Science on a Saturday Afternoon


Since I couldn't be with the Science Cheerleaders at the NYC Maker Faire today, I decided to go to a science event here in Huntsville. However, I did see that Dar managed to post a couple of pictures:

University of Alabama-Huntsville, located across the street from the day-job office, was hosting a "Weather Fest" to showcase the school's work in various aspects of meteorology. It was a nice example of "fun" and "science" not being incompatible (rather like the Science Cheerleaders, you might say).


The first thing I ran into was a trailer full of large, technical-looking equipment on it set up in the parking lot outside the Shelby Center. I asked the gent by the trailer to explain things, and he (Ryan Wade) did. He initially took me for a Huntsville Times reporter because I was asking a lot of questions and taking copious notes. Sorry, no. That's just me being me. :-)


Anyhow, the first machine he explained was a high-energy radar that fired its microwave pulses in three directions: toward the zenith (straight up), to the north, and to the east. By collecting data in these three directions, the radar can get a good reading on the atmosphere's temperature, moisture, and wind speed/direction.

Next to that was a radiometer, which passively detects microwaves (heat) generated by clouds, as well as moisture in the air. Between the radar and the radiometer, the meteorologists are able to get a lot more data points, the equivalent of "a weather balloon every minute," which is good, because weather balloons are expensive.

The impressive-looking bulb at the front end of the trailer was a vertically looking, dual-polarized X-band radar, which is what it sounds like: a radar that points straight up and sends pulses into to the sky. What does "dual-polarized" mean? I just learned this while trying to dissect some SERVIR stuff a couple weeks ago, so I'd better go ahead and explain it before I forget. If you've ever seen light waves depicted in science class, they look like waves that go up and down, more or less in the same plane. Well, radiation can be transmitted at almost any orientation (see image below), but human beings will generally detect or transmit radiation--like, say, microwaves--in one of two arbitrary planes, our own personal "vertical" or "horizontal." Most conventional weather radars have transmitted horizontally only. If you transmit radar signals vertically and horizontally, you can get a three-dimensional picture of the objects reflecting back signals to the dish. This is important for detecting the difference between rain, snow, or hail, all of which have different shapes. Another advantage of the dual-polarized radar is that it enables meteorologists to detect debris kicked up by a tornado because such debris would have a much different shape from rain or hail. 

The company responsible for changing over all of the National Weather Service radars from horizontal polarization to dual polarization is Baron Services, which all the UAH folks were very conscious of, because Baron is a Huntsville-based company.

One thing that I wanted to learn because it wasn't entirely clear to me was how tornadoes get formed in the first place--especially after the deadly dose of tornadoes we got April 27 this year. Tornadoes start as a result of a simple physical process: hot air rising and cooler air sinking. Obviously there's more to it than that or tornadoes would happen all the time. Other factors include large temperature differences between the air masses--say, between a really cold arctic air mass from up north and a relatively warm air mass coming up from the Gulf of Mexico in early spring. Instead of some air just rising and other air sinking, the air masses actually start rotating, creating a horizontal column of air in the sky. As the storm front moves forward and the cloud bases (bottoms) move closer to the ground, it is possible for this spinning column of air to turn become vertical, strike the ground, and move forward along the storm's path of forward motion. The tornado continues until it loses energy and dissipates.


So there ya go: your (and my) meteorology lesson for the day.


Another cool bit of machinery was a station wagon I dubbed the "Weather Car," which is its function if not its official name--that would be the Mobile Meteorological Mesonet. Festooned with a variety of instruments, including an annometer (for measuring wind speed), temperature and dew point sensors, and GPS unit, the car can take measurements even while in motion. That's probably a good thing, since a lot of the time the Weather Car can be sent out to chase storms, and probably doesn't want or need to get too close. Still, it looks a little like a practical joke played by the Meteorology Department on a school staff car.

In addition to the big machinery outside, inside the Shelby Center, the UAH Atmospheric Science Department had several display tables and other activities to engage the weather-interested, young and old. One interesting character in all this was The Weather Dude, who sang songs about weather education.

I also was impressed with the student who had a plate with some sort of flammable liquid in it, which she covered with a cylindrical screen that could rotate. The rotation of the air within the cylinder drew up the flames, creating a mini-tornado inside the cylinder.

One thing they were doing at the Weather Fest which I thought was kind of cool, in a science-geek sort of way, was raffling off a rain gauge. I put in for one, but didn't win. Boo.

And of course no weather excursion at UAH would be complete without the launch of a weather balloon. UAH launches a balloon once a week, at 1 p.m. on Saturday. The balloon carries up with it a variety of sensors for detecting the same things that the ground-based radars do: temperature, dew point, moisture, wind speed, and direction. The difference with a weather balloon is that the data is collected on-site, from ground to 110,000 feet (~20.8 miles or 33.5 kilometers). The Weather Fest provided a good opportunity for the university to explain what their role is with meteorology and atmospheric science, which of course brought the local TV stations, which in turn provided an opportunity for Huntsville Mayor Tommy Battle to make an appearance.

The Weather Fest also included snack and drink concession tables, a Chik-Fil-A table and one of the CFA cows walking around for pictures, a guy dressed up as a tornado character, mini-golf and activity tables for the kids, a guy selling storm/cloud photography as art, a student with a Tesla coil and a lot of things that could generate an electrical arc, and a TV with video from WAFF from April 27. A couple of side rooms had lectures at them, and I attended a couple, but was a little too caught up in all the other stuff to sit still. So all in all, it was a good event, but I'll bet it would've been even better with a few of the Science Cheerleaders around. The closest we got was that I saw a pom-pon on the Atmospheric Sciences table. Oh, well. Goooo Science!

Watching Our Favorite Star

"The problem is with the sun."
"The sun? What is it?"
"A big ball of gas at the center of our solar system, but that isn't important right now."
--Airplane 2: The Sequel

Most of us have general notions about the star at the center of our solar system: bright, big (compared to Earth, average or small compared to a lot of other stars), yellow, type G, 4.6 billion years old (but wearing it well), warm enough to allow liquid water 93 million miles out, boring.

So why should we be concerned about it in Huntsville, Alabama, aside from the fact that we've had temperatures in the upper 90s for the last week? Well, the latest telescope for sun watching is being built for an observatory at Haleakala, a mountain in Maui, Hawai'i. The administrative and research offices for this new telescope need to be attached to a research university, and the competition is down to Boulder, Colorado, and Huntsville. The team here in Huntsville includes the National Space Science and Technology Center (NSSTC) and the University of Alabama-Huntsville, and they gave a public talk on Saturday about the Haleakala Advanced Technology Solar Telescope (ATST--yep, another acronym). The talk was sponsored by my friends at Huntsville Space Professionals, who hosted the space career fair at ISDC.

Dr. John Horack, head of UAH's research office, gave some introductory remarks about ATST, explaining the importance of attaching "the premier ground-based solar observatory to the premier space-based observatories"--specifically, the Japanese probe Hinode, the Solar Dynamics Observatory, and the Marshall Space Flight Center-based Solar Physics group, which had a hand in developing the big X-shaped solar telescope in Skylab back in the 1970s.

The bulk of the talk was given by Mr. David Dooling, who is also a member of the Huntsville pitch team. He provided some eye-opening pictures and thoughts about why we should be concerned about our allegedly "boring" stellar neighbor.

Let's start with what the sun is: a naturally occurring nuclear bomb, converting billions of tons of hydrogen into helium through nuclear fusion and generating radiation in nearly every wavelength. This bomb also has a very intense magnetic field, which twists around its axis of rotation and interacts with its charged outer reaches in cells, loops, and whorls, "as if the sun was covered with tens of millions of lava lamps," as Dooling put it. Sometimes those loops of magnetic force, many times the size of Earth itself, burst forth from the sun's surface as fiery arcs called prominences or escape the sun's gravity entirely and blast forth into the solar system as solar flares.

Solar "weather" events can be deadly to astronauts outside the Earth's magnetosphere, as they consist of highly charged particles. One of the largest solar flares ever recorded occurred between Apollo 16 and Apollo 17; had it occurred while our astronauts were on the moon, it is likely that the astronauts would of died of radiation sickness.

The sun can't just create havoc in space--it can do so here on Earth. In the 19th century, a solar event overloaded what was then the world telegraph network. During World War II, the German fleet was able to escape the British fleet in broad daylight, in part because a geomagnetic storm blinded British radar. A massive blackout in Quebec in 1989 was caused by solar activity, also damaging global positioning satellites in the process. For such a "quiet" or "boring" star, why does our sun have such violent tendencies? How are those tendencies created, and when are they likely to cause damage? These are the sorts of mysteries the new 4-meter telescope at Haleakala will attempt to unravel.

The Haleakala telescope is being designed to observe the sun in wavelengths ranging from near-ultraviolet to optical to far-infrared. It is being built and deployed on the ground because launching a 4-meter telescope into space is cost-prohibitive. Plus, thanks to adaptive optics developed by the Strategic Defense Initiative (SDI, formerly known as the "Star Wars" program), Earth-based telescopes can now account for distortions in the atmosphere, giving the ATST a clear view of the sun without needing to go into space. It will concentrate its studies on the 630.2 and 430 nanometer wavelengths, as these will provide the best views of the sun's magnetic field activities as well as provide high-contrast images of the sun's bright surface, enabling scientists on Earth to see the details of the sun in action.

How does a telescope this big work? Most people's personal experience with telescopes are with the optical telescopes one can buy at a science-themed hobby shop, where one looks right down the barrel toward the objects in question. Given that it's a bad idea to stare at the sun with the naked eye, it's an even worse idea to gaze up close at the sun. Like most modern astronomical telescopes, the ATST is a reflecting telescope, capturing light from a 4-meter opening in a rotating/elevating building, the primary mirror reflects it to another mirror, and then several others before it is broken up by a series of prisms and filters. The images of the sun are then directed into several different instruments, each looking for specific aspects of the sun's behavior in specific wavelengths. The instruments for ATST are still in development, and are expected to be finished in five years, just around the time the building itself is completed.

What all goes into building such a complex piece of equipment? The ATST has a budget ceiling of $298 million, $145 of that paid out of the "stimulus" bill, the rest to come through regular National Science Foundation funding. It's not going to be an easy project. The Hawai'ians are concerned about the ATST's location on a sacred mountain. It's also on literally shaky ground because Hawai'i lies on a fault line and is subject to regular earthquakes. The heat generated by all that reflected light of the telescope can create difficult heat management issues inside and outside the observatory, where temperatures must be kept constant within 1 degree. And at the end of its 50-year life, ATST is to be dismantled as part of its environmental remediation plans. It is not an easy project, and development work will no doubt continue throughout the mission.

And Huntsville is in the running to be the administrative and research center for the project. I'm cheering on the home team, of course, but I'm looking forward to the outcome of ATST's research, regardless. If you had a bomb in your back yard, wouldn't you want to know what makes it tick?

Public Lecture Review: Dr. Roy Spencer, Global Warming Skeptic

Dr. Roy Spencer, a professor of meteorology at the University of Alabama-Huntsville (UAH), was the guest speaker for HAL5's monthly meeting this week. He is a self-described global warming skeptic, which is a label that is bound to cause him trouble in certain sections of the news media. Spencer has probably earned himself an extra dose of opprobium by being the "official climatologist" of Rush Limbaugh's Excellence in Broadcasting network.

Regardless of his reputation in the media, Dr. Spencer is a serious climate scientist, and seems a rather low-key guy to be associated with Rush. Be that as it may, Spencer is a clear, fine speaker with a good sense of humor and patient, calm demeanor, which he no doubt needs when addressing critics in the media, the classroom, or in Congress.

What, exactly, does it mean to be a global warming skeptic? In the case of Spencer, it means a few things:

• He does not deny that global warming has occurred in the last century. However, he notes that this is part of a general increase that has occurred since the "Little Ice Age," which lasted from around 1300 to 1850. The Little Ice Age, in turn, was preceded by the Medieval Warm Period, when average global temperatures were the same (or higher) than what they are now.
• He does question exactly how much of that warming is the result of human-based activities, such as burning fossil fuels.
• He does focus on the data related to climate change (actual numbers), not just rhetoric. (My big gripe with the global warming hysteria has been that I don't believe people repeating assertions proves that said assertions are true. Related to that gripe is a personal reaction to any mass movement: I don't like to be pushed around. People need to reason with me if they want to get their point across--I'll accept comprehensive data, not selective data, and not anecdote-based scare-mongering. But I digress.)
• He does question some of the assumptions made by the physics-based computer climate models that have been used by James Hansen and others to declare that a global warming crisis is in the making (or already happening).
• He does not believe that the Earth's climate system is hypersensitive to human activities.
• He does believe that the natural processes of our planet have a larger impact on weather (short-term trends) and climate (long-term trends) than human activities.
• He does believe that the climate model-makers have their causes and effects reversed.

I'll focus on the last point, since that was the focus of Spencer's talk. I'll have to use English-major terms here, since I'm not a scientist. He began by explaining that the Earth's atmosphere tends toward equilibrium, with the amount of heat absorbed from sunlight equalling the amount of infrared radiation (heat) radiated into space. The basic premise of global warming and the "greenhouse effect" is that excessive carbon dioxide created by human activities is disturbing this equilibrium. This is happening because carbon dioxide (CO2) is creating more clouds, preventing heat from escaping into space.

If I understand Spencer correctly, though, he believes that cloud changes affect temperatures more than temperatures affect cloud changes. At some point, he explained, scientists noticed that temperatures worldwide had increased, on average, and that carbon dioxide had increased as well. Scientists interpreted this coincidence of activity as a definite correlation--that is, A caused B. However, Spencer asserted (and this is the first time I'd heard this) that carbon dioxide increases occurred after the temperature increases. If true, this means that the temperature increases are due to something else.

Here's how Spencer explained the Earth's climate changes in response to increases in heat (wherever they come from):

• More heat is pumped into the system.
• More heat produces more water vapor.
• More water vapor means more clouds are created.
• More clouds in the Earth's atmosphere increases the planet's albedo (reflectivity), causing more sunlight to be reflected into space rather than reaching the surface. In this way, equilibrium is maintained.

So what's causing the temperature increases and ice ages? Here are some possibilities Spencer mentioned:

• The tilt of the Earth.
• The eccentricity of Earth's orbit.
• Changes in solar radiation. On this point, Spencer indicated that the amount of light put out by the sun was not enough to account for climate change unless the climate was exceptionally sensitive to such changes--a position he opposes.
• Natural fluctuations in heat circulation between the oceans and the atmosphere.

Spencer did show a lot of graphs and charts reflecting his models and the more traditional models being used by the global warming theorists. However, I must confess that I didn't "get" them. The numbers and the patterns of the lines on the charts (temperature on the X axis, changes in radiant energy lost on the Y axis) didn't tell a story I fully understood. I'd probably have to spend some more time with the equations and the data to understand the implications of what his model is showing.

However, Spencer's political comments were perfectly clear. He echoed the global warming believers' comments, mostly for laughs (this is, after all, Red State America):

• "Everything's going to get worse."
• "It's all George Bush's fault."
• "How could they be wrong? They spent hundreds of millions of dollars!"

His own responses to some of the alarmist talk in the climate change community offer the patient listener food for thought:

• "Most of the model makers were trained in physics, not meteorology. They're used to dealing with equations. The Earth's weather is biological in its complexity. It's really functioning according to chaos theory."
• "Any time you replace vegetation with man-made structures, heating increases."
• "Any time air is sinking in some places (the Sahara, parts of the Pacific), it's because air was forced to rise in other places."
• "Why do we allow trees to change the environment, but not humanity?"
• "It's not like I'm for pollution. Humans pollute just by existing. It's a matter of what you're willing to put up with."
• "It's only the wealthy economies that can afford to develop the technologies to find the solutions [to global warming]."
• "I"m probably being cynical, but I believe politicians and scientists who want to be politicians view this as an opportunity to control people by controlling their energy use."

It is this last statement that most likely wins over Limbaugh, though John Coleman (a former Chicago weather man--WLS-TV--and founder of The Weather Channel) has also taken issue with global warming alarmism. And Spencer's global average temperature chart, which I've seen in other places, does show a temperature drop for the last two years, coming down off a recent high in 2005. As Spencer put it in his low-key way, "It will be interesting to see if this trend continues over the next few years." The maximum temperature increase Spencer is predicting by 2100 is less than 1 degree Celsius, as compared to the 2.5 to 5 degrees predicted by the Intergovernmental Panel on Climate Change (IPCC). Which numbers do you think is more likely to get governmental attention and action?

I asked Spencer what he thought about solar power satellites, a favorite technology of mine and others in the pro-space community. I wanted to know, specifically, if he thought that the microwave power beams being transmitted to the Earth's surface would add considerably to the Earth's heat load. His response? "It sounds sexy, but it's just going to be excessively expensive compared to the amount of energy [production] you'll get."

Spencer is using cloud cover data gathered by NASA's Aqua satellite (and others). He is not making things up, nor is he exceptionally partisan. He is not shrill or screaming or pounding the table or denouncing global warming theorists as corrupt, evil, or part of some vast global conspiracy (governments are another matter entirely). What he is doing is asking these people to question their assumptions and their models, as good scientists should. He even admits, rather humbly, that "I could be wrong." It's unfortunate that the folks he's questioning do not have similar humility--that attitude used to be a cornerstone of the scientific method.