Authors@Google: Clifford Mass


Uploaded by AtGoogleTalks on 03.09.2009

Transcript:
>> MASS: Okay. Let me get myself ready. I've never had given myself an introduction, therefore,
that's good. Okay. Well, on we get started. My name is Cliff Mass and I'm a professor
of atmospheric sciences at the University of Washington. And my specialty is weather
prediction, the weather of the Pacific Northwest. I'm getting very interested in local climate
change too. And I guess I'm here because maybe not for that reason, but because of the book,
so whatever reason I'm here, okay? I'll go from there. And it's a pleasure to be here,
you know, a company that has, well, changed the way I work. I mean, it's really--my life
has radically changed because of Google in a positive way. And I should also say that
Google had an impact on this book and, in fact, if you go and look for the book, I do
have some 3D graphics that your company helped me put together. So it's in here. So what
I'm going to do is I want to talk about--I'll talk maybe 35 minutes on Northwest weather
and climate and then I'll open up to questions and I can go live too. You can see I'm on
the web too. We may have some fun with that. So let's talk about Northwest weather and
I'll start with 101, and I do teach 101. In fact, I'm teaching 101 in this fall, so I'm
authorized to do this. And I'm only going to give you a little bit of background that
will be useful for later on. Well, the keeping up on the Northwest Weather, it's dominated
by two things: the Pacific Ocean, the Mountains, and everything else is a detail. And, you
know, the first question people want to know is, why is the weather here generally pretty
temperate and mild, okay, except for the summer, of course. And the key thing is--one key thing
is the mountains over here, okay? Here in Seattle in Western Washington, we have double
protection against the cold air and the interior of the continent. Now, you have very cold
air that hits Eastern Montana and the central part of the continent, but we have two blocks:
one is the Rockies and one is the Cascades. And the way it works is this. It's an East-West
cross section here, so it's cold here in Montana and what happens is, the coldest air is basically
held back by the mountains. Some air that does get across, it sinks down into Eastern
Washington. But when air sinks, it warms, because you're going from relatively below
pressure here to high pressure down here. And so when you have air that goes to high
pressure, it's compressed and it's warm, just like in a bicycle pipe, you know, a bicycle
pump warms up as you pump it up. And then we have another filter. We have relatively
cooler air in Eastern Washington, only the--so some mild array gets across and as it sinks,
it warm up further. So because that we have these two mountain barriers, we cannot get
the primo cold air from the interior of the continent getting here into Western Washington,
unless it's the most unusual of circumstances. The other thing is the Pacific. You know,
the Pacific Ocean--and this is the SSTs, the sea surface temperatures of the Pacific--it
really is pretty mild and we're talking about the winter, you know, temperature offshore
here maybe 50 degrees and it's just not that much different during the summer time. Weather
tends to come from the West to move to the East. We're in the mid-latitudes. The weather
moves this way. And the air moves generally that way as well. So, during the winter time,
you know, we can't get the cold air from the interior, the air is going over the Pacific,
which is relatively mild, and so we just can't get that cold. In the summer time, which we
only have high pressure out here, we have some air coming in towards us off the ocean,
and that keeps the temperatures relatively low. I'm sure, you know, it's relatively low
in the summer time. So it's the mountains and the ocean. The other thing to keep in
mind is how much mountains affect precipitation. And, you know, I don't think I'm shocking
anybody to talk about this. When air rises, it tends to cool, right, because it's expanding,
right? You come from high pressure to low pressure and when air expands, it cools. And
the amount of moisture air can hold depends on temperature. Warm air could hold more moisture
than cold air. And so when it rises, it cools and eventually, you know, it maybe able to
hold the moisture down here when it's warm, but when it's colder, eventually, it gets
to a stage where you can just barely hold the moisture to start it off with. You push
it any further, you get cloud droplets and precipitation. So rising air, just cooling
and condensation, cloud precipitation, sinking is just the opposite. You get warming and
drying. And so, you know, this is the pattern we see all over the Northwest: up with rain
and clouds, sinking, the opposite. And it's just so dramatic, it's amazing. During the
winter time, the winds set to be out of the Southwest, okay, coming off the Pacific. So
air rises on the Olympics over here, and you get this tremendous rainfall. You get 150,
sometimes 200 inches on this side of the Olympics. And as the air sinks down into Sequim in this
area--you know, this is the famous rain shadow--you may have 15, 18 inches in the area here. That's
a tremendous variability. And you have the same thing to a lesser degree on the Cascades,
enhancement on one side and much less precipitation on the other. So, you know, on one side of
the Olympics, you got a rainforest and then the other side, you have Sequim. It was actually
cacti that are natural. And, you know, I get a lot of questions at UW from out of town.
From California, the number one question is people want--they can't believe this dry.
They want to check about retiring up here. I mean, Sequim is a retiree center. You may
know about that. They have all those golf courses there. So, Sequim gets about 16 inches
a year. Los Angeles gets about the same. So you have Los Angeles rainfall in Western Washington.
It's really--I think it's pretty, pretty, it's pretty amazing. The other thing is a
lot of exaggeration going on about how about wet the Northwest is, especially the West.
And our annual rainfall is really not that unusual compared to the rest of the country.
Seattle gets 38 inches; Portland gets 37; Houston gets, you know, 47; New York gets
43; Atlanta, 50; look at that, Miami, 57. So we don't--our total precipitation, we don't
get much here in the Puget Sound [INDISTINCT]. On the other hand, if you look at the number
of days of trace precipitation, just a hundredth of an inch. There, well, okay, we're the leader
there, right? But what really gets bad is the number of cloudy days, where we average,
you know--Portland, Seattle around 230 and, you know, I mean, that's why you go to Miami,
117, right? So it's not the total rainfall that's so crazy around here, right? Exactly,
we get a lot of light rain. I mean, that's the essence of the rain here. The other thing
people don't think about is that we have what we call a Mediterranean climate. So a Mediterranean
climate is one where you get a lot of precipitation in the winter and it's dry in the summer time,
okay? And this here is the Seattle, Tacoma's precipitation, okay? And here in the middle
of summer we are dry as hell and Ohio only gets typically about 0.7 inches. In fact,
last year, we got a lot less than that, okay? And then, it peaks up in the winter time,
November, December, January, February, right? So we really have two seasons. It's really
only bad around here rain-wise for about four months of the year. And we're drier than most
of the country during the middle of the summer compared to New York. Look at New York. This
is four inches here. They get about the same amount. So, okay, so you guys are real smart,
what's the difference between us and them? What don't we have that they have?
>> Attitude. >> MASS: Attitude is one. Look, it goes beyond
attitude. What don't we have in the summer that they have in the space of the East Coast?
>> Humidity and thunderstorms. >> MASS: Humidity and thunderstorms, right?
It's thunderstorms--and those are very related. In fact--yeah, it is thunderstorms. There
it is. And, in fact, if you look at the map of thunderstorms across the country, the annual
of number of thunderstorms, I mean, it's pathetic [INDISTINCT] of the West Coast. Look at that.
That's like ten, and here's Tampa. Here's their headquarters over here. Well, they get
over a hundred. So why don't we get thunderstorms? Well, it's related to the fact we don't have
humidity in the summer. Why don't we have humidity? Why is it? Why is East Coast really
humid in the summer and it's almost never that way here?
>> Mountains. >> MASS: What? Not the mountains. It's the
ocean. Strangely enough, it's the Pacific Ocean that does that. Because our air is going
over water, okay, you think you can pick all the water that you can think of, right? The
trouble is that water is pretty cold and so the amount of water vapor air can pick up
depends on temperature. So since the water is cold, even though you're going on all the
water you want, you can't pick up that much water vapor. And so we--our air is actually
quite dry that comes in on us over here in terms of how much water vapor that is in the
air, which is one way, well, one way that expresses dew point where you have very low
dew points. So that's one--and water vapor is important to thunderstorms because that's
an important source of energy for thunderstorms, is water vapor. Because when the air rises,
the water condenses and heat is released when the water is condensed. The other thing that
thunderstorms like are a big change in temperature with height. And this is sort of like--you
know, you can think of thunderstorms like your hot cereal pot. Do you ever make hot
cereal, right? You heat it up and it starts percolating, right, it causes convecting.
Convection occurs when this big change in temperature with height in your pot. Well,
the atmosphere is the same way. Well, to get a big change in temperature with height, you
need to warm up the surface a lot, right? But the trouble here is we don't--because
the air is coming up from the Pacific, we don't warm up that much [INDISTINCT]. So for
a number of reasons, we don't get a lot of thunderstorms and so we are dry. In fact,
in Seattle in July is drier than Phoenix in July. You know, you don't think about that,
but it's true. The other fun thing about the weather around here is the local weather features,
the fact that weather can be so different in one place, you know, compared to some other
place 20 miles away. And that's one of the things that got me really into this thing,
the local weather features. Well, in fact, here, this is--what I have here in the picture
is one of the number one local weather features here in the summer time. The big forecasting
problem in the summer is the onshore push. You may here this on TV, the onshore marine
push. Well, this is a visible satellite picture. This is the highest resolution satellite picture
that we get operationally from the weather service and, you know, we're right over here.
You can see these low clouds. These are all low clouds stress coming along the coast.
What happens is we can get a warm period, like we had, like, a week or two ago, where
it's all clear, very warm, and then the marine air pushes up along the coast with the low
clouds and then pushes in. And when it pushes in, our temperatures drop and we get the low
clouds coming in. This is called the marine push. This is the key summer time local weather
feature. Let me talk more about that later. Okay. So mostly, local weather feature has
something to do with mountains. The number one local weather feature where you are right
now, and the Puget Sound, is the Puget Sound Convergence Zone. Have you ever heard of that?
Yeah, you probably do. I got nods. Well, let me tell you about that. When the winds on
the coast are roughly between the West and the Northwest, the air goes around the mountains--and
here's Olympics over here--it goes around the mountains this way--they can't go for
the Cascades very well--they go around the Olympic this way, and then the air then converges
in on the opposite side. And what happens is, when air converges in, it just can't keep
on converging forever, right? You got the surface here, you have air converging, you've
got to force air to rise. And when the air rises, it cools and gets clouds and precipitation.
And so that's what happens here. The air converges together and rises. And there it is. Do you
see those clouds right over there? That's the Puget Sound Convergence Zone. Now, I'm
going to show you a weather radar image of it. All of you are used to weather radar,
right? You've seen it on TV all the time. Weather radar tells you where it's precipitating.
That's what it shows. And do you see that band over here. This is the heavier mountains
right in here. That's the convergence zone. Now, this is very useful knowledge if you're
recreationally-minded because if you know there's a convergence zone going on, what
you also know is you can get out of it very easily. So if you want to have a bike ride
or something, you know, and you're over here, you shouldn't give up on it. All you have
to do is, you know, put the bike in your car and go south, you know, 10, 15 miles and you
can be in complete sunshine over here, okay? As a matter of fact, that's something that
happens a lot. If you know the local weather features here, you can often get it to good
weather almost anytime of the year if you know where you go to--if you know where to
go. So here's the convergence zone. Okay. Oh, wrong way. Another type of local weather
feature that really affects things are the gaps. Okay, here's the Cascades here and there
are gaps in the mountains. There's the Columbia Gorge here, there's the Fraser River Valley,
there's the Strait of Juan de Fuca, and there's also another gap right over here. This is
not a sea-level gap. This is called the Stampede Gap. And if you actually look at the good
top of the graphic map, you'll see that the mountains are higher here, they're higher
here and there's a weakness in the mountains right over here. That actually is a very important
gap. I'll tell you about some examples of gap weather. All right. Some of you may have
been to Enumclaw, right? Enumclaw means place of evil spirits in the Native American vernacular.
And the question you may ask is why in the hell is that an evil place, okay? Well, one
thing you may see on the news all the time--does anybody live in Enumclaw here? I give the
trouble with the Enumclaw Chamber of Commerce. The thing about Enumclaw is they get these
amazing windstorms here or there where they can have winds of over 100 miles per hour,
where it's actually nothing is happening anywhere else. And here is an example. December 24th,
1983, I went there the next day to see this in front of my own eyes. So this is an example
of what happened on that day. The winds gusted to at least 118 miles per hour there before
the anemometer got blown away. Look mobile homes, you know, well, they always get it.
There's the BPA high-tension towers, they were crumpled up. You know, power coming in
from Eastern Washington just crumpled, well, like Tinkertoys, okay, roof damage like this.
It was--I couldn't believe it. And I did a paper on that, on this thing, and I did this
map of the winds based on observations. Hundred and twelve here, 8456, it's really localized
on the same night--and I remembered that night. It was dead calm here in Seattle while the
winds were blowing 118 plus over there, okay, dead calm. And these current of strong winds
came out here destroyed the--there was a boathouse there--it destroyed the boathouse there, all
kinds of fun things, power outages all out here. Well, why, why? Well, look at the terrain.
Here's a better map of the terrain. The shade, the dark shade is the high stuff and the less
high is by this model appearance. Can you see that there's a weakness here in the mountains,
if you look closely? And so when we get certain situations where we have cold high pressure
on this side, lower pressure on this side and some flow approaching the mountains, what
happens is, the air wants to find the weakness. And so the weakness is here, and so the air
accelerates through this gap, then it's kind of heavy and it accelerates down and accelerates
right into this area here given these very strong winds. So that's the reason why. And
we've simulated this numerically, so, you know, we can actually prove this is the case.
Now, winds can go the opposite direction in that gap and that makes possible this. There's
a big wind energy complex all around Ellensburg, around there. I don't know if you've ever
been there. And in fact, this is one of my favorite places to visit. I was there a few
months ago, again, the Wild Horse Wind Farm. And if you've ever been to that place, you
can go--Puget Sound Energy has this wind farm you can go visit, you know, not to far from
Ellensburg. Well, Ellensburg is a very windy place and the whole area is very windy because
when the winds go from the other direction, when there's higher pressure on Western Washington,
lower pressure on Eastern Washington, the air accelerates to the gap down to Ellensburg.
And this is from a U.S. government document showing you wind energy potential and, you
know, here's Ellensburg over here and a lot of wind turbines are on this Whiskey Dick
Mountain. That's where that--that's where those turbines I just showed were, okay? So,
tremendous wind energy and it's because of the gap, and Ellensburg is very windy or...
I don't know if you've ever been to Suncadia. It's a hotel there. I don't know if you've
been there. They put a golf course. It's up there in Cle Elum and it's so windy that they--people
almost can't play golf there because the balls go flying around. You know, we have--some
of our weather features are more benign and kind of interesting. Here's another example
of a local weather feature, lenticular or mountain wave clouds. Do you ever see these
things over here? Isn't that pretty? We'll try another one. And these are--and we see
these around here a lot. And this is caused by air going across the mountains. If you
have air approaching a mountain, it's pushed up by the mountain--and the air is relatively
stable, which means, if you push the air up, they'll go up and they'll tend to come back
down again. It's all like a swing, right? You can push a swing and it goes back and
forth, or the air does the same thing, or a pendulum. And so when the air rises, it
cools and you get clouds, and when it sinks, the clouds disappear, and so you often see
these, sort of, lens-shaped clouds that are often rows, that form and leave the mountains.
And here is an example from space. Now, one thing--oh, there was some fun slides I dropped.
Maybe I shouldn't have. What do those clouds look like? What do you think some people thought
these were? UFOs. And it's interesting story that, you know, the UFO craze started here
in the Northwest. It started in 1947. A pilot flying across the mountain, you know, he claimed
UFOs, okay? And later on, some people, someone from my department actually researched it
and found that it was perfect situation to get these mountain waves. Now, I could give
you one other example. Have you watched the presidential debate with Dennis Kucinich when
he claimed that he saw UFOs? Where do you think he saw it? He was staying in Graham,
Washington looking at the Mount Rainier. So I think there's a possibility that, you know,
it could be the same thing. Okay. All right. >> Why does the air go back up [INDISTINCT]?
>> MASS: Basically the atmosphere is stable and I can't get to the detail, but basically,
if you push air up--it's just one way to think about it--if you push air up, it becomes colder
because it rises. It becomes denser than the air around it and then it starts sinking down.
Then it goes down, it overshoots. It becomes too--it becomes warm than the air around it
because it's less dense and then it rises. It's kind of the hand waving wave. Well, the
most intense weather that we get around here are the Northwest windstorms, and I want to
mention that briefly. I have a chapter in the book. I love these things. We get some
world class weather around here and this is an example of one of them. This is what--it
was called mid-latitude cyclone, low pressure center in the mid-latitudes. And this is what
it looks like in a satellite picture. I mean, you don't have to be much of a meteorologist
to tell. It's right there, right? Okay. This is very intense, low-pressure center here.
So low-intense, low-pressure center, a cyclone in the mid-latitudes, that's called the mid-latitude
cyclone. This is the inauguration-day storm of January 20th, 1993. That's the date President
Clinton became president, okay? And I remember this one. I was in my office [INDISTINCT]
department. The winds gusted to 88 miles per hour UW. And I like [INDISTINCT] through hurricanes
and this was just like it. I mean, this was, you know, in every way. Here's a more recent
storm that some of you, you know, the younger guys, I remember, the Hanukkah Eve Storm,
December 14th, 15th, 2006, yeah? Some of you may have lost power for weeks. This is a surface
analysis of that storm right before it hit. These lines are lines of constant pressure
called isobars, and the thing I want you to notice is how many isobars there are. That
means there's a huge change in pressure, especially right there, okay? Now, winds are caused by
changes in pressure, differences in pressure with forced winds. And so you can imagine
what was going on there, right? And that area went right over us. And the next day, I went
out to Mercer Island to take a look around. Well, I couldn't drive anywhere. I had to
park the car near the freeway and walk in. I walked in about 5 miles, and this is what
all the roads look like. I mean, this was extraordinary damage due to this storm, you
know, hundreds and hundreds of millions of dollars of damage. And those were the reasons
why this storm was particularly bad and that's because so much trees went down. And why did
so many trees go down? Well, not only it had strong winds, but the month before, the precipitation
was very, very heavy, and what happens is the ability of soil to hold on to roots depends
on how saturated the soil is. Saturated soil doesn't hold roots very well. And so we had
strong winds, saturated soil, and so, you know, you can see what happened. But the strongest
storm, the strongest mid-latitude cyclone to strike the Northwest was this one. This
is the Columbus Day Storm of October 12, 1962. And this was probably the strongest mid-latitude
cyclone not only to hit the Northwest, but hit anywhere in the United States in the last
150 years. And just to show you where some of the winds are, this is some guy named Wolf
Read. He's really into this. He had done the Web. He has all these Web pages on the Northwest
windstorms. I want you to look at some of these winds, 138, 131, 100 in Renton; 116
in Portland, 145 plus in Cape Blanco. We're talking about winds over 100 miles per hour
all over the place. And so--this is at Cape Blanco. They had sustained winds of 150 with
gusts to 179. This storm was equivalent to a category 2 or 3 hurricane. I mean, we're
talking about the big time. And that's something that can't happen around here. I mean, this
was probably the strongest storm since the white men got to the Northwest. And, you know,
one thing I want to stress: trees really make it worse here. You know, people in Florida,
you know, they talk about their hurricanes, but what do they got, some palm trees or something?
You know, palm trees aren't going to do a lot. They're not going to hit your house.
You get hit by a 140-foot fir, right, you're going to know it, and your house can--just
cut the house in half, right? I mean, it's funny, but it's not so funny, right? This
makes things much, much worst here, here in the Northwest. You know, the most costly damage
here is not from windstorms. And it's actually from flooding. And if you look at the billion
dollar storms, the official National Weather Service documents, the billion dollar storms
across the United States, you know--you probably can't read this very well--but these things
are... So that's flooding examples. These are floods. I mean, the Columbus Day Storm,
if this went to [INDISTINCT], it would've been on there, okay? So we get--floods are
big things, wild fires in California and hurricanes in the Southeast, okay, and thunderstorms
in the Midwest. Most of our big floods are associated with something that on the media
they call it Pineapple Express. And that is when we have a current of moist warm air that
comes out of the subtropics. And this is a satellite image, because satellites can sense
the amount of moisture 3-dimensional in the atmosphere, okay, it's like Star Trek. We
could do it, okay? And so this is a plume of moisture coming in right from the subtropics
into the Northwest. And our great range, rough floods, and rainstorms are associated with
this. It has to be because the amount of water vapor in the air depends on temperature so
for us to have really moist air that has to be warmed to get the real primo floods. And
so this is an example of a pineapple express. Some people call it atmospheric rivers. And
the less, really super, the last one, happened in November 2006. You remember that one? And
you may not be able to read this page very well, but these values, we're talking about
here, the greens are 20 inches of rain in a matter of a few days. That is a lot of rain,
considering we got about 30 inches typically in a year. And Mount Rainier had 18 inches
in 36 hours. And I don't know if any you went there, at Mount Rainier, after that disaster,
but it costs tens of millions of dollars of damage, road taken out, you know, some of
my favorites places were washed away. Well, something I added here the last minute for
this talk I thought to be of interest is about Northwest heat waves, okay, somewhat extreme
that of events. You know, what we just went through was very a historic, you know, period.
And on the 29th of July, we had, you know, the old record was 100 degrees. And in Seattle,
we achieved 103 and many, many other places in the Northwest had their all-time records.
All kinds of records were broken. I mean, this--I mean, your grandchildren will ask
you about this storm, really. [INDISTINCT], right across the lake to me up here, you got
105 degrees, okay? And it was 103 in my house, which is not too far away. There's some place
down in--near Olympia that got close to 110. And these are amazing temperatures. And the
question the people want to know is why? What produce this heat? Well, we have this new--this
is an upper atmospheric chart, and this thing--you see an H, that's for high. This is what's
called a ridge of high pressure that builds over us and we have this ridge that developed,
that was of extreme magnitude and extreme persistence. So we start off with this tremendous--this
pool of very, very, warm air. And then, on the last day, ironically, some colder airs
started moving down into Montana over here. And that was so--so there was some high pressure
associated with that. We developed this large difference in pressure across the Cascades
and so air was pushed across mountains and sunk. It was sinking down on the Western slopes.
Sinking causes warming, right? And so you got this extra warming that occur and that's
what spiked this up. So we have warm air and then we had this--they had to spike up as
we got this offshore flow. And the other thing that was really extraordinary about this thing--I
mean, you guys are technologists. Well, I'll show off some of our technology. We forecast
this thing days ahead of time. This was from a website--they were a private called probcast,
www.probcast.com. This is the next-generation technology in my field for forecasting. And
two days before it, it went all three, and it just nailed it. And so--I mean, we've come
a long way to forecast extremes like that, is very challenging. Maybe the question is--so
I can tell you how we do it, but... Finally, the last thing I want to talk about is about
global warming around here and then I'll open up to questions. And, you know, you hear all
kinds of claims about global warming. Some people talk about how the mountain snowpack
has dramatically declined during the past several decades. You've heard that, right?
And in fact, Mayor Nickels is big on that one. I mean, he's claimed 50 percent drop
in snowpack. The number of heavy rain and windstorm events have already increased and
it will increase further in the global warming, right? The media likes to say that. Some people
suggest the Northwest climate around here is particularly sensitive to global warming.
Now, on the other hand, there are other people saying that global warming is some leftist
theory produced by Gore and his friends and we don't have to worry about it, that it just
cycles and mankind is not going to, you know, it has nothing to do with us. And I think
the truth of all of these is that none of these are true. And the problem that many
of you know is that greenhouse gases are increasing. And the greenhouse gas people talk about,
most of all, is carbon dioxide, right, and which is--which has increased rapidly during
the last several decades, and no matter what we do, it's going to pretty decrease quite
a bit during this upcoming century, okay? So CO2 is going up. Now, greenhouse gases
help keep us warm because they act like a blanket. They actually--what they do is absorb
and send back down infrared radiation. Now, I'll talk about that in a second. But greenhouse
gases are going up. Do you know what the number one greenhouse is? It's not CO2. It's water
vapor. Water vapor is a very potent greenhouse gas. So anyway, the greenhouse, this greenhouse
stuff is important. I mean, the way, you know, the way it works is our energy source is the
sun, so we have solar radiation coming in, and that's what warms--and the atmosphere
is relatively transparent to the sun's rays and hits the surface, the surface warms up.
And then, the surface then emits infrared radiation. In fact, everybody in this room
is emitting radiation. Anything that is above absolute zero emits radiation, okay? And so
you're emitting infrared, and so is the earth. The earth emits radiation, okay? Now, if there
was no atmosphere, that radiation would go happily out into space, and then you'd have
a balance between what's coming in and what's going out. Well, the atmosphere have gases,
like CO2, and methane and other gases that absorb some of the infrared radiation and
sends it back down to earth. It also emits some out to space. So, instead of the stuff
escaping, some of it is absorbed and sent back down. That acts to warm us up. It's like
a blanket, right? Why does the blanket keep you warm? Because it lessens--it slows down
radiation or energy away from you. The problem is, if you add a lot more greenhouse gases,
then you'll tend to increase this blanketing effect, causing you to warm up. In fact, it's
worse than that because if you warm up the earth, then that causes more water to evaporate
from the surface because evaporation depends on temperature and that gives you more water
vapor, which itself is a greenhouse gas which causes you even more warming, and so the whole
thing can rev up. Anyway, we understand this stuff really well. There's no doubt about
this business about greenhouse gases and how it causes warming. It's absolutely and completely
understood from a theoretical and practical level. We can simulate it, we can do everything.
Okay. So, the way we try to simulate the future climate is, basically, we use the same computer
models we use for forecasting, but we run them for hundred years and we look at how
the greenhouse gases vary. So these are climate models. Climate models are the same models
basically we use for weather forecasting. And weather forecasting models have gotten
better, right? I mean, you know, some people laugh about this, but actually we've gotten
much, much better at forecasting than we were, say, 20 or 30 years ago. The main reason is
because of these computer models. Anyway, this is a simulation, a hundred years into
the future, roughly, assuming that we don't change what we do, okay, that we follow the
same trends in the past. And the thing you keep in mind is that the Artic warms up the
most. The continents warm up more in the water and the Eastern oceans warm up less than the
Western oceans. Now, where are we downstream up? We're downstream of the ocean. Now, what
that does is that--and all weathers are coming off the ocean, so our--we're going to warm
up more slowly than most places because we're downstream of the ocean, which is going to
warm up more slowly. So, actually, where we are now is actually less sense to that global
warming than other places. I'm not saying it's not going to happen, but it's going to
be slower here. The magnitude is going to be somewhat less. Okay. And just to show you
what's happened in last several years. This is from '79 to 2008, the reds are warming,
but blue is actually cooling. The Eastern Pacific hasn't warmed up. [INDISTINCT] coming
in to us hasn't warmed up in the last 30 years. And, in fact, if you look at the snowpack
and the Cascades, you'll see that it's up and down a bit, 2006 from 1996, but there
is no real trend, and that is because the temperature of the ocean haven't change that
much. Now, eventually that's got to change. What we've done is we have used some of our
computer forecast models at high resolution and we've simulated forward a hundred years
to see what the implications of global warming is going to be here in the Northwest, and
I'm going to show you that right now. These are--I'm going to show you the change in temperatures
in the winter time at the other surface. Now, red is warming, blue is cooling. So this is
the difference in temperature between 1990s and 2020s. And I want you to look--you'll
see that generally, you know, between now and 2020s, I mean, we're talking about maybe
one or two degrees Fahrenheit, maybe something like that. Here's the difference between the
1990s and the 2050s. Okay. We're still going to see some temperatures getting up in to
the four degree range. And you see there are certain bendings, there are certain places
that
warm up more than others? That's where the snow melts, is melting off. And the snow melts
off, you get enhanced warming. But now let me show what it's going to look like between
1990s and 2090s. Some of you may live to see that, especially the younger people in the
crowd. That is a different world. We're talking about some--we're talking about 8 to 10 degrees
Fahrenheit warm ups in a lot of places. So, the warm up is not going to be linear. It's
going to be exponential. It's going to be a lot than that. And the big warm up is not
going to be for the next 20 years. It's going to be later in the century. And so, you know,
I wouldn't get my annual pass to see the snow [INDISTINCT]. I [INDISTINCT] the money down
right now for the 2008, if you'll play a bad investment. Now, everybody likes heat waves.
This is the number of summertime days with maximum temperature greater than 90 degrees
at Sea-Tac. These are only simulations, the number of days per decade. So, the 1990s,
2020s, okay, not that bad, you may not even have to buy an air conditioner, right? 2050s,
and here's the 2090s. A lot of people in the room got to see this one and some of you may
be lucky enough to see that one, right? It's going--it's going to be a different world.
Change in snowpack, dramatic reduction of snowpack in the Cascades by the time you get
to the end of the century, which has its own implications. As the last slide, I'll show--this
shows you the amount of snow at Stampede Pass, 4000 feet, you know, Snoqualmie Pass area.
Here's 1990s, 2020s, '50s, 2090s. It's a real different time. So that's what you got to
look forward to. We have a lot of work to do on these simulations, but this is a taste
of what we're finding. The other things--and I'll end with this--other major findings,
there doesn't seem to be any big change in precipitation over the next hundred years.
There is no reason to expect stronger storms, and it looks like we would become more like
Monterey. So you guys are in Mountain View and you're going to have something in common.
It turns out spring and early summer may become more--we have more low clouds here in Seattle
under global warming, because what happens is, the interior of the continent warms up.
That causes pressure fault because warm air is less dense than cold air. So you have lower
pressure in the continent, it's going to suck some of that marine air in and we could actually
end up with more low clouds during the spring and early summer. So, anyway, I think that's
where I'll end. Okay. You may talk and I'll open it up to questions. I hope this works--about
the book or anything else. Okay. >> Can you tell us a little bit more about
probcast, the com site you mentioned? >> MASS: Right. Okay. Now, the traditional
technology of weather forecasting is dependent upon numerical simulation. And so, [INDISTINCT]
work is we get all the information from the entire planet, okay, then we will have to
create a 3-dimensional description of the atmosphere, then we run our models, which
are called the primitive equations. These are the equations that describe the basic
physics of the atmosphere and we're able to then use that to simulate into the future,
okay? So the traditional way of forecasting was to do it once. The best shot of what you
think the initial state is, the best model, you forecast into the future, okay? We call
that deterministic forecasting. And that's where everything is kind of dependent upon
right now. But that is completely dishonest in a way, because there's all kind of uncertainties
there, right? Uncertainties in the initial state, there's uncertainties in the model.
For Jeff Renard or some TV guy to say, "The temperature three days from now is going to
be exactly that temperature is ridiculous." There is always uncertainty. The new way of
forecasting, the way that's going to dominate the century is probabilistic forecasting.
And the way it works is, you don't do one computer simulation. You do 50, you do 100,
you do 200, each slightly different, each reasonable differently. So you'll have a multitude
of forecast and you can use those multitudes of forecasting to get an idea of probabilities.
A gross example is, if half the simulation say it's going to rain and the half of it
says it won't rain, then you have, you know, it's 50 percent, okay? Now, probcast takes
it one step farther. We now have a collection of these forecasts. We call this the sum of
forecasts. It does statistical post-processing to optimize the probabilistic forecast versus,
you know--maybe one of those computer models are not as good as the other one recently.
It will weigh that one less. Anyway, it can massage statistically to produce a statistical
forecast that's optimal. And that's what the probcast--probcast stands for probability
forecast. And so, that's the--this is the first example of that kind of information
available on the Website. We've also tried to make it so it's successful to people. I
mean, you're in that business, too, to start to get complex information still in the way
people can--could get something out of. So that's what probcast is. Other questions.
Yes. >> It seems like it's going to be interesting
to see some postmortems on--when the forecast are grossly well. You say that occasionally,
very occasionally. I wonder if you go back and say, hey, we were saying, you know, Sunday
is going to be great and Monday is going to be raining, and it's the opposite or...
>> MASS: Oh, we do a lot of that. I mean, we do that both in case studies, we have verification.
There are different complex verification systems that are running on these forecasting systems.
So that is really important guidance that helps improve the system. That's why they've
gotten so much better. So there is a very active process to do that. You learn a tremendous
amount where things go wrong. >> [INDISTINCT]
>> MASS: Okay. >> Which I enjoyed very much like you.
>> MASS: So explain why things went wrong? >> Yeah. No. I'm saying I think that would
be interesting for people to say, hey, [INDISTINCT], like here's what's in the wrong analysis.
>> MASS: Right. And things go wrong, but they got less road than they're used to. Yes?
>> The different Website and different TV stations have different forecasts for the
future. You use the same model to do the meteorologist [INDISTINCT] but different models themselves
they share. How do they pick the kind of forecast...? >> MASS: Right. Well, you know, one of the
skills of a meteorologist is we have many different computer models and we have to decide
which ones we believe or don't believe or whatever. TV stations, they tend to be--there's
differences, but they tend not to be very large. In fact, I teach 101 and I had for
twice I've had my students write down all the forecasts from different TV stations,
and then to evaluate them. And what I found, there was no statistically significant difference
between their 0 to 48 hour forecast. They might get--they start with the service forecast
and they tweak it a little bit, but they don't really tweak it very far. Where the difference
is to develop are on the longer term, like the 5 to 10 days once. And, quite frankly,
God knows where some of them get that stuff, yeah? But there is very little scale. I mean,
what you got to keep in mind is a good weather consumer, is that forecasts are really good
for the first two days and it decreases in scale. By the time you get to three or four,
it's going down. Four or five, it's getting kind of marginal. And then, by the time it
gets to seventh day, the scale is dropping rapidly. So I wouldn't take those very seriously.
Yes. >> What do you think about the very local
measurement of forecasting [INDISTINCT] with those, that they have people, like, in weather
stations? I mean, are you familiar with that? >> MASS: Oh yeah, oh yeah, very much so. Well,
one of the great revolutions in our field is the availability of a multitude of surface
substations everywhere. [INDISTINCT] example of that. I mean, right now, in my department,
in real time, I get 72 different telemeter networks, including the weather underground.
What we get in Washington State alone, I think, approximately 4000 observations per hour,
from all the networks. And so, the weather--you know, weather undergrounds made that possible
that you can get weather instruments pretty cheap, that the interface of the Internet
or, you know, [INDISTINCT] with them, and so everybody is putting their weather observations
online. The only problem is the quality. Yes, a lot of people don't know where to put their
weather observations or they, you know, there's issues about where the placement, and--but
some of the [INDISTINCT] are very good. So it's a good thing. Yes.
>> As opposed to the [INDISTINCT] sensors that are on the ground, I've heard years back
that one of the [INDISTINCT] is there's really not a lot of sensors around in the oceans
so we'd only have data about the Pacific. >> MASS: Right. So the forecast scale is less
in the East Coast. And one of the reasons is, you know, we have the Pacific out there
where there's less observations. But that's less of a problem than it used to be because
of satellite assets. You know, I wasn't half joking when I was talking about Star Trek,
you know, when they go around a new planet, you know, depending how old you are, whether
it's Data or Mr. Spock, or whoever you want to think about here, you know, they go to
a planet, they scan the planet, right? We're doing that now. We have a multitude of satellites
up there that are 3-dimensionally probing the planet getting information, including
over the oceans. And so that has radically improved our ability to know what's happening
out over the Pacific. And because of that, the forecasts have gotten much better. One
proof of that is that the weather forecast in the Southern Hemisphere have now become
almost as good as Northern Hemisphere. That was never true before. And most of the Southern
Hemisphere is ocean, it's the fact our satellites can see what's happening 3-dimensionally,
you know, over the oceans. Now, it gives you the ability to forecast much better there
and here. Now, one thing I've been pushing forward is a radar on the coast, and we're
going to get that in two years. That could give us more information because we can't
see the details of stuff from a satellite. The weather radar can look hundreds of miles
offshore and be able to see that. So we're still not as good as--well off as East Coast,
but it's not that much different now. Yes? >> There's much forecasting done outside of
the government on a daily basis or is mostly the weather servers cause a little bit of
[INDISTINCT]? >> MASS: Well, the weather service is responsible
for the forecasting and warnings, but the private sector is really, you know, coming
into the forecasting business. In fact, some students of mine started a company called
3Tier, which is located downtown Seattle, and they're the number one wind energy prediction
company in the United States now, and they run computer models themselves, bring data,
and so they do a lot of the forecasting stuff, but this is for, you know, one application.
So the private sector is moving into that now.
>> Are the government also proprietary or they...?
>> MASS: No. None of these things are proprietary. They're all open. I mean, I run a numerical
weather prediction in my office and I run the different models. Yeah?
>> Are the insurance company starting take into account long-term forecasting, change
in development, that kind of stuff into setting insurance rates for...?
>> MASS: I know they're thinking about it. They show up at the meetings. They have been
hiring students. We had a number of our students at UW Atmospheric Science department, which
I'm in, who have been hired by insurance companies. I haven't debriefed them carefully in what
they're doing over there, but the implication is they're thinking about it at least.
>> That's kind of what I expected to see first thing, becoming a driver for people changing,
climate change behavior or credit mitigating some change behavior as the insurance companies
start to push it forward. >> MASS: That's funny, insurance companies.
I got a call from the City Seattle. They want to spend a quarter of a billion dollars into
drainage pipes. What's [INDISTINCT] should they be? These pipes are going to last three
quarters of a century. >> But bigger.
>> MASS: Well, that's true, but it costs a lot of money, okay? But they had spent tens
of millions into those extra for the big size, you know. What is the global warming research
indicates? Because that's--there's all kinds of industries. Yeah?
>> [INDISTINCT] >> MASS: Well, how much do you know? I mean,
the first place to go is the weather service because they--I mean, the people know what
they're doing. So that would be the first place I would go to. And in fact, you can
click on them on spots, so I think that's probably where I would start. If you could
interpret the data yourself, then there's all kinds of places to look for satellite
imagery, radar, whatever, the models, yeah, even our sites.
>> Speaking about forecasts, did you predict that strange, sort of, counterclockwise rotation
that happened over at the North Cascade during the heat wave? Is that part of the model?
>> MASS: Strange counterclockwise rotation? >> There was a tremendous amount of thunderstorms
going on the area. >> MASS: Oh, yeah. Oh no, the model said that.
Yeah. I mean, there was a trough and the thunders and the convection was coming around and,
yeah, the days before, you know, with the big day. And in fact, that had a big effect
on us here. One of the unusual aspects of that heat wave was how humid the air was.
You may have noticed that, right? The dew points were very high. And so, what I did
with my high-resolution computer models, I did the trajectories to find where did that
air come from that was so humid. It turns out they started over the lower slopes of
the forest of British Columbia. So you had all those thunderstorms dropping rain, so
it's very moist, and the air would ride over it and pick up the moisture and came into
us. That's where it came from. Yes? >> What's sort of the system do you run your
models on? >> MASS: We run on large Linux clusters. So
it's generally--my favorite purchase are these Duo Quad-core, you know.
>> As you know, we also run on large... >> MASS: I've heard of that, but I have a
feeling you got a lot more than I got. But, anyway, so I have clusters of these machines.
I have personally--I have maybe approximately 600 processors, you know. And the codes I
use--so the model I use now mostly is a WRF model, weather research and forecasting model.
That paralyzes very, very well. And so, I typically run that on several hundred processors
to do, you know, we do the real times--we have it on the Web, you can see our forecast.
And so that's kind of the hardware we use. Yeah?
>> Explain why the prevailing winds are just from the--you know, we get it from north in
the summer or from the south... >> MASS: Right. Sure. Well, during the summer
time, high pressure builds up in the Eastern Pacific because of the subtropical inter-cyclone
in the north. And so, when that--see, I think, it was high pushing up here. I have it on
my head. I don't know if I can communicate it. And so the air goes around the high, like,
of this, and so we're on this side of it, and so the air is coming from the north like
that. So it's because that high pushes up. During the winter time, low pressure gets
setup over the East Pacific and the flood of air comes around the other way, comes from
the south with that. I mean, I can try it in other ways, but it's due to the large scale
flow changes. Yes, sir? >> [INDISTINCT] with climate changes, how
far away we can go [INDISTINCT]? >> MASS: Well, in terms of climate change
or...? >> Not climate change, but with the general
[INDISTINCT]. >> MASS: So what are you looking to do? You
want to--I mean, is it just to know what's going on or the forecasting?
>> Just to know what's going on. >> MASS: Yeah. Well, I mean to know what's
going on we have all these observations of the surface. And so, you can, you know, in
our Website, we plot them all out regularly so you can see that. The computer models are
not running--are not of high resolution operationally could do that right now, but it will. Just
give it another three to five years. I will be running our computer models at one kilometer
grid spacing. But right now, I run it at four kilometer good spacing. But that will be changing,
yeah, width scaled by computer power. Yes? >> You were saying about the big factor in
our local weather stations [INDISTINCT], how much do you, sort of, these smaller lakes
and bodies of water [INDISTINCT]? >> MASS: Well, they have an effect if you're
right next to them, but they don't have a big effect, you know, sort of regionally.
I mean, the big regional bodies like, you know, Strait of Juan de Fuca and Puget Sound,
that affects the regional area. So the small you are, you know, the more localized the
effects are. You mean, your house is right next to it, yeah, it will affect you. Okay.
Any other questions? Yeah? >> You said you're working with the four kilometers?
>> MASS: That's the highest resolution I'm running on operationally.
>> Yeah. [INDISTINCT]? >> MASS: No. The way we run it--the typical
way to run it is nesting. We have a large domain with over 36 medium [INDISTINCT] to
12 and 4 over the area. And there are other approaches that there is all kinds of adapt-type
grid models, which are under development right now, that will adapt so you have more resolution
we needed. And, in fact, the next generation of models is going to be much more like that.
But right now, we use, basically, we cascaded and use aesthetic grid spacing.
>> What [INDISTINCT]? >> MASS: I think the big revolution is this
going probabilistic. In fact, this is only [INDISTINCT] business because we have these
massive amounts of information, much more information that we've had before, is probability
stuff, okay? I mean, we could tell you what's the probability the temperature will be over
65 over 67. You know, it was the probability you'll have between these amount and that
amount of rainfall. Of all these information, what people wanted, how you communicate it,
how do you communicate uncertainty, right? So that is the big, grand challenge for us,
is to create probabilistic information, find ways of communicating it to people in a useful
way. So that's the grand challenge, I think, right now.
>> So if you can do one kilometer right now, what do you think will be practical [INDISTINCT]?
Will we see better weather forecast in the news or would these be overwhelming data?
>> MASS: Well, and, again, that's how, you know, how do you show it? Like for instance,
our computer models right now don't really have like Washington, you know, and they don't
have the details of Puget Sound. It's all wrong, okay? So if we get high resolution,
we gain the ability to forecast those details. And then the question is how we communicate
it. It's going to have to be over the Web, I mean, or for some other media. That's why
the TV weather guys are in trouble, because how much can you communicate in a two and
a half minute broadcast. You can get all these details. So you have to use the Web or some
of the electronics, somewhere that's adoptive for people in their location to get their
weather donation across. So this is much in your area as it is in my area. Yeah?
>> Sounds like a business opportunity. >> MASS: Yeah. Go ahead.
>> First, [INDISTINCT] or they're lucky they have, like, the media today?
>> MASS: Oh, students take it very seriously. Well, I mean, you don't--anything would take
it too seriously. I mean, I can argue that there have been some over height amongst some
people. So, you know, at UW, believe me, it is taken seriously. Yeah, students take it
seriously. Yes? >> So you're saying that the kind of [INDISTINCT]?
>> MASS: Yeah, it decreases [INDISTINCT]. >> Yeah, so for your [INDISTINCT] can go out
like 100 years, like, what do you think the air [INDISTINCT]?
>> MASS: Right. That is one of
the most frequently asked questions I get, and especially people on the right hand--the
right side. I don't mean the right side being right. How can we possibly forecast 50 to
100 years ahead of time while we can't do it a week ahead? Is that an interesting question?
Now, what's the answer? There's two answers. One answer is we're not trying to do the same
thing. When we're trying to do a weather forecast, we're just trying to say, the temperature
at Seattle is going to be this exact temperature, the low pressure center is going to be exactly
there, right?
At this time, we don't do that with climate. On climate, we would say, what's the average
temperature going to be over a decade, okay? So we're not trying to that specificity. The
other thing is
the atmosphere is so strongly forced by the boundary conditions, by
the sun's radiation coming in
and the infrared going out. Now, actually, it really constrains what the atmosphere can
be doing out 50 or 100 years from now. So if we know how much Greenhouse gas there is,
which is uncertain in itself, we can't give you a pretty useful answer. There will be
uncertainties there, but it's still a useful answer. So that's the hand-waving answer to
that thing.
I think we can give you
something useful, okay? Out
of time? Okay. Cut.