SciTech Now Episode 516

In this episode of SciTech Now, studying the complex interactions between the air and the sea; the electric vehicle charger; and saving the American Chestnut.



Coming up... creating hurricanes with the flip of a switch...

With a little bit of time, a couple minutes, and some diesel fuel, we can generate a real wind speed of well over 200 miles an hour.

...the electric vehicle charger...

We expect there's going to be 2 1/2 million EVs on American roads in the next 3 years.

...saving the American chestnut.

This one gene from wheat allows the American chestnut to tolerate infections by the blight fungus.

It's all ahead.

Funding for this program is made possible by...


I'm Hari Sreenivasan.

Welcome to our weekly program, bringing you the latest breakthroughs in science, technology, and innovation.

Let's get started.

The powerful storm surge created by hurricanes often causes destruction.

In an effort to improve intensity forecasting, ocean science professor Brian Haus of the University of Miami Rosenstiel School of Marine and Atmospheric Science is studying the complex interactions between the air and the surface of the sea in extreme conditions.


At the surface in a Category 5 hurricane, there's so much bubbles in the water, and the spray that's in the air is so overwhelming and coming at such high velocities that it's just even difficult to tell where the surface is.

♪♪ And we can turn this on with the flip of a switch and a large diesel generator.

♪♪ As a Miamian, as somebody who lives here in this hurricane-prone place at the tip of a peninsula, there's a real visceral desire to get better forecasts, to get the information we need to keep all of us safe here in hurricane season.

I'm Brian Haus.

I study air-sea interaction and ocean waves in extreme hurricane conditions.

We're in the SUSTAIN Laboratory on the University of Miami's Rosenstiel School of Marine and Atmospheric Sciences.

The mission of the SUSTAIN Lab is to save lives by improving hurricane forecasting, particularly the intensity forecasting.

This is a unique facility in the world for doing wind-wave studies.

With a little bit of time, couple minutes, and some diesel fuel, we can generate a real wind speed of well over 200 miles an hour, the conditions equivalent to the most intense hurricanes that have ever been observed.

We can create a hurricane when we want it.

We can make it in the range of intensities we need to understand processes, and we can isolate key processes.

You can't isolate processes enough in the field to really understand the breaking waves, the dynamics, the spray, all of the stuff that happens in the real ocean.

The hurricanes get their heat from the ocean, the energy that powers them.

What's creating the spin of the storm, powering the storm, is the heat coming off the ocean, and that ocean surface has friction that it exerts on the storm.

So that's like pushing your hand across a glass tabletop versus pushing it across a rug versus pushing it across sandpaper.

That quantification of how hard it is to push, that's the drag coefficient.

To show the uncertainty, we're showing 1 mile of...

All of the forecast models are using a drag coefficient, and it used to be thought that it just increased with wind speed linearly, just kept going up.

But what we showed was that the drag coefficient, in fact, started to level off.

It didn't keep going up.

Now, the problem with that was what we had knew about the drag coefficient, that it wouldn't be possible to get a Category 5 storm.

What gives here?

Why is it that we know there's Category 5 storms, but the maximum potential intensity, based on what we know about the drag coefficient, wouldn't allow that?

That drag depends on the waves, the spray, all these sorts of things, and in ways that we don't fully understand.

So now we need to understand, 'Okay, how important is sea spray to this whole transfer process?'

And then that allows for the storm to go from a Category 3 to a Category 5 rapidly.

♪♪ When you're looking at the waves, your eye is drawn to the big huge waveforms.

And, really, a lot of the friction, a lot of the spray, a lot of stuff that's happening happens at centimeter scales.

Breaking down what happens at those small scales is critical for understanding how you integrate that over the whole ocean surface.

In the SUSTAIN Lab, we are using a lot of optical techniques to capture the quantity of spray.

We have what's called ultrasonic anemometers.

To measure the real fine-scale structure of the waves, we're using a technique called polarimetry, which is an optical technique.

That allows us to measure for every frame of the camera, for every pixel, what the local slope is, which is really powerful because optical techniques are great, but if you can imagine taking a picture of the ocean from a plane or something like that, you can't tell how big those waves are from that optical image.

Using this technique, we can actually get information on the shape of the surface and quantify what's going on.

If we are able to publish some, you know, good results on what the drag coefficient is up to a Category 5 hurricane, which we're going to be working on, people will start running tests with that new formulation immediately.

There's some things in science that we do that may take a decade to get through into what you're doing.

This is not one of them.

If you can show that with this new formulations that you get a better intensity forecast, that's going to be used by the next season.

Joining me now is 'Science Friday' video producer Luke Groskin.

You know, before we talk about building a hurricane in a box, define just what is a hurricane?

We all know the devastation that they cause, but what's happening weather-wise?

Well, obviously it's a storm.

It's a cyclonic, a spinning, storm that feeds off the heat of the ocean.

It's usually a low-pressure system usually.

I mean, we think of hurricanes in the Atlantic.

I think they're called cyclones in the Pacific.

They spin the opposite direction, and so the hurricanes, they start forming off the coast of Africa, and they start churning up all this heat, pulling up all this heat from the Equator, from the ocean along the Equator, and they build up speed, and they come colliding with, usually, the United States coast.


So how do you re-create something like that in a laboratory?

Well, you can create all the environmental conditions that are going on in the laboratory, so, I mean, you're not creating the overwhelming devastation, obviously.


But you are creating the wind speed.

You are creating the storm surge.

You are creating the heat.

You are creating the droplets that you would experience on the surface of the ocean during that storm, and all of that provides an enormous amount of information that you can't get from an actual hurricane.

You can't put a buoy out there and get the level of granular detail that these guys are getting in the lab at the University of Miami.

So tell me about those details.

I mean, what are they able to measure while they have turned on kind of the perfect hurricane?

They've got the warm water.


They've got the wind speed.

So the big things that they're looking for are, they're looking for the interaction between the actual ocean waves and the air above it.

So in a Category 5 hurricane, you really can't tell the difference between where the ocean stops and the air above it begins.

There is so much spray.

There is so much water getting whipped up off those waves, and you can see it in the video.

It's just... It's this really amazing, intense visual, and so much water droplets are getting lifted up.

Now, if you watch those things in slow motion, you can get a sense of how much water is actually being lifted up, how small those droplets are, how much energy is coming up with those droplets, and all of that informs how much energy is going to be lifted up into the air and then become part of this large storm system.

How do you get wind speeds that high in a controlled environment?

An enormous diesel generation and in a really, really tight funnel.

So it starts as, you know, this 25-foot... it looks like it's 25-by-25-foot set of fans, and that... All those fans are blowing towards this one tunnel, and they get consolidated.

All the air gets consolidated into one tube faster and faster.


Everything gets squeezed into this tight tub and then projected over this very narrow space, this box, and that allows you to create 200-mile-per-hour wind speeds.

What kind of discoveries have they made already, and what's the breakthrough that they're still looking for?

Well, the big thing that they're looking for, the big thing that's going to change people's lives, hopefully save people's lives, is this notion of the drag coefficient.

So the drag coefficient, you can think about it this way, is that if I rub my hand across the surface of this table, it's nice and smooth, and, you know, scientists and meteorologists thought that when you did that with a hurricane, when you run those winds of the hurricane over the surface of the ocean, you would have so much spray, it should be so smooth.


So their research has shown that after a certain point, you know, wind the wind speeds get built up, you don't get more drag out of it, so it levels off.

The drag coefficient levels off.

Now, if that's the case, Category 5 hurricanes shouldn't exist.

They shouldn't.

They just shouldn't exist.

There should be so much drag that the wind speeds shouldn't be able to get up to that level.


That's not the case, so they want to look on a very granular level.

What is going on here on the surface of the ocean with all this spray that allows a hurricane to get so fast so quick?

You know, I'm thinking recently of Hurricane Matthew and how when it made that turn up into the Gulf, it suddenly just... It went from, I think, like, a Category 1 or 2 to a Category 4 or 5, and it was almost overnight.

And what they want to do is, that drag coefficient and understanding it will get fed into the models that meteorologists use across the United States.

This kind of information feeds to meteorologists, and the meteorologists are able to predict better the type of intensity of the storm and obviously where it goes and so forth, and that way they can help people prepare to get out of the way faster.

Exactly, exactly.

You know, when you see those plots on the map where it's like, 'Oh, it could go this way.

It could go that way.

It could go this way,' usually meteorologists have a clear sense of, like, you know, exactly the rough region where it's going to hit.


What they don't know oftentimes is how hard it's going to hit and how much rain it's going to dump and, you know, how fast the wind speeds are going to be.

That's the level... That's where this sort of information, this lab, can really make a huge difference.

Nobody has had the ability to create a 200-mile-per-hour wind and see what that actually does to the surface of the ocean.

Like I said, you can't actually put monitoring equipment in the ocean while the hurricane is there or... you know, it's kind of like, you know, the movie 'Twister' where you try to, you know, put a buoy or... they put the thing in front of the twister, and then it goes up and it creates... They get all this data.

You can't really do that in a hurricane.

You have people that are flying over it, but you can't really tell what's going on right at the surface, and that's the amazing thing about this hurricane in a box that they've built, is that they can really look at the granular details there, and that has an enormous effect on the forecast model.

So when wind goes over water at 200 miles an hour, is it still water?

I mean, is it just spray?

Is it something that, like a mist?

Yeah, they call it spray.

They call it spray, and it's actually kind of terrifying.

It's this extremely violent surface, and, to me, it was kind of fascinating that they're, you know, they're using these 10,000-frame-per-second cameras to look at, on the centimeter scale, what that spray looks like, and you look at it, and it just looks kind of violent, but they're able to actually quantify it.

Anything coming at you at 200 miles an hour was going to hurt you, even if it's water.




If you're in some of these incredible winds, you're going to get hurt...


...just by standing in the water alone.


I mean, the number one question that they get is from people, especially very silly meteorological reporters is, 'Can I go in there during the...Can I actually step inside this box?'

Once you see this thing on, you're like, 'No. That's nuts.'

You would not want to be inside this thing.

It looks painful.

It looks dangerous.

I don't envy those people that end up going out in hurricanes.


Maybe that'll help convince some of these meteorologists not to do that.

All right, Luke Groskin, thanks so much for joining us.

Thank you.

With growing consumer interest and adoption of electric vehicles comes the need for charging stations.

Joining me now to discuss this growing need and industry is Cathy Zoi, CEO of EVgo.

Thanks for joining us.

So tell me, how big is this market going to get?

Huge, huge, huge, huge.

We expect there's going to be 2 1/2 million EVs on American roads in the next 3 years.

Okay, and that... Right now it is still the land of nerds, tree huggers, technologists that are really interested in it, but, I mean, are we talking about a wholesale change in the industry?

Because even if you have a couple of million cars, that's nothing compared to all the gas vehicles that are out there today.

Well, it's growing really rapidly.

I will tell you that since between September and June, the EV sales doubled.

I mean, it is really like a rocket ship growing.

Give me an idea of the scale of EV charging stations compared to gas stations today.

I mean, you've got a lot of catching up to do.

Oh, we sure do.

I mean, what we're trying to do is what Wayne Gretzky said -- We're trying to skate ahead of the puck.

So the cars are ramping, and we are... You know, EVgo, now, we've got more than 1,000 fast chargers out there.

We've got more fast-charging stations in the country than anybody else, but we're just beginning.

Right now, most of the EVs are being driven around in California with some in Northeastern states and few there round and about, but that's going to happen nationally.

So we're doing a national build-out to meet that demand.

Another thing you asked about was is it just tree huggers that are buying these cars?

And, you know, I could say... I would call them early adopters.


And for the most part, in the past few years, those early adopters bought an EV and had the comfort that they could charge at home.

Maybe they had a garage, but the whole -- as this product, as EV is becoming -- Those are people that live in apartments.

Those are people that don't have garages.

Those are ride-share drivers that are driving EVs.

So for us, EVgo, we're there ready to provide convenient, reliable, affordable charging away from home that's fast.

How fast is fast, right, and how is the technology improving?

What is a fast charge today would have been unthinkable 5 years ago?

When people charge at home, it normally takes overnight to charge your car, and that's what they call level two.

A DC fast charge takes somewhere around 30 to 45 minutes to get your car up to the proverbial full tank.

At the moment, the speed of fast charging is limited not by the charger but by the speed that the battery in the car can take.

Right now, one of the things that people are familiar with is it's about a, I don't know, 30, 45-second, maybe a 2-minute long job to pump your car full of gas.

Are we ever going to get to that point, where we can put in enough juice into a car to get you 100 or 200 miles in a very, very short amount of time?

Well, look.

The technology is changing really quickly.

What we have right now -- I mean, EVgo has a charger that is capable of 350 kilowatts, but there's only one car out there that can charge that fast, and so it will charge really quickly.

The practical engineering of it is, if you think about the cabling needs to be bigger.

It ends up being heavier, and it ends up being hotter.

So what you have to do when you go to these super fast chargers, you have to liquid cool the cables.

So all of those things are technologically handleable, but there's going to be a point at which you think, 'Well, isn't this fast enough?

Is 15 minutes fast enough?

Is 10 minutes fast enough?'

I mean, what we like to say to our customers is, 'Look, It takes you 1 minute to plug in, and then you have 29 minutes to go to something fun.

Go do your grocery shopping.'

I mean, we site our chargers at grocery stores and at shopping centers and near convenient things that people want to go spend some time on.

How about battery technology itself?

I mean, right now it seems that the capacity of vehicles and how far they can go on a charge is still using battery technology that hasn't advanced that much.

What's coming around the corner to -- What are the breakthroughs that you're seeing?

Well, I would argue that the battery technology has advanced.

I mean, I was...You know, in a previous incarnation, I was at the Department of Energy, and when I went to the Department of Energy in 2009, the cost of a car battery was about $1,200 a kilowatt hour.

It's now down to $100.

The energy density is much improved.

It's still lithium-ion, but they're basically changing little bits of chemistry in the lithium-ion, so it's dramatically improved.

Now, is it going to be exactly the same next year and the year after?

Probably not.

I mean, you know, my friends in Silicon Valley and in Cambridge and in Detroit are working on new battery chemistries all the time, so I think we're going to continue to see improvements that are really, really exciting.

Is there interoperability, meaning regardless of the type of car that I buy, if I go to your charger versus an automobile manufacturer's charger, am I going to be able to get that same amount of energy into my vehicle so I can keep driving?

You bet.

You bet.

I mean, we... EVgo chargers charge any car, so we charge the Nissan Leaf, the BMWs.

With an adapter, we charge the Teslas, so for us, it's all about a reliable, convenient customer experience.

All right.

Cathy Zoi, CEO of EVgo, thanks so much for joining us.

Thank you, Hari.


Chestnut trees are in danger due to an exotic fungus that entered this country more than 100 years ago.

With four billion trees being wiped out from this invasive fungus, researchers are now using technology to keep this tree species alive.

Check it out.

I'm Bill Powell.

I'm Andy Newhouse.

Both: And we're here to save the American chestnut.

[ Laughs ]

Well, the American chestnut, first of all, you need to know, is one of the most common trees in the eastern forests.

In some places, it was one out of every four trees, and it was also one of the largest trees, and it was very important to wildlife.

We used to say that it fed everything from bees to bears and everything in between.

We lost the American chestnut because of an exotic pathogen that was introduced in this country a little over 100 years ago, and that pathogen is a fungus, came over on the Asian chestnut trees that people were importing at the time, and it jumped off the Asian chestnuts onto the American chestnut.

American chestnut had never been exposed to this fungus and was highly susceptible to this disease, chestnut blight, and within about 50 years, wiped out up to four billion of the largest trees in our forests.

Wow, and four billion was bow many of the total number of American chestnut trees?

So it basically infected all the American chestnuts within its range, and today it hasn't gone extinct yet, and that's only because the chestnut can survive at the roots.

Basically, it has the ability to resprout at the root collar, and it's interesting.

The fungus cannot kill the roots because the soil microorganisms protect the roots from the fungus itself.

And therefore, the tree resprouts.

It grows for awhile, gets infected, gets killed back down to the ground, so it's in a kind of a Sisyphus-like cycle.

Eventually, the roots will run out of energy, and the whole tree will die, but we still have millions of stump sprouts out there that we can use for restoration.

So, Andy, thanks for having us in to the lab here.

Tell us where we are and what goes on here.


We're in the greenhouse at SUNY ESF here in Syracuse, and the noise is ventilation system, keep the temperature stable both winter and summer, keep ideal growing conditions for our chestnut trees.

Many of these are actually second-generation trees already, so we've taken the pollen from the first trees we produced in the lab and crossed that with wild-type nontransgenic trees in some of our field plots, and then the offspring from those crosses, some of those inherit the trans gene, and those that do, we're growing up in here.

What are you trying to do, generally speaking, to try to combat this?

How do you fight the blight?

Okay, so we've taken kind of a unique path.

Actually, back in 1990, the American Chestnut Foundation New York chapter came to us asking, 'Is there another way to produce a blight-resistant tree other than crossing it with the Asian species?'

And we said, 'Well, there's this new technique called genetic engineering.'

And so we partnered with them and started this process of trying to find a gene, just a single gene, that would actually confer blight resistance to the tree, and we've actually found that.

The gene that we've used is from wheat, just like bread wheat that we eat, and so it's familiar.

People eat it already.

It's already in the environment.

It's present in a lot of native species also, but this one gene from wheat allows the American chestnut to tolerate infections by the blight fungus.

The way the fungus attacks a tree is that it makes an acid, and this acid actually kills the tree cells, and when it does that, it forms what's called a canker on the tree, and that canker eventually grows around the stem, girdling that stem, and choking off everything above.

So the idea here is there something that can stop that acid.

And I actually came across an abstract from a meeting where someone was putting a gene into another plant, a tomato, and this gene happened to encode an enzyme called oxalate oxidase, kind of a weird name.

But this enzyme, what it would actually do, is break down oxalic acid.

This is the acid the fungus uses to attack the tree.

So, hey, right here, eureka!

This is how we can stop the fungus from attacking the tree.

We take its weapon away by detoxifying that acid.


Why is the American chestnut important?

Why should we care about this one?

Who cares if it disappears?

Right, so it's important for many different reasons.

One is for the ecosystem.

It had a very consistent mass crop or nut crop, but it's not just the nuts.

It's also the leaves.

The leaves were used by insects, terrestrial as well as aquatic, which then fed fish and other organisms, but also there's benefits to humans, such as the wood itself is very valuable.

It's rot-resistant.

It's very straight-grained, easy to work.

People would use it for mainly outdoor purposes.

The nuts we could eat also.

'Chestnuts Roasting on an Open Fire,' you've probably heard that song around Christmastime.

And you could actually grind the nuts into a flour and use it for baking.

You can use it for brewing, to make beer.

So all different kinds of uses for the nuts themselves.

Basically, we're trying to figure out, 'How can we produce enough trees that once we have approval, we have a lot to give out to the public and start restoration programs?'

And that's why we partnered with the American Chestnut Foundation, which is a public organization.

It's a NGO.

And so we're going to be working with them to try to get people to plant mother trees so that we can outcross those.

We're going to actually be a big distributor of pollen for people in the beginning, and then they can plant those trees, keep outcrossing, and eventually increase more and more of the trees in the forest.

Should people be worried about the idea that you are messing with Mother Nature?

You know, Mother Nature didn't create the American chestnut with this gene.

Who are you to add it?

Well, I would say that we, as humans, have been messing with Mother Nature since we've domesticated plants.

And, really, this is kind of an extension of classical breeding.

And the wheat that we eat, and just about all the foods that we eat are not recognizable compared to their original nonmodified forms.

So this is another technology to do the same thing, to improve our foods or plants.

The chestnut blight was brought over here by humans.

It was our problem.

So I think we have the responsibility to fix that problem, and we've tried to do it for the past hundred years.

We couldn't until we had this new technology, biotechnology, that actually has allowed us to do that.

So we should use that tool to bring back this tree.

And that wraps it up for this time.

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Until then, I'm Hari Sreenivasan.

Thanks for watching.

Funding for this program is made possible by... ♪♪ ♪♪ ♪♪ ♪♪ ♪♪