graphs. number of days with at least n- tornadoes, so n is four here. 1954 whereys in there were at least 10 tornadoes reported. that bounces around. as you get to the larger end, to
3:17 pm
16 and then to 32, you start to see this upward trend. what are we seeing? although the number of tornadoes in which thereys are big outbreaks is increasing. ok? it is like the atmosphere saves itself for a big day. in anthropogenic terms. that is what we are seeing it, and it is alarming. so we can do this in a slightly different way, talk about the probability of a day with at least 10 tornadoes. here, 8, 16, going up even more, and 32, going way up. just getting bigger outbreaks. what is happening? that is where my head is when i wake up in the morning.
3:18 pm
sorry. why is this happening, folks? can dohat is the -- i this slightly differently, thinking about it in terms of percent changed, different decades, but no matter which way you do it, it is not the number of events, but it is the big events. it is kind of like the hurricane problems. i said the strongest storms are getting stronger, no doubt about that. quantified it. we're not seeing more hurricanes, but the stronger ones are getting stronger. we are not seeing more tornadoes, but they are coming in bigger bunches. so there are fewer days without fewer is, -- there are days with tornadoes, but when they are coming, they are coming in bunches. there is a large-scale hypothesis that was put out. as soon as i tweeted this result, i got a lot of folks leading -- tweeting back.
3:19 pm
they were saying -- i think about this as efficiency. i actually like that way of thinking about it. i like that way of thinking about hurricanes, too. the atlas is becoming more efficient. -- the atmosphere is getting more efficient. it is about efficiency. the time and which hurricanes intensifies not going to change. that is because they have to come off ever got, move across the ocean, and the only have so much time to get strong. that is not going to change. the oceans are not getting wider, at least on the scale of humans. so they are going to have the same amount of time but getting stronger, which means they are more efficient. i like this idea of efficiency. same thing with tornadoes. we're not seeing more, but the atmosphere tends to be more efficient a jumping them from the clouds. so we call this the large-scale hypothesis.
3:20 pm
it involves large-scale dynamics, like wind shear. so my first thought based on this is the areas. we have a big day, and the area over which the 20 dozen dropping out of the sky -- they do not actually dropped out of the sky, tornadoes actually start from the ground-up. pro tip, they start from the .round-up i think waterspouts are probably different. but the tornadoes we talking about here start from the ground-up. thes like they come from cloud because the condensation comes from the cloud. that is what we see, the condensation first. but the spin starts of the ground. here and kind up of gets together and speeds up. we can have another lecture on that, but here, i am thinking
3:21 pm
maybe the atmosphere is just getting better over a larger area. let's look at a particular day, just one day in 2008, may 8. there were a number of tornadoes, but they occurred in two different regions. so i think about this is a cluster of tornadoes. this is a cluster of tornadoes. i just draw a box. so i makegrapher, these maps and draw out where the tornadoes occurred. what i think is happening, my hypothesis was that these things are getting bigger. more of them, so these areas are getting larger. example of two clusters. a tornado that represents the center of this set of tornadoes, the closest to the center. middle tornado.
3:22 pm
it is like the median or the mean, the medoid. i am going to get rid of alternators -- all tornadoes -- oops. ok. >> that is a new one. >> is it? anyway, not so important. what is important is that i was wrong about my hypothesis. ofs is the mean number clusters. we're not seeing more. that is pretty flat. although it is going up, it is not significant. the total area of clusters is flat. so i was wrong about this large-scale hypothesis. what is happening is we're getting more tornadoes. we saw that.
3:23 pm
but they are not getting bigger area to just more are occurring within a single area. look at then density. i can't say, how many tornadoes per cluster, tornadoes per 10,000 square kilometers -- i can say, how many tornadoes per cluster? it has a tremendously significant upward trend in the efficiency of tornadoes. a little disconcerting. well, why are saying, do you think -- i do not know the answer. cape -- it is not large-scale, not the shear probably, it is probably the local scale phenomenon making the clouds more efficient at producing this rotation.
3:24 pm
so it is back around to thermodynamics. what is thermodynamics? local.rmodynamics is so when you think about this increased low-level moisture because the atmosphere is warmer than it was years ago, it is more humid, therefore we can get more efficient tornadoes, as long as we have some kind of cap that keeps them from performing on more days, but it when it does pop, we get a lot of tornadoes. speculation at this moment. i do not have the answer. see me and about half a year. i have gone on for about 45 minutes, and i will say one more thing. our tornadoes getting stronger? we do not talk about the strength. we talked about numbers per area, numbers on the big days. the problem with the intensity of tornadoes is we do not really
3:25 pm
measure how fast these tornadoes a rotating. first of all, they are rotating so fast that if you had a wind instrument, it would probably be destroyed. there are lots of chasers now that try to put their cars or their instruments in the path of tornadoes, that is a very few. you are not going to get to many intercepts like that. have gotught, well, we to be able to back out the intensity of the storm from the damage field. so you can count the number of tornadoes. you can count the number of ef'' ef4's, but it does not tell you if the stronger ones are getting stronger. this is a tornado path, a damage path. moore, oklahoma, right here. this was the moore tornado from
3:26 pm
a few years ago, and the damage path is in gray. a couple things you can see. first, we can think about the area of that. how much area did that tornado cover? we can characterize the area by how long it is and how wide it is. lengthnd width -- and width are two ways to describe the path. these are the number of tornadoes by category, a lot strongak ones than sinceonly 14 ef5's 1954. here is the area in square kilometers. the big tornadoes are much longer. that makes sense.
3:27 pm
a tornado does not come out of the sky as an ef5. it is fairly small, rotating maybe 30 meters per second, and it can get up to 150 meters per second, but it takes some time. so it travels over longer distances, so the path area is much longer. i know path area. i can work out some kind of energy of that storm. this is the tornado energy over time. 1984 throughear, 2016, and you can see the approximate energy of the not only are they coming in bigger bunches, they are getting stronger. they are getting much longer and more energetic. that is really, really interesting but nobody has any answers on that yet. florida.this just for we see longer paths in florida.
3:28 pm
so you can see, i decided to do it a little bit differently. this is late to early, to today. this is the distribution of path length, how long they are. and you can see that over time they are getting longer. you can see this is moving to the right. that is the log scale, so that is a significant change. not uniformly over time, but you can see they are getting longer. these are just the florida tornadoes. of storm activity can be misleading when it comes to climate change. when people say we haven't her seen a hurricane forever, not really climate change. they say we used to see just as many as before, or we see more now, probably not.
3:29 pm
that is not it. that is not it. these are single metrics. how often and how strong are the two components of storm minas -- ess?minn and take any storm. you think about how frequently they occur and how strong they are when they occur. by analyzing them we can get this broad understanding of climatology. whether it's hurricanes or tornadoes. typhoons inicanes, the pacific, and hurricanes in the u.s. a fingerprint appears , to be fewer but stronger. this is the take-home graph to try to understand what global warming might be doing to hurricanes. ok? and maybe storms in general. we are kind of thinking about activity going on its merry way, some years active, some years in
3:30 pm
active. there's el nino events, there's all kinds of climate variation going on. and we may actually see falling occurrence of events, fewer days with tornadoes, and fewer hurricanes. but when we do get them they are strong. the separation in terms of frequency and intensity is may be what climate change is doing. maybe what climate change is and i will leave it at that. and i will open it up to questions. [applause] we will do something a little bit different. so -- [indiscernible] >> i have a question.
3:31 pm
james: yes? >> thank you about what you said about tornadoes. the -- tornado was one of the worst on record appeared do know what the -- on record. do you know what the rating on that was? james: great question. 1925. that was before modern record-keeping in the 1950's, but yes it is, it crossed several states illinois and , indiana. the ef scale was not invented then, it was invented by theodore fugita from the university of chicago in the 1970s and wasn't implemented by
3:32 pm
the national weather service until the early '80s. or maybe the late 1970's. i think what they are able to do with tornadoes like that is look at photographic evidence and say based on those photographs, the targets that were hit indicated ef-2 or ef-3 damage. i believe it is probably in the record book as an ef-5, but i'm not positive about that. that's a great question. >> the microphones are fighting with each other. [laughter] james: you guys would not believe me. >> that does not mean you cannot ask questions. james: yes? statisticalur
3:33 pm
approach very interesting, but i wonder have he really looked at the data collection on all of this information. they collect more data every year. and go back to the 1950's, communication, collection data was different in some ways compared to now. have you looked at that as a possibility? james: that is a great question. and it is a question that i think about quite a bit. because it is the, you know, it is the question that if i am wrong about the data, if i am mistaken and if i am assuming that things are this way and they are not, they are some other way, then my conclusions will come crumbling down. one of the things we do in my lab is we go out and try to survey the tornadoes. so we look at what they do in the modern time, currently.
3:34 pm
so that is one thing. the other thing, when we build models we take into account things like the ef scale that was implemented this year. statistician i can put that in my model and i can control for it. control not in a laboratory sense but in a statistical sense. so i am able to capture quite a bit of this stuff. there's all kind of stuff that could be there. but a lot of information and stuff tends to be random variations. it is not systemic. if there's anything systematic, my models will catch it. that's that's the nature of statistical models. they will catch it and leave the random variation as the residual. but i could interpret nonrandom
3:35 pm
nonrandom, i can interpret signal in the wrong way, but i try to work with folks that know a lot about the data set and i'm aware of a lot of the changes that have occurred over time but those are legitimate concerns. [inaudible] james: yeah. so people had talked with me before. the folks at the prediction center said does data have this population bias. they said, have you ever quantified the population bias? plot ig the snake quantified it. and, i can quantify it in such a is -- i can tell you when it is unlikely to have any population bias. at least population bias in the sense of gradient. i can do distance. i put the roadway network in
3:36 pm
there and i said okay, does the roadway give you better coverage. i can play the what if games with the information that i have. that's why, i think getting back to this idea about theory and -- if you have theory you can start doing things a lot stronger. if you're just playing with data , buyer are the caveats beware. go ahead. >> two quick questions. partners who are your in researching both tornadoes and hurricanes? , inthen a second to that this area one of the things that the data has been used, it just sort of shows them increasing in the area and a lot of insurance companies have left.
3:37 pm
youuc taking the data -- do see taking the data and using it like that? james: first of all, about the people that i work with. one of the guys that i lean on -- he is at the proper distance from me. we are not friends. but we are good colleagues. but you know, i pay attention to his work and he pays attention to mine. i have worked in the hurricane area with folks who have done some of the work, looking at coastal lakes and marshes and they have drilled down in coastal regions and looked for deposits and prehistoric hurricane even. you get the sand layers and sediment that shows an event like a hurricane. worked with him.
3:38 pm
i tend to be fairly isolated. tendsertise in statistics to keep me somewhat isolated. -- i work ale, i little bit with a guy named grady dixon. he tried to redefine tornado alley to include the south. the south has problems with tornadoes, the midsouth. so that is a person i have been leaning on. about the insurance, wonderful question. i have worked closely with insurance folks, not paid by them directly. my work has not been funded directly by insurance companies. but they pay a lot of attention to what i do. i think first of all with the problem with tornadoes, they tend to underestimate the risk.
3:39 pm
tornadoes are more common than people believe. in other words, if you look at an insurance policy in oklahoma you probably, i do not all about the policy, but i do know the risk is probably about, the risk of your house being hit by a tornado is about one in 1000 years. that is what they calculate. 500lieve it is one in years. it is about they are half. underestimating the risk of tornadoes in many places in the u.s. concerning the hurricane problem and the coastal rates i think the insurance companies got it wrong. i was part of that discussion. they came to us back in mid-2000 happensaid, what will with the hurricanes. 2004, 2005, in the big seasons they said to me and a group of us, what will happen? we said, basically we have seen a lot more storms in the atlantic, the atlantic is
3:40 pm
,arming up and they took it as they took that idea that the atlantic is getting warmer and transferred it to the coast. we tried to stop them and the correlation between coastal activity and atlantic activity is weaker. we have big seasons without any hurricanes and that is the piece that they missed. it was in their favor to raise the rates and they had the science to back them up. but the science on the coast is never there -- the storms are getting more frequent. losseslook at historical from texas all the way to main, the number of losses is not going up over time. a lost even, the magnitude, how much loss depends sensitively on ocean temperature. the warmer it is the more losses you get.
3:41 pm
controlling for inflation, controlling for everything that we know of. the stronger storms are produced by the warmer temperatures and that is not in doubt. it shows up. but whether we will see more loss events i don't buy it. , >> more generally, things that -- maybe we are getting fewer storms and things that interest me like drought, we are getting the same sort of predictions. while.been around for a i was wondering your theory good lead somebody in that direction? james: that is an excellent point. i think you're onto something. innow -- i want to put this
3:42 pm
or a, but it is not proper living organism, but the atmosphere does have this ecological constraints own most. if there will be fewer of them, then they need to be stronger. and it occurs with things like rain. so what is going on here, the system is being fueled and there's these counter forces that keep things in check, but when they go, they go hard. again, all i can offer is a few vague terms and maybe borrow from ecology at a certain point. but i think in thinking that way, it is to unify the science of climate change and storminess and maybe it takes biologists or ecologists to help us through the problem. but i love that idea. big and theyre
3:43 pm
come -- [indiscernible] are they going to get further apart and bigger than they have been? james: right. i have not studied that problem, but i think you could do similar diagnostics. i think the metrics -- i'd love to give another talk about that because i've actually done that. i have set up this phase space of frequency and intensity and it -- mapped that in the climate change and it is this notion of efficiency that maps onto climate change and it's exactly that. it would be fun to do it for a bunch of things like floods and drought. >> one more, because we've talked about changes in weather.
3:44 pm
seismicout - activity across the country? we have seen a change of the past 20 years. james: yeah, i don't know the answer to those questions. i do study them to the extent that they might impact the story rminess that i think about. arctice heard the term implication, this idea that it will get warmer in the arctic faster than it will and lower latitudes. , thateeds into this idea you will probably have fewer -- you see, to get a tornado you need to things, you need wind shear which is the opposite of the hurricane because the hurricane will get torn apart by windshear but thunderstorm needs
3:45 pm
to have a rotation in that rotation is those sharing win -- shearing winds. those shearing winds are caused by the jet stream. you will get a weaker jet stream so that would argue that would see fewer tornadoes but what you're seeing and you need moisture as well. the moisture is going up and the jet stream on average is getting weaker but when it does come down now you have more more moisture. in a hand waiting way you can kind of explain my results. i tried to connect them but i was shot down. but that is what i do. so that is fine. >> you said that hurricanes tend to go from the state of maine to florida. and -- has a good portion of through maine. was $500.nce in maine
3:46 pm
in florida it was $1000. -- [indiscernible] and i own property in coastal areas. no one seems to care. -- mortgage mode which my wife and i have done because we think that the insurance is terrible. i would like to know your personal opinion. [laughter] destroys new york city, which i think even a category 4 has hit maine, but this goes totally unrecorded and all of us .loridians pay huge insurance james: it is not clear if that is how the insurance companies work on it. they are highly regulated, at least primary insurers.
3:47 pm
[indiscernible] [laughter] james: they are. that is why they lobby. and they lobby at the state. it is largely at the state level. i do not have a lot of expertise , so i could easily say something stupid quickly if i go down this path. >> what about specifics on my insurance? james: i do say, you are paying 10 times more in florida then you do in the state of maine. i would say you are 10 times 3re likely to get a category hurricane in florida then you are in maine. so back of the envelope says your rates are commensurate with the relative risks. >> -- storm surge. james: but your insurance policy
3:48 pm
is wind. that is what i'm talking about. i am not talking about surge. >> that is what i'm saying. i am so confused. they break everything down now. james: those are great points but i don't have much expertise. talking about local tornadoes. -- about six miles wide stretched, parallel to the coast about 10 miles in, i personally responded to six or seven tornadoes through there. and our house then got hit. but over the years, it seems like, i am just wondering in the ocean if there was some atmospheric conditions coming together during thunderstorms
3:49 pm
getting those things going? james: that is a great question. oned have a figure, this showed the tornadoes over the last 30 years in this area, but it is not showing up. but -- night, just about three or four months ago we were watching the warning and it was heading straight to crawfordsville and they do that, they come parallel to the coast. james: you do have kind of a convergence going on here because of the shape of the coastline, so the, you know, the capeshat we call or label hell is a convergence zone -- it >> that is the area i am talking about. james:


info Stream Only

Uploaded by TV Archive on